Ribbonsnake DNA detective work being used to track elusive creatures
Researchers are using environmental DNA analysis to figure out where the elusive creatures are
A snake researcher is using DNA analysis to learn more about one of Nova Scotia's most elusive and threatened snakes.
The eastern ribbonsnake is 70 centimetres long and in the same genus as the common garter snake.
"They look very much like garter snakes to the uninitiated, but a dead giveaway is they have a crescent-shaped white scale right in front of their eye," said Steve Mockford, associate professor of biology at Acadia University and co-chair of the Ribbonsnake Recovery Team.
"So if you're close enough to see their eye, you can tell if you have a ribbonsnake."
The snakes are listed as threatened under the federal Species at Risk Act and the Nova Scotia Endangered Species Act.
Mockford said eastern ribbonsnakes received that designation after a 2002 study found little knowledge about the species.
"Now, 16 years later, as we're looking at recovery actions, one of the big threats is still lack of knowledge," he said. "They're a very cryptic species. They blend well with their environment and it's actually difficult to gain information on them, including knowing where they are."
His group is trying a new approach using environmental DNA extraction techniques to find the shy reptiles in their preferred habitats along the edges of rivers, lakes and bogs in the southwest interior of Nova Scotia.
As a snake slithers through the world, it sloughs off cells. Researchers collect water samples, filter out debris, and look there for ribbonsnake cells. They can get DNA from that.
"Provided you have a marker that's specific to the species, you can detect whether that species is within that environment," said Mockford.
He said the predictable degradation of DNA due to temperature and UV exposure gives scientists a rough window of time in which the creature was in the area.
In Canada the snakes only live in the Great Lakes region of Ontario and southwestern Nova Scotia.
Mockford said the snakes are harmless — but don't pick one up.
"If you pick one up and aggravate them, they will have a sort of bite response but they have quite a small mouth and there's very little chance that they'll break the skin," Mockford told CBC's Information Morning. "Many people tend to be afraid of snakes and they're not comfortable with them."
Mockford said over the next few weeks, the snakes will be leaving their overwintering habitat in upland areas of Queens, Lunenburg, and Annapolis countries, plus the border of Annapolis and Digby counties.
If people spot the snakes there are several places to report the sightings:
With files from Information Morning