Map turtles can only live for a few weeks at a time under the ice. To survive, they need to extract the oxygen dissolved in the water, (Photo: PXfuel)
What’s that getting into the swim of things under the icy surface of your neighbourhood pond? Well, a northern map turtle, of course!
While snappers and painted turtles can spend several months submerged under the ice with little oxygen, map turtles can only live for a few weeks at a time. To survive, they need to extract the oxygen dissolved in the water.
For years, researchers have observed map turtles wandering across the bottom of icy rivers and lakes. They knew they must be moving for a reason, but why?
They recently fit 40 northern map turtles in eastern Ontario with tri-axial accelerometers (essentially a turtle FitBit) and logged the data. The devices recorded the movement, depth and temperature of the turtles for the seven months they remained under the ice.
The researchers suspect that small amounts of activity may allow the turtles to replace the oxygen-depleted boundary layer of water on their skin with freshly oxygenated water, allowing them to better “breathe” through their skin.
Alternatively, they could just be looking for micro-climates with higher concentrations of oxygen or a preferred temperature or depth.
By better understanding the winter part of the turtles’ life cycle, the researchers will also better understand how climate change may impact these animals.