Rainy season 2022

Apr 2, 2022

Cuckoo finch egg in a zitting cisticola clutch

A fruitful 2022 rainy season of fieldwork is underway! Gabriel Jamie, Maggie Mwale, Cameron Blair and Jonah Walker travelled to Choma in February to reunite with Collins Moya, Silky Hamama, and all our Zambian colleagues, to carry on the wet-season projects which were cut short by Covid in 2020, and to begin exciting new lines of investigation.

Gabriel continued his Leverhulme Fellowship work investigating the genomics of polymorphisms across a wide range of species and working together with Maggie who was also collecting nests for the Livingstone Museum’s collections and an upcoming exhibition.

Cameron assisted with collecting data for Tanmay Dixit’s PhD by conducting egg-rejection experiments in the nests of tawny-flanked prinias and several cisticolas – the host species of cuckoo finches.

Jonah meanwhile has begun the field component of his project. He is quantifying the thermal and light environment of host nests and running thermal trials to determine the heating rate of eggs of different colours and patterning. Not everything has gone to plan, of course. Host parents were, perhaps unsurprisingly, unimpressed by the thin thermistor probes we placed in their nests — with one pair snapping the wire off and weaving it into their nest!

Collins and Silky, alongside supporting all this work, kept Chima Nwaogu’s long-term insect survey going. Now running for six months and counting, we look forward to seeing the outcome of this study, especially as it heads into the poorly-characterised cold season in Choma.

A huge thank you as ever goes to our colleagues in the field who made the work possible and so enjoyable!

News

Evolutionary Biology Crash Course

Tanmay Dixit was a member of a team organising and lecturing in the inaugural Evolutionary Biology Crash Course. This course, aimed at undergraduate or early-postgraduate students, teaches evolutionary principles to students who have had limited opportunities to be exposed to evolutionary ideas. The course is funded by the Equal Opportunities Initiative Fund of the European Society of Evolutionary Biology (ESEB). Tanmay presented lectures on behavioural ecology and evolution, focussing on kin selection, coevolution, and parasitism. Over 700 students, with the vast majority from the global South, attended the course, which was a resounding success!

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New paper on visual complexity & mimicry

Our paper “Visual complexity of egg patterns predicts egg rejection according to Weber’s Law” has just been published in the journal Proceedings of the Royal Society B. This research was led by Tanmay Dixit, and carried out together with Andrei Apostol, Kuan-Chi Chen, Tony Fulford, Chris Town and Claire Spottiswoode, in a collaboration between biologists and computer scientists. We used machine learning to compute a biologically-relevant measure of egg pattern complexity, and combined this with field experiments in Zambia to investigate how complexity evolves in an arms race between host egg signatures (by tawny-flanked prinias) and parasitic egg forgeries (by cuckoo finches).

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Fieldwork and teaching at APLORI, Nigeria

Dr Gabriel Jamie is continuing his fieldwork on the evolution of polymorphisms in cisticolas and prinias in Nigeria, where he is also a teaching fellow at the AP Leventis Ornithological Research Institute (APLORI). The image shows the 2022 APLORI MSc class during the Global Birding Big Day on 14 May. The team recorded 135 species while walking around the nature reserve surrounding the institute.

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New paper on the genetics of cuckoo finch egg mimicry

Our paper “Genetic architecture facilitates then constrains adaptation in a host-parasite coevolutionary arms race” has been published in the Proceedings of the National Academy of Sciences of the USA. In it, we address the long-standing puzzle of how exquisite mimicry of the eggs of several different host species can evolve within a single species of brood-parasitic bird. We show that in cuckoo finches in Zambia, egg mimicry of different host egg phenotypes is maternally inherited, which allows mothers to transmit host-specific adaptations to their daughters irrespective of which host species the father was raised by. This study was a team effort from colleagues at the University of Cambridge and University of Cape Town (Claire Spottiswoode, Wenfei Tong, Gabriel Jamie), at Boston University (Katherine Stryjewski, Jeff DaCosta, Evan Kuras and Michael Sorenson) and in the Choma community in Zambia (Ailsa Green, Silky Hamama, Ian Taylor and Collins Moya).

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