From female choice to social structure: Modeling harem formation in camelids

TL;DR

This paper presents an individual-based stochastic model of camelid female social behavior, revealing how individual strategies influence population structure and fitness, modulated by environmental and demographic factors.

Contribution

It introduces a novel modeling approach to understand the emergence of social structures in camelids driven by individual behavioral strategies.

Findings

Individual female behavior influences group size and fitness distribution.

Population density, sex ratio, and habitat heterogeneity modulate social outcomes.

Emergent properties arise from the interaction of behavioral and environmental factors.

Abstract

Herbivorous wild species constantly strive to optimize the trade-off between energy and nutrient intake and predation risk during foraging. This has led to the selection of several evolutionary traits -- such as diet, habitat selection, and behavior -- which are simultaneously shaped by the spatio-temporal variability of the habitat. Among camelid species, polygyny is a prevalent behavioral strategy that encompasses both mating and foraging activities. This group-level behavior has multiple interacting dimensions, contributing to an interesting ecological and evolutionary complexity. We developed an individual-based stochastic model in which camelid females transition between different familial groups in response to their environmental conditions, aiming to maximize individual fitness. Our results indicate that the behavioral strategy of individual females can shape, by itself, emergent population-level properties, including group size and fitness distribution. Furthermore, these properties are modulated, in a non-additive manner, by other factors such as population density, sex ratio and system heterogeneity.