I'm interested in the mechanisms and the evolution of cooperative behaviour
and in the cognitive capacities humans and other animals need to either act
cooperatively or to avoid costly conflicts.
Animal cognition
The differences in cognitive abilities between species might be strongly linked
to the challenges animals encounter in their natural and social environment.
Cleaner fish (Labroides dimidiatus) rely completely on the food they obtain
from the client fish that visit cleaner stations to get cleaned from their parasites.
However, besides removing the parasites from their clients tissue cleaners
appear to prefer to feed on their clients mucus they obtain when biting the
client fish. This results in a conflict of interests between cleaners and their
clients with regards to goods and services exchanged in interactions.
In current experiments I use a comparative approach to test the cognitive
capabilities of different species of wrasses in the context of cooperation from
an ecological perspective. To determine the relevance of ecology on cognition I
compare the performance of several fish species which differ in their degree of
cleaning behaviour in social- and non-social tasks.
Cooperative breeding
In the cooperatively breeding Lake Tanganyika cichlid Neolamprologus pulcher,
I investigated two main decisions of helpers: why they stay in the territory instead
of leaving to reproduce on their own, and why they help raising offspring of others.
I could show experimentally that ecological constraints, particularly the lack of
vacant sites suitable for independent breeding prevent helpers to disperse and
breed on their own. Further more I found evidence supporting the 'pay-to-stay
hypothesis' which proposes that, in order to be allowed to stay in the dominants
territory, subordinates pay a 'rent' by helping the dominants to raise their offspring.
Field observations and experiments suggest that helpers may strategically disperse
between groups which may lead to a biological market situation were helpers trade
for instance their ability to help for access to a high quality territory.
Primate behavioural ecology
In the Tai National Park in Ivory Coast I studied the link between feeding ecology
and the social organisation in the terrestrial sooty mangabeys
(Cercocebus torquatus atys). The results of this study suggest that mangabeys
react to changes in the distribution of food in time and space by adjusting their
group size.
