Photo courtesy of Andy Coleman.
Andy Coleman with an alligator snapping turtle in June 2020.
These turtles are not fighting inner-city evil at the tutelage of a rat sensei named Splinter, but they are living in city landscapes - making that two things they have in common with the Teenage Mutant Ninja Turtles. Now, a Trussville man who teaches biology at Talladega College is seeking to learn more about the alligator snapping turtles that have been discovered in recent years to call the Cahaba River home.
Andy Coleman, who also leads the Urban Turtle Project, studies turtle populations in the urban footprint of Birmingham.
“Even though we’re in a very urbanized landscape, we have a fair number of turtles living beside us, which is a really cool thing,” Coleman said. “I wanted to see what I could do to document it and start a long-term study to see how they do over time.”
Coleman’s been studying alligator snapping turtles for some time. A friend of his was fishing once and snagged one, which Coleman trapped, and he later tagged 20 individual alligator snapping turtles in a small stretch of the Cahaba River.
“This is North America’s largest freshwater turtle, can get up to 200 pounds, live decades,” Coleman said. “They’re just the coolest thing. You’ve just got to watch your hands, watch your fingers around them, and you’ll feel fine.”
Since discovering the surprising number of alligator snappers, Coleman has collaborated with the Cahaba River Society and The Birmingham Zoo to sample areas of the Cahaba River that are hard for him to wade into. For the most part, he said, alligator snappers are the top of the food chain as adults. They can eat whatever they can fit in their mouth.
“They’re known as ambush predators,” he said. “They can lie at the bottom of the riverbed, creek bed, still, with their mouths wide open. At the tip of their tongue they have a lure, a fleshy extension of their tongue that they can wiggle. They’ll do that to lure in a fish or some unsuspecting animal, and then the gate is shut closed. Goodnight for that animal. They can be ferocious when they need to. But they are not 100% carnivorous. They are omnivorous. They’ll eat plant material.”
Alligator snapping turtles can disperse vegetation on the river banks, which benefits their local habitat and waterways. They also control the population of weakened species.
Coleman is marking each alligator snapper with a unique tag. He is aiming to catch them each year, note their growth patterns and collect blood samples to collaborate with a Mississippi State University colleague to study heavy metal toxicity levels in their blood. Are they thriving in urban environments? Are they growing more or less than other alligator snappers? Are they living shorter or longer? Should the species be considered threatened?
“The number of questions can be numerous, but you’ve got to have turtles, got to have data, in order to see what questions may be worth asking,” Coleman said. “There’s no better place in the world to be a turtle biologist [than] Alabama. We are No. 1 in turtle diversity. It’s really cool to be able to do this work in my home state and contribute to the conservation of these various species.”
