Other Rodents
There are several other rodent species that can be found in Alameda County, including gophers, ground squirrels, tree squirrels, voles, deer mice, and wood rats. Some of these are widespread over a large geographical area, whereas others have a more restricted range. Some are considered native species, and some are considered nonnative. There are also differences in their diurnal/nocturnal patterns, whether they are burrowing or arboreal, their diets, and their commensal tendencies.
Vector Significance
- Many rodent species can harbor ectoparasites such as fleas, lice, or mites.
- Some are associated with specific pathogens such as hantavirus, plague bacteria and the Lyme disease bacteria.
- Yet still others may cause distress for property owners by damaging structures, landscapes, or gardens.
Vector Control Services
District Vector Control Biologists can:
- Identify the species of rodent that is present.
- Educate the public on the biology, ecology, and management of the species in question.
- Survey for disease when warranted
Requesting Services
What can the public do?
- Observe and report any signs of rodents. Early detections are important to prevent an escalation of rodent activity.
- Once the rodent species has been identified, appropriate habitat modifications and strategies such as vegetation removal, exclusion and trapping can be employed.
- In some cases, professional pest control may be needed to address challenging conditions.
Types of Other Rodents
Ground Squirrels
Ground squirrels (family: Sciuridae) are burrowing rodents commonly found in open habitats such as fields, parks, and golf courses. The group is diurnal and are often observed foraging close to burrow holes in the daytime. The California ground squirrel (Otospermophilus beecheyi) is commonly encountered in Alameda County, where it uses underground burrows to escape predators, store food, raise young, and sleep. The earthen tunnels they dig can reach up to six feet down and branch extensively throughout the substrate.
Fox Squirrels
The eastern fox squirrel (Sciurus niger) is very common in Alameda County. Originally native to the Eastern United States, this species was introduced to California about 100 years ago. They are gray with orange-colored fur on the belly and a long bushy gray tail with orange on the sides. Fox squirrels can live up to six years and females typically have 1-2 litters per year with 1-5 young in each litter. They are most active in the morning and late afternoon. They nest high above ground, usually in holes and cavities of trees.
Gophers
Of the five species of gophers found in California, Thomomys bottae is the most common in Alameda County. They are digging, tunneling rodents that typically remain underground in their burrow system and are active year-round. Gophers are omnivorous, feeding on tubers, leaves, and the stems from shrubs and trees. They chew the roots of plants from their tunnels and may pull the entire plant into the tunnel. Crescent-shaped mounds of soil are an indication of a gopher’s presence.
Voles
In Alameda County, the most widespread vole is the California vole, Microtus californicus. They spend most of their time below ground in their burrow system and are active day and night. Voles can reproduce rapidly and under favorable conditions populations can reach very high numbers. They are primarily herbivores, feeding on grasses and herbaceous plants. They are considered poor climbers and rarely enter homes.
Deer Mice
The deer mouse (Peromyscus maniculatus), or western deer mouse, is commonly found in California, but its distribution ranges from Mexico up to Alaska. Deer mice are similar in size to the house mouse but are easily distinguished by their bicolored tail. They can be found in a variety of habitats and are mainly grain feeders. They are known to inhabit vacated buildings, cabins, and other structures. In Alameda County they are primarily found where housing abuts more open lands/fields/forests.
Wood Rats
There are five species of wood rats in California. In Alameda County the dusky footed wood rat (Neotoma fuscipes) is the most common. They are primarily herbivorous and build large nests, called “middens”. They are commonly called “packrats” due to their habit of collecting and stashing small objects in their nests.