Wolf Predation: Where and How Wolves Kill Beavers, and Confronting the Biases in Scat-Based Diet Studies

<p>Beavers can be a significant prey item for wolves in boreal systems but how wolves hunt beavers is largely unknown. I inferred how wolves hunt beavers by identifying 22 kill sites using clusters of locations from GPS-collared wolves in Voyageurs National Park, Minnesota. Where wolves killed beavers varied seasonally with the majority (58%) of kills in the spring occurring below dams and on shorelines while the majority (80%) of kills in the fall were near feeding trails and canals. I deduced that the typical hunting strategy has 3 components: 1) waiting near areas of high beaver use until a beaver comes near or on shore, 2) using concealment, and 3) immediately attacking the beaver, or ambushing the beaver by cutting off access to water.</p> <p> Wolf diet is commonly estimated via scat analysis, and several studies have concluded that scat collection method can bias diet estimates. I tested whether different scat collection methods yield different diet estimates after accounting for other biases. I collected scats (2,406 scats) monthly from 4 packs via 3 scat collection methods in the Voyageurs National Park, Minnesota area, during April 2015–October 2015. Scat collection method did not yield different diet estimates but I did document temporal, inter-pack, and age class variability in diet estimates. To better estimate wolf population diets, researchers should collect ≥10–20 adult scats/pack/month from homesites and/or opportunistically from packs that are representative of the population of interest. </p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2016

Author dc:creator

• Gable, Thomas

Contributors dc:contributor

• John Bruggink

• Canis lupus
• Castor canadensis
• Wolf Predation
• Kill Sites
• Voyageurs National Park
• Diet Estimates
• Zoology

Repository record dc:identifier

https://commons.nmu.edu/theses/122

OAI identifier oai:identifier

oai:commons.nmu.edu:theses-1129