Research projects
Plumage color, gene flow, and phylogenetics of New World warblers
Hybridization among species is a important mechanism for adaptive evolution and speciation, and its full impacts are becoming better understood as modern genomics results in larger and more complete datasets. In this project, we sequenced whole genomes of multiple individuals from nearly every species of warblers from the family parulidae. We are using this dataset to better understand warbler evolutionary relationships and delve deeply into instances of interspecies and in some cases intergeneric introgression related to plumage coloration genes. For example, we found that carotenoid metabolism gene BCO2 has undergone at least eight instances of introgression between species and twice between genera. These findings advance our understanding of how sexual signals evolve in birds: "borrowing" them from related species may be quite common.
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Publications:
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*Shared first authorship
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In review Bennett KFP, Wood AWW, Baiz MD, Phung L-N, Lovette IJ, Toews DPL. The colorful legacy of hybridization in parulid warblers​
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In review 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
https://www.biorxiv.org/content/10.1101/2025.08.12.669906v1
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In review Bennett KFP, Gielow KH, Toews DPL. Genetic confirmation of an “Uncommon Mourningthroat” (Geothlypis philadelphia x G. trichas): a rare but persistent hybrid warbler.
Evolutionary implications of sexual trait introgression in a hybrid zone
In western Panama, male golden-collared and white-collared manakins perform acrobatic courtship displays for choosy females. The two species interbreed in a narrow hybrid zone, and the golden collar trait has introgressed into white-collared populations under positive sexual selection via female choice.
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Together with a large team of collaborators, I study the genetic, molecular, and chemical basis of traits under selection in this system, including plumage color, behavior, and feather structure. I am also studying the adaptive consequences of sexual selection on these traits and tracing their evolutionary history.
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To explore these topics, I have observed manakins in the field, studied museum specimens, and sequenced archival genetic samples.
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Publications:
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*Shared first authorship
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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, accepted.
https://doi.org/10.1093/evolut/qpaf146​
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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
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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
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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.
Genomic consequences of intense sexual selection in birds
In species like most manakins where males compete for choosy females, mating success is highly skewed among males, so only a small fraction of males will pass on their genes. As a result, we expect there to be genomic consequences, like reduced genetic diversity on chromosomes overrepresented in males (i.e., the Z chromosome in birds).
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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).
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I am working with collaborators in the Manakin Research Coordination Network to address genomic consequences of strong sexual selection across the manakin clade, which exhibits great variation in sexual selection intensity.
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Publications:
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Submitted 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. Genome evolution in a clade of birds under strong sexual selection.
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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.
Identifying vagrant songbirds through DNA sequencing
I received a small grant through the Maryland Ornithological Society (MOS) to sequence DNA I collected from the feces of a vagrant flycatcher (either a Pacific-slope or Cordilleran Flycatcher) that would represent a first state record.
As part of my work on the MOS Maryland/DC Records Committee, I am also re-analyzing a previous analysis of unidentified pewee DNA taken from museum specimens to determine whether we can add Western Wood-Pewee to Maryland's official bird list.
Abundance and activity patterns of free-ranging domestic cats
My Master's research advised by Alan Clark at Fordham University and Peter Marra at the Smithsonian Migratory Bird Center focused on domestic cats in residential areas across an urban-rural land-use gradient.
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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 using the camera data.
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I determined that cat abundance was greatest at intermediate urban intensity, and that cats at urban sites were more strictly nocturnal, while cats at rural sites were more crepuscular. The implication of these results is that more urban does not always mean more cats--especially when suburban residents leave out cat food--and cat surveys need to plan for differences in cat activity across land-use gradients to avoid bias.
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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 to access human-dominated areas, a necessary component of ecological research in an increasingly human-dominated world.
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Publications:
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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.
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*Shared first authorship