Blanding's Turtle

Emydoidea blandingii

Excerpted from: Animal Diversity

  Description

The smooth carapace of Blanding’s turtles ranges from dark brown to black. These ectothermic reptiles have yellow spots on their dorsal shells. As adults, their plastrons have a variety of black and yellow patterns, the most common being yellow with black spots along the scutes. The shells of adult turtles can stretch from 6-10 inches. Weights range from 1.5-3 pounds. Their heads are flat and the dorsal and sides are bluish-gray. Their eyes protrude, while their snouts do not. Yellow scales can be seen on the legs and tails and they have webbed toes. Although there are no significant size differences between male and female Blanding’s turtles, male plastrons are usually more concave than those of females.

  Lifespan

The minimum expected lifespan of wild Blanding’s turtles is 70 years, while the maximum is 77 years. There are no known captive breeding programs, so information on the lifespan of captive Blanding’s turtles is not available. There has been confounding studies on whether male or female turtles live longer. However, studies have shown that there is an overall positive correlation between the age of Blanding’s turtles and survivorship. The annual survivorship of male and female adults (14+ years of age) is over 93%, while that of juveniles (1-13 years of age) is around 72%

  Behavior

Although Blanding’s turtles are mostly aquatic, they commonly emerge from the water to rest on logs, sedge clumps, or any terrestrial land that is close to their aquatic homes. These turtles will usually move when searching for habitats that are plentiful with food, mate accessible and also when the females are finding a good spot to nest. Beginning in mid-April and continuing through mid-July, there is hardly any traveling among these turtles.

Turtles that inhabit the larger lakes will stay in their same locations for tens of years. Seasonal wetland inhabitants will change location and travel greater distances compared to the turtles occupying the lakes. Juvenile Blanding’s turtles also travel in their search for an aquatic habitat when they are first hatched, looking to find an adequate overwintering spot to lessen their chances of freezing to death. On land, males will travel more, found to on average travel over 10 km. Females however, only travel over 2 km, not including the nesting period of the females, where they can reach up to 7.5 km in travel. These turtles will travel between 1 to 230 meters daily in water.

During October and November, these reptiles will begin overwintering as a group, staying mostly in ponds, and they will hibernate until the end of March. Following their period of hibernation, they will begin breeding. Blanding’s turtles that are located in the more southern regions of their geographic range can withstand colder temperatures and will stay active in ambient temperatures as cold as 35 degrees F.

  Communication

During the mating season, male Blanding’s turtles rely on their tactile senses. Mounting is one of these tactile activities, as is gulping. In the latter activity, the males sway their bodies and spew water from their mouths onto the females’ head.

  Diet

Blanding’s turtles are omnivores, but half of their diet consists of crustaceans, including crayfish. These reptiles will consume their food alive, or as carrion. They also eat insects and other invertebrates. These turtles resort to aquatic insects such as dragonfly nymphs and aquatic beetles when crayfish are not available in certain geographic locations. Blanding’s turtles also will consume fish eggs, fish, frogs, and snails. They will eat coontail, duckweed, sedge, and bulrush as well, and will also eat seeds. The adult turtles are more carnivorous, with up to over 75% of the diet being meat, while the juvenile Blanding’s turtles eat more plants.

Further Reading:

 Beavers — Nature's Hydrologist, Part 2
 Garter Snakes — The Gardener's Friend
 Wisconsin Native Salamanders
 Goundhog or Woochuck: All The Facts
 Voles, Both The Good and The Bad