Ecology of the Arctic and Red Fox in the Greater Wapusk Ecosystem
Ryan Brook and Murray Gillespie*
Arctic fox pup chewing goose leg bone © M. Gillespie
Arctic fox in winter © Parks Canada
In Wapusk National Park (NP) and the surrounding ecosystem, it is not uncommon to see an arctic fox or a red fox in any month of the year busily searching for its next meal. Diets of the two species are very similar in that both will eat just about anything. They are classified as carnivores and consume rodents, birds, hares, fish, berries, and will scavenge on dead animals as well. During spring they eat and cache waterfowl eggs and feast on goslings. We found 86 gosling feet scattered around the top of one den and you can often find goose leg bands around dens, mostly from young birds.
Many times we have observed interactions between denning foxes and polar bears. Just as polar bears use their keen sense of smell to find seals during the winter period, they also locate fox dens in summer. A bear will repeatedly pound on the top of a den with its front feet, attempting to cave in the tunnels or dig the foxes out. Despite their enormous size and strength, bears are rarely successful because arctic fox dens have dozens of tunnels and entrances.
Adult arctic fox molting winter coat © M. Gillespie
There is a noticeable difference between the tolerance of arctic and red foxes to the presence of humans near their dens. Red fox mothers get very anxious and will ‘scream’ at you while quickly chasing their pups underground. Arctic foxes are usually more tolerant of visitors as long as they are respectful and keep back a reasonable distance of 200m or more. You can tell if a den is active when you see fresh digging and fresh prey remains. With some patience, visitors are usually rewarded with the opportunity to watch the amazing antics of the arctic fox, especially the pups that never seem to stop playing. Since arctic foxes have 11 pups in a litter on average, the den site is one of the most active spots you can find anywhere in the park!
We began our study of foxes in the region in order to see if, in fact, red foxes were moving northward as has been reported in many other locations in the world. Results from other regions showed that red foxes have invaded arctic fox range and limited or totally eliminated the arctic foxes mainly because red foxes are larger and more aggressive than arctic foxes.
Red fox © Parks Canada
We began monitoring fox dens in the mid-1990s looking at the distribution of arctic and red fox dens. We also wanted to collect baseline information on the distribution of the fox dens to see if that might change over time. Beach ridges are critical to both species and all of the dens we’ve located are in this type of habitat. However, in almost all cases, red foxes den farther away from the Hudson Bay coast and generally prefer areas with some tree cover, while arctic foxes choose sites closer to the coast in tundra areas with little or no trees and there appears to be a clear line separating them. In the 1990s, one red fox was recorded denning near Cape Churchill in what was normally an arctic fox area. Red foxes have not been recorded in this specific area since that single observation.
One of the factors that will likely influence the change in distribution of red and arctic foxes is global warming. As temperatures in northern regions continue to get warmer, the environment as we know it today will change, perhaps favouring the habits of the red fox over its cousin the arctic fox. Will arctic foxes adapt to these changes or will they move further north following the polar bears? Only ongoing monitoring will tell.
*Ryan Brook is an Assistant Professor with the Indigenous Land Management Institute at the University of Saskatchewan and he has been doing field research in what is now Wapusk National Park (NP) since 1994.
Murray Gillespie recently retired from being the provincial game bird manager for the Province of Manitoba and has been monitoring Canada Geese at Nester One research camp in Wapusk NP since 1973. He is currently on the Wapusk Management Board, and through his company ThinkWild, offers interactive, hands-on learning experiences for youth in Western Canada and beyond.