Exploring the diet of arctic wolves (Canis lupus arctos) at their northern range limit

Abstract

The grey wolf (Canis lupus L., 1758) is one of the most widespread large carnivores on Earth, and occurs throughout the Arctic. Although wolf diet is well studied, we have scant information from high Arctic areas. Global warming is expected to increase the importance of predation for ecosystem regulation in Arctic environments. To improve our ability to manage Arctic ecosystems under environmental change, we therefore need knowledge about Arctic predator diets. Prey remains in 54 wolf scats collected at three sites in the high Arctic region surrounding the Hall Basin (Judge Daly Promontory, Ellesmere Island, Washington Land and Hall Land, both northwest Greenland), pointed to a dietary importance of Arctic hare (Lepus arcticus (Ross, 1819), 55% frequency of occurrence) and muskoxen (Ovibos moschatus (Zimmerman, 1780), 39% frequency of occurrence), although we observed diet variation among the sites. A literature compilation suggested that Arctic wolves preferentially feed on caribou and muskoxen, but can sustain themselves on Arctic hares and lemmings in areas with limited or no ungulate populations. We suggest that climate change may alter the dynamics among wolves, Arctic hare, muskoxen, and caribou, and we encourage further studies evaluating how climate change influence predator-prey interactions in high Arctic environments.

The Dire Consequences of Specializing on Large Herbivores

“…Arctic wolf populations can potentially survive on a hare and lemming diet, while other wolf populations survive on mainly Odocoileus spp. (Murie 1944;Stebbler 1944;Cowan 1947;Mech 1970;Dalerum et al 2018). These are much smaller and faster prey than what made up the dire wolf diet.…”

“…Extant grey wolves regularly feed on prey from as large as moose (Alces alces) to as small as beaver (Castor canadensis), arctic hares (Lepus arcticus), and lemmings (Dicrostonyx groenlandicus) (Fox-Dobbs et al 2007;Mech 2007;Dalerum et al 2018). Fox-Dobbs et al's (2007) isotope analysis results for the diets of modern grey wolves differ by location.…”

“…Szepanski et al (1999) did a similar study of Alaskan wolves, finding that coastal wolves had a range of terrestrial and marine prey while wolves in the interior of Alaska mainly preyed on caribou and moose. Dalerum et al (2018) studied the diet of arctic wolves (Canis lupus arctos) at their most northern ranges in Nunavut and Greenland, showing arctic hares and muskoxen (Ovibos moschatus) are their primary food sources. They suggested that wolves can survive in the absence of ungulates if hare and lemming are present since it was the primary food source in all study regions and found in 100% of scat samples for Washington Land wolves (Dalerum et al 2018).…”

“…Dalerum et al (2018) studied the diet of arctic wolves (Canis lupus arctos) at their most northern ranges in Nunavut and Greenland, showing arctic hares and muskoxen (Ovibos moschatus) are their primary food sources. They suggested that wolves can survive in the absence of ungulates if hare and lemming are present since it was the primary food source in all study regions and found in 100% of scat samples for Washington Land wolves (Dalerum et al 2018). Canis lupus can supplement and possibly survive on smaller prey species, where there is no evidence to suggest Canis dirus did.…”

Long-distance, synchronized and directional fall movements suggest migration in Arctic hares on Ellesmere Island (Canada)

“…The Arctic hare ( Lepus arcticus ) is one of the largest lagomorphs and an important component of the polar desert food web 23 . It is omnipresent in the diet of multiple predators, such as Arctic wolves ( Canis lupus arctos ) 24 , 25 and Arctic foxes ( Vulpes lagopus ) 23 . Arctic hares are also generalist herbivores that are active year-round and can reach high densities 23 .…”