Many animals create underground dwellings, a testament to their adaptability. Some species construct extensive and intricate subterranean networks. These large structures serve various purposes for their inhabitants. Understanding these burrows and the animals that create them provides insight into wildlife survival strategies.
Key Diggers and Their Tunnels
Several species dig substantial holes and complex tunnel systems. American badgers excavate burrows typically 6 to 8 inches in diameter, often marked by a crescent-shaped dirt mound at the entrance. These burrows can extend up to 10 feet deep and 30 feet long. Groundhogs, also known as woodchucks, create main entrances around 10 to 12 inches wide, with tunnels reaching 5 to 6 feet deep and extending 25 to 30 feet horizontally. Their burrow systems often feature multiple escape routes.
Red foxes construct dens with main entrances about 8 to 12 inches in diameter, often on slopes or elevated areas for good drainage. These dens are extensive, with multiple entrances and chambers, sometimes repurposed from existing badger or woodchuck burrows. Coyotes also dig dens, or they may utilize natural shelters or abandoned burrows. Their den entrances are 10 to 12 inches wide, leading to a chamber where pups are raised.
Armadillos create burrows about 6 to 8 inches in diameter, identifiable by fresh, loose soil around the opening. These burrows are typically shallow, around 15 feet long, and used for shelter and foraging. Pocket gophers construct intricate tunnel networks close to the surface, identifiable by fan-shaped soil mounds with the dirt plug off to one side. Their main tunnels are 2 to 3 inches in diameter, used for foraging and food storage.
Prairie dogs are known for their extensive underground “towns.” Their burrows feature a distinct crater-shaped mound around the entrance, which helps prevent flooding and provides a vantage point. The main burrow shaft can descend 10 to 16 feet before leveling off into a series of tunnels and chambers that extend for hundreds of feet. These complex systems include specific chambers for nesting, sleeping, and waste, supporting large colonies.
Purposes of Excavation
Animals dig large holes for various survival functions. A primary purpose is shelter, providing protection from predators. Burrowing allows animals to retreat quickly into a secure space, evading above-ground threats. For example, foxes and coyotes use their dens as nurseries, safeguarding their young during early development.
Burrows also offer refuge from extreme weather, serving as natural insulators. In hot climates, the underground environment provides cooler temperatures. In cold regions, burrows offer warmth and protection from freezing winds and snow. Armadillos, for instance, use their burrows to escape intense heat and cold, maintaining a more stable body temperature.
Beyond protection, burrows are frequently used for raising offspring. Many species, including badgers and groundhogs, give birth and nurse their young in their subterranean homes. These dens provide a secure, undisturbed environment for the young before venturing above ground. Some animals also use burrows for food storage, particularly when food is scarce. Pocket gophers, for example, create dedicated chambers within their tunnel systems to hoard roots and tubers, ensuring a consistent food supply.
Identifying the Diggers
Determining which animal dug a particular hole involves observing several clues. The hole’s size and shape offer insights; a perfectly round hole suggests one animal, while an irregular shape might indicate another. For instance, groundhog burrows often have a large, singular main entrance, whereas gopher mounds are typically fan-shaped with a plugged entrance.
The dirt mound around the hole is also telling. Badgers often leave a distinct crescent-shaped dirt mound outside their burrows, while prairie dogs create a raised crater around their entrance. Observing the soil type and how it is displaced can further narrow possibilities.
Additional evidence includes tracks, scat, or other signs of animal activity near the burrow. Footprints in the surrounding soil can reveal the species, with distinct paw prints for canids like foxes and coyotes, or claw marks for badgers. The presence of animal droppings (scat) near the entrance can also provide definitive identification, as different animals produce uniquely shaped and sized scat. Examining nearby vegetation for signs of feeding or disturbance can also help identify the burrow’s occupant.