Prof. Claire Spottiswoode

Other Research Interests

heteromirafra

AFRICAN ORNITHOLOGY AND CONSERVATION. I am South African and my interest in ecology and evolution comes from a life-long passion for African birds and biodiversity. In the last few years I’ve been involved in conservation-related research in, particularly, the arid rangelands of southern and eastern Ethiopia (see publications 45, 383525232120) in collaboration with the Ethiopian Wildlife and Natural History Society and BirdLife International, and the montane forests of northern Mozambique (see 5143,1942), each of which is home to many biogeographically intruiguing and increasingly endangered endemic species. I’ve also co-written three birdwatching site guidebooks to southern Africa and Ethiopia.

sociable weaver

AVIAN SOCIALITY. My PhD research (2002-2005), supervised by Nick Davies, partly involved a detailed field study of a colonial, communal and cooperatively-breeding bird, the Sociable Weaver Philetairus socius. This is a remarkable bird of the Kalahari and Namib deserts of south-western Africa, where it builds enormous haystack-like communal nests in Acacia trees. Predation by snakes attracted by the size of weaver colonies appears to be a major cost of extreme sociality in this species. I showed that individuals in colonies of different sizes differ with respect to morphology and reproductive investment (see publication 16), and carried out various field experiments to attempt to distinguish whether these among-colony differences could be explained by adaptive life-history divergence in colonies of different sizes and hence predation risk (see 22). Further to predation, parasitism and disease are also potential costs of sociality. If so, then we would expect cooperatively breeding birds that live in groups to invest more in immune defence than pair breeding species. I carried out a comparative study of South African and Malawian birds and found that this was so, at least with respect to one measure of immunity (see 18). I continue to be involved, through historical data, in ongoing research on Sociable Weavers led by Rita Covas at the University of Porto and the Percy FitzPatrick Institute, University of Cape Town (see 6450, 4946423629). 

rosy pastor

SEXUAL SELECTION AND BIRD MIGRATION. Migratory birds arrive as early as possible on their breeding grounds not only because of its naturally selected advantages, but also because females prefer early-arriving males as mates. Anders Pape Møller and I showed that this could generate the latitudinal trend that is observed in rates of extra-pair paternity in birds, which are higher in the north-temperate zone where many species are migratory (see publication 7). But spring conditions are not remaining constant, and as the world’s climate warms many migratory birds are arriving earlier and earlier on their breeding grounds. However, the degree of such change varies greatly among species – why is this so? Anders Tøttrup, Tim Coppack and I showed that these differences in species’s responses to climate change might be explained by female choice, since in strongly sexually selected species there is the most incentive to arrive earlier as conditions become milder (see 12; also 10). Nicola Saino and I have written a review chapter on the potential relationships between sexual selection and climate change, in an OUP book published in 2010, Effects of Climate Change on Birds (edited by Møller, Fiedler & Berthold).

News

Dr Gabriel Jamie awarded a Leverhulme Early Career Fellowship

Dr Gabriel Jamie has been awarded a Leverhulme Early Career Fellowship based at University of Cambridge. For the fellowship Gabriel will build on his previous work on brood parasitism and the evolution of polymorphisms to understand the incredible diversity of egg...

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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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