Burrowing Non-Target Wildlife
|
Other wildlife may also use abandoned ground squirrel burrows or make burrows of their own. It is important to determine whether or not a burrow is being actively used by a ground squirrel to avoid harming non-target or endangered species. Before beginning any management plan, it is important to correctly identify the source of the damage and to be aware of any legal restrictions.
San Joaquin Kit Fox (Vulpes macrotis mutica)
The San Joaquin kit fox is an endangered species. It is important to know their distribution if you are controlling California ground squirrels in their range. They like to dig their dens in soft soil and often use abandoned rodent burrows, which they enlarge. Their dens have many chambers and entrances. The main entrance is large (approx. 8 inches in diameter, or larger) and shaped like a keyhole. Occupied dens can be identified by the presence of prey remains, scat, matted vegetation, and fresh paw prints. Kangaroo rats (Dipodomys spp.)
Kangaroo rat burrows can be confused with California ground squirrel burrows. These burrows vary in size depending on the species. Smaller species’ burrows, such as those made by the Fresno kangaroo rat (Dipodomys nitratoides exilis), are approximately 2 inches in diameter, while the giant kangaroo rats’ (Dipodomys ingens) burrows are as large as 5 inches wide. Kangaroo rats use dust baths, and these can often be found near the burrow entrance. Kangaroo rats sometimes use a soft dirt plug to close the burrow during the day, which helps maintain temperature and exclude predators. These soil plugs are close to the entrance of the burrow, whereas ground squirrels plug their burrow close to the nest, much further down the burrow system where the plug usually cannot be seen from aboveground. In California, many species of kangaroo rat are listed as threatened or endangered under the California Endangered Species Act. It is important to be aware of the presence of endangered species if you intend to control California ground squirrels. Burrowing Owls (Athene cunicularia)
Burrowing owls use abandoned rodent burrows for roosting and nesting. They may also dig their own burrows in areas where the soil is soft. Active burrowing owl burrows can be identified by examining the entrance for the presence of white excrement and prey pellets 0.35-0.55 inches wide. A close examination of the scat will reveal a dry, compact casting, containing purely feathers, fur and bones. |
(click map to enlarge)
|
(click map to enlarge)
|
(click map to enlarge)
|
(click map to enlarge)
|
Data for endangered species range maps created courtesy of IUCN (International Union for Conservation of Nature).
For more endangered and threatened species ranges, visit the IUCN Redlist.
For more endangered and threatened species ranges, visit the IUCN Redlist.
