It's a bird, it's a plane ... no, it's a northern harrier hawk.

For weeks now the presence of a not-so-common raptor has had bird watchers and others turning their heads, wondering what type of bird just flew by, as its appearance is not usual.

'There has been sort of an unusual fallout of northern harriers in the Whitehorse area, and particularly in the neighbourhoods and downtown Whitehorse,' Cameron Eckert, a director of the Yukon Bird Club, said this morning.

The male is light greyish in colour, with black wing tips and a white rump patch. The female is a light brownish colour, but with the white rump patch.

The northern harrier, or marsh hawk as it is commonly known, passes through here every year on its way north to as far as the Beaufort Sea and points in between, Eckert explained this morning.

He said while it would be common every year at this time to see a harrier moving through on the migration, for some reason, which he suspects is weather related, the migration seems to have stalled.

The result is the unusually high number of marsh hawks in the area and in backyards swooping around for food, said Eckert, who also works as a conservation biologist for the Department of the Environment.

He said he suspects the stall has something to do with the weather cooling off from a couple of weeks ago.

The weather may have also contributed by causing crusty snow conditions that inhibit the hawk's access to voles that live beneath the snow cover, Eckert explained.

But with limited access to voles, Mother Nature has sent along the annual arrival of red pole song birds that are congregating around backyard tree feeders and feeding off birch trees.

'So the northern harrier may have simply switched from voles to red poles,' said Eckert, which may explain the frequency of calls he's been receiving from locals reporting the sighting of a bird they don't normally see.

The harrier, he said, has somewhat of a flatter face that other hawks, which is likely why many of the reports coming in are of an owl-type of bird.

'As soon as the weather warms and we get some favourable south winds you can expect to see them move on.'

The harrier is a ground-nester, and found most commonly in marshes or other wetland areas.

It winters in southern B.C. and further south along the coast.