Pocket gophers, small burrowing rodents, spend almost their entire lives underground. Their presence is primarily known through the distinct piles of excavated soil they push to the surface. These unique soil piles, known as gopher mounds, clearly indicate an active underground network. Identifying these mounds is the first step in understanding the subterranean activity that can affect lawns and gardens. The specific characteristics of a gopher mound are easily distinguishable from the signs left by other common burrowing pests.
The Classic Gopher Mound
The most identifiable feature of a pocket gopher’s activity is the shape of the mound itself, which is rarely a perfectly symmetrical cone. Gopher mounds typically present a fan, horseshoe, or crescent shape, formed as the animal pushes excavated soil out of a lateral tunnel and onto the surface at an angle. These mounds often measure between 10 and 24 inches in diameter and reach heights of up to 6 inches, depending on the volume of soil expelled.
A key visual element confirming a gopher mound is the presence of a soil plug. The tunnel entrance is not in the center; instead, the mound forms a fan shape on one side of the opening. The gopher seals the hole completely with loose dirt pushed up from below. This off-center, sealed entrance is a reliable identifier, as the gopher packs the earth firmly into the opening to protect the tunnel system from predators and the environment.
The soil material is often fine-textured, loose, and appears freshly excavated, as it is sifted material brought up from deeper levels of the burrow system. Gophers prefer to burrow in soft, well-drained soils like sandy-loam, which makes the digging process more efficient. The color of the mound soil can sometimes be distinct from the surrounding topsoil, indicating it was brought up from a lower stratum.
Distinguishing Gopher Mounds from Mole Hills
While both gophers and moles create mounds of dirt, their appearance and construction methods are different, providing clear visual cues for identification. Mole hills are generally symmetrical and volcano-shaped, forming a circular cone of soil piled up as the animal pushes dirt vertically through a central opening. This symmetry contrasts sharply with the asymmetrical, fan-shaped gopher mound.
The entrance to a mole hill is typically situated in the center and may be left open or only loosely plugged, unlike the completely sealed, off-center plug of a gopher mound. Mole hills also tend to be smaller than gopher mounds, often only a few inches across, reflecting the mole’s different digging technique.
The activity of moles is also characterized by surface ridges, which are raised, vein-like lines of soil running across the lawn. These ridges are shallow feeding tunnels created just beneath the turf, as moles forage for insects and earthworms. Gophers, conversely, do not typically create these surface ridges because their main tunnel systems are deeper underground.
Gopher Mound Function and Tunnel Systems
The gopher mound serves as the disposal point for excess soil as the animal excavates and expands its underground home. Each mound represents the end of a short, lateral tunnel that branches off the main runway, allowing the gopher to push the dirt to the surface. A single gopher can create multiple mounds in a day, demonstrating the speed at which their tunnel systems grow.
These burrow systems are complex, consisting of deep main runways and shallower lateral tunnels used for foraging. The main tunnels, which serve as the gopher’s primary thoroughfare, are typically located between 5 and 18 inches below the surface, though they can be deeper depending on soil conditions. The branching tunnels are used for nesting, food storage, and waste disposal, sometimes reaching depths of several feet.
The constant creation of mounds is a byproduct of the gopher’s need to maintain and extend its network of tunnels, which can cover an area from 200 to 2,000 square feet. The visible mound is surface evidence of this extensive underground construction project, which the gopher relies on for protection, food, and shelter. The presence of a new mound signals active digging, as the gopher quickly plugs any open access points to its system.