Samenvatting

There are currently about 2220 individual ring-tailed lemurs (Lemur catta) living in Madagascar, which has caused the species to be red-listed as critically endangered since 2018. To prevent the species from going extinct conservation strategies have been established. Because ring-tailed lemurs have a complex social structure, it is extremely hard to start a breeding program, which involves adding a new individual to an already existing group. This makes it more difficult to keep a stable group of ring-tailed lemurs in captivity while participating in a breeding program to conserve the species. AquaZoo is a Dutch zoo that, as part of a breeding program, houses a group of ring-tailed lemurs where dominance and aggression play a major role. They want to add two white belted black-and-white ruffed lemurs (Varecia variegata subcincta) to look at what happens at the still unknown social structure of the group, after adding new individuals. The goal of the research is to increase welfare by having more insight into the structure. Research shows that within groups of ring-tailed lemurs, where aggression and dominance play a role, this is reduced when another species is added. The main question of this research is as follows: "What is the effect of adding white belted black-and-white ruffed lemurs on the social structure of a group of ring-tailed lemurs?”.