Gemma Clucas

Postdoctoral Fellow

I’m a salty seabirder at heart and so most of my projects focus on some aspect of seabird biology. During the summer, you’ll find me collecting fecal samples from terns and puffins in the Gulf of Maine to track changes in their diets over time. Seabirds are fantastic fisheries biologists and we can use changes in their diets to monitor changes in forage fish populations. In the winter, I migrate south to Antarctica, like an Arctic tern, where I will be tracking penguins and collecting fecal samples from them to monitor how warming around the Antarctic Peninsula is influencing food availability for the birds. The rest of the year, I’m either in the lab or at my desk analyzing genomic data from various species (not just birds, fish too!) to understand population structure and adaptive genetic differences among populations so that we can conserve them effectively.

Education

Ph.D., Earth and Ocean Sciences, University of Oxford and University of Southampton
M.Res., Ocean Sciences, University of Southampton
M.A., Natural Sciences, University of Cambridge

Recent Publications

Clucas, G. V., A. Stillman, and E. C. Craig (2024). From presence/absence to reliable prey proportions: A field test of dietary DNA for characterizing seabird diets. [Online.] Available at
Herman, R. W., G. Clucas, J. Younger, J. Bates, B. Robinson, S. Reddy, J. Stepanuk, K. O'Brien, K. Veeramah, and H. J. Lynch (2024). Whole genome sequencing reveals stepping‐stone dispersal buffered against founder effects in a range expanding seabird. Molecular Ecology 33:e17282.
Ensanyar-Volle, O., J. Appoo, N. Bunbury, G. Clucas, N. Khan, G. Rocamora, C. Sanchez, and A. Fayet (2023). Differences in foraging range between white-tailed tropicbirds breeding on inner and outer Seychelles islands. Marine Ecology Progress Series 724:141–154.
Flynn, C. M., T. Hart, G. V. Clucas, and H. J. Lynch (2023). Penguins in the anthropause: COVID-19 closures drive gentoo penguin movement among breeding colonies. Biological Conservation 286:110318.
Fayet, A. L., C. Sanchez, J. Appoo, J. Constance, G. Clucas, L. A. Turnbull, and N. Bunbury (2023). Marked differences in foraging area use and susceptibility to predation between two closely-related tropical seabirds. Oecologia 203:167–179.
Garnier, J., G. V. Clucas, J. Younger, B. Sen, C. Barbraud, M. Larue, A. D. Fraser, S. Labrousse, and S. Jenouvrier (2023). Massive and infrequent informed emigration events in a species threatened by climate change: the emperor penguins. [Online.] Available at
Clucas, G. V., V. Warwick-Evans, T. Hart, and P. N. Trathan (2022). Using habitat models for chinstrap penguins, Pygoscelis antarctica, to inform marine spatial management around the South Sandwich Islands during the penguin breeding season. Deep Sea Research Part II: Topical Studies in Oceanography 199:105093.
Caldwell, A., S. Brander, J. Wiedenmann, G. Clucas, and E. Craig (2022). Incidence of microplastic fiber ingestion by Common Terns (Sterna hirundo) and Roseate Terns (S. dougallii) breeding in the Northwestern Atlantic. Marine Pollution Bulletin 177:113560.
Renfrew, R. B., N. Perlut, L. M. Maxwell, M. Cadman, D. H. Kim, G. V. Clucas, and A. I. Kovach (2022). Population structure of a grassland songbird (Dolichonyx oryzivorus) to inform conservation units. Biodiversity and Conservation 31:77–96.
Frugone, M. J., T. L. Cole, M. E. López, G. Clucas, P. Matos‐Maraví, N. A. Lois, P. Pistorius, F. Bonadonna, P. Trathan, A. Polanowski, B. Wienecke, et al. (2021). Taxonomy based on limited genomic markers may underestimate species diversity of rockhopper penguins and threaten their conservation. Diversity and Distributions 27:2277–2296.
Dickens, J., P. R. Hollyman, T. Hart, G. V. Clucas, E. J. Murphy, S. Poncet, P. N. Trathan, and M. A. Collins (2021). Developing UAV Monitoring of South Georgia and the South Sandwich Islands' iconic land-based marine predators. Frontiers in Marine Science 8:654215.
Fayet, A. L., G. V. Clucas, T. Anker‐Nilssen, M. Syposz, and E. S. Hansen (2021). Local prey shortages drive foraging costs and breeding success in a declining seabird, the Atlantic puffin. Journal of Animal Ecology 90:1152–1164.
Walsh, J., A. I. Kovach, P. M. Benham, G. V. Clucas, V. L. Winder, and I. J. Lovette (2021). Genomic data reveal the biogeographical and demographic history of Ammospiza sparrows in northeast tidal marshes. Journal of Biogeography 48:2360–2374.
Levy, H., S. R. Fiddaman, J. A. Vianna, D. Noll, G. V. Clucas, J. K. H. Sidhu, M. J. Polito, C. A. Bost, R. A. Phillips, S. Crofts, G. D. Miller, et al. (2020). Evidence of pathogen-induced immunogenetic selection across the large geographic range of a wild seabird. Molecular Biology and Evolution 37:1708–1726.
Tyler, J., M. T. Bonfitto, G. V. Clucas, S. Reddy, and J. L. Younger (2020). Morphometric and genetic evidence for four species of gentoo penguin. Ecology and Evolution 10:13836–13846.
Kalvakaalva, R., G. Clucas, R. W. Herman, and M. J. Polito (2020). Late Holocene variation in the Hard prey remains and stable isotope values of penguin and seal tissues from the Danger Islands, Antarctica. Polar Biology 43:1571–1582.
Trathan, P. N., B. Wienecke, C. Barbraud, S. Jenouvrier, G. Kooyman, C. Le Bohec, D. G. Ainley, A. Ancel, D. P. Zitterbart, S. L. Chown, M. LaRue, et al. (2020). The Emperor Penguin: Vulnerable to projected rates of warming and sea ice loss. Biological Conservation 241:108216.
Cole, T. L., L. Dutoit, N. Dussex, T. Hart, A. Alexander, J. L. Younger, G. V. Clucas, M. J. Frugone, Y. Cherel, R. Cuthbert, U. Ellenberg, et al. (2019). Receding ice drove parallel expansions in Southern Ocean penguins. Proceedings of the National Academy of Sciences 116:26690–26696.
Clucas, G. V., L. A. Kerr, S. X. Cadrin, D. R. Zemeckis, G. D. Sherwood, D. Goethel, Z. Whitener, and A. I. Kovach (2019). Adaptive genetic variation underlies biocomplexity of Atlantic cod in the Gulf of Maine and on Georges Bank. PLOS ONE 14:e0216992.
Clucas, G. V., R. N. Lou, N. O. Therkildsen, and A. I. Kovach (2019). Novel signals of adaptive genetic variation in northwestern Atlantic cod revealed by whole‐genome sequencing. Evolutionary Applications 12:1971–1987.
Walsh, J., G. V. Clucas, M. D. MacManes, W. K. Thomas, and A. I. Kovach (2019). Divergent selection and drift shape the genomes of two avian sister species spanning a saline–freshwater ecotone. Ecology and Evolution 9:13477–13494.
Gemma Clucas
Center Avian Population Studies
Email gemma.clucas@cornell.edu
Website Website

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Golden-cheeked Warbler by Bryan Calk/Macaulay Library