Abstract:
The wide diversity in social structures is thought to be the result of selection for individual
behavioural strategies and inter-individual interaction patterns that maximise fitness under
different environments (van Schaik and van Hoff 1983, Kappeler and van Schaik 2002).
Recently, several simulation studies have attempted to generate social structure through
simple and general models (Ilany and Akçay 2015, Rios and Kraenkel 2017, Cantor and
Farine 2018) but have not simultaneously examined the effect of resource conditions on social
structure. Here, I describe a simulation study that I conducted to examine whether a social
structure emerged when individuals associated with others to different extents based on
familiarity, in a habitat with limited and patchy ephemeral resources that either varied in
quantity or stayed constant over time. Additionally, I also examined the sampling conditions
under which a social structure would be wrongly inferred even when associations were
random. Thus, the first question dealt with possible social structure emerging due to simple
rules, whereas the second dealt with possible apparent social structure when there was none.
Results from my simulations showed that when resources were limited and ephemeral, social
structure, characterised by low network density and high modularity, emerged only when all
the associations were with familiar individuals and there was no temporal variation in
resources. When there was temporal variation in resources, this structure broke down even
when many associations were with familiar individuals, becoming similar to that obtained for
random association. When associations were only with familiar individuals, social structure
could also emerge if resources were not limited. Simulations to address the second question
showed that low sampling intensity and a small sampling period could lead to apparent social
structure (with high modularity and low density) even in a population with random
associations. Moderately intense sampling conducted over long periods of time was essential
to detect social structure close to the true structure.
