The Birds

Brood-parasitic study systems

In Zambia we study four different groups of brood parasitic birds and their hosts, as well as some interesting non-parasitic birds, too.

Cuckoo Finch egg circle

Cuckoo Finches

Cuckoo Finches Anomalospiza imberbis are brood parasitic finches that exploit various species of warblers as their hosts. They have evolved beautiful mimicry not only of their different host species, but also of different host colour and patterns, or ‘forgeries’ to their hosts’ egg ‘signatures’.
Read more here…

Honeyguide

Greater and Lesser Honeyguides

Honeyguides are intriguingly bizarre birds with respect to most aspects of their lives. They guide humans to bees’ nests, are unusually brutal brood parasites of other birds and, it turns out, have a remarkably ancient history of specialisation on their particular host species.
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African Cuckoo

African and Diederik Cuckoos

African Cuckoo eggs are probably the very best forgeries of any brood parasitic egg in the world. They can so closely resemble those of their hosts that neither we nor the hosts can tell them apart.
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Indigobird

Vidua Finches: Whydahs and Indigobirds

Vidua finches, the indigobirds and whydahs, belong to the same family as Cuckoo Finches but have a fascinatingly different brood parasitic system involving beautiful mimicry of their host chicks’ bizarrely pattern mouthparts.
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Other interesting things we study in Choma

Great Reed Warbler

Migratory Birds

Marjorie Sorensen carried out her PhD research on the intriguing and little-known winter ecology of Palearctic-breeding migratory birds (Willow Warblers and Great Reed Warblers) that spend the non-breeding season in Zambia.
Read more here…

FN Nightjar

Nest Camouflage

We study camouflage and thermal ecology of eggs, chicks and incubating adults of ground-nesting birds in Choma: nightjars, coursers and plovers.
Read more here…

News

New paper published on Weber’s Law and mimicry

Our paper ‘Why and how to apply Weber’s Law to coevolution and mimicry’ has been published in the journal Evolution. This perspectives paper, written by Tanmay Dixit, Eleanor Caves, Claire Spottiswoode, and Nicholas Horrocks, argues that Weber’s Law of proportional processing can lead to otherwise counterintuitive predictions about the evolutionary trajectories of mimicry systems.  Weber’s Law states that when the magnitude of a stimulus is large, it is more difficult to discriminate a change or difference from that stimulus. In other words, relative differences are more salient than absolute differences. We show that Weber’s Law could have implications for mimicry: when stimulus magnitudes are high, it should be more difficult to discriminate a model from a mimic. This leads to testable predictions about evolutionary trajectories of models and mimics. We also present a framework for testing Weber’s Law and its implications for coevolution. 

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New paper on evolution of egg signatures

Our paper “Hosts elevate either within-clutch consistency or between-clutch distinctiveness of egg phenotypes in defence against brood parasites” has just been published in the journal Proceedings of the Royal Society of London B. In this study, led by Eleanor Caves, we asked how host eggs evolve adaptations that allow them better to discriminate their own eggs from parasitic eggs. Theoretically, hosts can generate their own individually-distinctive egg ‘signatures’ by laying eggs that appear similar to one another (consistency) but look very different from other individuals’ eggs (distinctiveness). In this new study, we show that host species of two African brood parasites deploy either consistency or distinctiveness, but not both, as defences, and achieve distinctiveness by combining egg colours and patterns in unpredictable combinations.

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Mairenn Attwood awarded Cambridge teaching prize

Congratulations to Mairenn Attwood for being awarded the Janet Moore Prize for teaching in the Department of Zoology at the University of Cambridge, for her outstanding tutorial supervision of final-year undergraduate students, who praised her breadth and depth of knowledge, enthusiasm, and friendliness.  Mairenn follows in the footsteps of Tanmay Dixit who was awarded the Janet Moore Prize in 2020. Well done both for inspiring the next generation of behavioural ecologists!

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