Animals are crafty. They have evolved complex survival strategies to meet the demands of their habitat. Through this, many have become amazing architects. Like their human counterparts, these animal architects create structures and devices in myriad ways. They excavate extensive tunnel systems, collect discarded items to construct homes, produce building supplies from their bodies and even use tools.
Let’s dig into this fascinating topic with a look at some of Georgia’s natural-born excavators.
By Ethan Hatchett
The Coastal Plain is a fertile ground for invention, rich in habitats that provide a playground for unique adaptions. The region’s sandy soil is easily manipulated by a host of animals with varied ways of approaching their daily dilemmas. Excavators mine the soil for food, create temperature-controlled homes for themselves and others, and shape the environment around them.
Snakes are limited in their ability to excavate but lacking limbs doesn’t stop the secretive pine snake. With two subspecies found in Georgia – the Florida pine snake in south Georgia and the northern pine snake ranging from the Piedmont region north – this snake is a great example of an excavator.
At the tip of the pine snake’s snout is a modified rostral scale that acts as a spade to move soil. The reptile spends most of its time in burrows it has dug or found. Females often visit the same burrow year after year to lay their eggs.
Pine snakes find prey above and below ground. The snakes feast on small burrowing rodents, some of which they encounter while digging. (Watch: Florida pine snake profile.)
One such rodent is the pocket gopher. Every part of this small mammal is adapted to life underground (see: “Not Your Average Rodent“). It has powerful forearms to move soil, eyes and ears that are shrunken to keep them clean, and a bottom lip that closes behind its teeth to prevent soil from entering the animal’s body. That body is even elongated to navigate through tunnels. The pocket gopher also has external fur-lined cheek pouches, where it stores food to carry to underground caches.
Another common name for the pocket gopher is “sandy mounder.” Living approximately 10 inches underneath the Coastal Plain’s sandy surface, the rodent creates a system of sealed tunnels longer than the length of a football field. Scattered along the length of its home, the pocket gopher deposits distinctive mounds of sand displaced when digging the tunnels.
The sealed tunnels provide unique microhabitats for insects, reptiles and amphibians. In digging and maintaining the tunnels, the pocket gopher helps aerate the soil, stimulate root growth (new research shows that the rodents crop roots that spread into their tunnels, spurring regrowth), and cycle nutrients between plants and animals. It’s a huge impact on the ecosystem for such a small animal. (Watch: Ranger Nick talks pocket gophers with biologist J.T. Pynne, now of the Georgia Wildlife Federation.)
But when it comes to digging, the gopher tortoise may be the most adept and effective excavator in Georgia.
Weighing up to 12 pounds, the gopher tortoise spends most of its life in and around its distinctive burrow. These burrows can reach 10 feet deep under the sand and stretch up to 40 feet long (watch: “Tortoise Tunnel Wonders“).
A burrow may sound like a crude structure for such a big creature, but the gopher tortoise creates one of the most practical homes in nature. The structures are essentially tortoise-built caves. The burrow has a shell-shaped opening, and often more than one. In front of each is a mound of rich soil mined from beneath the surface and called the apron. Sloping into the tunnel, the half-moon hole is as wide as the gopher tortoise’s shell, allowing the animal room to turn around if need and move with ease the entire length of the tunnel.
Gopher tortoises are sometimes referred to as “wild landlords” because their burrows are used by over 300 species of wildlife. Inside the burrow, temperatures and the levels of humidity and moisture are more consistent than above-ground, allowing the cold-blooded reptile, as well as the other occupants, to remain comfortable throughout the year. A single gopher tortoise will have a few burrows throughout its territory, providing shelter for innumerable wildlife.
The tortoise is equipped to get its job done. Its curved forelegs act as powerful shovels that clear soil, while the elephantine back legs keep it in place. Its build and strength allow the gopher tortoise to dig a sizeable burrow in a couple of hours.
All of these excavators are also listed as priority species in Georgia’s State Wildlife Action Plan. This plan is a statewide strategy to conserve populations of native wildlife species and the natural habitats they need before these animals, plants and places become rarer and more costly to conserve or restore.
The Coastal Plain is just one realm where animals can show off their ingenuity. Excavators can be found throughout Georgia, creating homes in clay, wood and gravel. Some are more familiar to us, like chipmunks and carpenter bees, and others are waiting to be discovered. A whole world of creative creatures lies beneath the soles of your feet.
Next up in Animal Architects: While some dig, others gather and use discarded materials, including even their prey. Meet the collectors.
Ethan Hatchett is a communications assistant in DNR’s Wildlife Conservation Section.