Sunday, October 4, 2009

Gopher Tortoises of Alabama

Having recently returned from this year's annual meeting of The Gopher Tortoise Council, I'm inspired to reprint a brief article about gopher tortoises I wrote for the Alabama Coastal Foundation's newsletter. Laura Wewerka of the GTC and Wally Smith of Alabama PARC and Alabama's second-most distinguished university provided input:

Gopher tortoises, Gopherus polyphemus, are perhaps one of the most recognizable animals found in Alabama. Plodding around the southeastern United States from South Carolina down through Louisiana, this shelled reptile can be found in Alabama south of the Fall Line.

They’re the only tortoise native to the southeastern United States, and adults can be distinguished from the box turtle, another terrestrial turtle, by their large size and gray un-patterned shell. Hatchlings and young tortoises typically have square brown markings encircling a yellow center on their carapace (top shell); these markings tend to fade with age.

The presence of tortoises is most often detected first by stumbling upon their characteristic burrows, shaped like half-moons. These animals spend most of their life underground in these holes, which they dig with their extremely strong front limbs. But they’re not the only ones who benefit from their frequent tunneling. Dozens, if not hundreds, of different species of insects, amphibians, reptiles, mammals, and even birds may find refuge within tortoise burrows. Some animals, like rabbits and ground-dwelling sparrows, may hide in tortoise holes when fire burns through an area. Others, like the federally threatened eastern indigo snake, spend their winters residing with the dark recesses of the tortoise lairs. When tortoises are removed from a forest, this may have serious implications for the remaining species that rely on their burrows for shelter.

Gopher tortoises are closely associated with longleaf pine forests, and the ranges of the two overlap across the country almost precisely. Tortoises like these savanna-like forests because a lot of light reaches the ground; this light encourages plant growth which provides food for the tortoise. This is why it’s so important to manage longleaf pine forests with periodic prescribed burning; the fire helps limit invasion of hardwood trees that would shade the area and eventually crowd out the pine trees. Tortoises living in a longleaf pine forest that isn’t managed with frequent fire will eventually try to disperse to more suitable areas or find refuge in sub-par habitats with more light streaming in, such as powerline corridors. Recent research, in fact, has suggested that the reintroduction of periodic burning has an incredibly beneficial effect on gopher tortoise densities when fire has been historically suppressed in an area.

Unfortunately, just as the longleaf pine forests have shrunk in size due to development and mismanagement, tortoise populations have declined as well. Perhaps the decline of the tortoise is linked most closely to the vanishing longleaf pine ecosystem, but they face other threats too, including collisions with cars, poaching for food, and disease. Without conservation efforts aimed at protecting tortoises and their habitat, they have a bleak future. Fortunately, there are some encouraging trends: Alabama recently outlawed the practice of gassing tortoise burrows. This irresponsible and environmentally destructive practice was undertaken to drive out rattlesnakes, which could then be either killed immediately or brought to rattlesnake roundups, where the snakes are killed later. Tortoise tended to stick around in their burrows after they were gassed, exposing the animals to lung damage and eventual death. Recent laws banning this technique, in concert with land conservation and proper forest management, may help ensure that future generations can look forward to encountering the gopher tortoise in Alabama.

6 comments:

Mark Bailey said...

Good one Dave.

Sorry I missed everybody at the GTC.

Oh, and I love the new treefrog thingy.

Anonymous said...

that's a Bewdyful Turtle!!!!!!!!!!!!!

Charles said...

An awesome example of a keystone species.

Frank Baron said...

Such an interesting animal! I hope the laws help sustain and grow the species. They sound like a very valuable part of the local ecology. Thanks for the info. :)

Anonymous said...

Hmm. I don't think there are any gopher tortoises still in NC. The herps of NC website (http://www.herpsofnc.org/herps_of_NC/turtles/turtles.html) doesn't list them, and I can't any site that mentions them living in NC. This site: http://www.defenders.org/wildlife_and_habitat/wildlife/gopher_tortoise.php gives the range, but it has no mention of NC.

David Steen said...

That should read South Carolina, thanks for catching that error. I have fixed it.