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Evolution of social systems

Species vary significantly in terms of the association patterns of individuals, on who interacts with whom within a social unit and how, on who mates with whom, and on who cares for dependent offspring and to what extent.
We study this diversity of social systems on three levels: describing component patterns through long-term demographic and behavioral data, examining ultimate and proximate determinants of the individual components, and the consequences of individual social factors for individual health and fitness.
By comparing sympatric species in Madagascar and Peru, we obtain additional insight into the social evolution and complexity of primate (and predator) societies.

Current Projects

Optimal group size in Verreaux’s Sifakas
(Katja Rudolph)

Association patterns in grey mouse lemurs
(Lluis Socias Martinez)

Social relationships and the microbiome of red-fronted lemurs
(Tatiana Murillo Corrales)

Sociality, stress and health in red-fronted lemurs
(Charlotte Defolie)

Social relations, social organization and genetic mating system of the coppery red titi monkey, Plecturocebus cupreus
(Sofya Dolotovskaya, in cooperation with Christian Roos, Primate Genetics, DPZ)


Dolotovskaya S, Flores Amasifuen C, Haas CE, Nummert F, Heymann EW (2019) Active anti-predator behaviour of red titi monkeys (Plecturocebus cupreus). Primate Biology 6: 59-64

Dolotovskaya S, Heymann EW (2020) Do less or eat more: strategies to cope with costs of parental care in a pair-living monkey. Animal Behaviour (in press)

Dolotovskaya S, Walker S, Heymann EW (2020) What makes a pair bond in a Neotropical primate: female and male contributions. Royal Society Open Science 7: 191489


Mating system and offspring care in black-fronted tamarins
(Darja Slana)

Evolution of pair-living in primates
(Peter Kappeler; in cooperation with L. Pozzi, UTSA)


Kappeler PM, Pozzi L (2019) Evolutionary transitions toward pair living in nonhuman primates as stepping stones toward more complex societies. Science Advances 5: eaay1276


Consequences of adult sex ratios on social behavior
(Peter Kappeler)

Evolution of social complexity
(Peter Kappeler)


Kappeler PM, Clutton-Brock T, Shultz S, Lukas D (2019) Social complexity: patterns, processes and evolution. Behavioral Ecology and Sociobiololgy 73: 5.



Behavioral Biology

Evolution of social systems





Population ecology