Alligator Snapping Turtle: Freshwater Species of the Week

Not as fierce as he looks: This alligator snapping turtle at an animal park in the Canary Islands is covered with a carpet of algae. Photo: Norbert Nagel, Wikimedia Commons


I had been standing still for at least a half hour, counting and identifying the birds that landed on a large snag — a standing dead tree — on the edge of a small wetland in rural southern Indiana, as part of undergraduate research. Sweating in my waders on that steamy summer day, I stood about ankle deep in a muddy creek.

Then I felt a large claw slowly press down on the top of my rubber boot. The sensation entered my consciousness gradually, so I slowly lowered my eyes.

The large head of an alligator snapping turtle broke through the water’s surface, staring up at me with beady reptilian eyes. I could now see the outline of the animal’s plated shell, easily more than two feet across. A few of the jagged spikes also pierced the surface.

We stared at each other for several moments, neither of us twitching a muscle. I could see a light carpet of algae growing on the prehistoric-looking creature.

After another moment, my curiosity and wonder began to give way to fear. Don’t they have the strongest biting force of any land animal, I thought? [Scientists have actually measured their bite strength at less than some other turtles, and about on par with human beings, although they are known to lop off fingers if provoked or carelessly fed.]

That impressive beak started to seem awfully close to my private parts.

In a move that I hoped wouldn’t be too threatening, I grunted and shifted my weight.

In an instant, the turtle slipped back into the murky water.  I never saw it again that day.

Later that summer, I saw a few large alligator snapping turtles cruising around the wetlands. Once I got a good look at a massive one as it hauled itself up onto a big floating log. I would also have intimate moments with a barred owl that followed me at dusk, a river otter that came within a few feet to sniff me, a beaver that torpedoed me to warn me of its lodge, and a great blue heron that tossed a fish at me to keep me away from its rookery.

On a recent trip to the Smithsonian’s National Zoo, I saw an alligator snapping turtle (Macrochelys temminckii) in an aquarium tank. It waited motionless in crystal clear water, its giant beak wide open. It flicked its tongue in the water, making a very convincing worm lure. The technique is the animal’s favorite hunting strategy: lure prey like fish and amphibians in and chomp down.

Despite their fearsome appearance, alligator snappers aren’t aggressive, and will only bite people if provoked or mishandled. They are not  closely related to “regular” snapping turtles, the genus Cheludra, and are the sole survivors of their own genus.

Alligator snapping turtles have declined significantly, thanks to harvesting for soup, bycatch from fishing operations, and loss of habitat due to widespread destruction of wetlands. The animals are officially classified as vulnerable by the IUCN, though they are considered endangered in Illinois.

An American species, Alligator snappers reside across the southeastern U.S., from eastern Texas to Florida and up into the lower Midwest. But due to their impressive appearance, the largely sedentary animals have been popular in the exotic pet trade. They are kept and sold around the world, especially in Asia.

Photo: Young alligator snapping turtle
The head of a young alligator snapping turtle. Photo: Stephen Friedt, Wikimedia Commons

There is an unverified report of an alligator snapper reaching a whopping 403 pounds (183 kg) in Kansas in 1937. More reliably, one 16-year-old specimen weighed in at 249 pounds (113 kg) at Shedd Aquarium in Chicago in 1999.

The average adult size is around 175 pounds (80 kg), with a shell length of 26 inches.

It’s a big animal to have step on your foot, though alligator snappers have a lot more to fear from us then we from them.


Brian Clark Howard is a writer and editor with He was formerly an editor at The Daily Green and E/The Environmental Magazine and has contributed to many publications, including,,,, Yahoo!, MSN and elsewhere. His latest book, with Kevin Shea, is Build Your Own Small Wind Power System.