Disputas: Philippe Sunil Sabarros

Prøveforelesning

Bedømmelseskomité

Professor Tim Blackburn, Institute of Zoology, Zoological Society of London, Regent's Park, London, United Kingdom
Dr. Per Fauchald, NINA Tromsø, Polarmiljøsenteret, Tromsø, Norway
Førsteamanuensis Anne Krag Brysting, CEES, Dept. of Biology, University of Oslo, Norway

Leder av disputas:  Professor Trond Schumacher

Veileder:  Prof. Nils Chr. Stenseth, Department of Biology

Sammendrag

Seabirds are threatened by human activities when they deteriorate their environment (habitat and resource). In South Africa, overfishing and environmental change have induced a shift in the distribution of seabird-prey (sardine and anchovy). I investigated whether seabird populations of African penguins, Cape gannets and Cape cormorants have been affected by this shift or not. Eventually, local conditions in resource availability directly control the number of birds that breed every year – with differences between species – and explain the apparent decline of populations in the region deprived of fish and the rise in the region where the fish moved towards. To further understand large-scale patterns in seabird populations it is necessary to develop insight in the respective fields of study of physiology, behaviour and population ecology, and to reconcile these levels. This is in this line of research that I pursued my work at CEES (Oslo, Norway). In order to understand the crucial process that is the acquisition of food, I analysed patterns in prey distribution and individual seabird movements in relation to physical structures of the oceans such as fronts. I evidenced that frontal structures are predictable areas where to find prey and that seabirds like Cape gannets adjust their foraging strategies to such structures in order to optimize their foraging success. The work I carried out underlines the importance of the spatial dimension in the relationships between seabirds and their prey, and highlights the importance of oceanographic features as catalysts of seabird-prey interactions.

Kontaktperson

For mer informasjon, kontakt Gry Slettner Windsland.