Characteristics of beaver kill sites from GPS-collared wolves in Voyageurs National Park in 2015.

<p>Characteristics of beaver kill sites from GPS-collared wolves in Voyageurs National Park in 2015.</p

Where and How Wolves (<i>Canis lupus</i>) Kill Beavers (<i>Castor canadensis</i>)

<div><p>Beavers (<i>Castor canadensis</i>) can be a significant prey item for wolves (<i>Canis lupus</i>) in boreal ecosystems due to their abundance and vulnerability on land. How wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. We inferred how wolves hunt beavers by identifying kill sites using clusters of locations from GPS-collared wolves in Voyageurs National Park, Minnesota. We identified 22 sites where wolves from 4 different packs killed beavers. We classified these kill sites into 8 categories based on the beaver-habitat type near which each kill occurred. Seasonal variation existed in types of kill sites as 7 of 12 (58%) kills in the spring occurred at sites below dams and on shorelines, and 8 of 10 (80%) kills in the fall occurred near feeding trails and canals. From these kill sites we deduced that the typical hunting strategy has 3 components: 1) waiting near areas of high beaver use (e.g., feeding trails) until a beaver comes near shore or ashore, 2) using vegetation, the dam, or other habitat features for concealment, and 3) immediately attacking the beaver, or ambushing the beaver by cutting off access to water. By identifying kill sites and inferring hunting behavior we have provided the most complete description available of how and where wolves hunt and kill beavers.</p></div

The 95% adaptive kernel home ranges of the 4 wolf packs studied in and around Voyageurs National Park (VNP), Minnesota, USA in 2015.

<p>The 95% adaptive kernel home ranges of the 4 wolf packs studied in and around Voyageurs National Park (VNP), Minnesota, USA in 2015.</p

Where and How Wolves (<i>Canis lupus</i>) Kill Beavers (<i>Castor canadensis</i>) - Fig 2

<p><b>Examples of evidence found at beaver kill sites (A,B,C), and of wolf behavior when in active beaver habitats (D) in Voyageurs National Park 2015.</b> A) Matted vegetation at kill sites provided important information about how wolves killed beavers. B) Co-author Homkes stands at Beaver Kill Site 13 <10 m below an active beaver dam. C) Beaver Kill Site 18 on a small point <5 m from the active dam where a wolf, based on the trampled vegetation, presumably pulled a kit beaver out of the water and consumed it. D) A wolf bed (lower left corner) found when examining clusters of GPS-locations in the spring. The wolf bedded for ≥4 hr next to this active beaver lodge without making a kill.</p