Other Research Interests
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, 38, 35, 25, 23, 21, 20) in collaboration with the Ethiopian Wildlife and Natural History Society and BirdLife International, and the montane forests of northern Mozambique (see 51, 43,19, 4, 2), 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.
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 64, 50, 49, 46, 42, 36, 29).
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).
See also: Prof. Claire Spottiswoode | | | |