At the university of Sheffield I am currently working in Prof Ben Hatchwell’s group as a NERC-funded Researcher Co-Investigator investigating the costs and benefits of cooperation in the sociable weaver, Philetairus socius. Specifically, I am investigating how sociable weavers avert the tragedy of the commons and what the functions and mechanisms of recognition systems are. My research combines field-based observations and experiments with population genetics and social network analyses to obtain a broad understanding of the evolution and maintenance of the extensive levels of cooperation in sociable weavers.
The sociable weaver is a colonial, cooperatively breeding passerine endemic to the semi-arid savannahs of southern Africa’s Kalahari Desert. We study these birds at Benfontein Game Farm near Kimberley in central South Africa, where a population of about 30 colonies has been monitored since 1993.
Sociable Weavers are renowned for their massive shared nests. These highly conspicuous structures, the largest nest of any bird species in the world, may be more than a metre high, measure several metres across and weigh over a ton – and they may persist for decades. The nests are used throughout the year for roosting and breeding and consist of a communal thatch within which the individual, downward-pointing nest chambers are embedded.
Currently, I am analysing whether sociable weavers avoid inbreeding by comparing the relatedness of pairs with that expected under multiple null models of pairing behaviour. Preliminary results suggest that sociable weavers actively avoid mating with relatives despite high risk of inbreeding. Furthermore, I am investigating how sociable weavers avoid inbreeding by studying kin recognition mechanisms. Using acoustic analyses of contact call recordings, I am analysing whether contact calls of adults differ between individuals and social groups and, using playback experiments, whether adults recognise calls of relatives and group members.
Other current research includes:
- dominance structure and cooperation in sociable weavers
- phylogenetic analyses of ornamentation and breeding systems of penduline tits
- sexual selection, breeding systems and melanin-based ornamentation in Kentish plovers