Efficient, Noninvasive Genetic Sampling for Monitoring Reintroduced Wolves

Abstract

Traditional methods of monitoring gray wolves (Canis lupus) are expensive and invasive and require extensive efforts to capture individual animals. Noninvasive genetic sampling (NGS) is an alternative method that can provide data to answer management questions and complement already‐existing methods. In a 2‐year study, we tested this approach for Idaho gray wolves in areas of known high and low wolf density. To focus sampling efforts across a large study area and increase our chances of detecting reproductive packs, we visited 964 areas with landscape characteristics similar to known wolf rendezvous sites. We collected scat or hair samples from 20% of sites and identified 122 wolves, using 8–9 microsatellite loci. We used the minimum count of wolves to accurately detect known differences in wolf density. Maximum likelihood and Bayesian single‐session population estimators performed similarly and accurately estimated the population size, compared with a radiotelemetry population estimate, in both years, and an average of 1.7 captures per individual were necessary for achieving accurate population estimates. Subsampling scenarios revealed that both scat and hair samples were important for achieving accurate population estimates, but visiting 75% and 50% of the sites still gave reasonable estimates and reduced costs. Our research provides managers with an efficient and accurate method for monitoring high‐density and low‐density wolf populations in remote areas.

Stable pack abundance and distribution in a harvested wolf population

“…We analyzed fecal samples at the Laboratory for Ecological, Evolutionary and Conservation Genetics at the University of Idaho, Moscow, USA, to identify individuals sampled each year. We followed DNA extraction and analysis protocols described by Stenglein et al (, ) and Stansbury et al (). We used a mitochondrial DNA species‐identification test to screen and remove non‐target species and low‐quality samples (De Barba et al , Stansbury et al ).…”

Evaluating genetic capture‐recapture using a chimpanzee population of known size

“…population size [Bellemain et al ], transects [Zhan et al , Arandjelovic et al ], visual count [Puechmaille and Petit ], tracking [Hájková et al ], camera‐traps [Janečka et al ], trapping sessions [Gerber and Parmenter ]). However, the use of such comparisons is limited if these other methods are themselves imprecise (Bellemain et al , Puechmaille and Petit , Stenglein et al , Gerber and Parmenter ).…”

A long-term population monitoring approach for a wide-ranging carnivore: Noninvasive genetic sampling of gray wolf rendezvous sites in Idaho, USA

“…The effectiveness of NGS for monitoring recolonizing gray wolf ( Canis lupus ) populations was first evaluated in Europe (Lucchini et al , Valière et al ). More recently, researchers have implemented NGS approaches to monitor the reintroduced wolf population in Idaho, USA (Ausband et al , Stenglein et al ). With the 2011 delisting of wolves in the northern Rocky Mountains (U.S.…”