Effects of breeder turnover and harvest on group composition and recruitment in a social carnivore. (3rd July 2017)

• Record Type: Journal Article
• Authors: Ausband, David E.; Mitchell, Michael S.; Waits, Lisette P.
• Editors: Prugh, Laura
• Is Part Of: Journal of animal ecology. Volume 86:Number 5(2017:Sep.)
• Page Start: 1094
• Page End: 1101
• Publication Date: 2017-07-03
• Subjects: breeder -- Canis lupus -- cooperative breeding -- grey wolves -- group size -- helping -- recruitment -- social carnivore; Animal ecology -- Periodicals; 591.7
• DOI: 10.1111/1365-2656.12707
• Languages: English
• ISSNs: 0021-8790

Abstract

Abstract: Breeder turnover can influence population growth in social carnivores through changes to group size, composition and recruitment. Studies that possess detailed group composition data that can provide insights about the effects of breeder turnover on groups have generally been conducted on species that are not subject to recurrent annual human harvest. We wanted to know how breeder turnover affects group composition and how harvest, in turn, affects breeder turnover in cooperatively breeding grey wolves ( Canis lupus Linnaeus 1758). We used noninvasive genetic sampling at wolf rendezvous sites to construct pedigrees and estimate recruitment in groups of wolves before and after harvest in Idaho, USA. Turnover of breeding females increased polygamy and potential recruits per group by providing breeding opportunities for subordinates although resultant group size was unaffected 1 year after the turnover. Breeder turnover had no effect on the number of nonbreeding helpers per group. After breeding male turnover, fewer female pups were recruited in the new males' litters. Harvest had no effect on the frequency of breeder turnover. We found that breeder turnover led to shifts in the reproductive hierarchies within groups and the resulting changes to group composition were quite variable and depended on the sex of the breeder lost. We hypothesize that nonbreeding females direct help away from non‐kin female pups to preserve future breeding opportunities for themselves. Breeder turnover had marked effects on the breeding opportunities of subordinates and the number and sex ratios of subsequent litters of pups. Seemingly subtle changes to groups, such as the loss of one individual, can greatly affect group composition, genetic content, and short‐term population growth when the individual lost is a breeder. Abstract : Breeder turnover can influence group size, composition and recruitment. Hypothetically, human harvest may further accelerate breeder turnover. The authors found breeder turnover led to shifts in group composition that were quite variable and depended on the sex of the breeder lost. However, harvest did not increase the frequency of breeder turnover.