Shells, claws and tails — turtles can seem confusingly similar.
However, if you know a few key differences to look for, you can soon confidently identify some common turtle species in Iowa. There are 13 turtle species known in Iowa, but we’re going to look at just five — Blanding’s turtles, painted turtles, red-eared sliders, ornate box turtles and snapping turtles. Box turtles and red-eared sliders have not been documented in Dickinson County, but we do have these species living at the Dickinson County Nature Center as animal ambassadors.
The most obvious difference between these five turtle species may also be the most obvious similarity. All turtles have shells, but the shape, coloring and texture of their shells varies greatly among species.
The Blanding’s turtle, a threatened species in Iowa, has a smooth shell. The carapace — upper shell — is black or dark brown and speckled with yellow dots and stripes. The plastron — lower shell — is yellow with darker smudges of black or brown around the exterior. The ornate box turtle is also threatened. It has a domed shell that is also dark with yellow marks, but the yellow is more apparent and streaky.
Both Blanding’s turtles and ornate box turtles have a hinged plastron that can come up to completely close in the head and front legs instead of just being able to tuck body away, like most other turtles.
Painted turtles also have a smooth upper shell that is dark green, brown or black with light lines scattered throughout. The plastron is red or orange with a blotchy pattern that may fade as the turtle ages. The bright plastron is where the turtle gets its name.
Red-eared sliders are actually not native to Iowa, instead coming from the southern United States, but they are quite common in the state now after having been released from the pet trade. They have a pretty smooth shell that is dark green on top, and each scale has a yellow bar with yellow rings around it. The plastron is a light yellow color with dark smudges.
The common snapping turtle can be found throughout the eastern two-thirds of the United States. It has a very rough shell with peaked scales that form three ridges down the back. The shell can range from brown to black but can also look green as algae grows on it. The older the turtle, the smoother the shell may become.
The Blanding’s turtle’s shell sometimes fades with age, so it can make it harder to identify, but its lower jaw and throat are yellow, making them easy to identify at any age. The exposed body is a bluish-black color.
Painted turtles have a dark head with bright yellow lines extending from the nose to the shell. These lines might confuse it with red-eared sliders, which have similar lines, but sliders have a red spot behind each eye. However, as sliders get older, they may lose the bright red blotch. Red-eared sliders and painted turtles also have a line that runs through the eye.
Ornate box turtles have yellow marks on the head and limbs, and many have large reddish-orange marks on the front legs. Males have red irises and females have yellow irises.
Snapping turtles have dark bodies and a tail that is as long as the shell with sawteeth on top. They have vibrant eyes with starbursts that stem from the pupil.
Blanding’s turtles have a shell that ranges from 5-8 inches. Painted turtles are a little smaller, ranging from 3.5-7 inches. Red-eared sliders are 5-11 inches; ornate box turtles 4-5 inches and snapping turtles come in at a whopping 8-14 inches and weigh an average of 23 pounds as adults.
Blanding’s turtles are semi-aquatic, which means they spend most of their time in shallow water but will move to land to forage for food or bask in the sun.
Painted turtles are found throughout much of the United States and Canada and love pretty much any aquatic area with vegetation and a muddy bottom they can dig into. They can be found in farm ponds, wetlands, slow-moving rivers, lakes and marshes.
Red-eared sliders love the water and rarely leave it unless it is to bask for short periods of time. Snapping turtles also spend most of their time in the water, usually in lakes and swamps but they can also be seen by deep lakes and rivers.
Ornate box turtles are terrestrial instead of aquatic, and they can be found in grasslands and agricultural areas. They spend much of their time underground, escaping the heat of the day.
In the past decade, concerns about the number of turtles in Iowa have spread, and in 2016, the Iowa Legislature passed a law establishing turtle trapping seasons and setting bag limits instead of allowing unlimited trapping. Daily catch limits are four snapping turtles, one painted turtle and one softshell turtle, and the season is closed mid-May through mid-July.
Want to learn more about the Dickinson County Nature Center’s turtles? Check out these great articles:
Five Facts You Probably Didn’t Know About Painted Turtles
Seven Things Teddy the Box Turtle Wants You to Know About Him
What Does Teddy the Turtle Eat?