Foxes are adaptable canids found across diverse landscapes. Digging is a fundamental aspect of their lives, serving numerous purposes essential for their survival. Understanding why and how foxes dig offers insights into their complex interactions with their environment.
The Depths of Fox Burrows
Foxes construct underground systems, known as dens or burrows, that vary in size. A typical red fox den can extend to depths of 3 to 8 feet deep, with main chambers up to 10 feet. These networks include complex tunnel systems, 10 to 75 feet long. The tunnels commonly descend at an angle of 40 to 45 degrees.
The entrances to these burrows are round or oval, 7 to 8 inches in diameter, allowing fox access while restricting larger animals. Many dens feature multiple entrances, serving as escape routes or access points. Within these systems, foxes create several chambers. Some function as main living spaces, while others are used for specific purposes, such as food storage. Foxes may maintain several dens within their territory, using different ones for various needs throughout the year.
Purposes Behind Fox Excavation
Digging is an instinctive behavior for foxes, driven by several essential needs. A primary reason is digging dens, especially for vixens (female foxes) to give birth and raise kits. These natal dens provide a safe, secluded nursery for vulnerable young during the breeding season. The security of an underground den shields the kits from predators and harsh environmental conditions.
Foxes also dig for refuge from various threats, including inclement weather and larger predators. A burrow offers a secure retreat where a fox can escape quickly if pursued. They also dig to cache excess prey. Foxes are known for being “surplus killers,” burying extra food in shallow holes for later retrieval. These small caches, often only a few inches deep, are scattered across their territory as an insurance policy against future food scarcity.
Another reason foxes dig is to hunt underground prey. They frequently excavate in lawns and flowerbeds to find earthworms and grubs, especially after rain when the ground is softer and prey is closer to the surface. Foxes also hunt rodents beneath the snow or in thick vegetation, using their senses to pinpoint prey before pouncing and digging to capture it.
Environmental Influences on Digging
The characteristics of the environment significantly influence where and how deep foxes dig. Soil type plays a substantial role; loose, sandy soils are easier for foxes to excavate, leading to more extensive burrow systems. Conversely, dense clay or rocky soils present greater challenges, often resulting in shallower or less elaborate dens. Loamy soils, a mix of sand, silt, and clay, also offer good drainage and structure, making them favorable for digging.
Foxes are opportunistic and frequently adapt existing structures rather than always digging new ones from scratch. They commonly take over and modify burrows created by other animals, such as groundhogs, badgers, or rabbits. In urban environments, they might establish dens under sheds, decks, or even in hollow trees or rock crevices. The presence of such structures can influence the overall design and depth of their dens.
Site selection is also influenced by the need for security and drainage. Foxes often choose locations on slopes, ridges, or knolls, which offer good drainage and help prevent flooding. Concealed areas with dense vegetation or near boulders provide additional protection, further guiding their digging efforts. These environmental factors collectively shape the architecture and strategic placement of fox burrows.