The effect of relatedness and pack size on territory overlap in African wild dogs

Craig R Jackson,Rosemary J Groom,J Weldon Mcnutt,Neil R Jordan

doi:10.1186/s40462-017-0099-8

Abstract

BackgroundSpacing patterns mediate competitive interactions between conspecifics, ultimately increasing fitness. The degree of territorial overlap between neighbouring African wild dog (Lycaon pictus) packs varies greatly, yet the role of factors potentially affecting the degree of overlap, such as relatedness and pack size, remain unclear. We used movement data from 21 wild dog packs to calculate the extent of territory overlap (20 dyads).ResultsOn average, unrelated neighbouring packs had low levels of overlap restricted to the peripheral regions of their 95% utilisation kernels. Related neighbours had significantly greater levels of peripheral overlap. Only one unrelated dyad included overlap between 75%-75% kernels, but no 50%-50% kernels overlapped. However, eight of 12 related dyads overlapped between their respective 75% kernels and six between the frequented 50% kernels. Overlap between these more frequented kernels confers a heightened likelihood of encounter, as the mean utilisation intensity per unit area within the 50% kernels was 4.93 times greater than in the 95% kernels, and 2.34 times greater than in the 75% kernels. Related packs spent significantly more time in their 95% kernel overlap zones than did unrelated packs. Pack size appeared to have little effect on overlap between related dyads, yet among unrelated neighbours larger packs tended to overlap more onto smaller packs’ territories. However, the true effect is unclear given that the model’s confidence intervals overlapped zero.ConclusionsEvidence suggests that costly intraspecific aggression is greatly reduced between related packs. Consequently, the tendency for dispersing individuals to establish territories alongside relatives, where intensively utilised portions of ranges regularly overlap, may extend kin selection and inclusive fitness benefits from the intra-pack to inter-pack level. This natural spacing system can affect survival parameters and the carrying capacity of protected areas, having important management implications for intensively managed populations of this endangered species.

Highlights

Spacing patterns mediate competitive interactions between conspecifics, increasing fitness
Patterns of dispersal in which dispersers establish themselves in Jackson et al Movement Ecology (2017) 5:10 close proximity to their place of birth result in kin-clustering; neighbouring individuals or groups share certain home range boundaries with close relatives
The Zimbabwe population is located in the Savé Valley Conservancy (SVC) in south east Zimbabwe, north of the Gonarezhou National Park, and has been studied since 1996

Summary

Introduction

Spacing patterns mediate competitive interactions between conspecifics, increasing fitness. The spacing patterns of groups or individuals result from interactions between conspecifics and their environment and these patterns may vary within and between populations of the same species [25, 52]. Spacing mediates competitive interactions and is a mechanism that . Patterns of dispersal in which dispersers establish themselves in Jackson et al Movement Ecology (2017) 5:10 close proximity to their place of birth ( referred to as “budding”) result in kin-clustering; neighbouring individuals or groups share certain home range boundaries with close relatives. While studies of inclusive fitness have typically focused on cooperation among related individuals within a group, kin-clustered spatial population organisation provides a mechanism for the evolution of cooperative behaviour between groups [22]

Methods

Results

Discussion

Conclusion