Sharon Writes

July 28, 2010

Signs of the Times

Filed under: Canadian Wildlife, Magazines and newspapers — Sharon @ 5:39 pm

Canadian Wildlife, July/August 2010

By Sharon Oosthoek

Assessing the impact of climate change on wildlife is tricky business. Any given year may be warmer or wetter than usual and still have nothing to do with climate change. That’s called weather.

Gambo, Newfoundland trapper Clarence Pritchett knows all about that. In his 35 years of trapping, he’s seen animals that have suffered through bad winters, and he’s seen the opposite.

This past winter was unusually temperate and animals such as otters and mink are now plump and healthy. “It’s not a pattern though,” says Pritchett. “We have good winters and bad winters. It changes drastically with the North Atlantic.”

But climate change is about patterns. Not seasonal or even yearly fluctuations, but long-term changes in temperature, precipitation, wind, and even ocean currents.

So a decade or more of unusually warm temperatures or lots of snow may signal climate change.

“In order to make that link, you have to have a long enough time series,” says Gary Stern, senior research scientist at the Department of Fisheries and Oceans in Winnipeg. “I would say 10-15 years of data on an annual basis … You have to monitor the biota (plants and animals) but you also have to the monitor the system that’s changing and try to link the two together, which is a difficult thing.”

Paul Wilson, a wildlife geneticists with Ontario’s Trent University, agrees that long-term patterns are key, and urges meticulous research to set baselines for comparison.

“I think we as scientists have to be careful we’re not jumping on the climate change bandwagon and trying to attribute everything we see to climate change,” says Wilson.

Other human-induced changes – fragmentation, pollution and introduced species – also make it hard to separate out what can and can’t be chalked up to climate change.

That’s why Jody Allair, a biologist with Bird Studies Canada, counsels caution.

‘Our scientists are finding it difficult to tease apart the variety of factors contributing to (bird) range shifts or to decipher an overall pattern,” says Allair.

Southern Yukon Tlingit elder Stanley James has also seen wildlife shifting ranges in the past few years, and like Allair, can’t say with certainty what is behind it.

“We’ve had polar bears coming down this way now, on the Dempster Highway. We have cougars coming in from the south. And then we’ve had muskox,” says James. All are unusual sightings near his home in Carcross.

“The animals know there is a change that is happening,” he says. “We used to have four feet of snow when I was on the trap line 60 years ago. Now you only have about 17 or 18 inches of snow.”

With these caveats in mind, we offer here a sampling of intriguing, and often troubling changes in the lives of Canada’s wild animals.

(more…)

July 4, 2010

Wasp Detectives

Filed under: Magazines and newspapers, YES Magazine: The Science Magazine for Adventurous Minds — Sharon @ 2:14 pm

YES Mag: The Science Magazine for Adventurous Minds, July/August, 2010

Wasp Detectives

by Sharon Oosthoek

A tiny black-winged wasp is about to become a detective in the case of the emerald ash borer, a beetle that has killed millions of ash trees in Canada and the United States.    The shiny green beetles hitched a ride from Asia about 10 years ago, hidden in wood packing materials for products shipped to North American stores. It’s the beetle baby that kills trees — larvae feed under the bark and destroy the system that transports food and water to a tree.

Luckily, researchers at Ontario’s University of Guelph found that a native wasp, Cerceris fumipennis, can detect beetle-infested areas. The wasp leaves its nest in search of prey and in as little as half an hour knows if beetles are present. That’s good news because the faster we find the emerald ash borers, the faster we can stop them. Fewer trees will have to be cut down or injected with expensive pesticides to stop the beetles’ spread.

“It’s like the wasp is Sherlock Holmes and we’re his assistant Watson,” says bug expert Philip Careless, who was a master’s student at the University of Guelph when he helped figure out the wasps make good investigators. “You have a partner — which happens to be a wasp — that is awesome at finding where these pests are that are moving into our neighborhoods to eat our trees.”

Careless, who is now a bug expert with the Canadian Food Inspection Agency, says the wasp is good at finding the beetle because it’s one of its favorite meals. Mother wasps bring the beetles back to the nest to feed their larvae. Careless knows this because he visited places known to have emerald ash borers, and then he looked for wasp nests on the nearby ground.

After the mother wasps left their nests to hunt, he put clear plastic cups over the nest entrances. When a mother returned and found her nest blocked, Careless grabbed her groceries. He found — you guessed it — emerald ash borers.

Unfortunately, the wasps kill too few emerald ash borers to stop them from spreading. That’s where humans come in. Forest managers in the U.S. are now training volunteers, including scouts and guides, to watch nests and tell them when the wasps bring back emerald ash borers. In Canada, Careless and his team will spend this summer finding out where the nests are and next year volunteers can take over.

Want to volunteer, but you’re afraid of a wasp sting? No worries. “These wasps have a stinger, but they don’t use it in defense. They use it to paralyze prey,” Careless says.  “We grab them all the time when we steal their groceries and they never sting us.” Beetles, beware.

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