The jury is still out on whether they would be considered come from aways.
Whisked from the wilds of Kejimkujik National Park as tiny eggs and raised for two years at the Toronto Zoo, a group of about 50 Blanding’s turtles has finally returned home from the big city.
The turtles, the focus of a continuing conservation effort involving Parks Canada and researchers at Acadia University and the Atlantic Veterinary College, were reared in captivity in order to boost their size and give them a leg up on survival.
“When they emerge from the egg, they’re about the size of a loonie and they only weigh five or six grams,” said Steve Mockford, an associate biology professor at the Wolfville university who has been studying Blanding’s turtles for years.
“They’re cute. There’s no doubt about that. But they’re also bite-sized for a whole wide range of predators.”
With a population of 300 to 500 in Nova Scotia, the turtles are considered an endangered species. Just one per cent of hatchlings survive to adulthood in the wild, due to a variety of threats and predators, including development projects along lakefronts and other turtle habitat.
When raised in captivity, they grow faster, and after two years, they are as large as a five-year-old turtle that lived in the wild.
Mockford calls the process “head-starting.”
While researchers have been head-starting Blanding’s turtles since the early 1990s, the group released back into Kejimkujik earlier this month was the first to make a pit stop in Prince Edward Island for surgery first.
Researchers at the Atlantic Veterinary College examined the turtles before their release, making a tiny incision on each in order to briefly insert a camera into its abdomen and ascertain its sex.
The sex of Blanding’s turtles depends on the temperature at which the eggs are incubated. The female turtle digs a hole in gravel, sand or soil, lays the eggs, covers them up and walks away — forever.
“That’s the end of her investment. There’s no maternal care,” said Mockford.
If the temperature is above a certain point, the eggs will produce female turtles, and if the temperature is below that threshold, the turtle will be male.
Researchers had incubated the eggs at different temperatures and wanted to know the sex in order to pinpoint the critical temperature for sex determination.
Since Blanding’s turtles don’t reach sexual maturity until about age 20, researchers would have had to wait a long time to know the reptiles’ gender without the surgery to help them.
Scientists haven’t yet crunched the numbers, but Mockford said when they do, the experiment will help them understand how the turtles may be affected by climate change.
“It’s really important to know, in terms of conserving bio-diversity overall, how various species are going to respond to climate change,” he said.
“In some cases, they may benefit. In some cases, they may suffer horribly. But it’s important in recovery and management of species at risk to be able to know what the looming threats are, not just what the current threats are.”
Volunteers at Kejimkujik will keep a close watch on the new kids on the block, monitoring their mating and reproduction as they grow up.
Researchers carve small notches in the shell of each turtle so they can identify it throughout its life, which can last up to 80 years.
Mockford said while his students are fond of naming the turtles as they pass through their care — there is Peggy, who has a missing hind leg, and others named after students’ boyfriends and girlfriends — he tries to steer clear of the name game.
But there is one whose name has stuck.
“The only one whose name I remember all the time is the very first turtle who was ever marked in the park,” he said, noting that she was notched by Parks Canada staff, likely in the 1960s.
“Turtle No. 01 is Eve.”