Identifying gray wolf packs and dispersers using noninvasive genetic samples

Abstract

Many animals, including gray wolves (Canis lupus), live in social groups. Genetic techniques can help reveal the structure and composition of social groups, providing valuable information about group and population dynamics. We evaluated the effectiveness of using noninvasive genetic sampling (NGS) of fecal and hair samples at wolf rendezvous sites combined with spatial and genetic assignment criteria for assigning individuals to packs, detecting dispersers and lone wolves, determining the number of packs in an area, and obtaining group metrics. We applied this approach in 4 study areas covering 13,182 km2 in Idaho, USA while concurrently monitoring wolves using telemetry techniques. We assigned pack affiliation to 78–97% of individuals across study areas and identified 12 potential dispersers. We detected a successful gene flow event by reconstructing a breeding male's genotype and tracing it back to a pack of origin using genetic assignment techniques. Average pack size was consistent between our NGS- and telemetry-based counts (x¯ = 10 for both), and both methods detected similar age composition within groups (31% pups and 69% adults for NGS and 33% pups and 67% adults for telemetry). Our NGS approach has the advantage of providing pack metrics including sex ratio, inferred breeders, and intra-pack relatedness that telemetry and observational techniques alone cannot. This NGS field sampling strategy combined with our pack assignment method was successful and provides an approach for characterizing functional social groups in the absence of previously acquired NGS, telemetry, or other observational data that may not be available when sampling new areas. © 2016 The Wildlife Society.