Squirrels are familiar sights in many environments, recognized for their quick movements and active ground behaviors. These small mammals frequently engage in digging, an activity that serves various purposes in their daily lives. Observing squirrels interact with the soil offers insights into their survival strategies.
Reasons Behind the Digging
Squirrels dig primarily for three main reasons, each tied to their survival. One primary reason is food caching, an instinctive behavior of burying nuts and seeds for later consumption, especially when food is scarce. This “scatter hoarding” involves hiding individual food items in many spots, distributing their food supply.
Another reason for digging relates to shelter and nesting. While tree squirrels often nest in trees, some species, especially ground squirrels, construct burrow systems. These burrows offer protection from predators, harsh weather, and serve as safe places for raising their young.
Squirrels also dig as part of their foraging efforts. They create shallow holes to search for food items like insects, fungi, or to retrieve previously buried caches. This helps them locate sustenance and maintain a varied diet.
Typical Digging Depths
Digging depth varies significantly by purpose and squirrel species. When creating food caches, squirrels dig shallow holes, just enough to cover the item. These small holes are usually only 1 to 4 inches deep, allowing quick concealment of food. Many of these caches are temporary, serving as short-term storage.
For burrows and shelter, digging is more extensive. While tree squirrels might create shallow scrapes for temporary refuge, ground squirrels are known for their underground systems. These burrows can extend several feet deep and horizontally, with a network of tunnels and chambers.
California ground squirrel burrows are typically 2 to 3 feet deep, some reaching over 6 feet. These systems can range from 5 to 30 feet long, with multiple entrances.
Foraging digs are the shallowest type of excavation. These are mere surface disturbances or small scrapes made as squirrels search for food just beneath the ground. Such digging is not for long-term storage or shelter, but for immediate consumption.
Identifying Squirrel Digging
Identifying squirrel digging involves recognizing specific visual cues. Squirrel holes are small and conical, appearing as neat, round depressions without significant mounds of displaced soil. For food caches, these holes might be partially filled or plugged with soil or debris after the item is buried.
These small holes are found scattered throughout lawns, near trees, under shrubs, or in garden beds where nuts or seeds are abundant. Ground squirrel burrows, in contrast, have larger, more open entrances, around 4 to 5 inches in diameter, and may have scattered soil in front.
Distinguishing squirrel digging from that of other animals like moles or gophers is possible by observing these characteristics. Unlike moles, which create raised tunnels or conical mounds of soil without an open hole, squirrel digs are open at the surface. Gopher mounds are crescent-shaped with a plugged hole, differing from the open, smaller holes made by squirrels. Squirrel holes lack the extensive tunnel systems moles create.