Of the 21 species of reptiles in Wisconsin, 11 are turtles. Here we will focus on the largest and heaviest, the common snapping turtle, Chelydra serpentine.
Like all turtles, the snapper is cold blooded, obtaining heat from the sun. Unlike the familiar painted turtle, snappers seldom crawl onto logs to sun themselves, but often float at the surface. They are almost entirely aquatic, with females coming to shore to lay eggs primarily in May and June. They will travel some distance to find a suitable egg laying site, having been found as far as a mile from water. Fortunately, the attempted housebreaking depicted in the side photo is not common behavior.
On land, snapping turtles can be quite aggressive. They should be handled only by those who truly know how. Lifting by the sides of the upper shell is dangerous, as they have a very long and mobile neck-the species name serpentine means “snake-like.” Their bite can easily sever a finger. Lifting by the tail could cause them permanent spinal damage. It is best to just watch them from a distance. In the water they are not a threat to humans, and when encountered they will swim away or hide in the muck or under vegetation.
Adult turtles have few predators, but the eggs are another matter. Nests are frequently raided by raccoon and skunks. Eggs that survive hatch in 80 to 90 days, although some overwinter in the nest. When a tiny turtle is seen heading for water in the spring, if is from an egg laid the prior year.
Snapping turtles are omnivorous, eating plants and just about any animal or fish they can catch, although their reputation as a duckling predator has been highly exaggerated. Younger turtles will forage for food, but the big ones hang motionless in the water, hunting by ambush.