There are two species of snapping turtles in North America and both of them can be found in Illinois: the common snapping turtle (found throughout Illinois) and the alligator snapping turtle (found in the southern region of Illinois). Even though both species live in Illinois, odds are if you’ve seen one, it’s a common snapping turtle, according to the Forest Preserve District of Will County. They look different physically because alligator snappers look prehistoric with large spikes on their shells while common snapping turtles have smooth shells.

According to the Illinois Department of Natural Resources, there are 260 species of turtles that occur worldwide. Seventeen of these species inhabit Illinois, dwelling in forests, prairies, marshes, swamps, ponds, lakes, streams and rivers. Snapping turtles communicate to mates with leg movements while the turtles face each other. Snapping turtles also use their sense of smell, vision, and touch to detect prey. They may sense vibrations in the water. The mating season lasts from April through November, although most mating occurs in late spring. The female digs a nest in soil in mid-May or early June and deposits 20 to 40 eggs. Eggs hatch in September and October.

Common snapping turtle (Chelydra serpentine)

The common snapping turtle is the most widespread and well know of the species. Common snapping turtles range from south-central and southeastern Canada to the US Gulf Coast and from the central Great Plains to the Atlantic Seaboard, inhabiting a wide variety of freshwaters across that large range and even occupying partly salty coastal waters, according to Sciencing. 

The common snapping turtle spends much of its time on the bottom of bodies of water. They are primarily nocturnal, but will feed underwater during the day ambushing their prey. Snapping turtles are ill-tempered and capable of producing a very serious bite. They live 30 to 40 years and eat anything from insects to small mammals. A common snapping turtle can weigh 20 to 75 pounds.

While this snapping turtle cab be very aggressive out of water and will attempt to bite, in water it is calmer, according to the IDNR. It spends much of its time on the bottom of a water body waiting for prey items to come close. It buries itself in the mud in winter, often near other snapping turtles. The snapping turtle eats almost anything it can catch and swallow, including insects, crayfish, fishes, birds, amphibians, reptiles and mammals. It also does some scavenging and eats vegetation.

Alligator snapping turtle (Macrochelys temmincki)

North America’s largest freshwater turtle is the alligator snapping turtle whose natural range is in the southern part of the Illinois. The alligator turtle is endangered in Illinois.  In some locations it may grow to a shell length of 30 inches (77 cm) and a weight of more than 250 pounds (112.5 kilograms). The largest Illinois specimen on record weighed about 160 pounds. The Chicago Tribune reports that “the turtles can reach more than 240 pounds and live 70 years. In the wild, they play a defining role in their local ecosystems, in part by eating invasive fish.”

According to the National Wildlife Federation (NWF), alligator snapping turtles are sometimes described as dinosaur-like because of their spiky shells and primitive-looking faces. They have three pointed ridges along their shells that run from head to tail. Unlike all other species of snapping turtle, this one has eyes on the sides of its head. Some myths claim that alligator snapping turtles are known to attack people, but this isn’t the case. But with a bite force of 1,000 pounds, their powerful jaws can snap through bone—so they should never be handled in the wild.

Alligator snapping turtles have a specially adapted tongue – a lure-like projection – that attracts curious fish that swim right into the turtle’s mouth. The NWF says “To attract an unsuspecting victim, this turtle will lay on the bottom of the riverbed and open his jaws to reveal what looks like a delicious bright red wriggling worm, luring prey by fiendishly twitching this appendage back and forth. A fish that gets duped by the turtle’s tongue will swim right into the range of the hungry predator’s jaws.”