Classified under the reptile order Testudines, turtles in Idaho, and turtles in general, are characterized by a hard shell that protects their soft underbelly, head, and feet. Two groups of turtles further divide the order Testudines–the hidden-necked turtles (Cryptodira), and the side-necked turtles (Pleurodira). Freshwater terrapins (semi-aquatic turtles) and terrestrial tortoises are also classified as true turtles.
Turtles live on nearly all continents, in warmer ocean regions, and on several islands scattered mostly over the Pacific Ocean. Like mammals, birds, and other reptiles, turtles are amniotes, or animals that lay eggs and breathe air. However, turtles do not lay their eggs in water. Instead, they lay eggs in nests or bury the eggs in sand or loose dirt.
4 Species of Turtles in Idaho
Here are four turtle species living in various regions of Idaho: the western painted turtle, snapping turtle, box turtle, and the red-eared slider.
Wild turtles in Idaho should never be approached or captured to keep as pets. All turtle species can carry and transmit the Salmonella bacteria to animals and humans. If touching a wild turtle is necessary, always wash your hands well with soap and water afterward.
1. Western Painted Turtle
- Length: eight to 10 inches (shell length)
- Life span: 25 to 30 years
- Reproduction: females lay between three and eight eggs between April and late June. Nests consist of a hole dug near water. After laying eggs, female western painted turtles cover up the hole with vegetation using their back legs. The eggs incubate for three months, with warmer weather leading to shorter incubation periods.
The western painted turtle is native to Idaho, and can also be found throughout northern Oregon, and the central and southern U.S. Species of painted turtles are named according to their geographic location, such as the midland painted turtle and the southern painted turtle.
Idaho’s western painted turtle prefers shallow water depths like those edging ponds, small lakes, and streams. They will bask in the afternoon sunlight on branches or logs lying over or near shallow water sources after feeding on vegetation, worms, snails, and insects. Although the western painted turtle is omnivorous, it does prefer to eat terrestrial and aquatic plants over fleshy protein.
Vivid colors decorate the carapace (shell) of the western painted turtle. Bright yellow, orange, and red markings mingle with green, brown, and black lines and spots over the shell. The appearance of having colors painted on their shell gives the common name “painted turtle” to all types of U.S. painted turtles.
2. Red-eared Slider
- Length: seven to 12 inches
- Life span: 30 to 40 years
- Reproduction: female red-eared sliders can lay up to 30 eggs at one time. Incubation time is between 50 and 60 days, depending on the temperature and climate during the time the eggs are buried.
A semi-aquatic turtle that is an invasive species in Idaho, the red-eared slider lives in creeks, ponds, and small lakes where they prey on insects, snails, and small fish.
Red-eared sliders will also venture out on land to forage for berries, wild vegetables, and other ground-sprouting edibles. Their name comes from the red stripe that surrounds the ears and the turtle’s excellent ability to slide off rocks and logs in the water to escape threats.
3. Snapping Turtle
- Length:10 to 18 inches long (shell length)
- Life span: 30 to 50 years
- Reproduction: Early summer is the peak time for female snapping turtles to lay eggs. However, females can retain sperm from male snapping turtles and use that sperm when they are prepared to lay eggs. After finding sandy soil in which to dig a hole, the female snapping turtle will lay between 25 and 75 eggs annually. The incubation period is typically two to three months. Higher temperatures will accelerate the incubation time.
Western Idaho is home to the snapping turtle, a tough-looking turtle with a ridged shell, strong jaws, and a flexible neck and head. When threatened in the water, snapping turtles head to the bottom where they bury themselves in sediment.
When threatened on land, they may become aggressive and attempt to bite the animal or person threatening them. Instead of basking in the sun on land, snapping turtles float on the surface of ponds or lakes with just their shells exposed. They breathe by raising their head just above the surface of the water and inhaling oxygen using tiny nostrils located at the end of their snout.
Due to the agility of their neck and head, omnivorous snapping turtles in Idaho can ambush frogs, birds, and even smaller turtles more successfully than other turtle species. Male snapping turtles can weigh as much as 25 pounds. Females generally weigh around 18 to 20 pounds.
4. Box Turtle
- Length: up to eight inches
- Life span: 20 to 80 years (reports of box turtles living to be 100 years old are unverified)
- Reproduction: females dig holes and lay four to six eggs in the holes before covering them up with soil and rocks. Incubation is between two and three months.
Found only in the easternmost areas of Idaho, the box turtle is aptly named because of its dome-shaped shell. Box turtles can immediately withdraw their heads and feet into the safety of this roomy shell when threatened.
Box turtles use their sharp sense of smell to catch worms, frogs, rodents, and small birds. Like all other turtles, they are omnivorous and also feed on flowers, berries, and edible plants.
Box turtles have been spotted munching on roadkill occasionally at night, which explains their high mortality rate around busy roads and highways.
When threatened, box turtles can issue a hissing sound as loud as the noise made by a vacuum cleaner. Scientists also think this same hissing sound may be associated with male box turtles seeking female box turtles for mates.