Early environment and the development of social behaviours in the Trinidadian guppy, Poecilia reticulata

One of the many advantages of group living is the swift transfer of information between group members. Social learning – learning from others – offers a quick and economical way to acquire information about the local environment and is considered adaptive under a wide range of circumstances. However, social information can be unreliable or quickly become outdated in rapidly changing environments. Thus flexibility in the utilization of social learning, depending on the associated costs and benefits, would be expected to be advantageous in most situations. Early environment plays a major role in shaping the morphological, physiological or behavioural phenotype of an animal, and conditions and experiences during early life can potentially prepare (or program) a developing individual for the environment it will encounter when adult. In this project we examined whether social behaviours such as grouping and social learning could be influenced by early life conditions and to what extent. For this purpose, we used two different strains of the guppy (domestic and wild-origin), Poecilia reticulata, a popular study system in behavioural and evolutionary ecology with well-described social behaviour. Overall, we found evidence for consistency and heritability in grouping behaviour, but although grouping tendencies were (to some extent) correlated with social learning propensities, we found no evidence for consistency and heritability in social learning. Furthermore, we saw that early environmental conditions and experiences play a major role in shaping the behavioural phenotype of an individual. We found that both cues about the value of social information and context cues like predation risk and population density in early life, can influence an individual’s reliance on social information later in life. Moreover, as males and females differ significantly in their strategies to maximise fitness and survival, these early life cues can affect the behaviour of the two sexes in different ways.