Our Eastern painted turtles (Chrysemys picta picta) have been rising from their murky winter hideaways and trying to soak up some sun:
I’m guessing that this one is a male because of its relatively long and substantial tail. Female PTs, although larger in total body than males, have shorter, stubbier tails to facilitate mating.
Being cold-blooded (“ectothermic”), the turtles’ body temperatures are determined by their environment. They must maintain an internal temperature of between 63 and 73 degrees (F) to be active, according to reports. Basking in the sun, especially on a surface that warms up below them, is a principal way that PTs and other cold-blooded animals can maintain enough heat to be active.
In PTs, the heat that they absorb increases their metabolism, helps them digest, and induces males to produce sperm, researchers have found. The sunlight reportedly also strengthens their shells, attacks algae that can cause infection, and enables turtles to produce vitamin D 3, which is needed for the absorption of calcium used in structural growth. (Images taken in Brooklin, Maine, on April 19, 2024.)