Constraints and flexibility in mammalian social behaviour: introduction and synthesis

Abstract

This paper introduces a Theme Issue presenting the latest developments in research on the interplay between flexibility and constraint in social behaviour, using comparative datasets, long-term field studies and experimental data from both field and laboratory studies of mammals. We first explain our focus on mammals and outline the main components of their social systems, focusing on variation within- and among-species in numerous aspects of social organization, mating system and social structure. We then review the current state of primarily ultimate explanations of this diversity in social behaviour. We approach the question of how and why the balance between behavioural flexibility and continuity is achieved by discussing the genetic, developmental, ecological and social constraints on hypothetically unlimited behavioural flexibility. We introduce the other contributions to this Theme Issue against this background and conclude that constraints are often crucial to the evolution and expression of behavioural flexibility. In exploring these issues, the enduring relevance of Tinbergen's seminal paper ‘On aims and methods in ethology’, with its advocacy of an integrative, four-pronged approach to studying behaviour becomes apparent: an exceptionally fitting tribute on the 50th anniversary of its publication.

Socio-sexual and probable mating behavior of Cook Inlet beluga whales, Delphinapterus leucas, observed from an aircraft

“…The distribution, habitat use, and grouping behavior patterns of mammals have been linked with ecologi-cal parameters such as food and mate availability or distribution and predator avoidance (Davies et al, 2012;Kappeler et al, 2013). Both of our reported beluga whale sightings occurred in the same general area, suggesting importance of this area.…”

Competing pressures on populations: long-term dynamics of food availability, food quality, disease, stress and animal abundance

“…This begs the questions: is disease/parasitism offsetting the benefits of increased habitat-wide food (quantity and quality as indicated by the habitat-wide assessment), or is the population responding in compensatory ways to the increased risk of disease, possibly via behavioural flexibility (e.g. avoidance of infected individuals or increased clique formation within social networks) [90,92,93,95]? As the number of studies on different populations of the same species accumulate, there is increasing recognition that there can be considerable flexibility in behaviour and demographic structure, which presumably can influence the numeric response of a species to a given environmental change [96][97][98][99].…”

Intraspecific variation in social organization by genetic variation, developmental plasticity, social flexibility or entirely extrinsic factors

“…Presently, the phylogenetic approach to understanding the evolution of different social systems is flourishing [9][10][11], but it requires each species to be categorized correctly with regard to its social organization. However, apart from the standard categories (e.g.…”