Yellowknife (Nov 22/04) - You'd need Noah's ark to house all the animals that have been popping up around Yellowknife recently: cougars, caribou, coyotes, bears, magpies and seagulls.

Unusual patterns have been noted, including caribou on the Ingraham Trail as early as mid-October and cougars close to Yellowknife in May.

This past week - and for the first time in the city's history - there was an older 400-pound male grizzly bear on a walk through the western outskirts of the city. It was shot when it charged wildlife officers investigating the bear's activities. The bear was in ill health and starving.

A recent study of climate change in the Arctic found that in past decades temperatures have risen at almost double the global rate. The study predicts worldwide increases of 1.4C to 5.8C in the next century.

So, is climate change affecting animal movements around Yellowknife?

The seagull diaspora in May might suggest that. Gulls were gathered on rooftops throughout the city earlier this year because of late break-up on the lakes.

Ecology North's bird expert Bob Bromley has also noted a large increase in magpies in the city, more signs of pileated woodpeckers, and evening grosbeaks -- "something we never had before," he said.

"When taken in tandem, it's probably climate change," said Bromley. "It fits the pattern."

"One of the big predictions is unpredictability (in weather)," he added.

Tracy Hillis is not so sure. An RWED wildlife biologist who studies climate change, Hillis put changing climate low on her list of factors affecting animals.

For instance, the coyotes spotted recently around Yellowknife -- which Bromley said have been here for years, but now have much larger numbers -- gravitated here because "it's coyote heaven," said Hillis.

"The way the city is designed with beautiful open spaces in between urban spaces is perfect for them," she said.

Because coyotes are both resourceful and opportunistic, said Hillis, Yellowknife's numerous dogs, cats and other small mammals make it a natural choice for the hungry animals.

They also scavenge at the dump when food is scarce.

"I don't think climate change is a main theme; I think it's an underlying theme," said Hillis.

As aggravating factors, she places population pressures within natural ranges, new habitats opening up, exploratory tendencies and opportunism above climate change.

"Before the last Ice Age, this area was a grassy steppe and we had woolly mammoths and sabre tooth tigers," said Hillis.

"What's not to say that within the natural variability of the planet, these things aren't going to come back?"

Hillis is skeptical because, she said, so many predictions are linked to only a few years of data.

As for the seagulls, "Great Bear and Great Slave lakes are big enough to create their own weather patterns" and do not necessarily represent overall climate change, she said.

Climate and caribou

Caribou biologist Anne Gunn, also of RWED, said climate change could affect caribou if it altered vegetation. Caribou eat young grass in the summer and lichen and flowers -- among other things -- throughout the year.

Warmer temperatures would likely encourage shrubs, which would grow at the expense of lichen and flowers.

"A longer growing season will not necessarily produce more food (for caribou)," she said.

Also, changing patterns in lake ice could affect their movements.

Caribou are excellent swimmers, but choose to walk around larger lakes.

If the timing of freeze-up changes, larger lakes will act as a barrier until they are safe for walking. Recently, Gunn said a herd split at Gordon Lake when some caribou chose to swim, while others went around.

Additionally, more caribou could fall through.

"(Caribou) are smart. They're versatile, but things will stack up against them," said Gunn.

"I don't think caribou will go extinct as a species, but it will put pressure on individual herds."

Gunn and Hillis both pointed out that if average temperatures increase and lead to more forest fires, it would provide more food for animals like deer and moose, which thrive on post-fire vegetation. Caribou wouldn't be so lucky.