Comparison of hair and DNA-based approaches in dietary analysis of free-ranging wolves (Canis lupus) in Alberta, Canada

Abstract

Dietary information of free-ranging animals is essential for understanding their ecology, conservation and management. Carnivore diet is most frequently estimated using morphological analysis of prey remains found in scats. However, genetic methods are becoming increasingly common and may identify prey parts that are unidentifiable with morphological methods (Symondson 2002). We developed an easy and accurate molecular approach to assess occurrence of prey species in the diet of free-living wolves (Canis lupus) and compared the results to analyses of prey hair in the same samples. The occurrence of DNA and hair remains for moose (Alces alces), woodland caribou (Rangifer tarandus caribou), deer (Odocoileus sp.), snowshoe hare (Lepus americanus) and American beaver (Castor canadensis) were compared in wolf scats from northeastern Alberta, Canada. Detection of any prey species was 1.34 times as likely with DNA analysis than with hair analysis. DNA analysis showed significantly higher occurrences of every prey species (p<0.05) except deer. These findings highlight the advantage of molecular dietary analysis in differentiating between taxonomically similar prey species and increased prey detection rates as compared to morphological analysis.