No one would ever accuse a moose of looking like an arctic species. They are usually described as boreal forest specialists, eaters of twigs and browsers of brush.

But over the last decade, more and more moose have been spotted on the North Slope, trotting along creekbeds and travelling right out to the Beaufort Sea in the summer.

Last March biologists had a chance to confirm that moose are indeed thriving in the northern Yukon. When they ran a repeat survey in the northern Richardson Mountains, and its adjacent coastal plain, they found that moose numbers had increased by 67 percent since the last survey in 1989.

The moose are not evenly spaced across the tundra and mountain slopes typical of the area. They stick to the creek beds and river bottoms, and their densities in these areas are almost five times higher than the Yukon average.

"What we found was that if you look at the entire landscape the moose density was quite low, but if you just look at moose habitat in the area, the density is very, very high," says Rick Ward, the moose management specialist with the Yukon Department of Renewable Resources.

For the whole survey area, there were about 48 moose for every 1,000 square kilometres. But when only the areas of habitable range were considered, densities jumped to 730 moose per 1,000 square kilometres, among the highest densities to be found anywhere in the territory.

"The habitat where the moose are found is very high quality. It tends to be in the riparian zone where there is a high abundance of browse such as willows and with patches of spruce providing good cover in winter," says Ward.

The 1989 survey was conducted as part of the Inuvialuit Final Agreement, and a study at that time pointed out that moose populations in the area are vulnerable to both over-harvesting and development since moose habitat is so limited in the area.

When the biologists returned for the repeat survey, which was also funded primarily by the Inuvialuit, they did not know exactly what they would find. In the mid-1990s, a large number of moose had died on Alaska's North Slope of undetermined causes.

Biologists can only speculate on why moose are doing so well high above the Arctic Circle. But one possibility is that there are not as many wolves preying on the moose as there are in the southern Yukon.

For one, wolf densities are thought to be lower in the northern Yukon than in other parts of the territory. Secondly the wolves may prefer eating caribou to moose.

"Predators in general, and wolves in this case, tend to develop a search image of their prey. They know what they are looking for, and they may not immediately recognize a moose as prey when they are looking at it," says Ward.

Climate change could also be a factor, and Ward thinks that moose and moose habitat could possibly act as indicators for climate change in the area. He found little evidence for a warming trend in the winter months over the past 30 years, even though there has been a slight increase in precipitation during this time. The major warming has occurred in the spring, and Russell wonders how this trend is affecting the spring snowpack.

In the southern Yukon it is known that the distribution of moose has changed a great deal over the last few centuries. According to traditional knowledge and the accounts of early traders, moose were scarce in the southern Yukon in the mid-1800s, a time when caribou were abundant in the same area.

Moose in the northern Yukon are a different subspecies from their southern cousins. It is known that Alces alces gigas evolved in the ice-free area known as Beringia during the last Ice Age. But not much is known about their more recent history.

While many artifacts made of caribou have been found in the northern Yukon, few tools or worked bones made of moose have been discovered. Caribou continue to be the species of choice for people living in the northern Yukon, as moose in the Richardson Mountains are not heavily hunted.

Ward does not think that moose numbers are increasing now because more animals are packing their bags and moving north. Rather it is thought that they are expanding their range. In the 1989 survey, most of the moose were living on the south slope of the Richardson Mountains, but now more moose are living year-round on the north side of the range. Moose have even been seen wintering on the coastal plain.

Moose in the Richardson Mountains remain vulnerable to an increase in hunting or development in their habitat. But if all things stay the same, the sight of a moose on the Yukon's North Slope could become a more common arctic image.

Rick Ward can be contacted at 667-5787 or by e-mail at rick.ward@gov.yk.ca.