Where and How Wolves (Canis lupus) Kill Beavers (Castor canadensis)

Abstract

Beavers (Castor canadensis) can be a significant prey item for wolves (Canis lupus) 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.

Association of moose parturition and post‐parturition habitat with calf survival

“…Movement through thick forested cover may be even more dangerous. Wolves may use vegetation to ambush prey in a variety of landscapes and seasons (Kunkel and Pletscher , Gable et al ). Wolf movement rate explained more variation in kill rates of moose in winter (Vander Vennen et al ), yet protective cover can aid prey in avoiding detection (Kunkel and Pletscher ).…”

Do wolves ambush beavers? Video evidence for higher‐order hunting strategies

“…When actively hunting beavers, wolves appear to wait concealed near areas of high beaver activity and ambush beavers once they come nearby (Gable et al. ). In Wisconsin, a wolf was observed successfully killing a beaver using this strategy (R. Schultz, personal communication ).…”

“…Indeed, the fact that wolves will wait near areas of high beaver activity for hours to hunt beavers implies this is the case (Gable et al. ). Such a strategy requires prior knowledge of beaver behavior which is either learned from observing other wolves hunting beavers or through individual encounters with beavers.…”

“…This indirect approach to understand how wolves hunt beavers was necessary because no documented observations of wolves killing beavers exist, despite the thousands of hours of wolf observations that have occurred around the world (Gable et al. ). Herein, we describe the first observation of a gray wolf killing a beaver.…”

Berry Important? Wolf Provisions Pups with Berries in Northern Minnesota

“…Wolves in the GVE primarily preyed upon adult and neonatal white‐tailed deer ( Odocoileus virginianus ; density = 2–4 deer/km 2 ; Gable et al 2018 a ) and beavers ( Castor canadensis ; density = ~1 colony/km 2 ; Gable et al 2018 a ). Wolf densities during summer were 4–6 wolves/100 km 2 (Gable et al 2016). See Gable et al (2016) for additional details about the study area.…”