Consequences of within- and between-group conflict in dwarf mongooses

Abstract

Conflict is rife in the natural world and is widely recognised as a powerful selective pressure in social evolution. For group-living species, conflict over valuable resources arises between members of the same group (within-group conflict) and with conspecific outsiders (between-group conflict; also called outgroup or intergroup conflict). Traditionally, research on nonhuman animals has focused on the contests that arise within- and between groups; in the former case, there have also been extensive studies of the immediate consequences of aggressive interactions. By contrast, relatively little is known about the short-term consequences of between-group conflict and, for both conflict types, there has been little empirical consideration of the longer-term consequences. In this thesis, I combine detailed behavioural observations, field experiments and long-term life-history data to investigate the consequences of within- and between-group conflict over different timeframes, using wild dwarf mongooses (Helogale parvula) as a model system. First, I show that unresolved within-group conflict can have cumulative behavioural effects and present evidence for delayed post-contest management by bystanders (Chapter Two). In the remaining data chapters, I focus on between-group conflict. I find consequences of outgroup threats in the short-term (in the hour after exposure) for within-group affiliation, foraging and sentinel behaviour (Chapter Three). I then demonstrate that such threats can also influence behaviour over longer timeframes, with carryover effects on affiliation into the following day, and cumulative effects on affiliation, foraging, sentinel and territorial behaviour, as well as body mass, after repeated outgroup encounters across a week. Lastly, I examine the reproductive consequences of between-group conflict and, unexpectedly, find a positive relationship with pup survival. By demonstrating an array of effects over timeframes rarely addressed previously, I help shed light on the more-lasting consequences of social conflict which is important for a greater understanding of how it shapes the lives of group-living species.

Date of Award	23 Mar 2021
Original language	English
Awarding Institution	University of Bristol
Supervisor	Andrew N Radford (Supervisor) & Innes C Cuthill (Supervisor)