Combining Harvest and Genetics to Estimate Reproduction in Wolves. Issue 3 (9th January 2020)

• Record Type: Journal Article
• Authors: Clendenin, Heather R.; Adams, Jennifer R.; Ausband, David E.; Hayden, James A.; Hohenlohe, Paul A.; Waits, Lisette P.
• Is Part Of: Journal of wildlife management. Volume 84:Issue 3(2020)
• Page Start: 492
• Page End: 504
• Publication Date: 2020-01-09
• Subjects: Canis lupus -- genetic monitoring -- harvest -- reproduction -- sibship reconstruction -- western United States; Wildlife management -- Periodicals; Zoology -- Periodicals; 333.954
• DOI: 10.1002/jwmg.21820
• Languages: English
• ISSNs: 0022-541X

Abstract

Abstract : Genetic reconstruction of sibling groups from harvest samples is an efficient, reliable way to estimate a minimum count of reproductive packs of wolves using an opportunistic source of samples. Application of this method to other systems will be affected by background population knowledge, marker number, allelic richness, and heterozygosity of the markers used. ABSTRACT: Parameters of reproductive success are important to the management of wildlife populations. Genetic monitoring can be an effective approach for acquiring this important demographic information when traditional methods are unsuccessful, inefficient, or too expensive. This study demonstrates a novel application of genetic data opportunistically collected from harvested game to estimate a minimum annual count of breeding packs of gray wolves ( Canis lupus ) and to provide a coarse index of harvest vulnerability of young of the year (YOY) across packs. We used 18 microsatellite loci to genotype 98 gray wolf YOY from 2014 and 105 from 2015 harvested in Idaho, USA. Using this genotype data, we reconstructed sibling groups for each cohort using the program COLONY and treated full‐sibling litters as proxies for unique packs. In addition to evaluating our marker panel using simulations, we assessed the accuracy of empirical relationship assignments by adding YOY of known relationship from long‐term study packs to the dataset (27 individuals from 2014 and 61 from 2015) and tracking correctly reconstructed relationships. We varied COLONY input parameters to evaluate the power of relationship assignments under conditions that may be encountered when working with empirical data. We also compared COLONY's estimates of effective number of breeders based on sibship frequency to estimates based on a commonly used linkage‐disequilibrium method. All COLONY runs for both cohorts correctly identified the known sibling relationships. Among the other individuals, changes in the geographic clustering of putative siblings, probabilities of inclusion and exclusion for reconstructed sibling groups, and consistency of relationship assignments across COLONY runs suggested that marker number had a larger effect on accuracy than access to population‐level genetic data. Our estimates of breeding packs subjected to harvest within the state (52 for 2014 and 63 for 2015) differed from estimates reported by Idaho Department of Fish and Game by ≤6 for both years. Among packs that had pups harvested, most packs had 1–2 YOY harvested, whereas other packs had as many as 5 YOY harvested. All estimates of the number of effective breeders had overlapping confidence intervals regardless of method, though sibship frequency‐based estimates had larger confidence intervals than estimates using the linkage disequilibrium method. Our study shows that sibling relationships can be accurately and reliably reconstructed from harvested gray wolves, and demonstrates a valuable new use of samples collected through harvest. © 2020 The Wildlife Society.