The Williams lab studies Savannah sparrows (Passerculus sandwichensis), small migratory songbirds that live in grassy fields across North America (Cornell Lab). Savannah sparrows have been the subject of a long term study at Bowdoin College’s field research station on Kent Island in New Brunswick, Canada. 

The Kent Island research station. Cabins and the main building are photographed from the field designated for Savannah sparrow, herring gull (Larus argentatus), and tree swallow (Tachycineta bicolor) research. (Photo credit: Dan Mennill)

The Kent Island research station. Cabins and the main building are photographed from the field designated for Savannah sparrow, herring gull (Larus argentatus), and tree swallow (Tachycineta bicolor) research. 

Savannah sparrows have been recorded on Kent Island since the 1960s and their songs have been recorded intensively since 1980 (Williams et al., 2018). Clara Dixon, who thoroughly recorded songs in 1980 and 1982, inspired a continued in-depth study of Savannah sparrows to this day because their songs are an excellent model for studying cultural evolution, the socially learned traits of populations change, and the bird song learning has parallels with the development of human speech (Williams et al., 2022). Male Savannah sparrows learn components of their songs from various tutors, including their biological father, social father, and both hatching and breeding-year neighbors. They then use these songs to attract mates and defend their territories.

Savannah sparrow on Kent Island. A key characteristic to help identify these birds are their distinctive yellow plumage above the eye, as shown in the photo. (Photo credit: Dan Mennill).

Professor Heather Williams first went to Kent Island in 1973, her first year of college. She has maintained her connection to the island, and realized the potential to contribute to the Savannah sparrow research by studying a local population in Williamstown since 2005. Birds are systematically color-banded—given a unique three band color combination on their legs so that they can be identified with binoculars—and their songs are recorded. In addition to analyzing songs, observing birds’ responses to variations in note count and spacing in songs is valuable for understanding which factors drive changes in song traits over time. To study birds’ reactions, our lab conducts playback experiments, which entail placing a speaker in the middle of a bird’s territory, playing stimuli of songs with either variable note spacing or note type, and recording a bird’s response. 

Example song from N.YR.

Birds may sing an additional ‘chuck’ note in either an earlier or later interval, variable spacing between x notes, and other soft notes that fall between the introductory notes. Last summer, we investigated what drives the changes in the occurrence and number of chuck notes in songs, and how the spacing of x and other notes may influence a bird’s reproductive success.

Henry Alexander ‘27 and Prof. Heather Williams in the field on Grand Manan, New Brunswick, Canada. Both Williams and Alexander carry microphones used to record bird songs. (Photo credit: Hannah Cumming)

Birds typically seek out the source of the song in a playback study. Placing a fake bird near a hidden speaker can enhance a playback because the bird directs its behavior towards the specific target. Taxidermy Savannah sparrows have been used in such experiments, but as Professor Williams warned us throughout the summer, they do not last long. The real birds aggressively attack and eventually destroy that type of model. 

We asked the Makerspace to 3D print a durable bird that we could repeatedly use in these playback experiments. The students brought a free 3D model of a Song Sparrow to Alice Sore ’27, a Makerspace student worker, since it was similar in appearance to the Savannah Sparrows we study. Using Blender, Alice modified the model by removing the legs, which would have been too fragile to print and nearly impossible for the bird to balance on. She replaced them with a simple base that could be hidden among leaves or grass in the field. After an initial failed print, Alice successfully produced two near-perfect models, which were then handed over to our lab for painting. A member of our lab, Hannah Cumming ’28, who is a prospective Biology and Studio Art double major, painted the models to match a Savannah Sparrow’s typical plumage. A member of our lab, Hannah Cumming, who is a prospective Biology and Studio Art double major, then painted the model to match a Savannah sparrow’s typical plumage. We gave our two painted models an imaginary three-band color combination as their name, choosing B.OG (Black band on the left leg, Orange band over Green band on the right) for one, and GO.B (Green band over Orange band on the left leg, Black band on the right) for the other. The names were inspired by the amazing peatland environments on Kent Island. 

3D printed Savannah sparrow model created by the Makerspace. Our lab painted this bird to use in our field experiments.

B.OB, a Williamstown bird, demonstrates our color-banding system. He has Black over a US Fish and Wildlife Service aluminum band on his left leg, and Orange over Black on his right leg (from the perspective of the bird).  (Photo credit: Hannah Cumming)

B.OG, like some of his living and wild counterparts, migrated to Canada with our lab this summer to spend time on Kent Island. We used the model bird in playback experiments to test female responses to song variations. We placed B.OG in the mown path in the middle of a territory and hid the speaker nearby in taller grass. We then conducted the playback experiment to see whether females would respond aggressively to the songs or with intrigue. Approaches without aggression by a female would indicate that certain song traits are “sexier,” meaning the trait improves a male’s reproductive fitness. An aggressive approach would indicate that female choice is not driving changes in this song trait.

Kate Swann (‘26, left) and Hannah Cumming (‘28, right) excitedly preparing to conduct playback experiments on Kent Island. (Photo credit: Ian Kyle)

Due to the timing of our experiment, females were feeding their nestlings and did not respond to the songs or birds. Due to the timing of our experiment, when females were actively feeding their nestlings, they did not respond to the songs or birds. This highlighted for us the importance of seasonal timing in behavioral experiments.

We later used GO.B to test male responses in Williamstown. We placed the 3D printed model on a stake in the meadow and played songs to stimulate birds’ responses. Subjects flew around the model and treated it the same as live birds also sitting on posts: the subject approached the bird (whether live or 3D printed), and when it did not fly away, the subject returned to its original post.

This project also taught us how interdisciplinary collaboration between biology and technology can open up new methods for fieldwork. Our lab is excited to continue using the model birds in future research projects! In the future, we hope to expand the use of these models to test additional song traits and to explore how responses vary across seasons and populations.

B.OG perched on a Kent Island tree. We used this 3D printed and painted model to test female responses to song variations on Kent Island. (Photo credit: Heather Williams)

B.OG analyzing his fellow birds’ songs, shown in the background. (Photo credit: Hen

Kate Swann presented her research at the Summer Science Research Poster Session on August 8, 2025

Works Cited

Cornell Lab or Ornithology. (2025). Savannah sparrow in All about birds. Cornell University. https://www.allaboutbirds.org/guide/Savannah_Sparrow/overview. 

Williams, H. et al. (2018). The buzz segment of Savannah sparrow songs is a population marker. Journal of Ornithology 160, 217-227.

Williams, H. et al. (2022). Cumulative cultural evolution and mechanisms for cultural selection in wild bird songs. Nature Communications 13, 4001.