African Cuckoos

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Tanmay’s research addresses how mechanisms influence the coevolution of brood parasites and their hosts. 

His passion for brood parasitism, ornithology, and animal behaviour was inspired by his love of natural history. This fascination with natural history, alongside his interest in how species interact in life’s complex web led to him studying Natural Sciences at the University of Cambridge. During and after Tanmay’s undergraduate degree, he has conducted projects across the world, including in the neotropics (Panama and Trinidad), and in Africa. It was in Africa that he joined the African cuckoos team in 2017. 

Tanmay began his PhD research in October 2018, studying the antagonistic interactions between cuckoo finches Anomalospiza imberbis and their hosts (family Cisticolidae) in Zambia. He collaborated with mathematicians and computer scientists such as Prof. L Mahadevan (Harvard) and Dr. Christopher Town (Cambridge) to use top-down and bottom-up approaches to study the evolution of egg signatures and forgeries. In particular, he studied the evolution of egg pattern complexity, the optimality of egg pattern traits, and imperfect mimicry. His PhD was awarded in 2023. 

In 2023, he began a Research Fellowship at Jesus College, Cambridge. He continues to study cuckoo finches and their hosts, now focussing on mechanisms underpinning coevolution. He is particularly interested in whether perception of egg colours and patterns is continuous or categorical, and how cuckoo finches respond to host perceptual capabilities and phenotypic distributions. He is also a Research Associate at the Fitzpatrick Institute, University of Cape Town.

Tanmay’s focus on mechanisms and their effects on evolution requires cross-disciplinary approaches to studying both adaptation and maladaptation, and he particularly enjoys collaborating with researchers across a range of fields. Nevertheless, he is particularly delighted to be able to pursue scientific questions in the beautiful setting of Zambia’s miombo woodland.

• McClelland, S. C., Lund, J., Dixit, T., Hamama, S., McClean, L. A., Spottiswoode, C. N., White, C. R., Louder, M. I. M., Hauber, M. E., Honza, M., & Portugal, S. J. (2024). Highly virulent avian brood-parasitic species show elevated embryonic metabolic rates at specific incubation stages compared to less virulent and non-parasitic species. Biology Letters, 20(9), 20240411. https://doi.org/10.1098/rsbl.2024.0411

• Dixit, T. 2023. A synthesis of coevolution across levels of biological organisation. Evolution 78(2). qpad082. https://doi.org/10.1093/evolut/qpad082

• Dixit, T., Lund, J., Fulford, A.J.C., Apostol, A.L., Chen, K.-C., Tong, W., Feeney, W.E., Hamusikili, L., Colebrook-Robjent, J.F.R., Town, C.P., Spottiswoode, C.N. 2023. Chase-away evolution maintains imperfect mimicry in a brood parasite–host system despite rapid evolution of mimics. Nature Ecology & Evolution 7. 1978-1982. https://doi.org/10.1038/s41559-023-02232-4. (also see blog post at https://ecoevocommunity.nature.com/posts/an-evolutionary-chase-how-mimicry-remains-imperfect-despite-rapid-evolution-of-mimics)
• Dixit, T., Chen, K.C., Stoddard, M.C., Mahadevan, L., Town, C.P., Spottiswoode, C.N., 2023. Repeatable randomness, invariant properties, and the design of biological signatures of identity. Evolution 77(10), 2224-2233.
• Lund, J., Dixit, T., Attwood, M.C., Hamama, S., Moya, C., Stevens, M., Jamie, G.A., Spottiswoode, C.N., 2023. When perfection isn’t enough: host egg signatures are an effective defence against high-fidelity African cuckoo mimicry. Proceedings of the Royal Society B. 290: 20231125.
• McClelland, S.C., Attard, M.R.G., Bowen, J, Horrocks, N.P.C., Jamie, G.A., Dixit, T., Spottiswoode, C.N., Portugal, S.J., 2023. Eggshell composition and surface properties of avian brood-parasitic species compared with non-parasitic species. Royal Society Open Science 10: 221023. https://doi.org/10.1098/rsos.221023
• Dixit, T., Choi, G.P.T., al-Mosleh, S., Lund, J., Troscianko, J., Moya, C., Mahadevan, L., Spottiswoode, C.N., 2023. Combined measures of mimetic fidelity explain imperfect mimicry in a brood parasite–host system. Biology Letters, 19: 20220538.
• Dixit, T., Apostol, A., Chen, K.-C., Fulford, A.J.C., Town, C.P., Spottiswoode, C.N., 2022. Visual complexity of egg patterns predicts egg rejection according to Weber’s Law. Proceedings of the Royal Society B: Biological Sciences. 289: 20220710. 
• Cram, D.L., van der Wal, J.E.M., Uomini, N.T., Cantor, M., Afan, A.I., Attwood, M.C., Amphaeris, J., Balasani, F., Blair, C.J., Bronstein, J.L., Buanachique, I.O., Cuthill, R.R.T., Das, J., Daura-Jorge, F.G., Deb, A., Dixit, T., Dlamini, G.S., Dounias, E., Gedi, I.I., Gruber, M., Hoffman, L.S., Holzlehner, T., Isack, H.A., Laltaika, A.E., Lloyd-Jones, D.J., Lund, J., Machado, A.M.S., Mahadevan, L., Moreno, I.B., Nwaogu, C.J., Pereira, V.L., Pierotti, R., Rucunua, S.A., dos Santos, W.F., Serpa, N., Smith, B.D., Sridhar, H., Tolkova, I., Tun, T., Valle-Pereira, J.V.S., Wood, B.M., Wrangham, R.W., Spottiswoode, C.N., 2022. The ecology and evolution of human-wildlife cooperation. People and Nature 4(4), 841-855.

• van der Wal, J.E.M., Spottiswoode, C.N., Uomini, N.T., Cantor, M., Daura-Jorge, F.G., Afan, A.I., Attwood, M.C., Amphaeris, J., Balasani, F., Begg, C.M., Blair, C.J., Bronstein, J.L., Buanachique, I.O., Cuthill, R.R.T., Das, J., Deb, A., Dixit, T., Dlamini, G.S., Dounias, E., Gedi, I.I., Gruber, M., Hoffman, L.S., Holzlehner, T., Isack, H.A., Laltaika, A.E., Lloyd-Jones, D.J., Lund, J., Machado, A.M.S., Mahadevan, L., Moreno, I.B., Nwaogu, C.J., Pereira, V.L., Pierotti, R., Rucunua, S.A., dos Santos, W.F., Serpa, N., Smith, B.D., Tolkova, I., Tun, T., Valle-Pereira, J.V.S., Wood, B.M., Wrangham, R.W., Cram, D.L., 2022. Safeguarding human-wildlife cooperation. Conservation Letters 15(4), e12886.
• McClelland, S.C., Reynolds, M., Cordall, M., Hauber, M.E., Goymann, W., McClean, L.A., Hamama, S., Lund, J., Dixit, T., Louder, M.I.M., Safari, I., Honza, M., Spottiswoode, C.N., Portugal, S.J., 2021. Embryo movement is more frequent in avian brood parasites than birds with parental reproductive strategies. Proceedings of the Royal Society B 288: 20211137.
• Dixit, T., Caves, E.M., Spottiswoode, C.N., Horrocks, N.P.C., 2021. Why and how to apply Weber’s Law to coevolution and mimicry. Evolution 75(8), 1906-1919.
• Caves, E.M., Dixit, T., Colebrook-Robjent, J.F.R., Hamusikili, L., Stevens, M., Thorogood, R., Spottiswoode, C.N., 2021. Hosts elevate either within-clutch consistency or between-clutch distinctiveness of egg phenotypes in defence against brood parasites. Proceedings of the Royal Society of London B 288: 20210326.
• Dixit, T.*, Riederer, J.M.*, Quek, S., Belford, K., Tavares de Wand, T., Sicat, R., Jiggins, C.D., 2020. Plasticity in flower size as an adaptation to variation in pollinator specificity. Ecological Entomology 45(6), 1367-1372.
• Sorensen, M.C., Dixit, T., Newton, J., Kardynal, K., Hobson, K., Bensch, S., Jenni-Eiereman, S., Spottiswoode, C.N., 2019. Migration distance does not predict blood parasitism in a Palearctic-African migratory bird. Ecology and Evolution 9(14), 8294-8304.
• Pickup, M., Brandvain, Y., Fraïsse, C., Yakimowski, S., Barton, N.H., Dixit, T., Lexer, C., Cereghetti, E., Field, D.L., 2019. Mating system variation in hybrid zones: facilitation, barriers and asymmetries to gene flow. New Phytologist 224(3), 1035-1047.
• Dixit, T., English, S., Lukas, D., 2017. The relationship between egg size and helper number in cooperative breeders: a meta-analysis across species. PeerJ 5: e4028.

Packages:

Worsley, M.Z., Dixit, T. 2024. kber: Estimate the strength of the magnitude effect. https://github.com/mzw22/kber

Non-peer-reviewed articles

Dixit, T. 2024. The cuckoo finch and the Red Queen. African Birdlife. 12(2): 24.

Dixit, T. 2023. An evolutionary chase: how mimicry remains imperfect despite rapid evolution of mimics. Springer Nature.

Dixit, T., Walton, J., Lund, J. 2019. Malachite sunbird promiscuity. Promerops 315: 23.