Water temperature of fifty-nine degrees Fahrenheit is the magic number for Painted Turtles in the fall. Below it, their metabolism slows to a near standstill – their heartbeat slows to only one beat every few minutes and they do not breathe through their lungs (if conditions allow, they may absorb oxygen dissolved in the water through specialized skin cells near the tail). Their body temperature averages 43°F. when hibernating in the mud at the bottom of ponds. Occasionally a Painted Turtle is seen swimming under the ice, but for the most part, hibernation rules from October to April in northern New England.
When the water reaches 59°F.- 64°F. in the spring, Painted Turtles become active again. In addition to foraging, they immediately start basking in the sun. Being cold-blooded, or ectothermic, they need this external source of heat to warm their body, but the UV light also regulates their metabolism and breeding as well as helps produce Vitamin D3, which is essential for the health of their bones as well as their internal organs.
Basking can also help relieve aquatic turtles of ectoparasites. Leeches are a blood-sucking ectoparasite that can cause anemia in reptiles. Drying out in the sun causes the leeches to shrivel up and die. Algae on basking aquatic turtles can also dry out and fall off, allowing the shells to retain their aerodynamic nature.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.