By Justin Monk, Wildlife Biologist, Alabama Dept. of Conservation & Natural Resources
--Photos courtesy US Fish and Wildlife Service
In the Southeastern United States, gopher tortoise burrows are wonderful, important critters.
That’s because as many as 360 species of animals may visit a burrow during their lifetime.
These animals in no way, shape, or form harm the tortoise. If you look across the Southeastern U.S., it will be difficult to find another species of animal that is as important a presence as the gopher tortoise is to its surrounding environment.
Gopher tortoises are land animals found in the scrub pine habitat and coastal dune areas, in the kind of habitat of sandy soil the gopher tortoise needs to dig its burrows.
They are often referred to as a keystone species because of the gopher tortoise’s ability to keep the environment it occupies stable. It’s the burrow of the gopher tortoise that makes it a keystone species.
Many other species require the gopher tortoise burrow for shelter and nesting grounds. Without the availability of gopher tortoise burrows, several species of snakes and small rodents would not be able to utilize what is otherwise suitable habitat because of their inability to dig underground shelters for themselves.
Not only do these species need the burrows for nesting, but they also count on them for refuge from predators. Some species live in the burrow with the tortoise while others find empty burrows to occupy.
A gopher tortoise will dig many burrows during its lifetime. Escaping from predators is only one advantage of the burrows.
To keep from overheating, the tortoise escapes to its burrow for shelter from the hot sun. The burrow keeps the gopher tortoise cool during the summer months, but also offers protection from the cold of the winter months.
The burrow of the gopher tortoise requires a lot of energy during construction. You won’t find any excess tunnels branching off of it. With only one entrance, there is only just enough room for the tortoise to turn around inside. Depending on the size of the tortoise and the type of soil, burrows usually vary from 6 to 10 feet deep, but burrows have been found as deep as 40 feet below the surface.
The burrow tends to gently slope downward. When the burrow is being used by the gopher tortoise, smooth drag marks atop the sandy entrance are usually seen. It will be clean of debris and will have a half moon-shaped opening.
Juvenile tortoises, diamondback rattlesnakes, lizards, toads and the Florida mouse all depend upon the burrow. Larger animals such as armadillos, rabbits, foxes, skunks and opossums also use the burrows occasionally for shelter. Some birds, such as the burrowing owl, use the burrow for shelter and also feed on insects inside of the hole.
The gopher tortoise burrow is very important in providing an endangered species, the Eastern indigo snake, with a place to raise its offspring. There are some species such as the gopher frog, gopher scarab beetle, gopher cricket and the gopher moth that are rarely found anywhere but in the gopher tortoise burrows.
Many invertebrates, such as worms, scorpions, spiders, ticks, flies, beetles and ants, also live in the burrow.
For more information on the gopher tortoise, visit the Watchable Wildlife section of www.outdooralabama.com or the Gopher Tortoise Council’s website at www.gophertortoisecouncil.org.