Grad Publication: Carolyn Shores takes a very close look at what wolves eat
As a BioGrad, Carolyn Shores worked in Sam Wasser's lab, AKA the UW Center for Conservation Biology, finding new and better ways to look at wolf poop! Carolyn's work, co-authored by Samrat Mondol (former Post-doc, now at the Wildlife Institute of India) and Sam Wasser, recently appeared in Conservation Genetics Resources. Carolyn is continuing her research on the effects of predators in the Predator Ecology Lab in the UW School of Environmental and Forest Sciences. Here she describes what the recent study was all about.
|Adult gray wolf traveling through snow as seen |
through sight scope. Photo: Carolyn Shores
Given how the diet of large carnivores defines their interaction with humans, it is essential for their conservation and management that we understand their dietary ecology. In a paper recently published in Conservation Genetics Resources with my co-authors Drs. Samrat Mondol and Samuel Wasser, we developed a molecular method to study the diet of wild wolves (Canis lupus) in northeastern Alberta, Canada. This is the first time genetic methods have been used to study the diet of wild wolves.
|Pack of wild gray wolves (Canis lupus). Photo: Shane White|
|Wolf scat samples were collected by the hard-|
working Conservation Canine Crew during
the winter in northeaster Alberta. Here,
Orienteer Nick Bromen collects a scat sample
while doghandler Canyon rewards CK9 Chester
by playing fetch! Photo: Jennifer Hartman
We found that DNA methods detected significantly (p<0.01) more prey than morphological methods overall and for every prey species except deer. The difference in detection rates with DNA was greatest (8.75 times higher) for moose. This significant difference in prey composition between the two methods could lead to very different management of wolf populations. Two of our prey species, deer and caribou, had strikingly similar hair cell patterns which made them difficult to differentiate with morphological analysis if color had been leached from the hair. With DNA analysis, the issue of differentiating similar taxa was eliminated. Deer was the dominant prey under both methods, making up 43% of the diet using DNA methods. Under DNA analysis, moose made up 26% of the wolf diet, while caribou was present in only 16.2% of wolf scats. Snowshoe hare and beaver both made up less than 10% of prey species.
Our results contribute to previous research that suggests a significant shift in the prey of wolves in the boreal forest of the Canadian oil sands. In the mid-1990’s, wolves ate primarily moose in northern Alberta, and deer made up only a tenth of their diet. However, in the past decade, deer have become the primary prey of wolves, and aerial ungulate surveys confirm a 17.5 fold increase in the deer population. This could be due to a combination of the destruction of older boreal forest by industry and climate change, which has allowed deer to expand north outside of their normal range. The increase in deer may present already threatened caribou with a novel competitor, not to mention the influx of disease vectors that could jump to caribou.
|Woodland caribou in northeaster Alberta on a seismic line cut through the |
boreal forest to test for the presence of oil. Photo: Jennifer Hartman
The full citation for the article is: Shores, C; S Mondol; S Wasser (2015). Comparison of DNA and hair-based approaches to dietary analysis of free-ranging wolves (Canis lupus). Conservation Genetics Resources. 7(4): 871-878.
The direct link to the article is found here (paywall). You can request an electronic reprint from Carolyn through her ResearchGate profile.
If you enjoyed reading about what we can learn from animal poop, you might also want to check out Jen Day's post on hunting jaguar scat.