Names and Classification
Thomomys bottae. French settlers may have named gophers, applying a word for honeycomb or waffle (gaufre), perhaps because the unfamiliar New World creatures honeycomb the ground with their burrows, leaving surface mounds and indentations resembling a waffle. The pocket in their name refers to two fur-lined cheek pouches used for carrying food and nest materials. Other rodent families use their cheeks for shopping bags, but gopher pockets open outside the mouth, can extend back to the shoulders, and can be turned inside out for emptying!
Endemic to North and Central America, pocket gophers are burrowing rodents in the family Geomyidae. Taxonomy is in flux, but there is a handful of genera (five or six) within the family, and about three dozen species. The Thomomys genus is also known as western pocket gophers. The species name honors Paul-Emile Botta, a naturalist and archeologist who collected mammals in California in 1820s–1830s.
Range and Habitat
Botta’s pocket gophers live almost everywhere in California, and much of the West, limited only by major rivers, barren deserts or rocky terrain. They’re at home in a variety of soil types and habitats, including grasslands, chaparral, scrubland, and woodlands, as well as agricultural lands and suburbs. This wide range is possible partly because western pocket gophers rely more on their teeth for digging. Most gophers dig primarily with their claws, which are softer and wear down faster, limiting them to softer soils. Look for gophers in Edgewood’s grasslands.
What to Look for and Notice
It’s easy to see the work gophers do, but it usually takes patience to see a gopher. Keep your eyes open for asymmetric mounds of fresh soil! A gopher can make several mounds a day. As it digs tunnels searching for food, it periodically pushes loosened dirt up to the surface with its head and front legs. The debris is pushed ahead, right and left, creating mounds shaped like fans, or hearts.
Tunnels (up to 200 yards-worth per burrow system) are generally one-way (~3-inch diameter) so gophers somersault to turn around. A burrow system typically includes long, shallow (~4–12-inch deep) tunnels for foraging, and deeper (up to 6 feet!) tunnels and chambers used for larders, latrines or nesting. Burrow systems are closely regulated microenvironments, and any opening gets plugged within a day. Thus, an open hole with fresh dirt might mean the occupant is still digging. Hang around quietly and you might see a gopher.
Built like blunt torpedoes with short, strong legs, gophers are adapted for digging and tunneling. Roughly 7 to 10 inches long, including about 2 inches of tail, they have large claws on their front paws, and small eyes and ears. Large, ever-growing front teeth loosen soils and rocks, and also chomp roots. Their lips close behind those incisors, preventing mouthfuls of soil. Sensitive whiskers help find the way forward, and gophers run backward almost as fast as forward, probably aided by their sparsely-haired tails. Short, rich brown fur can trend reddish or yellowish, often closely resembling local soil color.
Life and Behavior
Pocket gophers are territorial and solitary, except during breeding season when young live with their mother. Males are larger, nearly double the weight of females. Their territories are larger too. Gophers aggressively defend areas bigger than their own burrow systems, maintaining unoccupied “demilitarized zones” between neighboring burrow systems. Where food is abundant they can breed year-round, but in general, they breed early spring to early summer, producing one litter of 3 to 5 pups. (Gestation ~18 days.) Born hairless and blind, pups remain in the nest for 5–6 weeks before wandering off (above ground) to establish their own territories. They live one to two years. Gophers spend nearly all their time underground, but may emerge at night to forage. They’re active year-round, about 9 hours a day, at any hour. They’re quiet creatures, but communicate with clicking noises, soft hisses and squeaks.
What They Eat, and Who Eats Them
Gophers eat vegetation only—a LOT of it— including plant parts encountered underground, as well as leaves and stems of plants around tunnel entrances. They find food by sense of smell, and get enough moisture from their diet, so don’t need a water source. They eat a lot for their body size, possibly because they use so much energy digging. They’re choosy about the plant parts and species they eat, possibly for the same energetic reasons.
Birds of prey catch gophers above ground — hawks by day, owls at night. Coyotes, foxes, bobcats, domestic dogs and cats catch gophers at burrow entrances, and by digging. Other predators hunt them down in their burrows, including skunks, rattlesnakes, and gopher snakes, as well as badgers and some weasels. (The last two are not found at Edgewood.)
Roles in Ecosystem
Sometimes nicknamed “Nature’s rototillers”, their constant burrowing helps keep soil loosened and aerated, while burying vegetation that enriches the soil. Depending on circumstances (soil, climate, etc.), a single gopher may rearrange more than two tons of soil in a year, mostly below ground. The flora of gopher mounds often differs from surrounding areas, and their presence can increase plant diversity. Gopher holes/burrows can capture runoff, allowing it to sink in, which can conserve both water and soil. But, extensive burrowing sometimes increases erosion on slopes. Gophers can kill trees and sometimes become pests in agricultural areas. A variety of other animals use their burrows, and as herbivores gophers turn plants into meat.
Not to Be Confused with…!
The word “gopher” sometimes gets used loosely to refer to any burrowing animal, but nothing else is like a true pocket gopher. Ground squirrels are rodents, but they’re not closely related to gophers, and none live at Edgewood. (Think chipmunks or prairie dogs, which are easy to spot running around in daytime.)
Like gophers, moles live alone underground, rarely leaving their tunnels. Moles create somewhat similar earthworks, and are generally beneficial for similar “rototilling” reasons. But moles are smaller, and their mounds tend to be symmetrically conical. Moles are insectivores, not rodents. They prefer moist areas where they eat earthworms, snails, grubs, and insects.
Where should I look for signs of gophers at Edgewood?
Gopher mounds and sometimes open holes are easily seen along the trail in grassslands, in the Day Camp lawn area, and woodland clearings like those near the intersection of the Sylvan and Baywood Glen Trails. Digging can continue year-round, but in drier areas like Edgewood, you may notice more mounds in spring or fall, when moister soil makes digging easier, and mounds more obvious.
How often do people observe gophers at Edgewood?
In the rainy season and spring, when green vegetation is plentiful, day hikers occasionally (not too often) see gophers foraging from just inside the gopher’s hole. If you spot a a gopher’s upper body popping back into a hole, stop about 10 feet away. If you are still and quiet, the gopher may emerge again to reach its mouth toward greens around the entrance of its home.
Can I see signs gophers are affecting their environment?
During the spring, watch for seedlings growing in the loose soil of gopher mounds.
Family Geomyidae. Animal Diversity Web.
Thomomys bottae Botta’s pocket gopher. Animal Diversity Web.
Botta’s pocket gopher Thomomys bottae. Ojai Valley Land Trust.
Botta’s pocket gopher. California Department of Fish & Wildlife Range Map.
By Carolyn J. Strange. Science writer Carolyn J. Strange has written hundreds of articles. She became an Edgewood neighbor in 1998, a Friends of Edgewood docent in 2003, and has served the Friends of Edgewood in various ways ever since.
All photos taken at Edgewood Park and Natural Preserve. Used with permission.