As the leaves turn colors and fall off the trees and the temperatures start to get colder, most of the migrant birds have left Connecticut for their wintering grounds and many mammals have fattened up and found dens or other shelters.
But, what do cold-blooded animals like turtles do to prepare for the difficult winter ahead? Cold-blooded animals rely on their surrounding environment to keep warm. When cold weather hits, turtles go into a hibernation type state called “brumation” to help them survive the winter.
“Brumation is triggered by cold weather and shorter periods of daylight,” said Jenny Dickson, a wildlife biologist with the Department of Energy and Environmental Protection (DEEP) Wildlife Division, in a prepared statement from the DEEP.
“Turtles in Connecticut generally begin brumation in late fall.” During brumation, turtles become less active, their metabolism slows, and their body temperature drops. However, turtles will often “wake up” to drink water.
Turtles do not breathe during brumation, instead relying on oxygen stored in blood vessels in the throat cavity and anal sacs. To cope with the cold, turtles that live in aquatic environments move to the bottom of the pond or creek. It is advantageous if they can go deeper than the frostline, where winter temperatures tend to stabilize above freezing. Some turtles, like painted turtles, are tolerant of freezing to a certain degree. These turtles’ cryogenic properties, or cryoprotectants, are even being studied to determine if they would be helpful in preserving human organs for future transplants.
When spring arrives with its warmer temperatures, most turtles emerge from brumation, becoming active and seeking spots to bask in the sun.
“Young aquatic and land turtles that hatch from eggs that were buried in the ground over spring can either dig out of the hole, or ‘nest,’ in the fall and brumate as the adults do, or they can remain in the nest, possibly digging further into the soil,” added Dickson. “This demonstrates why female turtles must choose an optimum site to place their nests – the female must be able to detect features of the area that make it suitable for the eggs. Therefore, whenever homeowners witness a turtle nesting in their yard or garden, they are encouraged to allow the turtle to dig its nest where it chooses and leave the turtle and eggs alone.”
Whether turtle hatchlings emerge from the nest in the fall or in the spring, the DEEP Wildlife Division reminds residents not to collect hatchlings for pets. Leaving turtles alone and observing them from a distance is best for the turtle and also for your own health, as turtles can transmit Salmonella to humans.
The DEEP Wildlife Division has been highlighting Connecticut’s native turtles during 2011 as part of the Year of the Turtle awareness campaign with the Partners in Amphibian and Reptile Conservation (PARC). One of the best ways to learn more about turtles is to visit the DEEP Wildlife Division’s Year of the Turtle Web page at www.ct.gov/deep/yearofturtle and to subscribe to the DEEP’s Connecticut Wildlife magazine (www.ct.gov/dep/wildlifemagazine). You also can visit PARCs Web site at www.yearoftheturtle.org.