Density regulation in small isolated populations
Evidence for the way density dependence works in natural populations is extremely rare. My doctorate research has improved our understanding of how competition between individuals can affect population regulation (J Anim Ecol 2006). Furthermore, in collaboration with Nature Seychelles, I had the unique possibility to be involved in translocations of endangered Seychelles warblers to previously uninhabited islands and follow the populations during the process of saturation. The empirical data from these translocations combined with population dynamical models showed that population growth is constrained in a density-dependent manner by competition for food (Ecology 2009). Furthermore, by creating multiple simultaneous breeder vacancies we were able to determine the relative importance of parent presence, age and sex differences in dispersal, territory acquisition and mate choice (Beh Ecol 2007, 2009 & 2016, J Avian Biol 2008, Behav 2010). The introduction of these highly threatened birds to new islands has strongly improved the species’ chances of avoiding extinction, making it one of the most successful cases of combining fundamental research with applied conservation biology.
Evolutionary drivers of cooperative breeding
During my MSc with Prof. Michael Taborsky and Dr. Dik Heg I studied cooperatively breeding cichlids in Lake Tanganyika, Zambia. Many of the Lamprologine cichilds from this lake delay dispersal to help rear the next brood. We experimentally investigated the evolutionary drivers of cooperative breeding and the role of helpers and found that that predator presence is a constraint for independent breeding and prevents dispersal. The presence of non-breeding helpers is thus really helpful as they increase the chances of successful reproduction.