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Winter 2010

Urban Jungle

The changing natural world at our doorsteps | Illustration and text by Patterson Clark      

painted turtle

February 2, 2010

Painted turtle brumation


At the bottoms of marshes, lakes and slow-moving streams, painted turtles are brumating in the mud. (Brumation is a reptilian form of hibernation.) During winter warm spells, turtles may emerge and bask in the sun, but they won't eat until the water temperature climbs to 60 degrees.

A turtle’s winter

  • ♦ The turtle's metabolism drops 90 percent, and the animal uses stored glycogen for sustenance. (Mammals use stored fat).
  • ♦ Without much oxygen in its blood, the turtle's metabolism turns anaerobic, producing lactic acid, which is neutralized by magnesium and calcium stored in the turtle's shell.
  • ♦ Painted turtles can survive in 37-degree mud for 150 days, and can even stand freezing temperatures for 11 days.

SOURCE: Davidson College Department of Biology