Kay Horlacher

Different forms of cooperation are widespread in animals. In females, alliances are usually formed for foraging purposes or against predation. In males on the other hand, alliances may be formed to consort females. This is harder to explain, because mating success is an indivisible resource.

Male bottlenose dolphins in Shark Bay, Western Australia, have, apart from humans, the most complex social structure, with three levels of alliances. The main unit consists of 6 – 14 individuals, called a 2^nd-order alliance. Males in 2^nd-order alliances associate in variable groups of two to three animals, called 1^st -order alliances, which consort females for mating.

The aim of my master thesis is to identify factors affecting paternity success in bottlenose dolphins. I will be looking at several factors that might influence male reproductive success, such as consortship rates, body size (measured using a laser photogrammetry method), age, and home range size.