A hare of a different color
This article appears courtesy of Time for Nature,
a Parks Canada series

Since 1996, biologist Shawn Gerrow has been studying the Arctic hare in Gros Morne National Park of Canada in Newfoundland, and after a decade of research, he still finds the species fascinating.

The range of the Arctic hare in Canada extends from Newfoundland to the High Arctic. The hares that live in Gros Morne are near the species' southern limit, and inhabit a distinctly different environment than those in the High Arctic. The hares in the park have developed some different characteristics than their cousins farther north. Mr. Gerrow believes these differences may be due to natural selection.

How Arctic hares adapted to Gros Morne

The hares in Gros Morne, like all Arctic hares, are big: the Arctic hare is the largest type of hare in North America. In the High Arctic islands, the species' fur is almost entirely white year-round. In Gros Morne, the hares change colour in the spring, from winter white to grey. Mr. Gerrow says that protective coloration may be the key - darker colour provides better camouflage from predators once the snow melts.

Hares in the park also have bigger feet than those found elsewhere, which Mr. Gerrow suspects is a survival advantage. Gros Morne receives considerably more precipitation than much of the Canadian Arctic, so Mr. Gerrow says the hare population in the park may have developed big feet "because they have to deal with far more snow." Having big feet is like having snowshoes - they help the hares stay on top of, instead of sinking into, the snow.

In most of its range, the Arctic hare's chief predator is the wolf. However, wolves are extirpated from the island of Newfoundland. Coyotes and foxes still pose a threat to young hares, but large adults are often able to escape these predators. Unlike the High Arctic, there are small trees and shrubs that provide cover for the hares in Gros Morne. This might explain why the Gros Morne hares don't stand tall on their hind legs, searching the horizon for threats the way their northern cousins do.

Despite the scarcity of predators, Arctic hares occur in low densities in Gros Morne, where females have, on average, three young per litter. More northern populations can have litters up to twice as large. Mr. Gerrow believes that sunlight may be one reason for this difference. During the spring breeding season, High Arctic hares are exposed to many more hours of daylight, which stimulates production of hormones that influence litter size.

A snowmobile census

In order for Parks Canada to gain a better understanding of the health of the Gros Morne Arctic hare population, Mr. Gerrow and his colleagues set out every few years to tally hare numbers. They extrapolate the results of these tallies to estimate the number of hares in the entire park. Since hare habitat in Gros Morne is remote, the team has to use snowmobiles to comb selected areas. Their surveys suggest that the population has been increasing, and that there are more hares in the park than was previously believed.

Related Links:

• Time for Nature – Parks Canada
• Gros Morne National Park - Monitoring Projects
• Ukaliq: The Arctic Hare - Canadian Museum of Nature

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