Turtles are among earth's oldest reptiles
Turtles, turtles everywhere. Lately I've seen them sunning on logs and digging in the sand. It's that time of year when turtles often are seen lumbering across highways and byways. Many times we stop our car to give aid and assistance to these slow-moving travelers. Most times it is painted turtles, but this week I saw a young snapper trying to dodge vehicles.
When we safely passed the turtle I proceeded to the next road and turned the car around. As we headed back, a shiny red pickup pulled off the road near the turtle. A young man hopped out, picked up the snapper and released it on the other side of the road. It was good to see that our family isn't alone in its efforts to rescue turtles from tires.
Since turtles are so visible this time of year, let's look at their lifestyle. Before getting into specifics, you may find a little ancient history worth noting.
Turtles may be the earliest reptiles known to humankind. These armored vertebrates outdate lizards and even dinosaurs and have changed little in the past 200 million years. Until this century it appears that turtles have neither increased nor decreased in number since prehistoric times.
Names such as tortoise, terrapin and turtle sometimes lead to confusion. Most people categorize all of these interesting characters into one collective group called turtles, although there are differences between the various types.
Turtles that live on land are called tortoises. Hard-shelled, slow moving, with strong feet and claws for walking on land and digging, most are vegetarians that forage on a wide variety of plants. In North America tortoises number three: the gopher tortoise of the Southeast, the desert tortoise of the Southwest and Berlandier's tortoise of southern Texas and Mexico.
Freshwater edible turtles are known as terrapins. They often end up on gourmet menus. Four terrapin species -- Cumberland, Mobile, Florida and red-bellied -- are widely used for food and known as "sliders" in the southeastern states. The diamondback terrapin of southern salt marshes is also prized for its meat.
Large ocean-dwelling turtles with limbs in the form of flippers are true turtles. Five North American species -- green, hawksbill, loggerhead, Ridley and leatherback -- all are giant sea turtles that can reach weights of several hundred pounds. They return to land only to lay eggs on sandy beaches.
Scientifically, in the Order Testudines there are six families of turtles: snapping, musk and mud; box and water; gopher tortoises, sea turtles and softshell turtles. Worldwide there are more than 240 species. Only eight are found in Minnesota.
Our turtles are divided into three categories: pond, river and marsh turtles. Each name describes the habitat in which it's found.
Almost everyone is familiar with painted and snapping turtles, the two most common pond turtles. The painted, also known as the mud turtle, spends summer days basking on rocks and logs on the edges of lakes and ponds. It's easily identified by its bright red plastron, or under-shell. The snapping turtle, weighing up to 75 pounds, is the largest species in Minnesota.
River turtles include three types of map turtles (common, false and Ouachita false), two softshell (smooth and spiny) and the wood turtle. The map turtle's name comes from the yellow stripes on the head and neck, as well as the circular marks on its shell, which resemble contour lines on a map. They frequent the large rivers of the Mississippi Drainage.
Softshell turtles, also called pancake turtles, stick close to medium to large river shallows. They bury themselves in the river bottom, exposing only their heads as they prey upon unsuspecting small fish that venture near.
The wood turtle, one of two threatened Minnesota species, is found along small, clear streams. In spring and summer the "woody" spends considerable time in the adjacent forests, where its diet consists partly of strawberries, raspberries and worms.
The only marsh turtle in our state is the threatened Blanding's. In some places it's referred to as a box turtle, but true box turtles are found south of Minnesota. Blanding's turtles tend to migrate in the spring. To assist the rare turtles during this vulnerable time and to alert motorists, "Turtle Crossing" signs have been erected along roadways where Blanding's are known to cross.
Next week I'll write more about these interesting, but often overlooked, inhabitants of the wild.