1. society

10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
List of oral presentations (alphabetical order)
Session 5 (23)
How to trigger mating behaviour of Zambian Fukomys anselli mole-rats?
Begall, Sabine; Vole, C.; Garcia-Montero, A.; Malkemper, E.P. & Burda, H.
University of Essen, Department of General Zoology, 45117 Essen, Germany
Fukomys mole-rats are subterranean rodents that live in eusocial families. Only the founder pair
reproduces, whereas their offspring remains reproductively quiescent while staying within their
home family. Incest avoidance between parents and offspring and between brothers and sisters is
based on individual recognition, most likely via olfactory signals. If two unfamiliar mature nonbreeders of opposite sex meet, in many cases mating takes place soon after their first encounter.
Previously, we investigated the mating behaviour of Fukomys anselli from Zambia by using adult
mole-rats that were non-reproductive at the time of first testing. Pairs that showed courtship
behaviour were tested repeatedly (maximally three times a week for up to 10 weeks). The animals
copulated frequently within one session and had an increased interest in sexual behaviors during the
whole study period. Recently, we compared the copulation frequency of breeding pairs of
established families under different experimental conditions. Factors implying a new surrounding
could trigger a higher occurrence of copulations. We speculate, that the reproductive pair
strengthens its pair bond after encountering new environmental conditions. Although the
subterranean ecotope is buffered against many fluctuating abiotic factors for most time of the year,
seasonal events (e.g. heavy rains) could lead sporadically to entirely new conditions (e.g.
abandonment of the burrow system). Alternatively or in addition, the pair might soothe stressful
situations by oxytocin release during orgasm. Our results are of considerable importance for fertility
studies in wild animals and could prove valuable for successful keeping and breeding of mole-rat
colonies in the lab.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 2 (10)
Adolescent social experience influences adult courtship and aggression - tracking
developmental mechanisms
Bölting, Stefanie & von Engelhardt, N.
University of Bielefeld, Department of Animal Behaviour, 33615 Bielefeld, Germany
Differences in adult behaviour may be due to effects of the size, age-class and sex composition of a
social group individuals experience during development. Specifically, the frequency & type of social
interactions may influence speed of maturation & physiology. We investigated how the social
environment during adolescence influences the behavioural, morphological and hormonal
development of male zebra finches (Taeniopygia guttata) and compared their courtship & aggressive
behaviour as adults. Males were kept either in mixed-sex juvenile pairs (1m/1f), mixed-sex juvenile
groups (3m/3f) or mixed-sex mixed-age groups (3+2m/3+2f) from shortly after nutritional
independence until adulthood. We found in group-housed males a higher total frequency of social
interactions during development and a more rapid maturation of the sexually-dimorphic colouration
compared to pair-housed males. We will also present in how far particular interaction partners or
interaction types may play a prominent role in shaping the adult behavioural differences and
whether these are related to differences in plasma testosterone and corticosterone levels during
development. As adults, males housed in juvenile groups sang at a higher rate than pair-housed
males Our results suggest that in zebra finches a high amount of social interactions during
development can lead to a faster morphological and behavioural maturation of males, which may be
adaptive at high social densities in this species.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 3 (16)
Task context influences dogs’ reaction to inequity
Brucks, Désirée; Essler, J.; Marshall-Pescini, S. & Range, F.
University of Veterinary Medicine Vienna, Messerli Research Institute, 1210 Vienna, Austria
Inequity aversion, defined as the negative reaction to unequal outcomes, seems to be present not
only in humans but also in other species, amongst them dogs. Humans’ reaction to inequity is based
on a social comparison process, whereas we do not know which mechanisms underlie the reaction of
non-human animals to unequal treatment. To understand the mechanisms involved in dogs’ reaction
to inequity, we tested pairs of familiar dogs in two tasks with a different context (apparatus vs.
experimenter causing inequity). In the ‘asocial’ task, dogs were sitting in adjacent enclosures and had
to press a buzzer to receive rewards, delivered via bowls and without human involvement. For
validating and comparing this task, the same dogs were tested in a ‘social’ task, in which the dogs
were alternately asked to give their paw to the experimenter to obtain rewards (see Range et al.
2009). We ran the same conditions as Range et al. 2009 and added a food control to assess individual
frustration. In both tasks, dogs reacted to unequal reward distribution. However, only in the ‘social’
task, dogs stopped performing the task sooner in the inequity condition (i.e. partner rewarded but
not the subject) than in the control condition where they were asked to perform the behavior alone
and without being rewarded. Hence dogs’ reaction is context specific and requires 1) a donor to
whom ‘inequity’ is attributed to, i.e. experimenter in the ‘social’ task, and 2) some control over the
outcome of the task (expectation about equal humans vs. unpredictable apparatus).
Reference:
Range, F., Horn, L., Virányi, Z., & Huber, L. (2009). The absence of reward induces inequity aversion in
dogs. Proceedings of the National Academy of Sciences, 106(1), 340–345.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 3 (17)
How vocal plasticity in birds facilitates communication in fluctuating environments
Brumm, Henrik
Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
All social behaviours are based on the exchange of information between individuals. However, signal
transmission in any modality is crucially constrained by the environment. I will review recent findings
on how birds adjust their vocalisations in response to fluctuating environments. The function of bird
song is closely linked to sexual selection and thus differences in the efficiency of song transmission
are likely to have major fitness consequences. A previously undescribed phenomenon of vocal
plasticity in birds is related to high intensity noise pollution: songbirds in the vicinity of a major
European airport began singing significantly earlier in the morning than their conspecifics at a quieter
control site. As birds at both sites started singing before the onset of air traffic in the morning, this
suggests that the birds in the vicinity of the airport advanced their activity to gain more time for
unimpaired singing before the massive plane noise set in. Our study offers a new perspective on the
effects of noise pollution on wildlife, indicating that airport noise forces birds to adjust their mating
signals and time budgets. On a broader note, our data illustrates how birds adjust their signalling
behaviour to maintain communication in fluctuating environments.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 6 (33)
Altruism is affected by familiarity in pet dogs
Chaumette, M.; Dale, R.; Marshall-Pescini, S. & Range, F.
University of Vienna, Comparative Cognition, Messerli Research Institute, University of Veterinary
Medicine, 1210 Vienna, Austria
Prosocial and altruistic behaviors are defined as voluntary actions that benefit others. However, by
definition, whereas prosocial behaviors do not involve a cost to the donor, altruistic acts do. Altruism
routinely occurs in humans and can be directed towards complete strangers, however most
occurrences of altruistic behaviors tend to be directed towards kin, social partners and in-group
members. Similarly, pro-social tendencies in non-human primates have been found to be strongest
towards familiar and bonded partners such as group members. In the current study, using a bar
pulling paradigm, we sought to determine whether pet dogs would exhibit altruistic behaviors in
terms of delivering food to a conspecific (while obtaining none themselves) and whether they would
do so more for a familiar social partner than for a stranger. Importantly, it is the first study using this
paradigm, which included controls to look at potential social facilitation effects. Results showed that
dogs exhibit altruistic behaviors towards a familiar conspecific but not towards a stranger dog.
Hence, we conclude that dogs are capable of altruistic behaviours and are more willing to exhibit
these towards familiar social partners.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 4 (21)
Geographical differences in the use of male mating tactics in a sexually cannibalistic spider
Cory, Anna-Lena; Husmann, I. & Schneider, J.M.
University of Hamburg, Biocenter Grindel, Ethology, 20146 Hamburg, Germany
The spread to new environments can affect the sexual selection regime through changes in
phenology and variation in fitness traits. Plastic mating tactics that rely on perception of social
information may be an ideal precondition facilitating a rapid adaptation to novel conditions. The
sexually cannibalistic orb-web spider Argiope bruennichi has recently expanded its range northwards
and is now widespread all over Europe. The spiders show a monogynous mating system but males
from Northern populations are known to adopt a bigynous mating tactic if a female’s quality falls
below a certain quality threshold which is strongly based on female body size and fecundity.
However, females in southern (S) source populations are much larger and mature less synchronously
than females in northern (N) invasive populations. Hence, we expect different decision rules
underlying tactic choice of N versus S-males. We use experimental choice arenas to compare the
frequencies of bigynous tactics between N and S-males. Males had a choice between three N or Sfemales of different body sizes. We found that N-males and S-males used bigynous mating tactics
with the same probability. However, all males mated with the first female they encountered but Nmales adjusted their tactic to the relative quality of that female independent of her origin. N-males
monopolized the relatively largest female in the arena but adopted a bigynous tactic if a larger
female was available. S-males did not show such a female-quality dependent choice of tactics. This
may suggest that female quality is less relevant for male reproductive success in S-populations than
in N-populations.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 5 (28)
Personality and female behaviour under risk of infanticide in the bank vole (Myodes
glareolus)
Folkertsma, Remco; Herde, A. & Eccard, J.
University of Potsdam, Institute of Biochemistry and Biology, Animal Ecology, 14469 Potsdam,
Germany
The aim of this study was to determine if personality affects the behaviour of female bank voles in a
potential infanticidal situation. Female bank voles can conceive again immediately post-partum, thus
they can be pregnant and lactating at the same time and therefor carry a trade-off between current
and future reproduction. Females recognize the sire of their current litter and they prefer the
presence of the sire over the presence of unfamiliar males. Next to being a potential mating partner,
male bank voles are, if not the sire of a litter, potentially infanticidal and form a threat for the
investment into a females current litter. Thus for a lactating non-pregnant female, the presence of an
unknown male causes a conflict between leaving the nest to mate and ensure future reproductive
success and staying in the nest to protect her current reproductive investment. We investigate if this
conflict is associated with personality measurements of exploration. Personality has a heritable
component and is related to life history traits such as age specific mortality rates and reproductive
investment. It is shown that more explorative individuals favour investment into current
reproduction over investment into future reproduction. In our experiment lactating non-pregnant
females, previously tested for personality, were set out into outdoor enclosures and presented with
the presence of an unknown male individual. We followed their behaviour with automated
radiotelemetry and RFID-systems. Results suggest that more explorative individuals allocate more
time into nest protection and thus focus on protecting their current reproductive investment.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 6 (32)
Habitat and predation explain population divergence in cooperatively breeding cichlids
Frommen, Joachim G.; Groenewoud, F.; Tanaka, H.; Jungwirth, A.; Josi, D. & Taborsky, M.
Insttitute of Ecology and Evolution, 3032 Hinterkappelen, Switzerland
Environmental conditions are generally assumed to be of crucial importance for the evolution of
cooperative breeding. Subordinate individuals staying in the territory of dominants decide about
dispersal and cooperative effort in dependence of the quality of the home territory and of alternative
locations. However, there is currently little evidence from cooperatively breeding vertebrates that
large-scale ecological patterns determine group structure and cooperative behavior of group
members. Here we measured biotic and abiotic factors of potential importance for behavioral
decisions of group members in eight populations of the cooperatively breeding cichlid
Neolamprologus pulcher, which is distributed across a wide range of habitats in Lake Tanganyika. Our
data show that habitat quality, substrate complexity and predation risk all differ substantially
between the surveyed populations. This correlates with highly significant differences between
populations in group size and composition, and with marked divergence in the type and quantity of
cooperative behaviors exhibited by group members. Group size related to habitat type, with habitats
demanding more help yielding larger groups. The demand for protection and help seem to largely
determine group composition and cooperative behavior, which is in accordance with the “pay to
stay” hypothesis postulating that subordinate individuals pay as much as needed to evade being
evicted from the territory, if alternative options are scarce or unfavorable. This is confirmed by
laboratory experiments showing that breeders more readily accept subordinates if the demand for
help is high.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 2 (12)
Within-litter differences in personality and physiology relate to size differences among
siblings in cavies
Guenther, Anja & Trillmich, F.
University of Bielefeld, Department of Animal Behaviour, 33615 Bielefeld, Germany
Many aspects of an animal´s early life potentially contribute to long-term individual differences in
physiology and behaviour. Most mammals grow up with siblings, and the interactions among them
can strongly affect an individual’s early development. Offspring with a greater number of littermates
may receive less milk, leading to reduced postnatal growth and potentially to slower physiological
development. In a highly precocial rodent, the wild cavy (Cavia aperea), siblings of the same litter
differ in birth weight. We asked whether such differences between siblings affect an individual´s
personality. Therefore, we measured personality traits directly after birth and shortly after weaning.
In addition, we measured several physiological parameters such as resting metabolic rate and
baseline cortisol levels. We find that siblings of the same litter differed in personality traits as early as
three days after birth. Pups born heaviest in the litter were more explorative and in general more
risk-prone than their smaller siblings. Physiological traits were tightly correlated with personality
traits and also influenced by the relative size within litter, suggesting that the size relative to
littermates constitutes an important factor in shaping an individual´s developmental trajectory. Our
data add valuable information on the stability of developmentally influenced behavioural and
physiological traits and indicate how personalities are shaped during early phases of life.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 1 (4)
Cognitive judgement bias reflected in frontal brain activation in sheep?
Gygax, Lorenz; Guldimann, K.; Vögeli, S.; Wolf, M. & Wechsler, B.
Agroscope, Institute of Livestock Sciences ILS, Tänikon, Centre for Proper Housing of Ruminants and
Pigs, Federal Food Safety and Veterinary Office FSVO, 8356 Ettenhausen, Switzerland
Animal affective states play an important role in proximate control of behaviour. Long-term affective
states, that is, mood may modulate short-term emotional reaction. One paradigm to assess mood is
the non-verbal cognitive judgement bias test. Here, we conducted a spatial variant on 24 focal sheep
kept under either unpredictable, stimulus-poor or predictable, stimulus-rich housing conditions. We
measured haemodynamic frontal brain reactions during 10 seconds in which the sheep could observe
the configuration of the cognitive judgement bias trial using functional near-infrared spectroscopy
and measured their assessment based on the go/no-go reaction. We used (generalised) mixedeffects models to evaluate the data. Sheep from the unpredictable, stimulus-poor housing conditions
needed more training sessions and were less likely to reach the learning criterion. They also reacted
slightly more optimistically in the cognitive judgement bias test. A frontal cortical increase in d eoxyhaemoglobin and a parallel decrease in oxy-haemoglobin were observed during the 10 seconds
assessment of the test situation, indicating a frontal cortical brain deactivation. This deactivation was
more pronounced with the provenance of the sheep from the unpredictable, stimulus-poor housing
conditions, the proximity of the cue to the negatively reinforced cue location, or the absence of a go
reaction in the trial. Sheep from the unpredictable, stimulus-poor in comparison to sheep from the
predictable, stimulus-rich housing conditions seemed to deal less easily with the test conditions rich
in stimuli. The long-term housing conditions seemingly did not influence mood as measured in the
cognitive judgement bias paradigm. Stimulus-evaluation can be related with brain deactivation.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 3 (15)
Strategic sperm allocation in response to perceived sperm competition risk in the lekking
lesser wax moth Achroia grisella
Jarrige, Alicia; Riemann, D.; Goubault, M. & Schmoll, T.
Institut de Recherche sur la Biologie de l'Insecte (IRBI), Tours, France
Sperm production is costly and limited in a male lifetime, selecting for strategic allocation of sperm
expenditure depending on the likely benefits. In particular, the presence of rival ejaculate(s) will
inevitably impact a male’s chances of fertilization. Therefore, male mating behavior and ejaculate
expenditure is predicted to vary according to perceived sperm competition risk (the probability
another male’s ejaculate is present). Although sperm competition risk has been demonstrated to be
a strong selective force in shaping male ejaculate traits in polyandrous species, its influence is often
expected to be low or absent in lekking mating systems, because females mating decisions appear
relatively unconstrained and female remating rate is generally low. Here, we investigated male
mating behavior and strategic sperm allocation in the lekking moth Achroia grisella (Lepidoptera :
Pyralidae), experiencing either a competitive (one competitor present), or a non-competitive (no
competitor present) social environment during early adulthood. This species is an established study
model for precopulatory sexual selection mechanisms as males display elaborated ultrasonic
courtship songs targeted by female choice. However, little is known about the relevance of postcopulatory mechanisms although females frequently remate, thus creating the potential for sperm
competition. Our results clearly demonstrate that males allocate higher proportions of available
sperm reserves during virgin copulations when experiencing a sperm competition risk environment.
Our study provides rare evidence for strategic sperm allocation in relation to sperm competition risk
in a lekking insect, suggesting that sperm competition might represent an important selective force
also in lekking systems.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 6 (34)
Free amino acids can mediate social interactions in fish
Kleinhappel, Tanja K.; Burman, O.H.P.; John, E.; Wilkinson, A. & Pike, T.W.
University of Lincoln, School of Life Sciences, Lincoln, UK
In aquatic animals, chemical cues are used in a variety of contexts such as habitat and conspecific
recognition, foraging and predator avoidance. However, the perception of chemical signals can
greatly depend upon the habitat in which an animal lives. Recent studies have revealed that diet
alone is sufficient to change the chemical profile of individual fish, and with it, the way other
individuals perceive and interact with them. It has been suggested that free amino acids may
mediate these diet-related social preferences, yet to our knowledge, there is no empirical evidence
to confirm this. The aim of this study was therefore to test the hypothesis that free amino acids are
able to mediate inter-individual shoaling preferences. We quantified the association preferences
within replicated three-spined stickleback shoals comprised of fish fed on diets which differed by a
single free amino acid. The results suggest that fish are able to discriminate between the free amino
acids, and can use them to mediate their inter-individual association preferences. To control for
possible changes in behaviour caused by the different diet treatments, we conducted a second
experiment using model fish designed to mimic the odour of live fish from the different experimental
diet treatments. The findings of this experiment exactly mirrored those from the first, indicating that
free amino acids alone are sufficient to elicit association preferences in this species. Overall, this
study gives important insights into the mechanisms underpinning inter-individual social interactions
within free swimming fish shoals.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 8 (39)
Male song facilitates the natal dispersal of females in a polygynous bat
Knörnschild, Mirjam
University of Ulm, Institute of Experimental Ecology, 89069 Ulm, Germany
Offspring dispersal is an important factor in shaping the social structure of a given species. While the
causes and consequences of offspring dispersal have been studied in detail for some species, the
actual mechanisms facilitating natal dispersal events have received less attention in the past. Female
greater sac-winged bats (Saccopteryx bilineata) disperse after weaning from their natal colonies
which is crucial to avoid father-daughter inbreeding. How young females find new colonies suitable
for dispersal was unclear so far. We provide experimental evidence that dispersal females eavesdrop
on male territorial songs to locate new colonies. Territorial songs are low-frequency vocalizations
that are produced by territorial males at dusk and dawn to defend their territories against male
competitors. When broadcasting territorial songs at dawn from potentially suitable day-roosts that
were currently uninhabited, we attracted dispersal females and, in rare cases, adult females, and we
were able to catch the bats with mist-nets when they were trying to land in the vicinity of the
speaker. During silent control trials, no bats were caught. Using a formula originally developed to
calculate maximum detection distances in echolocating bats, we estimated the minimum and
maximum detection distances of male territorial songs for flying dispersal females. Our results
indicate that the dawn chorus of singing male S. bilineata constitutes an acoustic beacon in the
landscape that can help dispersal females to locate new colonies. Such an acoustically mediated natal
dispersal has, to the best of our knowledge, not been experimentally shown in bats so far.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 1 (5)
Did cooperative orientation towards humans change in dogs as compared to wolves?
Kotrschal, Kurt; Hampl, C.; Auer, M.; Heberlein, M.; Baxter, E.; Virányi, Z. & Range, F.
Konrad Lorenz Forschungsstelle and Wolf Science Center, University of Vienna, Biozentrum UZAI,
1090 Vienna, Austria
Wolf domestication was mainly a social adaptation towards humans. Hence, “dogification” may serve
as a selection model for social behaviour changes. The wolf-dog genomes split some 35 000 years
ago. Did dogs indeed became intrinsically better than wolves in cooperating with humans, as most
domestication hypotheses imply? To compare the quality of co-action with differently familiar
humans we used leash walking with a total of 9 dogs and 11 wolves, all 8-14 months of age and
equally raised and kept at the Wolf Science Center. This was repeated with 6 wolves and 6 dogs at 26 years of age. From the video-taped walks 125 behavioural variables were coded, including
attentiveness, leadership and leadership conflict, command execution (sit, down), etc. In general,
wolves and dogs behaved very similarly on the leash. In the younger animals, GLMM showed
significantly more leadership conflicts and more improper command executions in the dogs than
wolves. With the older animals this was reversed. We conclude that carefully socialized wolves on a
leash are similarly cooperative with humans as equally socialized and kept dogs. In general, wolves
were more attentive towards their surrounding whereas dogs were more attentive towards their
walker. Our results contradict most domestication hypotheses. It seems that domestication did not
increase general cooperativeness towards humans, but rather emphasized attentiveness and
dependence, particularly in the older dogs. Wolves, in contrast, became more independent from
their human partners with age, but still remained similarly cooperative as dogs.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 8 (40)
Early conditions and mismatched adult environments: evidence for a silver spoon effect
but no thrifty phenotype in zebra finches
Krause, E. Tobias; Krüger, O. & Schielzeth, H.
University of Bielefeld, Animal Behaviour, 33615 Bielefeld, Germany
Developmental plasticity is a key feature of organisms and individuals could benefit from optimizing
their phenotype for the expected subsequent environmental conditions based on those experienced
early in life. This is particularly the case for nutritional conditions. Long-lasting beneficial effects of
early life are known as `silver spoon effects´. However, environmental matching or mismatching
during early and adult life might modify this effect. The ‘thrifty phenotype’ hypothesis predicts better
performance under matched than under mismatched conditions. We experimentally manipulated
early dietary conditions of zebra finches (Taeniopygia guttata) at the brood level and used a splitbrood design for manipulating nutritional conditions for the entire lifespan after independence from
parental care. Developmental trajectories of all individuals were followed for more than three years.
We found substantial life-long effects of early nutritional treatments on the adult phenotype, which
provides evidence for a silver spoon effect. Morphological parameters were most strongly affected.
However, our data provide no support for the thrifty phenotype hypothesis, as we do not find any
robust interactive effects between early and late nutritional treatments. Furthermore, we find sizable
residual effects of the early rearing environment that slowly, but steadily declined with age.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 7 (38)
Collective cognition in human crowds. Decision making under uncertainty
Kurvers, Ralf H.J.M.; Wolf, M.; Clement, R. & Krause, J.
Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), 12587 Berlin, Germany
Decision accuracy is a key factor shaping the evolution of behaviour. Individuals in groups can
increase decision accuracy by using information of conspecifics. For example, individuals under
predation risk can benefit from the predator detection capacities of group members to increase
predator detection rates. However, individuals might also make mistakes (e.g., false alarms) and this
can give rise to cascades of false information, whereby the whole group is led into a wrong action.
How sensitive should individuals then be to information of conspecifics? In a series of simulated
predator detection experiments, using human groups, we investigate how individuals react to
information of group members, and how this in turn affects, decision accuracy. We show that
humans use quorum rules whereby the trustworthiness of information depends on the frequency of
the group deciding for a particular option. Individuals do not follow simple majority rules, but
instead, optimally adjust their response thresholds to the detection capabilities of their group
members: in groups in which few individuals detect a predator, a small critical mass is needed to
initiate an escape response, whereas in groups harbouring many individuals that detect the predator,
the critical mass to initiate an escape response is much larger. By following these rules, individuals
managed to make better decisions in groups than when alone.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 3 (14)
Linking social environment, endocrinology and behaviour across generations
Langen, Ester M.A.; von Engelhardt, N. & Goerlich-Jansson, V.C.
University of Bielefeld, Animal Behaviour, 33615 Bielefeld, Germany
The social environment of breeding birds affects circulating hormone levels as well as the deposition
of hormones to the yolk. Yolk hormones in turn influence offspring development, physiology and
behaviour. By studying the link between these factors across four generations of Japanese quail
(Coturnix japonica), we aim to understand in which way the social environment induces maternal
effects, thereby preparing offspring for the environment into which they hatch. We investigated
whether the social environment of adult females – pair vs. group living - affects body mass, plasma
hormone levels and the response to physiological challenges (restraint stress, GnRH stimulation of
testosterone production). Additionally, we measured how pair vs. group housing affects egg size and
yolk testosterone levels, potential mediators of maternal effects. To test for effects of the maternal
social treatment on offspring, we recorded chick behavioural responses in a tonic immobility and
emergence test. Our results indicate that social conditions affect maternal mass and plasma
testosterone levels, while indicators of stress - baseline corticosterone levels and the response to
restraint - are not affected. Accordingly, we find no effects of the maternal social environment on
offspring fearfulness in the tonic immobility test, but group and pair offspring differ in boldness and
exploration behaviour in the emergence test. In conclusion, our study demonstrates that the social
environment affects body mass and the endocrine profiles of breeding females, which may explain
the observed effects on the behavioural responses of their offspring.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 1 (6)
Early environmental conditions shape personality differences in a jumping spider
Liedtke, Jannis; Redekop, D.; Schuett, W. & Schneider, J.M.
University of Hamburg, Biocenter Grindel, Ethology, 20146 Hamburg, Germany
Consistent behavioural differences among individuals are widespread across various taxa in the
animal kingdom. The existence of such personality differences is puzzling, given that it would seem
sensible for individuals to be plastic and adjust their behaviour adaptively to changes in the
environmental conditions. Understanding which aspects of the environment are important for the
development of personality differences is crucial since this will be a first step towards elucidating
which mechanisms are important for generating and maintaining personality differences. Here, we
investigated the development of personalities in a jumping spider (Marpissa muscosa). We tested
whether the physical or social environment influences the development of individual differentiation.
We used a split-brood design and raised spider siblings in three different environments: a deprived
environment with no enrichment, a socially and a physically enriched environment. This design
allowed us to test for genetic, environmental and genotype by environment effects on personality
and plasticity. We focused on exploratory behaviour and repeatedly assessed individual behaviour in
a novel environment and a novel object test. Results show that the early environment, in which
spiders were raised had an effect on their exploratory tendencies and the investigated behaviours
were repeatable, indicating that external stimuli can influence the development of personality traits
in a jumping spider. We also found genotype by environment interactions on behavioural traits
potentially suggesting that plasticity itself might be under selection.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 6 (31)
Parturition and postnatal care in a eusocial rodent, the naked mole-rat (Heterocephalus
glaber)
Morhart, Michaela & Hildebrandt, T.B.
Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany
The naked mole-rat (Heterocephalus glaber) is a eusocial rodent, in which survival of the progeny and
the whole group depends on the colonies social interactions. Therefore it is important to survey how
the colony as a whole takes care of the pups. Cooperative brood care as such is a great selective
advantage and further questions like how and which colony member assists the breeding female
(queen) around parturition. Here we challenge the common assumption that the colony and the
breeding male (king) in particular, do not assist the queen during parturition. Along with this
question we documented in detail the birth in naked mole-rats. Once the birth contractions have
started the queen becomes restless, running through the system, autogrooming intensively and
frequently licks her urogenital region. During birth, the queen is assisted by other colony members,
and, as we found, particular by the king. In our studies, the king provided the major support during
parturition. He licks amniotic fluid before birth, cleans the pups and their nostrils from the embryo
membrane, consumes the placenta, carries neonates, rebuilds the nest, nuzzles and cleans the
queen`s vagina. This newly described role of the colony and the king during the birth process,
especially the primary attention to the neonates in the first minutes after birth may explain the high
pup mortality seen in other captive naked mole-rat colonies when the helpers are absent at birth.
Thus, support provided by the colony seems to be an important factor for offspring survival in this
species.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 5 (24)
External female genital mutilation
Mouginot Pierick & Uhl G.
University of Greifswald, Zoological Institute and Museum, General & Systematic Zoology,
Greifswald, Germany
In many species, females gain benefits from mating with multiple males. Polyandry results in sperm
competition and reduced paternity success. Consequently, counteradaptations in males that help to
reduce female remating probability or reduce sperm competition are selectively favored.
Monopolization strategies such as mate guarding, the production of mating plugs or antiaphrodisiaca may improve male paternity success. However, they entail costs for the male in terms
of time and effort spent on monopolizing that is lost for the additional mating opportunities. Thus, a
male monopolization strategy that entails little costs and is highly effective at the same time would
be favored. A possible strategy is to mutilate the female genitalia to impede remating with another
male. In organisms in which the females possess an external genital structure which the male
genitalia need to grasp in order to mate, this structure represents a preadaptation for a mutilation
strategy to evolve. In many orb-weaving spiders, a female external genital structure called scape is
essential for achieving genital coupling. A search through the taxonomic literature revealed that
female genital mutilation seems to be a widespread but as yet unexplored phenomenon. We present
data on the occurrence of external female genital mutilation and its efficacy as a strategy to secure
paternity in the orb-weaver Larinia jeskovi.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 5 (27)
Vocal complexity in giant otters (Pteronura brasiliensis)
Mumm, Christina A.S. & Knörnschild, M.
University of Ulm, Institute of Experimental Ecology, Faculty of Natural Sciences, 89069 Ulm,
Germany
Communicative complexity is thought to be shaped by the social environment a species lives in. The
number of individuals, their social roles and their interactions add to the complexity of the social
organization. Variations in repertoire size, occurrence of graded vocalizations, call combinations or
syntactical structure and vocal signatures can be used to assess vocal complexity. These social and
communicative factors may correlate, or have an influence on each other. Otters show a wide variety
of social organizations, ranging from mostly solitary to very gregarious species. Giant otters stand out
from the other otter species due to their highly cohesive family groups, alloparental care and help for
the elderly, and their loud and frequently emitted vocalizations. They have the richest vocal
repertoire among the otters and we could detect vocal signatures in four distinct vocalization types.
Vocal individuality is encoded in two types of social cohesion calls, whereas group differences exist in
alarm screams and group chorusing of giant otters. The animals themselves make use of these
signatures to discriminate among individual otters and own versus alien groups. Furthermore, a
preliminary analysis suggested the occurrence of a syntactical structure in giant otter call sequences.
A comparison among the 13 otter species suggests a coevolution of social and vocal complexity.
Overall, giant otters represent the socially and vocally most complex otter species.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 2 (8)
Effects of conditions during adolescence on male song learning and female preferences in
zebra finches
Honarmand, M.; Riebel, K. & Naguib, Marc
Wageningen University, Behavioural Ecology Group, Department of Animal Sciences, Wageningen,
The Netherlands
Bird song is a sexually selected signal that functions in intersexual competition and mate attraction.
Suboptimal conditions during early development have been shown to impair song learning thus
providing a mechanism for condition-dependency of learned signalling. Yet, to date studies almost
exclusively focussed on stressors experienced during the first month (i.e. pre nutritional and social
independence), using zebra finches (Taeniogygia guttata) as model organism. The critical phase for
song and song preferences learning, however, is during the second month post-hatching and after
chicks forage independently and join larger social groups, begging the question how diet quality and
peer group composition during this adolescent stage affect male song and female song preference
development. To test these ideas adolescent birds we housed birds in peer groups of varying size and
sex ratios and assigned them to either a HIGH or LOW quality diet. The results of the experiments re
veal effects of both diet and of social group composition on song learning and female song
preferences, highlighting how the quality of the rearing environment and social factors contribute to
birdsong learning. These findings shed new light on factors effecting maintenance of variation in
sexually selected signals and the preferences for these signals.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 1 (3)
The adaptive value of social learning
Romero-Mujalli, Daniel; Cappelletto, J.; Herrera, E. & Tárano, Z.
GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
Previous affiliations, where the work was done: 1) Instituto de Biología Experimental, Facultad de
Ciencias, Universidad Central de Venezuela, Caracas, Venezuela 2) Departamento de Estudios
Ambientales, Universidad Simón Bolívar, Caracas, Venezuela,
Learning is defined as behavioral modification due to experience, social or asocial. Social learning can
reduce the cost of asocial learning and allow the rapid accumulation of learned traits through
generations. However, the adaptive value of social learning in changing environments is not well
understood yet. In this study, we used "agent-based simulations" to examine the adaptive value of
social learning in a static and a dynamic environment, compared to asocial learning and genetic
evolution. Learning (social and asocial) was modeled using neural networks, and genetic evolution
was modeled using genetic algorithms. The performance of 10 mobile simulated agents was
measured (cumulative mortality and number of agents showing the correct answer during 20000
iterations) under three-environment scenarios: static, abrupt-change and gradual-change. We found
that social learning allows a better performance compared to asocial learning in static and abruptchange scenarios. In contrast, when changes are gradual, social learning delays achieving better
alternatives, while asocial learning escapes the conformism, and a mixed population (social and
asocial learners) performs best. Our results corroborate the advantage of social learning in a static
environment, and show that its adaptive value depends on the nature of environmental change,
performing poorly when the environment is characterized by small cumulative changes.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 1 (1)
Effects of heavy metals on stress coping abilities and social support in barnacle geese
(Branta leucopsis)
Scheiber, Isabella B.R.; van den Brink, N.; Loonen, M.J.J.E. & Komdeur, J.
University of Groningen, Centre for Ecological and Evolutionary Studies, Behavioural Ecology and
Self-Organization, Linnaeusborg, 5172.0878, 9747 AG Groningen, Netherlands
Environmental stressors, including heavy metal pollution, can provoke physiological responses that
may affect the functioning of individual organisms, including the impairment of the hypothalamicpituitary-adrenal (HPA) stress axis. One major HPA function is the excretion of glucocorticoids (e.g.
cortisol, corticosterone) to restore physiological homeostasis. Whereas short-term activation of the
HPA axis may be beneficial, chronic activation is harmful, as it challenges e.g. the immune system.
One key feature to counteract chronic HPA activation is social support, defined as the stress-reducing
effect gained through the presence of social allies. Social support so far has been studied in the
context of the social environment only. We proposed the novel idea that individuals with a proper
social embedding will also cope better with stressors stemming from the physical environment, i.e.
heavy metal contamination. The area around Ny-Ålesund (Spitsbergen) offers itself for investigating
this question, as the soil around a former coalmine still shows elevated mercury levels relative to
unexposed areas. In 2014 we performed an experiment with 16 human-raised barnacle goslings, half
of which predominantly fed in contaminated or clean areas, respectively. We performed stress tests,
and measured the goslings’ behavioural and physiological responses. Detailed chemical analyses and
biochemical responses in body tissues are used to underpin behavioural observations, relating
effects among different levels of biological integrations (behaviour, stress responses and cellular
toxicity effects) to the exposure to mercury. We will discuss the impacts of environmental stressors,
such as climate change, on the vulnerability for birds breeding in the Arctic.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 2 (7)
Effects of female choice on female fitness - A combined behavioral/molecular genetic
study on Poecilia latipinna
Scherer, Ulrike1; Schlupp, I.2 & Tiedemann, R.1
1
University of Potsdam, Institute of Biology & Biochemistry, Falkensee, Germany
2
University of Oklahoma, USA
Mate choice behaviour is quite abundant in a huge variety of species within a broad range of taxa.
Being choosy can be advantageous over random mating when reproduction is associated with costs
that can be alleviated through gaining direct or indirect benefits from choosing the better mate. In
Poeciliid fishes, females show clear mate preferences for certain males. But in this highly
promiscuous taxon males do not contribute anything to reproduction but sperm, so females do not
receive any direct benefits post-mating. Here we investigated the assumption that mate preferences
of female Poecilia latipinna (sailfin molly) increase their fitness through indirect effects, such as good
genes, leading to a higher quality and/or quantity of offspring. Furthermore the influence of mate
quality (male size) on female preferences and reproductive success was analyzed. We gave 27 P.
latipinna females the opportunity to mate with both - a preferred and a non-preferred male and the
resulting offspring was analyzed using life history as well as genetic techniques. The dry weight of
embryos was determined as a measurement for offspring quality and the paternity was assigned via
microsatellite-analysis. DNA could be preserved through gentle desiccation at a low temperature,
allowing life history measures without destroying the DNA for further genetic analyses. This
integrative study is the first of its kind to methodically combine life history and genetic analyses of
poeciliid fish embryos.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 4 (22)
The transfer of alternative tasks in reciprocal cooperation
Schweinfurth, Manon. K. & Taborsky, M.
University of Bern, Institute of Ecology and Evolution, Behavioural Ecology, 3032 Hinterkappelen,
Switzerland
Experiments have revealed that direct reciprocity can establish stable cooperative interactions
between animals. Evidence for reciprocal cooperation in nature is elusive, however. A possible
reason for this ambiguity is the standard assumption that the same commodity is exchanged
between social partners. Yet, an exchange of different favours, or an exchange of service across
different social contexts, appear more likely in a natural setting. This might be cognitively
demanding, however, because experienced help in one context needs to change the motivation to
help the social partner by different means or in a different context. We tested whether Norway rats
(Rattus norvegicus) transfer help from one social context to another, which would exclude the
possibility that reciprocal cooperation in rats is merely reflecting the copying of previously
experienced behaviour of a social partner. In an iterated prisoner’s dilemma game individuals could
provide food to either previously cooperative or defective partners. In so doing, the test rats had to
use a different mechanism to produce food for their partner than the partner had used to help them
before. Test rats indeed helped previously cooperative partners more often than defective ones by
using a different provisioning mechanism. This implies that rats realize the cooperative propensity of
social partners, which they consequently reward by altruistic help of a different kind. Our results
suggest that animals may indeed show reciprocal trading using different commodities and services,
which highlights new possibilities for reciprocal altruism under natural conditions.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 2 (9)
The Corvid Cognition Battery - Cognitive Development in Ravens (Corvus corax)
Sima, Miriam Jennifer & Pika, S.
Max-Planck Institute for Ornithology, Humboldt Research Group „Development of communication“,
82319 Seewiesen, Germany
The culture intelligence hypothesis is one of the theories that try to answer the question why
humans have evolved their advanced communicative and cognitive abilities. This hypothesis predicts
that in early ontogeny the main difference in cognitive abilities between human infants and
nonhuman apes are in social-cultural cognitive skills but not in physical cognition. To test the culture
intelligence hypothesis, Herrmann and colleagues (2007) developed a test-battery, the so-called
Primate Cognition Test Battery, which consists of 16 different tasks to test physical and social
cognitive abilities. They showed that human children outperform captive chimpanzees and orangutans in social but not physical cognitive abilities. Furthermore, Schmitt and colleagues (2012) found
similar results for two monkey species. However, does this distinction also apply for non-primate
species, which are known for their sophisticated cognitive abilities such as corvids? To address this
question, we investigated the physical and social cognitive skills of a member of the corvid family,
ravens by designing a similar test battery. Furthermore the study was conducted during ontogeny to
also investigate cognitive development in ravens. The study was performed on eight hand-raised
ravens throughout their first year of life. Preliminary results suggest that ravens show similar
performance than nonhuman apes in the test battery and outperform nonhuman apes in some of
the social cognition tasks.
Herrmann et al. 2007. Humans Have Evolved Specialized Skills of Social Cognition: The Cultural
Intelligence Hypothesis. Science, 317.
Schmitt et al. 2012. Old World Monkeys Compare to Apes in the Primate Cognition Test Battery. PloS
one, 7.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 6 (29)
Social personality traits and salivary cortisol in common marmosets
Slipogor, Vedrana; Millesi, E. & Bugnyar, T.
University of Vienna, Department of Cognitive Biology, 1090 Vienna, Austria
Personality is a correlated suite of behavioural traits, consistent across time and/or contexts. The five
generally observed personality traits, namely three non-social traits (boldness-shyness, explorationavoidance and activity) and two social traits (aggressiveness and sociability) are sometimes linked to
physiological mechanisms that may provide a proximate explanation for the maintenance of
consistent inter-individual variation. Therefore, in this study we combined behavioural and
physiological parameters to study consistent inter-individual differences in common marmosets
(Callithrix jacchus). We assayed salivary cortisol and its relation to social personality traits of
individually separated marmosets (n = 15) in two blocks of behavioural tests. In a Mirror Test, we
placed the mirror in front of the experimental enclosure; and in a Video Test, we replaced the mirror
with a computer screen on which an image of an unfamiliar same sex individual was presented.
Saliva samples were taken before, immediately after and 10 minutes after the tests, while all
behavioural responses during the tests were recorded with two video cameras. In both tests, we
predicted that seeing an “unfamiliar conspecific“ would evoke a social response (either affiliative or
agonistic) in this highly territorial species, yet that the degree of this response may vary consistently
between individuals. We will discuss whether inter-individual differences in cortisol levels are
correlationally linked to the social personality traits, i.e. more social individuals show lower or higher
salivary cortisol levels after seeing an unfamilar conspecific than less social individuals.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 5 (25)
Social and communication networks in territorial great tits
Snijders, Lysanne; van Oers, K. & Naguib, M.
Wageningen University, Behavioural Ecology Group, Animal Sciences Department,Wageningen, The
Netherlands
Individuals in various animal species differ consistently in their behaviour, often referred to as
personality. In several species these personality differences also correlate with differences in social
behaviour. Using social network analysis, recent studies have furthered our understanding of the role
of personality in the social environment, usually by focusing on swarming or flocking populations.
However, social associations in such populations are fundamentally different from those in territorial
populations, where individuals meet less frequently and where the costs and benefits of spatial
associations differ from those for swarming or flocking species. We therefore tested whether social
network position is related to individual differences in exploration behaviour, an established
measure of an avian personality trait, using a wild, territorial, personality-typed great tit, Parus
major, population. By means of novel, large-scale, automated tracking (Encounternet) we show that
slower exploring males had less central social network positions. Yet, slower explorers overall did not
travel shorter distances than faster explorers, suggesting that a less central social network position
was not merely a consequence of lower activity. Hence, territorial individuals could be influencing
the structuring of their own social environment in relation to their personality. Moreover, the social
environment of territorial songbirds also includes so-called communication networks. Here we will
show that repeatable song traits in territorial male great tits varied in relation to their social
environment. These findings are relevant, because the establishment of social relations and
familiarity with possible competitors is predicted to be important in many territorial populations.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 1 (2)
Boldness influences strategic male mate choice
Sommer–Trembo Carolin; Plath M. & Bierbach D.
J.W. Goethe University Frankfurt, Department of Ecology & Evolution, D-60438 Frankfurt am Main,
Germany
Few studies to date have investigated male mate choice copying, but livebearing fishes (Poeciliidae)
are an example of a group in which this phenomenon has been described for several species. Poecilia
females mate multiply with different males, leading to strong sperm competition. In particular, both
the copying and the copied male face an increased sperm competition risk (SCR). Especially for the
copied male considerable costs arise, and so males alter their mate choice behavior strategically
when observed by a rival (termed audience effects): males temporarily move away from the
preferred female and approach non-preferred females, probably to mislead the audience male.
However, responding with audience effects bears the risk of losing the preferred female. In many
species, including our study species, the Atlantic molly (Poecilia mexicana), individuals differ
consistently in risk-taking behavior. Whether and how personality differences affect audience effects,
however, remains to be investigated. We initially characterized males along the boldness-shyness
behavioral axis. In addition, we tested whether competition levels affect audience effects and
subjected half of the males to a low competition (single-male housing) and the other half to a highcompetition treatment (group housing) before they were tested. In mate choice tests, only males
from the high-competition treatment ceased expressing preferences when confronted with a rival.
Bolder males within this cohort showed stronger audience effects corroborating our prediction that
bold males are more willing to take the risk of losing the preferred female.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 7 (36)
Green cities: Vegetation structure can increase reproductive success in urban great tits
Sprau, P.; Hutfluss, A. & Dingemanse, N.
Ludwig Maximilians University Munich, Behavioural Ecology, Martinsried, Germany
Next to climate change the United Nations considers urbanisation the biggest environmental
challenge of our time. In the coming decades the growth of urban areas is expected to attain
unprecedented levels with detrimental effects on ecosystems. Whether wild animals will be able to
survive in an increasingly urbanized world will depend on their capacity to adapt to these new
environmental conditions. In this study we investigated the impact of a suite of environmental traits
– i.e. temperature, noise, light, human activity and vegetation structure – that were quantified along
urban gradients on reproductive success in an urban great tit (Parus major) population. Our results
revealed that the use of urban nest boxes as breeding sites was associated with the vegetation
structure: the greener the area around the nest boxes the more likely they were occupied. Moreover,
we found that about 50% of the broods remained unsuccessful. Reproductive success of great tits
breeding in nest boxes was strongly associated with vegetating structure; greener habitats led to
more fledglings. These findings show that vegetation – and not so much environmental traits such as
temperature, light and noise – is a key component for fitness traits in urban environments.
Therefore, future urban development measures should take sufficient green areas into account.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 2 (11)
Environmental versus social transmission: How Escherichia coli spreads through a lemur
population
Springer, Andrea; Fichtel, F.; Mellmann, A. & Kappeler, P.M.
German Primate Center, Behavioral Ecology and Sociobiology Unit, 37083 Göttingen, Germany
Increased exposure to infectious disease is assumed to be one of the major costs of group-living. The
relative importance of environmental versus social transmission of infectious agents remains unclear
in many cases, however. We investigated the spread of the ubiquitous, usually non-pathogenic
bacterium Escherichia coli in a population of Verreaux’s sifakas (Propithecus verreauxi) in their
natural habitat in Madagascar. We used a molecular epidemiological approach to investigate genetic
similarities between E. coli bacteria from different individuals and groups to infer transmission
pathways. Using network analysis, we show that sharing of E.coli multilocus sequence types is
significantly correlated with belonging to the same social group. Furthermore, we show that
intergroup encounter rate is a more potent explanatory factor for E.coli type sharing between social
groups than home range overlap. Hence, E.coli appears to be transmitted predominantly via social
contact in this populat ion and may serve as a model organism for other fecal-orally transmitted
infectious agents. More generally, our results demonstrate that integrative field studies on the health
status of wild primate populations are feasible and that they can potentially shed light on central
questions linking sociality, ecology and conservation.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 5 (26)
Higher fundamental frequency in defensive calls triggers responses in free-ranging ravens
Szipl, Georgine & Bugnyar, T.
University of Vienna, Department of Cognitive Biology, 1090 Vienna, Austria
Common ravens aggregate at feeding sites, where they compete over food, thereby uttering
defensive calls. The audience (bystanders not directly involved in an interaction) can eavesdrop on
defensive calls to engage in an on-going conflict. Furthermore, signalling behaviour can change in the
presence of specific affiliated conspecifics or competitors. We monitored aggressive interactions and
recorded defensive calls of marked individuals during feeding situations in a well-studied group of
individually marked free-ranging ravens foraging in a zoo in the Austrian Alps. In addition to
observational data, we tested ravens' responses to defensive calls in a playback experiment.
Specifically, we tested whether ravens would be sensitive towards changes in call duration and
fundamental frequency. For this, we selected defensive calls and manipulated the duration (50%
longer or 50% shorter) and the fundamental frequency (shifted up or down by 100 Hz). In each
session, we played back the unmanipulated call and two manipulated calls (either manipulated in
duration or in fundamental frequency) in randomized order. Mean response rate over all sessions
was at about 10%. No differences in response were found when playing unmanipulated calls and calls
that varied in duration. However, when testing responses to defensive calls manipulated in
fundamental frequency, significantly more ravens responded to calls with higher fundamental
frequency. As fundamental frequency increases with arousal, ravens seem to pay attention to the
degree of arousal in attacked conspecifics.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 4 (19)
Stability and change: Cortisol stress responsiveness over the life time
Tiedtke, Tobias; Kaiser, S. & Sachser, N.
University of Münster, Department of Behavioural Biology, 48149 Münster, Germany
The activity of the hypothalamic-pituitary-adrenal (HPA) stress system is modulated by the social
environment during various life stages. However, we know very little about individual consistencies
in stress responsiveness across development. In guinea pigs, a series of experiments provide insight
into the stability of inter-individual differences in HPA reactivity during different life stages. When
male guinea pigs housed in large mixed-sex colonies were repeatedly exposed singly to a novel
enclosure, the acute cortisol stress response was remarkably stable during postweaning and early
adolescent phases. That is, cortisol response values were individually consistent over retesting
intervals from 20 to 30 days and 30 to 55 days, respectively. This stability was confirmed for adult
animals (approximately 7 to 17 months) over even longer retesting intervals of about 2 months. In
contrast, no significant consistency of cortisol responses was found from early to late adolescence
(55 to 120 days), which covers the phase where colony-housed males show a socially mediated
suppression of HPA reactivity. On the other hand, pair-housed males, which do not show suppressed
HPA responsiveness during adolescence, exhibited highly stable individual differences in cortisol
responses over exactly the same period. Taken together, individual cortisol stress responsiveness
seems to be a highly stable trait during most life stages. However, the social environment has
remarkable influence on this stability during phases of increased developmental plasticity.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 7 (35)
Evidence for loss of nepotism in the evolution of permanent sociality
Berger-Tal, R.; Bilde, T.; Lubin, Y.; Settepani, V.; Majer, M. & Tuni, Cristina
Ludwig Maximilians University Munich, Planegg-Martinsried, Germany
Kin selected benefits of cooperation result in pronounced kin discrimination and nepotism in many
social species, favoring the evolution of sociality. However, low variability in relatedness among
group members, infrequent competitive interactions with non-relatives, and non-kin selected
benefits of cooperation, may relax selection for nepotism. We tested this prediction in permanently
social spiders that fulfill these conditions, and where kin discrimination plays a role in the evolution
of sociality. We examined whether nepotism occurs in cooperative feeding in experimental replicates
where we varied genetic relatedness among group members. We found no effect of relatedness on
feeding efficiency, growth rate or participation in feeding events. This contrasts with previous studies
on ancestral sub-social species, which found strong effects of varying relatedness on cooperative
feeding. The lack of such effects in this social species indicates a loss of kin-directed cooperative
behavior. This implies a reduced role of nepotism in cooperative interactions when permanent
sociality evolves in certain environmental and genetic contexts.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 7 (37)
Mating, but not aggressive behavior or parental care correlates with testosterone in a
socially monogamous territorial songbird
Villavicencio, Camila P. & Goymann, W.
Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
Seasonally reproducing birds express higher plasma levels of testosterone during the breeding
season than during the rest of the annual cycle. In socially monogamous birds, high levels of
testosterone often correlate with mating, territorial and aggressive behavior and may interfere with
parental care. The black redstart (Phoenicurus ochruros) is a socially monogamous songbird that is
territorial during breeding but also defends a territory outside a reproductive context. Here, we
investigated the relationship between testosterone, aggressive behavior, parental care and mating
behavior (extra-pair paternity) in male black redstarts. We found that testosterone did not correlate
with aggressive behavior or parental care. But testosterone levels remain high after the first brood
and males mate for a second time. Testosterone was related to paternity loss: males that maintained
higher levels of testosterone towards the end of the breeding season experienced a lower degree of
paternity loss than males with lower levels of testosterone at the end of the breeding season. Our
results do not support a role of testosterone in the control of territorial behavior or parental care,
but suggest that the hormone is mainly related to mating behavior. Hence, in species that are
territorial year-round testosterone may be decoupled from aggression and parental care. Our study
shows that the relationship between hormones and behavior may differ among bird species with
different life styles.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 4 (20)
New evidence for kairomone-guided food search in common mole-rats (Cryptomys
hottentotus) from the field
Vole, Christiane; Burda, H.; Avenant, N.L. & Begall, S.
University of Duisburg-Essen, 45117 Essen, Germany
In previous laboratory studies it has been shown that Ansell’s mole-rats (Fukomys anselli) are able to
detect a carrot kairomone-gradient in a distance of 30 cm. The gradient resulted from carrots that
had been growing for a period of one week in either of the two terminal boxes of the two-choice
labyrinth. We tested the hypothesis that common mole-rats (Cryptomys hottentotus) search not
“blindly” for food in the field. We prepared ten tunnels with a field of nine carrots (3 x 3) on one side
of a straight tunnel. We had to drill holes into the soil in order to place the carrots that were watered
and allowed to grow for one week. The control field consisted of nine holes (3 x 3) that we drilled on
the opposite side of the tunnel. We watered the holes of the control with the same amount of water
as the carrot field. After one week, we opened the tunnels and checked for signs of carrot
consummation. We found in all ten burrow systems evidence for mole-rat activity in the carrot field
(side tunnels leading to the carrot field and/or bite marks), in only one case there was also a side
tunnel leading to the control field. We can thus conclude that mole-rats can also detect a kairomonegradient from carrots in the field that the animals can exploit. Previous theoretical modeling of molerats’ food search should be revisited taking the new aspect of gradient detection into account.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 8 (42)
Are stressed helpers better workers? Relationship between Glucocorticoids and individual
work rate in subordinate female Damaraland mole-rat (Fukomys damarensis)
Philippe Vullioud
University of Cambridge (UK), Department of Zoology, Cambridge, UK
Large differences in individual propensity to help are paramount within animal societies. This is
particularly conspicuous in the context of cooperative breeding where a majority of helpers forfeit or
forego their own reproduction and support a majority of breeders in their reproductive effort.
Although evolutionary explanations to this variation have flourished, its underlying physiological
mechanisms remain poorly understood. There is indication that Glucocorticoid hormones (GCs) may
through their pleiotropic effect mediate helpers behavioural profile, including investment in
cooperative activities, yet biologically relevant experimental manipulation are still crucially lacking. In
captive Damaraland mole-rat (Fukomys damarensis), we artificially increased GC concentration of
female helpers within the physiological range of non-manipulated subjects by the injection of a 7
days GC release subcutaneous implant. GC treatment led to a dramatic increase in helpers’ work
rate, which in artificial tunnel system was measured by individual participation in tunnel
maintenance (dig and sweep sand, build nest, carry food). Helpers’ individual working effort is of
cooperative nature since it benefits other group members. Our results are in line with the positive
metabolic effect of GCs and confirm that GCs may positively regulate cooperative behaviours in
systems where such activities are energetically demanding. Ultimately, this raises the hypothesis that
breeding female may socially stress helpers to make them work harder.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Session 8 (41)
Inter-individual variability and collective thermoregulation in bumblebee colonies
Weidenmüller, A.
Universität Konstanz, FB Biologie, LS Kleineidam/Galizia, 78464 Konstanz, Germany
Animals in social groups often show consistent differences in behavior. How does this behavioral
variability arise; and what effects does it have on the collective properties of a group? I address these
questions in social insects, where inter-individual variability plays a prominent and long recognized
role: division of labor, frequently regarded as the key component of the vast ecological success of
social insects, is believed to be based on behavioral differences among the workers of a colony.
Increasingly, the intrinsic variability of workers comprising an insect colony is viewed as a key
component of its self-organized collective phenotype. Using brood-thermoregulation in colonies of
bumblebees as experimental system, I investigate both the mechanisms generating inter-individual
behavioral variability in the thermal responses of workers and the effect of this variability on the
collective homeostatic abilities of a colony. I will present my experimental approach in measuring
inter-individual variability and discuss data shedding light on the modulatory effects of both
preimaginal and adult experience on the behavioral differentiation of bumblebee workers.
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10th topical meeting of the Ethological Society
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Session 3 (13)
(Poecilia mexicana)
Zimmer, Claudia Z.; Ho, J.H.K.I.; Lewer, M.L.; Plath, M.P. & Bierbach, D.B.
Goethe University, Institute of Ecology, Evolution and Diversity, Frankfurt am Main, Germany
Predation and the avoidance of predators are central components affecting individuals’ immediate
survival and thus, fitness. Extreme environments—like sulphidic and cave habitats—with their
truncated predator communities can serve as refuges from predation, and costly anti-predator
behaviour ought to be reduced under relaxed selection pressure. Nevertheless, previous studies
found predator recognition and innate avoidance behaviour to persist even in habitats that lack
certain predator types, either through a “ghosts of predators past” mechanism, or because prey
might experience other forms of predation. In any case, anti-predator behaviour ought to correlate
with the degree of threat a given predator poses to its prey. We investigated predator avoidance in
relation to predators’ body size in the neotropical fish Poecilia mexicana from a suite of extreme
habitats in Southern Mexico, using digitally animated predatory cichlids (Cichlasoma salvini). Fish
stemming from cave en vironments retained a size-specific response to predators; however, while all
populations increased predator avoidance with increasing predator size, cave mollies overall showed
reduced anti-predator behaviour compared to surface populations. Beside potential changes in
motivational state and neuronal processing of predator-related information, another possible
explanation for these population differences is reduced eye size and thus, a reduced ability of cave
fish to respond adequately to predators.
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10th topical meeting of the Ethological Society
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Session 6 (30)
Division of labor in Damaraland mole-rats
Zöttl, Markus; Vullioud, P. & Clutton-Brock T.H.
University of Cambridge, Cambridge, UK
Investment in cooperative behaviors among members of stable social groups differs often with
respect to sex, size, age and the group composition they live in. This kind of division of labor appears
in its most extreme form in eusocial insect societies like ants and termites. In highly social,
cooperatively breeding vertebrates division of labor might be important with respect to work-load
distribution and task specialization within a colony and it has been suggested that variation in helping
is associated to different life-history trajectories. Here, we present behavioural data on workload
distribution collected in 20 colonies of Damaraland mole-rats (Fukomys damarensis) housed in
artificial tunnel systems that allow detailed behavioral observation. We test life history-theory and its
predictions regarding growth, sex, size and colony composition and discuss the implications for the
evolution of extreme mammalian sociality.
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10th topical meeting of the Ethological Society
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List of Posters (alphabetical order)
Poster (20)
Does helping behaviour increase the quality of nestlings in varying environmental
conditions? - Case study on the Azure-winged Magpies (Cyanopica cyanus Pallas, 1776) in
northern Mongolia
Bayandonoi, Gantulga
Georg-August University of Goettingen, Workgroup on Endangered Species Conservation,
Department of Systemic Conservation Biology, Faculty of Biology, Göttingen, Germany
Behavioral patterns are typically determined from single population studies, assuming that patterns
do not vary among populations of the same species. As complex behaviors can vary adaptively
among environments, it may not always be applicable. Due to flexibility of the social system, we
cannot assume that all breeding colonies have a cooperative breeding system and that it works in the
same way in varying environmental conditions by studying only one breeding colony. The Azurewinged Magpie (Cyanopica cyanus) has a flexible cooperative breeding system, which appears
irregularly in some populations. Therefore, we investigated the flexibility and effect of helping
behaviour by studying three breeding colonies of the Azure-winged Magpie which are located
relatively far from each other thus representing different environmental conditions in Northern
Mongolia. Cooperative breeding system were recorded in all three breeding colonies. The food
supply in Sugnugur breeding colony was much higher than in Khonin Nuga and Songino breeding
colonies. As a result, in Sugnugur breeding colony the total feeding rate in nests with helper was not
larger than in nests without helper. On the contrary, feeding rate was higher in the other two
breeding colonies. Nestlings were considerably heavier in nests with helper compared to nests
without helper in Khonin Nuga and Songino breeding colonies, but this was not the case in Sugnugur.
Chick rearing stage was significantly shorter in nests with helper than nests without helper in all
breeding colonies. Our results suggest that helpers' contribution may have played a key role on the
quality of nestlings that could increase their survival when ecological conditions are unfavourable.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (12)
“Old guys‘ singing: how song features change with age in the Common nightingale
(Luscinia megarhynchos)
Bienasch, Adrienne & Kipper, S.
Freie Universität Berlin, Institute of Biology, Department of Animal Behaviour, 14195 Berlin, Germany
In many species, social and communicative behaviour is experience- and age-dependent and thus
changes in lifespan. If such behavioural plasticity concerns sexually selected signals, it can be used by
receivers as an honest indicator for experience or age of the signaller. Birdsong is a well-investigated
signal system in that regard. But how does song change with age over an individual’s lifespan? As
common nightingales (Luscinia megarhynchos) are open-ended learners with a large repertoire size,
they are a good model species to study age-related song variability. Previous studies have shown that
1-yr-old males increase their repertoires considerably for the following breeding season but not
thereafter. The present study is based on a unique longitudinal dataset of a population of freeranging nightingales with known individual life history. We focussed on differences in repertoire sizes
of males late (after their second year) and very late (three or four years in between) in their lives
(N=7). “Old” in this context means ages far above the adult average life expectancy of a little more
than one year. Only very few males of our study population reach such a high ages. Firstly, to the
best of our knowledge, this study extended previous findings of highest age in free-ranging
nightingales. Secondly, complementing to expectations of earlier findings, the study revealed that
the repertoire sizes of old males continue to increase later in their lives. These findings provide
supporting evidence that repertoires vary over an individual’s lifetime; potentially allowing it males
might signal their age and females to use this information in the courtship context.
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10th topical meeting of the Ethological Society
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Poster (22)
Benefits of adversity?! The impact of life history and serotonin transporter genotype on
the behavioral profile of mice
Bodden, Carina; Richter, S.H.; Heiming, R.S.; Kloke, V.; Gerß, J.; Palme, R.; Lesch, K.-P.;
Lewejohann, L.; Kaiser, S. & Sachser, N.
University of Münster, Department of Behavioural Biology, 48149 Münster, Germany
Behavioral profiles are influenced by life history and genotype. Traditionally, accumulating adversity
is considered to predict increased anxiety-like behavior. The alternative mismatch hypothesis
suggests increased levels of anxiety if the early environment differs from the later-life environment.
Thus, there is a need for a whole-life history approach to gain a deeper understanding of how
behavioral profiles are shaped. Our aim was to elucidate the effects of life history on the behavioral
profile of mice varying in serotonin transporter (5-HTT) genotype, an established mouse model of
increased anxiety-like behavior. Mice grew up under either adverse or beneficial conditions during
early life. In adulthood, they were further subdivided so as to face a situation that either matched or
mismatched the previous condition, resulting in four life histories. Subsequently, mice were tested
for anxiety-like and exploratory behavior. The main results were: (1) Life history profoundly
modulated behavioral profiles. Surprisingly, mice that experienced early beneficial and later
escapable adverse conditions showed less anxiety-like and more exploratory behavior compared to
other life histories. (2) Genotype significantly influenced behavioral profiles, with homozygous 5-HTT
knockout mice displaying highest levels of anxiety-like and lowest levels of exploratory behavior. Our
findings concerning life history indicate that the absence of adversity does not necessarily cause
lower levels of anxiety than accumulating adversity. Rather, some adversity may be beneficial,
particularly when following positive events. We conclude that for an understanding of behavioral
profiles, it is not sufficient to look at experiences during single phases of life, but to consider the
whole life history.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (3)
Not all that organises is pheromones: No evidence that pheromones affect excavation
choice in ants
Bruce, A.I.
Monash university, School of Biological Sciences, Melbourne, Australia
Ants can excavate large tunnel systems as part of their nest construction. The size of these nests
scales with the number of individuals present. This matching of nest digging effort to need is an
example of an efficient allocation of labour to a task. However, the mechanisms that underlie this
regulation are not understood. It has been hypothesized that pheromones on the digging face play a
key role in this regulation through the processes of application, attraction, and evaporation. This
hypothesis has previously been supported by both modelling and evidence. This study tested this
theory by presenting groups of 5 Acromyrmex lundi with the choice of two tunnel faces in which to
dig, one with pheromones (or potentially with pheromones) that had just been exposed to active
digging, and the other with little or no pheromone, where digging had also been present but was
stopped for one hour to allow any previous pheromone deposition to dissipate. It was expected that
more excavation would occur over the course of one hour at the 'fresh' tunnel faces than at ‘old’
faces. However, this was not the case and the difference in the weight of excavated soil between the
two conditions was non-significant (Wilcoxon test, p=0.523, n=96). This surprising result suggests
that pheromones might not be present on the digging face, or at least do not function to regulate
group investment in tunnel excavation. This suggests that our understanding of the social regulation
of nest construction requires revision.
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10th topical meeting of the Ethological Society
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Poster (18)
Determinants of between-year cave re-occupation in a German colony of the European
Bee-eater Merops apiaster
Brust, Vera; Bastian, H.V.; Bastian, A. & Schmoll, T.
University of Osnabrueck, Department of Behavioural Biology, 49072 Osnabrück, Germany
Documentation of a repeated use of breeding cavities in the European bee-eater (Merops apiaster) is
scarce and has mostly been interpreted as finishing a tunnel that was begun in a previous season. In
fact, most of the literature record states that breeding cavities are obligatory build anew each year.
The few sources that consider re-use report single cases or at least do not use a solid data basis to
give quantitative information. In this study we analyze cavity re-use systematically over a period of
eleven years for the first time, taking also ecological variables into account. In contrast to the
statements in the literature, cavity re-use is frequent in our study population in Rhineland-Palatinate.
Out of 179 broods 54% were located in caves that had been used already in a previous year. Single
cavities were re-used up to a maximum of eight times. Factors that further influence the re-use
probability are age of the cavity, number of cavities available in the breeding wall and population
size. Our findings clearly deviate from the present literature record. However we are aware of the
limited nature of this study containing only data from one breeding colony. Hence an analysis of
more data sets in a similar fashion is needed to achieve a better understanding of the general
preconditions that determine the re-use of cavities in the European bee-eater. With such information
at hand a better protection of this flagship species would be possible.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (5)
Determination of the coping-type by using behavioural und physiological traits in dwarf
goats (Capra hircus)
Finkemeier, Marie-Antonine; Meyer, S.; Langbein, J. & Puppe, B.
University of Rostock, Agrar- und Umweltwissenschaftliche Fakultät, Professur für Verhaltenskunde,
18059 Rostock, Germany
Personality in animals is a vast topic and much research has been conducted to quantify individual
differences in a large number of species. One of many approaches to understand personality is to
divide animals in coping-types: pro-active and re-active. Pro-active individuals are more aggressive
towards conspecifics, show more dominant behaviour and take more risks. Moreover, they are more
explorative, bold and active. Re-active animals are considered less explorative and less active and
more shy. Furthermore, they show less risky behaviour and show more submissive behaviour
towards conspecifics. Some studies show, that the used behavioural traits to assess personality can
be correlated with each other and even with physiological traits. Only a few studies found evidence
for correlations between behavioural traits (e.g. activity and exploration in an open field) and heart
rate in animals. Therefore, behaviour seems to vary a lot between individuals and to correlate with
physiological traits, especially the heart rate variability. We want to investigate correlations between
behaviour as related to a specific coping-type and heart rate variability (HRV) by using the dwarf goat
(Capra hircus) as model organism. We will measure various parameters conducted in a number of
behavioural tests (open field, novel object, social isolation, activity, holding-test, dominance-test).
Additionally, we will record HRV parameters (SDNN, RMSSD) and run a principle-component-analysis
with all measured parameters. The aim of this study is to divide the dwarf goats in different copingtypes and to find a correlation between the coping-type and heart rate variability.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (23)
Fluctuating asymmetry as a measure of habitat suitability for Rattus rattus
Andrianasolo, T. & Ganzhorn, Jörg U.
University of Hamburg, Biocenter Grindel, Animal Ecology and Conservation, 20146 Hamburg,
Germany
Different degrees of fluctuating asymmetry can reflect living conditions of organisms. Increasing
asymmetry is interpreted as increasing levels of stress (including parasites). We use this measure to
assess the suitability of various types of habitat for rats in Madagascar. For this we captured rats that
had been introduced to Madagascar and have colonized almost all native habitats of the island in a
wide range of anthropogenic and native habitats (villages, spiny bush, evergreen rain forest) and
investigated the degree of cranial asymmetries in males and females in relation to habitat and
intestinal parasite loads.
Supported by BMBF SuLaMa and DFG SPP 1596, Ga 342/19-1.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (10)
Effectiveness of relaxing the 2 °C climate target
Hagel, Kristin; Milinski, M. & Marotzke, J.
Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
Limiting global warming to less than 2 °C is widely accepted as a means to avoid dangerous climate
change. However, it appears increasingly unlikely that greenhouse-gas emissions will fall soon and
fast enough to meet the 2 °C target, raising the question whether it must be modified. While some
research exists on policy consequences of potential target modifications, empirical evidence for
behavioral consequences is lacking. We report on experiments in which subjects must invest from an
initial endowment in order to reduce the risk of simulated dangerous climate change. If they fail as a
group to reach a set target sum, they lose the remainder of their endowment with a certain risk. We
apply three different treatments: (1) high risk of dangerous climate change for any failure to reach
the target sum, interpreted as failing to reach the 2 °C target; (2) an additional intermediate target
sum (interpreted as a climate target of 3 °C), beyond which the risk decreases linearly; (3) the risk
decreases linearly with group investments until it reaches zero at the target sum. Investments reduce
the remaining endowment but also the risk of losing it. For each treatment there is thus an optimal
investment that maximizes final payoff. The subjects almost maximized their payoff, by balancing
successfully the risk posed by dangerous climate change and the effort to avoid it. As a consequence
they invested most when the 2 °C target was fixed. Thus, relaxing the 2 °C climate target is likely to
cause enhanced warming.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (7)
One for all vs. all for one: Are a few small groups more successful in reaching a common
goal than one large group?
Milinski, M; Hagel, K & Hundertmark, Antje
Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
The change of the global climate is an issue that concerns the whole population of planet Earth. If no
measures are taken, the climate will change in an unpredictable, probably dangerous way which will
lead to severe human, ecological and economic losses. To avert dangerous climate change in the
future actions have to be taken now. Two large models are proposed how to prevent dangerous
climate change. The supporter of the global approach state that only a global control institution can
lead people to save Earth’s climate. Promoters of the decentralised, polycentric, bottom-up approach
postulate that local groups with local targets will, by reaching said targets, also accomplish the global
goals. For our experiments we recruited students from the Universities of Kiel and Hamburg. We
assessed the performance of one large group compared to three small groups of participants in a
collective-risk social dilemma game. In a third treatment the players had the option to sanction
uncooperative groups. The small groups without the sanctioning option did not reach the aim of the
game more often than the large group. To our surprise also the small groups with the sanctioning
opportunity did not show a better performance than the other groups. This is a new finding which
makes repeating the experiments with students from other universities worth considering.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (8)
Consistent individual differences in social behaviour of bank voles (Myodes glareolus)
Hurtienne, Katharina; Folkertsma, R.; Herde, A. & Eccard, J.A.
University of Potsdam, 14469 Potsdam, Germany
Animal personality is defined as individual differences in behaviour which are consistent over time
and over different situations. Personality traits are quantified by measuring behavioural differences
within one species in boldness, exploration-avoidance, activity or sociability. Several studies of
nonhuman animals give evidence that some individuals avoid social interactions while others search
for conspecifics. Such social traits have been shown to be important for individual competition and to
have ecological consequences on different life-history traits like reproduction and dispersal. Little is
known about individual differences in social behaviour of bank voles (Myodes glareolus) although it is
a common species in ecological research. Hence, the aim of this study was to establish behavioural
tests measuring such differences in social behavior. We measured the repeatability of 69 adult bank
voles by testing individuals twice in 5 behavioural tests which represent different social situations
using two already established tests for this species: 1) dominance toward a same-sex conspecific and
2) infanticidal behaviour, and three novel tests: 3) interactions between same-sex conspecifics, 4)
maternal care and 5) behaviour toward three different indirect conspecific cues (a) visual, b)
olfactory and c) a combination of the two).Using a combination of already established and novel
tests, we can demonstrate that bank voles show consistent individual differences in social behaviour.
Furthermore, relationships among the tests shed light on whether individuals react similar in
different social situations. Thus, the personality of bank voles includes a social component which
should not be neglected in ecological studies with this species.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (6)
Does vegetation structure affect reproductive success in urban areas? A case study in great
tits
Hutfluss, Alexander; Sprau, P. & Dingemanse, N.J.
Ludwig Maximilians University Munich, Behavioural Ecology, Munich, Germany
Urbanisation, i.e. the rapid growth of cities, is one of the biggest challenges of today’s world and has
vast implications for wildlife. Yet, the exact consequences of urbanisation on animals remain largely
unknown. In this study we assessed the consequences of urban vegetation structure on reproductive
success in great tits (Parus major). Therefore, we observed great tit breeding performance at 75 nest
boxes that were located along urban rural gradients in the city of Munich, Germany. Vegetation
structure was assessed from satellite images that allow quantifying the average vegetated surface
around nest boxes by means of normalized difference vegetation indices (NDVI). We then tested
whether brood fitness (i.e. nestling condition (i.e. mass corrected for tarsus length), survivorship of
nestlings (i.e. proportion of nestlings that hatched and survived to fledge from the nest) and the
occupancy (i.e. whether the nest box was or was not used by great tits) would vary as a function of
vegetation structure.We found that vegetation structure positively affected reproductive success and
survival with “greener” habitats leading to an increased survivorship of nestlings. Furthermore the
vegetation strongly predicted whether nest boxes were occupied or not.Together thus study shows
that green areas within urban areas have positive effects on fitness traits in animals. We therefore
conclude that green spaces should be considered a key factor for urban planning.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (4)
Benefits of a “vulnerability gene” – a study in serotonin transporter knockout mice
Kästner, Niklas; Richter, S.H.; Lesch, K.H.; Schreiber, R.S.; Kaiser, S. & Sachser, N.
University of Münster, Department of Behavioural Biology, 48149 Münster, Germany
Over the past years, certain “vulnerability genes” have been identified that play a key role in the
development of mood and anxiety disorders. In particular, a low-expressing variant of the human
serotonin transporter (5-HTT) gene has been described that renders individuals more susceptible to
adverse experience and hence to the development of psychiatric diseases. However, some authors
have recently argued that lower 5-HTT expression not only increases vulnerability to adverse
experiences, but also enhances susceptibility to beneficial experiences, thus promoting phenotypic
plasticity. The aim of the present study was to assess the effects of 5-HTT expression on susceptibility
to beneficial experience in a hypothesis-driven experimental approach. Using a well-established
rodent model for the human polymorphism, male heterozygous 5-HTT knockout (HET) and 5-HTT
wildtype (WT) mice were either provided with the beneficial experience of cohabitation with a
female (mating experi ence) or kept as naïve controls in single-housing conditions. Following the
experimental treatment, they were tested for their anxiety-like behaviour and exploratory
locomotion in three widely used behavioural tests. Interestingly, while cohabitation reduced anxietylike behaviour and increased exploratory locomotion in the open field test in HET mice, it did not
affect WT mice, pointing to a genotype-dependent susceptibility to the beneficial experience. Thus,
our results corroborate the view of the low expressing version of the 5-HTT gene as a “plasticity”
rather than a “vulnerability” variant.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (13)
The elongated arm - Tool use in three species of lemurs
Kittler, Klara; Fichtel, C. & Kappeler, P.M.
German Primate Center, Leibniz-Institut für Primatenforschung, Abt. Verhaltensökologie &
Soziobiologie, 37077 Göttingen, Germany
Apes and other haplorrhine primate species are known to routinely make use of tools. In
strepsirrhine primates the manipulation of objects or even the use of tools has rarely or never been
reported, neither in the wild nor captivity, which might be due to the fact that they do not have
precision grip due to a lower dexterity. Although it has been shown that lemurs do have an
understanding of tool properties, tool use has not been studied systematically. Therefore, we
experimentally tested tool use skills in 54 lemurs from 3 species: 15 grey mouse lemurs (Microcebus
murinus), 12 black-and-white ruffed lemurs (Varecia variegata) and 29 ringtailed lemurs (Lemur
catta). In two different setups of a fishing rod task they had to use a round and a squared stick
respectively to obtain an inaccessible piece of banana. Overall, in both setups only 4 individuals
managed to get the banana into reach during their first attempt using the stick. The other 25
individuals that succeeded in one of the two setups needed an average of 5 (±2) trials to do so. Of
the unsuccessful individuals 43 did not appear to understand the task, whereas 31 at least tried to
use the stick to get the banana into reach but had problems to grab it correctly and coordinate the
movement. Thus, although some lemurs managed to use the tools, most individuals did not
understand the task or lacked the necessary fine motoric skills to do so.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (25)
The behavior of ravens in sheep flocks
Korsch, Jana
University of Hamburg, Zoological Instutute at the University of Hamburg, Hamburg, Germany
Common Ravens (Corvus corax) are intelligent corvids with a strong social behavior and that have
long been associated with humans and other animals. As ravens feed socially on ephemeral
resources such as carcasses they are often under suspicion of being involved in the death of livestock
such as sheep and cattle.The birds now start to develop new behaviors that have a devastating effect
for the farmers. Injured tails of sheep caused by the pecking of ravens lead to severe economic
losses. The aim of the present study was to investigate the behavior of ravens in livestock of sheep
and to describe factors and causes that determine the occurrence of ravens in livestock and the
development of their new behaviors. Behavioral observations were made to explain the interaction
between ravens and sheep and to explore patterns of behavior that can lead to traditions and
culture. The results of the study show that the number of non-breeders has increased in the last 20
years.The behaviors observed in interaction with sheep show how diverse the lifestyle of ravens is
and how much they have adapted to the landscape and its resources. Flocks of sheep are used by
non-breeders as a meeting place, where they -play, feed, mate and learn. A tradition formation and
binding to livestock requires appropriate nonlethal methods to prevent damage in livestock. On the
basis of the acquired knowledge about patterns of social behavior and external causes, a future
Aversion-strategy can be developed and implemented to avoid new conflict.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (24)
Mating behaviour in Darwin’s bark spider involves oral lubrication of female genitals
Kralj-Fišer1, Simona; Klavdija Š.1; Ren-Chung, C.1, Gregorič1, M. & Kuntner1,2,3 M.
1
Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts,
Slovenia
2
Department of Entomology, National Museum of Natural History, Smithsonian Institution,
Washington, DC, USA
3
College of Life Sciences, Hubei University, Wuhan, Hubei, China
The mating behaviour of Darwin’s bark spider (Caerostris darwini), a sexually size-dimorphic species
from Madagascar, is largely unknown with the exception of preliminary reports of genital damage,
mate plugging, and male eunuchs. We conducted a two-week field survey in Madagascar to record
elements of C. darwini natural history, focusing on sexual behaviour. We observed intense male-male
competition, their persistent pre-copulatory guarding of subadult females, and opportunistic mating
with teneral females. Adult females typically responded aggressively to male courtship, and
successful copulations with older females were shorter and more often resulted in sexual
cannibalism when compared with copulations with teneral females. We also staged matings (N=17)
of freshly moulted females in the laboratory. Males engaged in intensive courtship that combined
mate binding with a hitherto unknown spider sexual behaviour, namely that of “oral lubrication of
female genitals”. Matings, lasting up to 19 minutes, averaged 1.53 insertions. All insertions resulted
in male palpal damage, and the males self-emasculated their damaged palps to become eunuchs.
Subsequent to mating, most females were aggressive towards males (76%), sometimes cannibalizing
them (35%). While males cannot reuse their damaged palps, previously mated females were able to
reuse their plugged genital openings, suggesting a polyandrous mating system in C. darwini. Our
study adds to a more general understanding of how spider sexual dimorphism relates to sexually
conflicted phenotypes.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (19)
The difference is droll – Towards a cognitive bias test in mice
Lewejohann, Lars; Kloke, V.; Schreiber, R.S.; Booden, C.; Kaiser, S. & Sachser, S.
University of Osnabrück, Behavioral Biology, 49076 Osnabruck, Germany
Cognitive bias refers to altered information processing resulting from an individual's emotional state.
Comparable to anxious or depressed humans, animals in a putatively negative emotional state are
more likely to judge an ambiguous stimulus as if it predicts a negative event, while animals in a
putatively positive emotional state are more likely to judge the same stimulus predicting a positive
event. We aimed at establishing a cognitive bias test for mice by validating measurements of
different expectations related to an ambiguous stimulus: mice having learned to expect something
positive within a maze showed a more positive judgment of an unfamiliar location than animals
expecting something negative. In a second step, we confirmed that the mice's interpretation of an
ambiguous stimulus depended on its spatial location, with a position exactly midway between a
positive and a negative reference point provoking the highest level of ambiguity. In a pilot study we
analyzed cognitive bias in serotonin transporter (5-HTT) knockout mice, a well-established mouse
model for the study of anxiety- and depression-related behavior. The anxiety- and depression-like
phenotype of 5-HTT knockout mice manifested - comparable to human conditions - also in a trend
for a negative distorted interpretation of ambiguous information, albeit this effect was not statistical
significant. The results suggest that cognitive bias tests are useful to study emotional states in mice,
which may not only increase the translational value of animal models in the study of human affective
disorders, but which is also a central objective of animal welfare research.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (9)
Consistency of personality in aged male cavies
Löher, Svenja & Guenther, A.
University of Köln, Lehrstuhl für allgemeine Ökologie, Köln, Germany
Bielefeld University, Department of Animal Behaviour,33615 Bielefeld, Germany
Animal personality is defined as consistent individual differences in behaviour, but recent studies
revealed that personality changes during ontogeny: for wild guinea pigs (Cavia aperea) it has been
shown that personality differs shortly after weaning (~ 25 days) and around sexual maturity (~90
days). A correlation between boldness and exploration emerged in mature cavies. Here, we looked at
personality of old cavies (~4 years) to get an overview on personality development throughout life.
As signs of old age we consider weight loss and death of ~40% of the original population. Three
behavioural tests were conducted with the same males at 6, 12 and 36 months of age: boldness, free
and forced exploration, together with fearlessness. Also, basline cortisol-levels were measured in
young and old animals. Over short periods of time, behaviour was consistent. Comparing the
behaviour across these three stages, we see a significant decline in boldness in old cavies, compared
to you ng and mature animals. In old animals, boldness correlates strongly with cortisol-levels, a
correlation absent in young or mature animals; in these stages cortisol correlates with fearlessness.
Old animals explore a long corridor voluntarily as often as do young animals while the frequency of
exploration is higher in younger adults. Fearlessness (shown as activity in the Open Field) does not
differ significantly between the three life stages, wherefore this behaviour can be seen as consistent
across development. The results show that although personality is consistent over the short term, it
changes during the whole lifespan of cavies.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (14)
The effects of serotonin-transporter genotype and social experience during adolescence on
anxiety-like and aggressive behaviour
Meyer, Neele; Kloke, V.; Schreiber, R.; Kaiser, S.; Lesch, K.-P. & Sachser, N.
University of Münster, Department of Behavioural Biology, 48149 Münster, Germany
Across mammalian species, behavioural traits like anxiety and aggressiveness are means to optimally
cope with environmental challenges. However, in their exaggerated form they pose psychiatric
problems to human societies and are regarded as pathologies from a biomedical viewpoint.
Extensive research has shown that anxiety and aggressiveness can be shaped by genotype and
experiences during early life phases. However, the period of adolescence has mainly been neglected
so far. To elucidate how levels of these behaviours are shaped by genotype and experience during
adolescence, experiments were conducted with serotonin-transporter (5-HTT) knockout mice. During
adolescence, males of all three genotypes (wildtype, heterozygous and homozygous 5-HTT knockout
mice) either experienced a mildly adverse social situation or they found themselves in an excellent
social environment. For this purpose both groups were housed in custom-made cage systems. Mice
experiencing a mildly adverse e nvironment were repeatedly introduced to the territory of an
established couple; but had the possibility to escape to a safe cage. Mice encountering beneficial
social conditions had free access to a mating partner. Afterwards, anxiety-like behaviour was
assessed in three standardised tests; aggressive behaviour was determined in a resident-intruder
paradigm. The main results were: (1) Surprisingly, unfavourable conditions during adolescence led to
decreased anxiety-like behaviour and increased exploratory locomotion. (2) Aggressive behaviour
was more pronounced in animals that experienced social adversity. (3) Concerning genotype,
homozygous knockout mice were more anxious and less aggressive. In conclusion, genotype and
environment during adolescence can profoundly shape anxiety and aggressiveness.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (21)
Seasonal changes in song behavior mechanisms of an equatorial songbird
Quispe, Rene & Gahr, M.
Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
In songbirds, it is generally assumed that singing activity increase in the spring when days become
longer and plasma levels of testosterone are high. Seasonal changes in singing activity often parallel
morphological changes in the song control system. This plasticity occurs in a highly synchronous
manner within populations. One central nucleus of the song control system is the HVC, which
functions as a sensorimotor integration area and expresses androgen and estrogen receptors.
Thereby, the activation of song behavior involves a compound interaction of testosterone with
photoperiodic changes. However, most of the knowledge about singing mechanisms comes from
studies on species from temperate regions, while a great diversity of songbirds inhabits in the
tropics. We conducted a field study to investigate song behavior mechanisms in an equatorial
population of a neotropical songbird, the Silver beaked Tanager (Ramphocelus carbo). During one
year we examined anatomical changes in the song control system of males and collected extended
data of plasma levels of testosterone and song behavior. We found strong seasonality in singing
activity. The activation of the song behavior occurs several months in advance of the increase in
circulating testosterone, which is facilitated by an expansion of the androgen receptors’ distribution
in HVC. Thus, in this equatorial species the song behavior appears as androgen sensitive as in
temperate zone species although the control mechanism seems to be different since there is little
photoperiodicity.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (26)
Home ranges of radiated tortoises Astrochelys radiata: under the impact of habitat
alterations on the Mahafaly plateau landscape, South-western Madagascar
William M. Ronto1,2; Ganzhorn2 , J.U. & Rakotondravony1 D.
1
Université d'Antananarivo, Faculté des Sciences, Département de Biologie Animale, Antananarivo,
Madagascar
2
University of Hamburg, Biocenter Grindel, Animal Ecology and Conservation, 20146 Hamburg,
Germany
The radiated tortoise (Astrochelys radiata) is one of the four endemic Malagasy tortoise species
threatened by habitat loss and poaching. Space requirements under different ambient conditions
represent critical information on the behavioral and ecological flexibility of the species that can
contribute to the design of conservation activities. We used radio-telemetry to study the movement
and space use of radiated tortoises in relation to size, sex, season and habitat characteristics in the
Tsimanampetsotsa National Park. Home ranges were estimated with minimum convex polygons
(MCP). Male and female A. radiata did not show sexual dimorphism. The ranges used by male and
female radiated tortoises did not differ in size, though the range size of females varied significantly
more than the size of male ranges. Home ranges of both sexes showed no relationship to body size.
Home range size changed between seasons and was significantly larger during the wet than during
the dry season (Student t-test, P < 0.001). Forest fragmentation differed significantly between study
sites, but home ranges of tortoises showed no difference between habitats and were uncorrelated
with the percentage of forest cover within their home ranges neither during the wet nor during the
dry season. Home ranges of the same individual in the wet and the dry season showed about 50%
overlap, thus reflecting site fidelity. The finding that forest cover is unrelated to home range size
indicates that radiated tortoises would be able to survive in a large variety of habitats as long as they
are not threatened by poaching. Supported by BMBF SuLaMa.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (1)
The effects of the early social environment on shaping emotionality and stress reactivity in
Wild Cavies
Sangenstedt, Susanne; Sachser, N. & Kaiser, S.
University of Münster, Institute of Behavioural Biology, Department of Neuro and Behavioural
Biology, 48149 Münster, Germany
The social environment of an individual can have profound effects on its behavioural development,
including the expression of emotionality, as well as on stress reactivity. Not only the current
generation, but also the F1-generation can be influenced in its behavior, physiology and reproductive
success by the social environment the parental generation experiences. In several species, mothers
can influence the development of their offspring during the prenatal and early postnatal period i.e.
via behavior or hormones, which provides them with the opportunity to adjust the offspring’s
phenotype to fit future environmental conditions in an adaptive way. The present study aims to
reveal differences in behavioral profiles and stress responsivity in male adolescent wild cavies whose
mothers lived either in a social stable (SE) or in a social unstable (UE) environment during pregnancy
and lactation. It was shown before that male wild cavy offspring of mothers living in an unstable
social environment display a behavioural infantilization with an increased and prolonged display of
juvenile behavioural patterns. Our findings show that UE-sons stay less anxious over adolescence
whilst SE-sons get more anxious over time. Further, stability in emotionality traits and plasma
testosterone concentrations in UE-sons is revealed whereas in SE-sons stability in physical responses
to stress is detected. It appears that UE-sons have a more flexible inner physiology, which is
reprogrammed during adolescence, whilst they display a rather fixed behavioural profile over time.
SE-sons, on the contrary, show a plastic behavioural profile, but a stable inner physiological reaction
to stress.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (17)
Social interactions after mixing pregnant sows housed in small groups
Schalk, Christiane; Flauger, B.; Geiger, S.; Schmucker, S. & Stefanski, V.
Institute of Animal Husbandry and Animal Breeding, 70599 Stuttgart, Germany
In the European Union, housing of gestating sows in social groups is mandatory at least from four
weeks after service until one week before farrowing since 2013. This often involves mixing of
unfamiliar sows or alterations in the composition of existing groups which may lead to social stress
due to aggressive interactions. We investigated the number and type of social interactions following
a social mixing treatment for sows housed in small groups during gestation. Furthermore, blood
samples were taken for analysis of cortisol and immunological parameters (e.g. numbers of blood
immune cells). Pregnant sows (German Landrace) were housed in 4 small groups of 5 animals. Two
groups were assigned to a social mixing treatment (MT) by the interchange of 2 sows between the
groups from week 11 to week 4 pre partum. The two other groups remained in their original
composition without mixing (NON-MT). The total number of social interactions in MT groups
increased after the first introductions and gradually decreased to pre-mixing levels thereafter. The
higher level of interactions primarily resulted from a higher number of aggressive behavior, but also
from increased non aggressive displacement and nose to-body contact. Contrary to our predictions,
the differences to the NON-MT groups were not as pronounced as expected. Irrespective of the
treatment, low ranking sows always received higher numbers of aggressive behavior, while in MT
groups also middle ranking sows were exposed to these conditions. Preliminary analysis indicates
that not the mixing treatment itself, but social rank and aggressive behavior received by an individual
influence the physiological outcome.
63
10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (2)
The behavior of bank vole females as a function of infanticide risk and mating interest
Schirmer, Annika; Folkertsma, R. & Eccard,J.A.
University of Potsdam, Animal Ecology, 14469 Potsdam, Germany
Infanticide, the killing of conspecific young, is a widespread behavioral trait in the animal kingdom.
One of the most suited model organisms for investigating the behavioral implications infanticide has,
for example regarding counter strategic behavior, are the rodents. The present study investigated
the behavior of bank vole females as a function of infanticide risk and mating interest under
laboratory conditions. Two levels of infanticide risks were simulated via exposure to the scent of
either the sire of the litter or an unfamiliar male. It was assumed, that female bank voles adjust their
avoidance behavior according to the potential infanticide risk a male poses. Simultaneously bank
voles are able to conceive another litter while still weaning the present one. Hence a further
assumption was that the behavior is not only influenced by the infanticide risk but also by the
potential mating opportunities presented. To observe the behavior females and their corresponding
litter were transferred into metal indoor arenas and confronted with the different scent types on
successive experimental days. Initial results showed that a difference in behavior due to scent type
was observed in the amount of time spent outside the nest and the intensity of the scent
investigation. Observations suggest that females recognize different levels of infanticide risk and
their allocation of time towards nest protection versus mate search is depending on that. Thus, in a
species with high risk of infanticide females use adaptive behavioral strategies to reduce the
infanticide risk.
64
10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (15)
Flight initiation distance: A measure of boldness in free ranging red-fronted lemurs?
Sperber, Anna; Sanders, H.; Kappeler, P.M. & Fichtel, C.
German Primate Center, 37077 Göttingen, Germany
Animal personality refers to consistent inter-individual differences in behaviour. Individuals often
differ in their behaviour in risky situations, from shy individuals, who take little or no risk, to bold
individuals, who follow a high risk – high reward strategy. Flight initiation distance (FID) is a measure
used for assessing inter-individual differences in boldness. As part of a project aiming to identify redfronted lemur (Eulemur rufifrons) personality traits, we tested FIDs of 31 individuals in the field in
Kirindy Forest, Madagascar. FIDs were assessed by walking at a constant speed towards focal
individuals sitting close to a pathway until they moved away. The distance between the experimenter
and the original resting place of the animal was measured up to 3 times per individual. FIDs ranged
between 36 cm and 312 cm. Overall, males showed on average larger FIDs than females. Moreover,
FIDs were influenced by the height the animal was resting at (on the ground or up to 2m), with
animals sitting above the ground showing a shorter FID. Although there was habituation between the
first and second trial, FIDs were repeatable. Thus, FID might be a good proxy for risk-taking
behaviour, but further experiments are required to assess whether inter-individual differences in FID
correlate with inter-individual variation in behaviour in other risky situations.
65
10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (11)
Costs and benefits of cognition measured in male laboratory mice
Terzenbach, Janine1; Brust, V.1; Guenther, A.2 & Lewejohann, L.1
1
University of Osnabrück, Behavioral Biology, 49072 Osnabrück, Germany
Bielefeld University, Department of Animal Behaviour,33615 Bielefeld, Germany
2
Short living species such as mice are able to cope with a wide diversity of environmental challenges.
The effects of living either in a simple and predictable or in a cognitively challenging environment on
behavioural and physiological parameters in mammals are not fully understood. Although there are
some indications for a vital role of cognitive skills for fitness and mate choice, the number of studies
dealing with cognitive costs and benefits is limited. The aim of this study was to analyse costs and
benefits of cognition and its physiological and behavioural impact on male C57BL/6J mice. For this
purpose 16 individuals of the experimental group were exposed to a variety of different cognitive
tests. Another group of 16 mice was also exposed to the test apparatuses without the ability to learn,
and a control group of 16 mice was not experimentally handled. Analyses regarding weight, resting
metabolic rate and the outcome of a female choice experiment were carried out. The experimental
group had a lower metabolic rate than the handled no-learning group. In the female choice test the
females spent least time with the cognitively challenged males. Surprisingly and in contrast to the
literature record our study thus shows clear costs of cognition with regard to lower attractiveness to
mates. On the other hand their lowered resting metabolic rate can be interpreted as beneficial with
regard to a prospectively enlarged lifespan. Future experiments will have to investigate if these
results can be explained by different life history strategies.
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10th topical meeting of the Ethological Society
11th – 14th February 2015, Hamburg
Poster (16)
Basic burrow architecture of Microtus arvalis on a slope under semi-natural conditions
Walther, Marcus & Eccard, J. A.
Potsdam University, Institute of Biochemistry and Biology, Department Animal Ecology, 14469
Potsdam, Germany
Many fossorial species of small mammals live in subterranean burrows and have therefore direct
impact on soil processes as well as on ecological interactions. Macropores and the tunnel network
are main connectors between above and below ground ecological functions. The structure of
burrows, for example their complexity, length and depth can affect ecological functions. On the
other hand, burrow structure may be adjusted to soil parameters or slope of the location of the
burrow, possibly also affecting ecological functions. We investigated the burrows from M. arvalis
under natural-climatic conditions and absence of plant/root diminutions. For ten days, voles were
allowed to establish a burrow in a cylinder with 1.2m diameter and 35cm depth. Half of the cylinders
tilted, simulating a slope of 20 degrees, the other half was planar (0 degrees slope). Using graph
theory for a burrow-length independent comparison, we could differentiate amongst 3 types of
burrow systems structures comparable with previously published studies: a) linear, b) mixture of
linear and cyclic, and c) essentially cyclic. The nest is generally closer to a central point or/as well as
to the entrance than would be expected by chance. Borrows on a hill were in average deeper (mean
and maximal depth) than flat systems, however they did not differ in the average angle to horizontal
line or in their main orientation. Further burrow structure characteristics will be discussed. Finally we
can conclude that the common vole's (M. arvalis) basic burrow structures and digging performance
were not affected by slope.
67