Behavioural Ecology
Universität Bielefeld > Faculty of Biology > Animal Behaviour > Behavioural Ecology

Behavioural Ecology

Prof. Dr. Fritz Trillmich
Behavioural Ecology


We investigate life history- and reproductive strategies.

Sex, age at maturity, litter size, offspring size at birth and length of reproductive cycles count among important life history features. Reproduction represents one of the most important aspects in the life history of an individual and parental care represents one important component of fitness. One focus of our investigations concerns allocation decisions and trade-offs in parental care. As parental care is a valuable and limited resource, conflict about parental care is expected. Our investigations are carried out using guinea pigs, cavies and sea lions.

We focus on:

  • Plasticity of behaviour and physiology
  • Allocation decisions
  • costs of reproduction and brood care
  • parent-offspring conflicts
  • reproductive strategies of males and females
  • effects of an unpredictable environment (global warming) on population dynamics


Research interests

Ontogeny of behavioural phenotype in cavies

Life history strategies (of cavies)

  • age at maturity
  • costs of reproduction
  • consequences of litter size
  • influence of food on reproduction

Demography and reproductive strategy (of sea lions)
Parent-offspring conflict


Research projects

Phenotypic Plasticity

Research unit:
"Reduction of phenotypic plasticity in behaviour by early experience: functional consequences of an adaptive mechanism?"
Research unit main page
Project page

Sea Lion Project Galápagos

The consequences of life-history decisions of individuals on reproductive success have only rarely been documented in sufficient detail to allow understanding phenomena at the level of population dynamics. This study proposes to analyse the consequences of life history decisions of male and female individuals under environmental uncertainty and to model the demographic consequences of individual decisions in a large mammal, the Galápagos sea lion (Zalophus wollebaeki).


Prof. Dr. Fritz Trillmich

University of Bielefeld
Department of Animal Behaviour
PO Box 10 01 31
33501 Bielefeld