Socially stable territories: the negotiation of space by interacting foragers.
This article presents a theory of territoriality that integrates optimal foraging and conflict resolution through negotiation. Using a spatially explicit model of a sit-and-wait forager, we show that when resources are scarce, there is a conflict between foragers: there is not enough space for all individuals to have optimal home ranges. We propose that a division of space that solves this conflict over resources is the outcome of a negotiation between foragers. We name this outcome the socially stable territories (SST). Using game theory we show that in a homogenous patch occupied by two interacting foragers, both individuals receive identical energy yields at the socially stable territories; that is, there is economic equity. Economic inequity can arise in a heterogeneous patch or from asymmetries in fighting abilities between the foragers. Opportunity costs play a role in reducing economic inequity. When the asymmetry in fighting abilities is very large, a negotiated division of space is not possible and the forager with lowest fighting ability may be evicted from the habitat patch. A comparison between territories and overlapping home ranges shows that energy yields from territories are generally higher. We discuss why there are instances in which individuals nevertheless overlap home ranges.
Pereira
Henrique M
HM
Department of Biological Sciences, Stanford University, Stanford, California 94305, USA. hpereira@stanfordalumni.org
Bergman
Aviv
A
Roughgarden
Joan
J
D000818:Animals; D003299:Cooperative Behavior; D003365:Costs and Cost Analysis; D004734:Energy Metabolism; D004777:Environment; D005716:Game Theory; D008954:Models, Biological; D012919:Social Behavior; D013731:Territoriality