Research
The major goal of my research is understanding the evolution of sexual signals in birds. I use integrative methods, including genomics, spectrophotometry, high-resolution imaging, and field observations to fully describe sexual phenotypes and investigate how they arise, proliferate, and change. A central component of this work is studying how gene flow among species contributes to the evolution of plumage coloration. Because understanding relationships among species is critical for understanding trait evolution and gene flow, phylogenetic analysis is an important element of my work.
At every step, my research relies on museum collections. See the Museums tab above for more.
The genetic and physical basis of avian plumage colors
Birds are beloved for their incredible variety of colors, which has also fascinated biologists for centuries. With technological advancements in sequencing and high-resolution imaging, the genetic and physical contributors to bird colors are now being revealed. My research explores the genetic basis of feather color in birds and the micro- and nanostructural features that can modify how colors are perceived or even create new colors.
Publications:
*Shared first authorship
2026 Cespedes Arias LN*, Bennett KFP*, Campagna L, Wood AWW, Bonaccorso E, Cuervo AM, Cadena CD, Lovette IJ, Toews DPL. Diversification and divergence in Myioborus warblers: insights into evolutionary relationships and plumage genetics. Evolution, 80(8): 1703–1718. http://doi.org/10.1093/evolut/qpag085.
2025 Bennett KFP, Wood AWW, Baiz MD, Phung L-N, Lovette IJ, Toews DPL. A colorful legacy of hybridization in wood-warblers includes frequent sharing of carotenoid genes among species and genera. PLOS Biology, 23(12): e3003501. https://doi.org/10.1371/journal.pbio.3003501.
2024 Lim HC*, Bennett KFP*, Justyn NM, Powers MJ, Long KM, Kingston SE, Lindsay WR, Pease JB, Fuxjager MJ, Bolton PE, Balakrishnan CN, Day LB, Parsons TJ, Brawn JD, Hill GE, Braun MJ. Sequential introgression of a carotenoid processing gene underlies sexual ornament diversity in a genus of manakins. Science Advances, 10:eadn8339. https://www.science.org/doi/10.1126/sciadv.adn8339
Hybridization, gene flow, and the evolution of sexual signals in birds
The genomics revolution has led to a revolution in our understanding of the prevalence and importance of hybridization in animal evolution. Adaptive traits are now understood to spread between species through introgression fairly frequently, and sexual traits are no exception, particularly in birds. My research has explored instances of plumage introgression between species and genera in birds, including uncovering the apparent spread of “colorful” genes among many species of warblers.
More broadly, I am interested in the larger evolutionary forces controlling these situations. Why do some traits spread more easily than others? How do selection for a favored trait and selection against “foreign” DNA interact in hybrids? Do bright colors in birds serve as “honest signals”? I explore these questions through integrative methods, including field observations, analysis of museum specimens, and DNA/RNA sequencing.
Publications:
*Shared first authorship
2025 Bennett KFP, Wood AWW, Baiz MD, Phung L-N, Lovette IJ, Toews DPL. A colorful legacy of hybridization in wood-warblers includes frequent sharing of carotenoid genes among species and genera. PLOS Biology, 23(12): e3003501. https://doi.org/10.1371/journal.pbio.3003501.
2025 Bennett KFP, Gielow KH, Toews DPL. Genetic confirmation of an “Uncommon Mourningthroat” (Geothlypis philadelphia x G. trichas): a rare but persistent hybrid warbler. Wilson Journal of Ornithology, 138(2): 303–314. https://doi.org/10.1080/15594491.2025.2584827.
2025 Bennett KFP, Bolton PE, Brumfield RT, Wilkinson GS, Braun MJ. Impact of a putative riverine barrier on genomic population structure and gene flow in the presence of sexual selection. Evolution, 79(10): 2181–2192. https://doi.org/10.1093/evolut/qpaf146
2024 Lim HC*, Bennett KFP*, Justyn NM, Powers MJ, Long KM, Kingston SE, Lindsay WR, Pease JB, Fuxjager MJ, Bolton PE, Balakrishnan CN, Day LB, Parsons TJ, Brawn JD, Hill GE, Braun MJ. Sequential introgression of a carotenoid processing gene underlies sexual ornament diversity in a genus of manakins. Science Advances, 10:eadn8339. https://www.science.org/doi/10.1126/sciadv.adn8339
2024 Long KM, Rivera-Colon AG, Bennett KFP, Catchen JM, Braun MJ, Brawn JD. Ongoing introgression of a secondary sexual plumage trait in a stable avian hybrid zone. Evolution, 78: 1539–1553. https://academic.oup.com/evolut/article/78/9/1539/7675325.
2021 Bennett KFP, Lim HC, Braun MJ. Sexual selection and introgression in avian hybrid zones: spotlight on Manacus. Integrative and Comparative Biology, 61: 1291-1309. https://doi.org/10.1093/icb/icab135.
Avian systematics
I use genomics of modern blood samples and archival museum tissues to investigate species’ relationships and histories of diversification.
Publications:
*Shared first authorship
2026 Cespedes Arias LN*, Bennett KFP*, Campagna L, Wood AWW, Bonaccorso E, Cuervo AM, Cadena CD, Lovette IJ, Toews DPL. Diversification and divergence in Myioborus warblers: insights into evolutionary relationships and plumage genetics. Evolution, 80(8): 1703–1718. http://doi.org/10.1093/evolut/qpag085.
2025 Bennett KFP, Wood AWW, Baiz MD, Phung L-N, Lovette IJ, Toews DPL. A colorful legacy of hybridization in wood-warblers includes frequent sharing of carotenoid genes among species and genera. PLOS Biology, 23(12): e3003501. https://doi.org/10.1371/journal.pbio.3003501.
Genomic consequences of intense sexual selection
In species like manakins where males compete for choosy females, mating success is highly skewed, so only a small fraction of males will pass on their genes. As a result, there should be measurable genomic consequences, like reduced genetic diversity on chromosomes overrepresented in males (i.e., the Z chromosome in birds).
In fact, little hard evidence for this phenomenon exists, and one study found exactly the opposite: species predicted to be under stronger sexual selection had increased Z diversity (Huang and Rabosky 2015).
I am working with collaborators in the Manakin Research Coordination Network and at Cornell University to address genomic consequences of strong sexual selection across the manakin family, which exhibits a wide range of sexual selection intensity.
Publications:
In review Anderson HL, Bennett KFP, Long KM, Brawn JD, O’Dea A, Parsons TJ, Johnson PLF, Braun MJ. Can the Z:A ratio serve as a genomic index of sexual selection? An assessment across space and time in a genus of lekking birds. https://doi.org/10.64898/2026.07.21.739449.
2026 Balakrishnan CN, Toda Y, Ko M-C, Wirthlin ME, Driver RJ, Bolton PE, Miller ET, Mendez-Aranda D, Dikow RB, Frandsen PB, Shogren EH, Bennett KFP, …46 authors…, Baldwin MW. Genomic and physiological changes in a sexually selected and frugivorous bird radiation. Current Biology, 36(12): 3061-3076. https://doi.org/10.1016/j.cub.2026.05.021
2021 Bennett KFP, Lim HC, Braun MJ. Sexual selection and introgression in avian hybrid zones: spotlight on Manacus. Integrative and Comparative Biology, 61: 1291-1309. https://doi.org/10.1093/icb/icab135.
Abundance and activity patterns of free-ranging domestic cats
My master’s research focused on domestic cats in residential areas across an urban-rural land-use gradient. I used motion-sensor cameras and conducted transect counts at sites across the Washington-Baltimore metro area to estimate cat abundance and how abundance co-varies with urban intensity. I also measured activity timing of cats across the land-use gradient.
This work relied on the generosity of over 50 community science participants who allowed me access to their yards for camera-trapping. Community science is key for accessing human-dominated areas, a necessary component of ecological research in an increasingly human-dominated world.
Publications:
2021 Bennett KFP,* Evans BS,* Clark JA, Marra PP. Domestic cat abundance and activity across a residential land-use gradient. Frontiers in Ecology and Evolution, 9: 643845. https://doi.org/10.3389/fevo.2021.643845.
*Shared first authorship