Sable Island horses, walruses to be discussed at meeting

A glimpse into the mating patterns of Sable Island horses will be part of a free public talk Wednesday at Saint Mary's University.

Three scientists will join an archeologist from Parks Canada in the discussion about Sable Island and its wildlife. 

The event will also highlight research showing the windswept sandbar was once home to thousands of Maritime walruses.

Brenna McLeod Frasier, a biologist and research associate with the Nova Scotia Museum, says accounts from early explorers suggest there were as many as 100,000 walrus in the Maritimes, including in the Bay of Fundy, Sable and Magdalen Islands.

The walruses disappeared by the end of the 1700s.

What happened to the walruses?

"People were hunting them for their tusks which were almost like an ivory similar to an elephant ivory," says McLeod Frasier, who is also an educator with the Canadian Whale Institute.   

"They also wanted the hide and their blubber. The walrus had a lot of blubber which could be rendered down to an oil which could be used for various products," she said.

McLeod Frasier has taken DNA, tusks and jawbones from 278 specimens found on Sable Island in recent decades to conclude the mammal here was different from the walrus found today in the North.

"Our Maritime walrus, as we have 'tagged' them, were larger and more robust animals. They were also genetically distinctive," she said.

'Left-handed' walruses

The biologist has also found some evidence to suggest the critters may have been "left-handed" — or at least left-tusked.

McLeod Frasier says, on average, the right tusk of the walrus skulls measure ten per cent longer than the left.

Based on research on marine mammals off Greenland, where walruses were observed using their snout to suck up prey along the ocean bottom while swimming on one side with one fin pointing up, McLeod Frasier theorizes that might explain why the right tusks turn out to be longer than the left.

The long-gone Maritime walrus may be just one of many creatures that adapted to the iconic isolation of Sable Island.

More horses than people

Horses were introduced by would-be settlers in the 1700s.

Today the horse population has grown to 500 — the highest it has ever been.

Zoe Lucas, a Sable Island resident and researcher, has more than 30 years of biological data on the horses. Her findings are being analysed by Tim Frasier, a population geneticist who is married to McLeod Frasier and teaches at Saint Mary's University.

"Our overall goal is to understand the factors that are driving the dynamics of the Sable Island horse population," he said.

"To see how inbreeding or low genetic diversity is influencing health, reproductive success and mortality in conjunction with other ecological factors such as cold winters and low food supply."

A smaller subset of Frasier's research looks at how far male and female horses will roam from their parents when they reach sexual maturity to try and avoid choosing a partner that is a close family member.

The meeting, hosted by the Friends of the Green Horse Society and the Ecology Action Centre, will also include presentations from Lucas, a naturalist, and Charles Burke, an archaeologist.

Burke will unveil results from the first survey — done in the summer of 2015 — of human settlement on the historic Island.

Sable Island visitors

About 350 people have visited Sable Island in the past two years since it became a park reserve managed by Parks Canada.

The federal department says none of those visitors have been permitted to stay overnight and that all have come by private plane or charter boat — with access controlled through a registration system.

That number compares with 50 to 200 people a year over the past decade, according to figures provided to CBC by Parks Canada.

A management plan for the ecologically sensitive area to "further define the visitor experience" is targeted for release in 2017.

Despite concerns the remote sandbar, with its unusual flora and fauna, may suffer because of increased visitation, Parks Canada says, so far, the change has had "little impact."

The talk will be held Wednesday at 7:00 p.m. at the McNally Auditorium at Saint Mary's University.