SPANISH FORT, Ala. — Dr. David Nelson didn’t start out life with a burning desire to study red-bellied turtles. And he didn’t start college thinking that becoming a herpetologist (someone who studies reptiles) would be his life’s work.

“I was pre-med,” said Nelson, a Spanish Fort resident.

But a few required biology classes at Baylor University in Texas got Nelson thinking about reptiles in a whole new way.

“I discovered ecology,” said Nelson.

After graduating from Baylor, Nelson earned a Ph.D. in vertebrate ecology from Michigan State University, where he became “enamored by reptiles.” He is now a professor at the University of South Alabama.

But, with the hundreds of thousands of reptiles out there, why the red-bellied turtle?

“I was asked if I would be interested in pursuing research on red-bellied turtles,” said Nelson. And according to the Alabama Department of Archives and History, the Alabama red-bellied turtle is the state reptile.

“There was (once) very little information on the turtle,” said Nelson, adding that he received a grant to study the endangered species in 1994. This is a grant that has been “renewed almost every year since then,” he says.

According to the Department of Archives website, “The red-belly inhabits the fresh to brackish waters of the Mobile Delta in Mobile and Baldwin counties. The Alabama red-bellied turtle and related species are often seen basking on logs. It is found nowhere else in the world.”

One of the first thing Nelson and his students did was set up 15-foot “hoop traps” in areas where the turtles might be to get an idea of how the population was doing. Nelson declined to number the current population.

“We got quite a few alligators as well,” chuckled Nelson.

What Nelson learned was that while endangered, the turtles, “were common around the Causeway (Battleship Parkway).” The turtles can also be found in the Fish River, the Tensaw and in Bayou LaBatre.

“We find them in rivers that empty into Mobile Bay, not the Gulf,” said Nelson.

The turtles eat underwater plants and control vegetation, producing space for other creatures to live, keeping the ecosystem of the delta in balance.

Although the environment was being relatively kind to the red-bellied turtle in kind, the busy Causeway proved to be a different story.

The turtle has to leave the water to lay her eggs, so there were a number of female turtles crossing the roadway, looking for a dry place to lay their 12 to 14 eggs. That led to plenty of vehicle-turtle contact.

Although the turtles are tough and their shell design tends to spin them away from glancing contact, according to Nelson, he says “12-20 females were hit by cars every year.” He pointed out that overall, more than 100 turtles were killed each year.

“We were finding hatchlings and females hit,” Nelson said. He says fish crows and raccoons find turtle eggs delicious so not all the eggs would become hatchlings. Worse, it takes the females 15-17 years to become sexually mature, so if a female was lost, it would be at least 15 years before one of her daughters could take her place reproducing the species.

Much of the Mobile-Tensaw River Delta is owned by the state these days, so the turtle has places to go that “are not that developed,” Nelson says.

And in 2007, the Department of Transportation installed a short chain-link fence along the Causeway that blocks most turtles from accessing the road.

“That has reduced mortality by 75 percent,” Nelson says.

And if you find a turtle while out and about? Nelson’s advice is to stay away unless the animal is in some sort of distress (and then expert help may be needed), that’s probably best.

“I tell kids most turtles bite,” he said with a smile.