Investment strategies of parents and helpers in a cooperatively breeding bird

Supervisor: Professor Ben Hatchwell
Co-supervisor: Dr Jim Briskie (University of Canterbury, New Zealand)

Keywords: kin selection; cooperative breeding; parental care; sexual dimorphism; Acanthisitta chloris

The evolution of helping behaviour in cooperative breeders is problematic because individuals are expected to try to increase their own fitness, rather than that of conspecifics. One solution to this paradox is that helping is the product of kin selection, whereby help is directed towards kin and enhances helpers’ inclusive fitness. However, even within kin groups there is conflict among parents and helpers over how much each should invest in a brood. The outcome of this conflict is extremely variable across species, resulting in diverse investment strategies by parents and helpers. The aim of this studentship is to use field observations, experiments, and molecular genetic analyses of the rifleman Acanthisitta chloris (a New Zealand endemic) to test hypotheses concerning the investment strategies of parents and helpers in relation to kinship and offspring sex. In this species, breeding pairs may be assisted in rearing their young by helpers who are either offspring reared earlier in the same season, or adults that may be either breeders or non-breeders. Previous work shows that helpers are typically related to the brood that they help to rear, and that there is marked sexual size dimorphism at both nestling and adult stages. Therefore, this unusual cooperative breeding system provides an ideal opportunity to test hypotheses in this field. The student will join the large Evolution and Behaviour research group in Sheffield, and fieldwork will be conducted on a marked, nestbox population of rifleman in collaboration with colleagues at the University of Canterbury, New Zealand.

For more information about how to apply, or the application process, please contact Mrs S Carter (s.a.carter@sheffield.ac.uk).

To apply now go to: http://www.sheffield.ac.uk/postgraduate/online