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Caitlyn Gillespie and Joseph J. Fontaine
Nebraska Cooperative Fish and Wildlife Research Unit
University of Nebraska-Lincoln
Rainwater Basin Joint Venture Informational Seminar
February 10, 2015
Migration: a common life history strategy
Photo: J.J. Fontaine
Stopover habitat is essential
Migrants must frequently
make habitat decisions in
unfamiliar environments
Tree phenology
Migratory species have evolved strategies
to cope with environmental uncertainty
For example, birds time
arrival to coincide with
regional and seasonal
peaks in food abundance
# Migratory birds
http://nationalzoo.si.edu/
McGrath et al 2009
http://nationalzoo.si.edu/
Migrants are known to
make habitat decisions
based local food resources,
which are often annually
and regionally predictable
Proportional use by migrants
Migratory species have evolved strategies
to cope with environmental uncertainty
Tree species
McGrath et al 2009
Shorebird stopover habitat is unpredictable
Ephemeral wetland habitat is
annually and regionally variable
Skagen and Knopf 1994
Map: University of Delaware, College of Earth, Ocean, and Environment
Photos: C. Gillespie, J.J. Fontaine
Not all wetlands are created equal
Photos: J.J. Fontaine, C. Gillespie
Shorebird stopover is highly correlated
with local resource phenology
Stutzman and Fontaine In Press-- Studies in Avian Biology
Photo: J.J. Fontaine
Landscapes are changing
Land-use change alters
wetland availability,
distribution, and function
Photos: K. Hayes, C. Gillespie
Climate change also disrupts wetland
availability and phenology
Art: R. Rohde
Photos: K. Hayes, J. Dupuie, C. Gillespie
What are the consequences?
Shorebirds can adjust their
stopover decisions in
response to natural variation
in wetland conditions and
abundance
Does behavioral plasticity allow individuals to cope effectively with
anthropogenic disturbance across the landscape?
Photos: C. Gillespie
How does anthropogenic change influence
stopover decisions of migratory shorebirds?
Photo: C. Gillespie
Calidris shorebirds
• Arctic-nesting sandpipers
• Long-distance migrants
Photo: C. Gillespie
Rainwater Basin
• Important stopover site for
many migratory species,
including Calidris shorebirds
• Fewer than 10% of historical
wetlands remain
Cultivated Crops
Wetland Basins
Nebraska
NLCD 2011, RWBJV 2012
Photo: C. Gillespie
What are the local wetland attributes
predicting Calidris shorebird habitat
use in a highly altered landscape?
Photos: J.J. Fontaine
Shorebird Surveys, Spring 2013 and 2014
Photos: C. Gillespie, J. Dupuie, C. Jordan, E. Rodriguez, N. Staton, R. Stutzman
Occupancy
Birds respond predictably to local
habitat attributes
Percent Mud
χ2 (1)=9.54, p<0.01
Photo: C. Gillespie
Colwell and Oring 1988, Davis and Smith 1998,
Skagen and Knopf 1994, Stutzman 2012
Probability of Calidris occupancy
Birds find wetlands with food
Invertebrate Abundance
Photo: C. Gillespie, C. Jordan
χ2 (1)=5.59, p<0.05
Birds time arrival with peak food abundance
180
2013
160
Total Abundance Total Abundance
140
Total Abundance
2014
2013
120
100
80
60
40
20
0
2014
600
2014
500
JulDay vs AllPeeps
JulDay vs Invert
Migrants
Invertebrates
400
300
200
Migrants
Invertebrates
100
0
80
100
120
140
160
Julian Day
Julian Day
Photo: C. Gillespie
Flock Size
…but food abundance does not
predict bird abundance at wetlands
Invertebrate Abundance
χ2 (1)=7.21, p<0.01
Photo: C. Gillespie, R. Stutzman
Foraging habitat can disappear quickly
Photo: G. Jukkala, C. Gillespie
Art: C. Gillespie
Occupancy
Shorebirds still need shore
Percent Mud
How does the availability of suitable habitat
change over time?
Photo: C. Gillespie
Habitat changes seasonally
May 2
Percent Mud
April 23
May 12
Julian Day, 2013
May 21
Mud: χ2 (1)= 30.69, p<0.001;
Green: χ2 (1)=382.58, p<0.001;
Short: χ2 (1)=22.22, p<0.001
Photos: C. Gillespie, N. Staton, E. Rodriguez
Wetland availability often declines
seasonally
Wetland Area
2013
Julian Day, 2013
χ2 (1)= 393489, p<0.001
Photo: E. Rodriguez
Wetland landscapes also respond
quickly to weather events
May 8
Photos: K. Hayes, C. Gillespie
May 18
Late spring thunderstorms can increase
wetland availability seasonally
Wetland Area
2014
χ2 (1)= 409630, p<0.001
Julian Day, 2014
Photo: K. Hayes
Percent Mud
Heavy rainfall changes habitat availability
both within and among wetlands
Julian Day, 2014
χ2 (1)= 6.53, p<0.05
Photo: C. Gillespie
What are the consequences of
unpredictable habitat for migratory
stopover?
Photos: C. Hause, G. Jukkala
Art: C. Gillespie
Habitat availability changes annually
Even in wet years, habitat within the Rainwater Basin is limited
Nebraska
RWBJV 2012
Photo: C. Gillespie
All Water in the Rainwater Basin,
Spring 2013
Nebraska
Photo: C. Gillespie
Flooded acres on WMA/WPAs in March
What role does landscape-scale habitat
availability play in stopover decisions?
3500
Distribution of water on
landscape has relevance
for shorebirds
3000
2500
2000
1500
1000
500
0
RWBJV 2014
Photo: C. Gillespie
2013
2014
Water availability was
much higher in 2014
Skagen and Knopf 1994, Farmer and
Parent 1997, Albanese and Davis 2013
What are the consequences of limited
habitat on migratory stopover?
1400
Calidris shorebirds in the
Rainwater Basin
1200
#Birds
1000
800
600
Spring 2014
400
200
0
27-Mar
Spring 2013
6-Apr
16-Apr
26-Apr
Date
6-May
16-May
26-May
5-Jun
Photo: C. Gillespie
# Birds per Used Wetland
Individual wetlands in dry years have fewer
birds, despite habitat scarcity
2013
χ2 (1)= 796.76 p<0.0001
2014
Birds appear to
respond to landscape
dynamics and alter
stopover decisions
Photo: C. Gillespie
Prairie Pothole Region
How do birds respond to
landscape differences within
years?
Photos: Google
Rainwater Basin
# Birds per Used Wetland
Bird abundance was also higher in the
PPR in 2014
Spring 2013
χ2 (1)= 1679.4 p<0.001
Spring 2014
Photo: C. Gillespie
Landscapes have relevance across years
2000
1800
2013
1600
1400
1200
1000
800
600
400
#Birds
200
0
2000
1800
2014
Calidris shorebirds in
two landscapes
1600
1400
1200
1000
Rainwater Basin
800
600
Prairie Pothole Region
400
200
0
2-Mar
22-Mar
11-Apr
1-May
Date
21-May
10-Jun
30-Jun
#Birds per Used Wetland
Wetlands in landscapes with more
habitat support more birds
Rainwater Basin
Region: χ2 (1)=9.56, p<0.01;
Percent Mud: χ2 (1)= 5.33, p<0.05;
Year: χ2 (1)= 295.82, p<0.001
Prairie Pothole Region
Photo: C. Gillespie
How do species in dynamic systems
cope with anthropogenic change?
Shorebirds may
respond to increasing
change by skipping
historically beneficial
stopover sites
Photo: C. Gillespie
How do we manage for migratory species
while considering the full scale at which
birds make stopover decisions?
Photo: J.J. Fontaine
Shorebirds respond to landscape habitat
availability, not just local wetland conditions
Delivering water to isolated wetlands may support a few
birds, but may be insufficient to support a population
Phenology of late-spring habitat may be highly
subject to the structure and function of wetlands
in response to local temperature and precipitation
Wetlands do not necessarily
dry out at the same rate
Photo: C. Gillespie
Wetlands may support more migrants
if management focuses on maintaining
habitat at a landscape scale
Photo: C. Gillespie
Landscapes are vital for the support of
migratory populations in dynamic systems
Habitat conservation efforts
must consider landscape
context to best mitigate the
effects of escalating change
Photos: J. Dupuie, C. Gillespie
Acknowledgements
Fontaine lab (past and present): TJ Fontaine, Lucia Corral, Kent Fricke,
Chris Jorgensen, Jessica Laskowski, Mandy Lipinski, Dustin Martin, Lindsey
Messinger, Ryan Stutzman, Lyndsie Wszola
Committee members: Gwen Bachman and LaReesa Wolfenbarger
Funding sources: USGS Climate Change and Wildlife Science Center,
Rainwater Basin Joint Venture, Great Plains LCC, Nebraska Game and Parks
Housing: Crane Trust, USFWS
UNL and Coop Unit Grad Students and Staff, Technicians, Private Landowners