When the mighty beaver thrived on Ellesmere

OTTAWA — Musk ox, hares, caribou, migrating birds and wolves are among the hardy animals that now live on Ellesmere Island.

But paleontologists, scientists who study ancient bones, have found that many other critters lived in the High Arctic of the past.

Ten to 15 million years ago or more, when the climate of the High Arctic was much, much warmer than it is now, the wildlife on Ellesmere Island included animals that looked much like today’s hippos, alligators and turtles.

Even up until two million years ago, when the glaciers reappeared in northern latitudes, creatures resembling shrews, mice, bears, wolverines, weasels, horses, deer and beavers lived on Ellesmere Island.

Richard Harington, now a distinguished retired researcher with the Canadian Museum of Nature, has spent many summers on Ellesmere Island. There, he’s excavated an ancient beaver pond, which is estimated to be two to five million years old.

Harington had previously uncovered many fossil remains of the giant beaver that once thrived in today’s Yukon.

On Ellesmere Island, Harrington didn’t find any signs of the giant beaver, but near Strathcona Fiord, he did find a large section of a smaller beaver’s skeleton and many beaver-cut sticks and saplings.

“We know that this beaver, about two-thirds the size of the living beaver and ancestor to the giant beaver that died out at the end of the last glaciation 10,000 years ago, lived at the site,” Harington said.

Harington said the climate in the high latitudes must have been much warmer then, with sea ice “drastically reduced” or even absent over most the Arctic Ocean.

The average July temperature at the beaver pond site would have been about 5 C higher than today. That’s close to the average temperature some climatologists are predicting for the High Arctic by the end of this century.

The fossil remains of alder, birch and larch trees look much like trees found today at the edge of the tree line.

“I think the beavers were well adapted to their environment,” Harington said.

Finding this unique site was a fluke. A geologist with the Geological Survey of Canada noted a fossil outcrop there in 1965, but Harington didn’t get back to take a closer look until nearly 30 years later.

When he was able to start excavating the site, Harington uncovered a jaw bone with a tooth, which immediately made him think of the giant beaver bones he had found.

“The bones are so similar,” he said. “And the tooth patterns are very much like the giant beaver’s.”

Because the site is 300 metres above sea level on a plateau, the daily task of getting to the fossils wasn’t easy.

After a steep climb, Harington and his helpers would spend the day excavating material through loose pebble gravel and boulders. Occasionally, they would retreat to a tent that offered some shelter from the weather, which included gale-force winds and blizzards.

Funding to support this arduous fieldwork was so limited that Harington sometimes covered his own plane fare from Ottawa to Resolute. Once there, he was able to get logistical support from the Polar Continental Shelf Program in reaching Strathcona Fiord.

During his last field season at the beaver pond in 2001, Harrington found what he thinks is a beaver dam made of sticks and small stones. It looks like the same dam-building technique still employed by modern beavers living thousands of kilometers to the south.

However, Harington isn’t planning to return to the Strathcona site to continue the excavation. That’s because he needs to go back with heavy equipment to remove some of the heavy boulders covering the surface: an impossible task.

Meanwhile, erosion is always exposing new and possibly more interesting fossil sites elsewhere on Ellesmere Island and nearby Axel Heiberg Island.

Every summer, paleontologists from the Canadian Museum of Nature conduct research in the High Arctic. The museum is responsible for discovering and describing Canadian species and their history. Since 1913, the museum’s researchers have gone to the High Arctic, researching, documenting and collecting the region’s plants, animals and minerals.

Harington said there’s 100 years of unpacking and studying ahead, even just to process fossil material already stored at the museum’s warehouse in Alymer, Quebec.

He still has many boxes of excavated material from the beaver pond on hand to sift through and study and mull over.

Harington believes remains from plants or animals from that period will provide clues to changes that may occur if predictions of rapid global warming come true.