Who is the Wood Turtle (AKA Bog Turtle)?

By Ben Betterly, Wildlife Educator

Wisconsin is home to 11 species of turtles.  If you’re in the Northwoods and near water, there’s a good chance that you’ll see some of our most common species, including the Painted Turtle, Eastern Spiny Softshell Turtle, and our largest species, the Common Snapping Turtle.  But, if you’re really lucky you might spot the less common Wood Turtle.

The Wood Turtle is a medium sized turtle that is most easily recognized by sculptured growth rings on each scute of its shell.   The shell (or carapace) is usually medium brown, and occasionally has black flecks and faint yellow rays. The bottom plate (or plastron) is yellow with black blotches toward the outer edge. The head is dark brown and without markings (and big black eyes), while the skin on the neck and leg sockets varies from pale yellow to orangish-red.

This Wood Turtle was spotted while paddling the Manitowish River.

Photo by Ben Betterly

Wood turtles are semiaquatic and prefer rivers or streams with moderate to fast flowing water.  They also spend a great deal of time in forested habitats adjacent to water, where they feed on berries, vegetation, mushrooms, worms and other invertebrates. Because they frequently bask on land, Wood Turtles are less observable than other riverine turtles.

Of the 11 species of turtles native to Wisconsin, 6 are considered to be moderately declining, 2 are of special concern, 2 are threatened, and 1 is endangered;  The wood turtle is currently one of those 2 species considered to be threatened (along with Blanding Turtle). The main reason for the decline in turtle populations in Wisconsin is due to habitat loss or fragmentation, human harvest (for food and pets), and increased rates of predation.  To make matters worse, the recovery of many turtle populations is limited by slow maturation rates, and thus it takes a long time for some species to rebuild their population. The Wood Turtle is one of those species, and consequently cannot breed until it is at least 12 years old (Blanding’s can take up to 20 years to mature!)

Caption: Naturalist Licia Johnson showing the plastron of a specimen she found along the Flambeau River. Photo by Heather Palmquist

Though slow to mature, Wood Turtles can live to at least 50 years old and possibly upwards of 100! Unlike most other turtles, Wood Turtles add annual growth to their shells without shedding their scutes; which results in a pattern on the shell that is synonymous with the annual growth rings of a tree. Like the rings of a tree, it is possible to age a wood turtle (to a limited degree) by simply counting the rings of its shell…hence the name “Wood” turtle!

Scutes that resemble the growth rings of a tree have earned the Wood Turtle its name.