Cultural Evolution of Carpodacus mexicanus
In Memoriam: Dr. Paul C. Mundinger
Charles G.P. Maniego, Julieana Steiner, Khaleda Khan, and David C. Lahti Department of Biology, Queens College Cultural evolution is the change in socially learned traits over time, due to errors in copying and individual innovation. House finches (Carpodacus mexicanus), were introduced to New York from California in the 1940’s.
They sing complex and variable songs that are socially learned, modified during learning, and culturally transmitted, making them an ideal model for cultural evolution. Using the extensive house finch recordings collected
over the last forty years, as well as song analysis software designed in our lab, we aim to answer two questions: 1) How has house finch song diverged over time? And 2) How do house finch songs vary geographically?
Methods
Background
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Cultural evolution (CE) is the change in socially learned traits over
time. It is the result of the accumulation of differences during copying and
Using the computer program Audacity, individual male house finch
songs can be extracted and categorized from Dr. Mundinger’s digitized
reproduction. Unlike genetic evolution, cultural evolution exists outside of
field recordings.
gene differences. CE occurs faster, through passing generations. This is
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evident in birdsong variation.
The extracted songs can be further analyzed by using the software
FinchCatcher, developed by Lahti Lab PhD student, Chenghui Ju.
Carpodacus mexicanus, commonly known as the house finch, is a
songbird native to California and Mexico. Population introduction to the east
FinchCatcher allows individual house finch songs to be analyzed by
coast and proliferation since 1940 makes them an ideal model for studying
eliminating background noise and categorizing specific syllable types.
CE, along with their long and complex song.
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Dr. Paul C. Mundinger, a Queens College biology professor,
finch syllable features. The extracted data can be read like a
Figure 1: Diagram noting C. mexicanus population expansion in the East,
as well as dates of various recordings
recorded house finch songs from 1970-1981, through locations on the east
phylogenetic tree.
coast and California. He was interested in house finch song and the interplay
between genes and culture. The Lahti Lab took up his project in 2010. Lab
Users can set their own specific parameters in differentiating house
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members have also recorded house finch songs recently in the New York
With this, the change in house finch song can be examined
geographically (dialect), and through various generations (inheritance).
City and Long Island areas.
Research Questions
How do house finch songs vary spatially?
4a
4b
How do house finch songs vary over time?
2a
2b
3a
3b
Figure 4: Images from FinchCatcher, developed by PhD student Chenhui Ju
(4a) shows 140 different house finch syllable types, grouped by syllable size and pitch
(4b) groups different syllables by frequency. This shows varying syllable composition in localities
Future Research
•  Possibly use female house finches as a point of study.
Figure 2: Two examples of male C. mexicanus song, taken from the program Audacity. These two
spectographs show geographic song variation. (2a) is a male song from July 7, 1981 in Rye, New York.
(2b) is a male from Bloomsburg, Pennsylvania, recorded May 30, 1981. Differences in syllable and trills
in male C. mexicanus song can be seen.
Figure 3: Two examples of variation in time and generations in C. mexicanus song, within the same area, also taken
from Audacity. (3a) is a male house finch song from June 22, 1975 in Nassau County, New York (Massapequa.) (3b)
is from June 8, 1981 in Nassau County (Plainview.) Variation can be seen over time, even within proximate
geographic areas.
•  Aspire to further analyze house finch dialects, and distinguish spatial
and generational variation
•  Consider the effects of cultural evolution on other songbird species