By: Dr. Robert Wrigley
While researching the mammalian fauna of Manitoba as a Manitoba Museum Curator, I was particularly interested in determining the accurate ranges of each of the 90 species known to have occurred here in historical times. There had been few mammalogists working in Manitoba over the last century, so my assistants Jack Dubois and Herb Copland and I succeeded in extending the distributions of a number of species.But two records stood out beyond the rest -- Arctic Fox (Vulpes lagopus) and Polar Bear (Ursus maritimus), both residents of the Tundra and Arctic Marine biomes.
In mid-December 1974, a female Arctic Fox was shot as it fed on a goose carcass along the frozen shore of East Shoal Lake in southern Manitoba, less than 145 km (90 mi) from the North Dakota border. I was given a photograph of the fox, held up alongside a Coyote (Canis latrans) trapped nearby. Amazing! A tundra fox in the same location as a prairie-dwelling Coyote! This diminutive fox, weighing only about 3.2 kg (7 lbs) must have travelled a minimum distance of 840 km (522 mi) from the species’ closest summer range at York Factory on Hudson Bay, and more likely came from the barren-ground tundra about 1000 km (622 mi) to the North. This record was one of the farthest south ever recorded for Arctic Fox in North America. Its short legs would have floundered in the deep snow of the boreal forest, so the animal likely took advantage of the wind-packed snow cover on major rivers and lakes and of snowmobile trails.
A pair of Arctic Fox from the Churchill area exhibited at the Assiniboine Park Zoo. (photo by Darlene Stack)
My museum colleague David Hatch and I decided to investigate records of past immigrations of the foxes into the boreal forest by examining Manitoba Conservation’s fur-trapping records from 1919 to 1975. There were also notations of mass influxes of foxes in the literature as early as 1784 (T. Pennant), 1795 (Samuel Hearne), 1886 (E.T. Seton, and 1902 (E.A. Preble). We found that numbers of foxes taken far to the south of the tundra, into the boreal coniferous forest, occurred at intervals averaging three years (varying from two to seven years), with numbers trapped ranging from 24 to 8400. Migration years were related directly to the three- to four-year cyclic declines of the fox’s main prey species - the Richardson’s Collared Lemming (Dicrostonxy richardsoni). Following years of increasing lemming numbers, fox litter size and survival increase, but when lemming and vole populations crash, the starving foxes head south in search of food, and appear in dozens of traplines throughout the boreal forest. How many foxes survive the winter and make the return journey is unknown. David and I published our results in 1976 in “Arctic” - the Journal of the Arctic Institute of North America.
Thirty years later, when I was the Curator at the Assiniboine Park Zoo, I decided to acquire this species for exhibition, because I found it such a fascinating and appealing animal. Plus, captive individuals were known to demonstrate high levels of activity in all types of weather. Surprisingly, however, no other zoos in North America had this species in their collections at the time. Consequently, I recruited the assistance of colleagues at Manitoba Conservation and the Manitoba Trappers Association, and in the following summer, six young foxes were live-trapped from several dens near Churchill and shipped to Winnipeg. These paired off and produced dozens of offspring over the years, which we sent to numerous zoos in North America and Europe.
This species remains one of my favourite mammals because it is so entertaining to watch. One of my memorable observations occurred when a zookeeper entered one of our two fox enclosures with a bucket full of dead chicks. The ten subadults and their two parents retreated to the opposite side of the enclosure, watching intently as the keeper tossed the chicks here and there. As soon as he left and locked the gate, all pandemonium broke loose. Each fox darted forward, trying to be the first to grab a chick in its mouth, and then tried to find a secluded spot to stash it. Round and round the 12 foxes ran at blinding speed, not even slowing down as their snapping jaws secured another chick before its siblings could reach it. Every fox soon had a chick in its mouth and then attempted to pick up a second and a third, but one of the chicks kept falling to the ground. It was such a comical scene for me, but of course, for the foxes, “first come, first served” has great survival value in the wild, especially on the tundra where food is usually scarce, and a litter could be as high as 18 pups (generally 3-12). When lemming and vole numbers are low, a nutritionally-stressed female absorbs many or all of her embryos.
The other Manitoba species capable of incredibly long over-land and over-ice journeys is the Polar Bear. A recent study tracked a female from the Yukon’s Beaufort Sea to Wrangle Island, Russia, which travelled an astonishing 12,686 km/7883 mi in 789 days. I received notice that a subadult bear had been seen at Oxford House in central Manitoba, which is 290 km (180 mi) south of York Factory on Hudson Bay - the closest possible source location for the bear. Now while this distance was certainly not an over-land record for the species, it was most unusual because it was so far south into the boreal forest, and certainly not suitable habitat. Sadly, the bear had to be put down because it was causing trouble near the reserve (likely driven by hunger). I thought this an interesting subject for a paper, and so I began collecting from the literature other instances of long-distance travels in Arctic North America and Eurasia. I even had Dr. Bill Pruitt, Professor of Zoology at the University of Manitoba, translate Russian articles on the topic for me.
Debby the Polar Bear, one of over 30 orphaned Polar Bear cubs cared for since 1939 at the Assiniboine Park Zoo. (photo by Darlene Stack)
When I was just about ready to send the paper to a journal, my assistants and I left the Museum for a research trip to northern Manitoba. On the return trip, we stopped at a small town and were enjoying dinner at the only bar and restaurant when I overheard a gentleman at the next table mention a Polar Bear. Of course I listened intently and was shocked to hear the conclusion of his story, which resulted in much laughter from the other patrons. Apparently the story-teller was a helicopter pilot who had been hired to pick up an anesthetized, troublesome Polar Bear yearling from near Churchill and fly it for release north along the coast of Hudson Bay. After taking off with the drugged bear sleeping soundly in a suspended net, he decided to fly south instead, so that he could attend a party. He had dropped the bear off on a lake shore in the forest, whereupon the unfortunate animal ended up at Oxford House. What was the probability that I would overhear this conversation at that particular moment in an isolated northern town? All my work on the topic of Polar Bear travels suddenly became moot, but I was much relieved that I found out in time the circumstances of the Oxford House Polar Bear.
Daryll Hedman, Regional Wildlife Manager for the Northeast Region, Manitoba Sustainable Resources, informed me that a yearling Polar Bear turned up in Pikwitonei (335 km/208 mi SW York Factory) in 1998, which was subsequently tranquilized and released along the coast, and other bears have been seen at Sundance on the Nelson River and at Fox Lake (120 km/75 mi and 180 km/112 mi SW York Factory, respectively), all well within the boreal forest. There is even a record of a bear reaching northeastern Saskatchewan, so this species is capable of moving long distances (mainly taking advantage of waterways) away from its usual habitat along Hudson Bay. So many creatures travel almost unbelievable distances during migration and during unusual circumstances. I suspect some just get lost.