Botta’s Pocket Gopher
Also known as: Valley Pocket Gopher
Thomomys bottae
Characteristics
Five species of pocket gophers are found in California, with Botta’s pocket gopher, T. bottae, being most widespread. Depending on the species, they are 6 to 10 inches long, weighing a few hundred grams. Within any species, the males are larger than the females and can be nearly double their weight. Most gophers have brown fur that often closely matches the color of the soil in which they live. Their most characteristic features are their large cheek pouches, from which the word “pocket” in their name derives. These pouches are fur-lined, and can be turned inside out. They extend from the side of the mouth well back onto the shoulders. They have small eyes and a short, hairy tail, which they use to feel around tunnels when they walk backwards. The teeth of the pocket gopher continuously grow to accommodate the near constant wear and tear exerted upon them.
Habitat
A gopher needs dirt, an area of ground in which to build a home, mostly ruderal plant species to eat, and an area that is not inundated with water to survive. Gophers breathe air like we do, and if the soil is soaked with water, no oxygen will be present and they will suffocate.
The pocket gophers burrow system will typically consist of a main burrow with a number of laterals branching off from it. Systems found to be linear rather than branched are believed to belong to a male pocket gopher searching for a mate. Burrow diameters tend to be around 3 inches; areas larger than this diameter are believed to be resting or feeding areas. The nesting area of the pocket gopher will be filled with grass and other plant debris that the pocket gopher has formed into a ball – some as deep as 5 or 6 feet underground. A single pocket gopher can dig a burrow system consisting of up to 200 yards of tunnel in a year displacing as much as 2 ¼ tons of soil.
Diet
Pocket gophers are voracious herbivores; although they tend to prefer forbs and roots the pocket gopher will eat nearly any type of plant it comes across including grasses, shrubs, seedlings, and trees. Any animal matter consumed in its diet would most likely have been ingested by accident. Pocket gophers are most likely to consume plants in one of the following ways:
- Root feeding on plants they come across while foraging for food or searching for a mate. The pocket gopher commonly will clip the roots off below the surface where the damage done is not apparent. Occasionally the pocket gopher will clip the base of a plant to just above the surface.
- Pulling plants down into their tunnel from below.
- Occasionally the pocket gopher will venture up to a body length from its burrow opening to consume surface vegetation. This activity only seems to happen during the growing season.
Behavior
Gophers are active all year around, and live underground, in burrows that they dig themselves. Pocket gophers find their food by sense of smell. They either dig a tunnel toward a good smelling plant, or come upon the plant randomly in their digging, smell the plant, and then either pull the plant into their tunnel and eat it, or chew on the roots of the plant, or continue digging. Also, gophers take their food down into their burrow and store it for later use, and the burrow can be 6 feet or deeper below the surface. They don’t see or hear too well, and use the whiskers on their face and hairs on their tail to help them navigate their way around their underground world.
Only one gopher lives in each burrow system consisting of a main burrow and burrow side branches, and between each burrow system is a zone not used by any gopher; this zone is kind of like a demilitarized zone, a space that neither neighboring gopher uses, maybe to reduce conflict (gophers are very territorial). Pocket gophers expend so much energy building their burrows, many, many times more than any animal aboveground, that they probably have no extra energy for fighting. Their territory (their burrow system) size, and the size of the “demilitarized zone” changes somewhat depending on the amount and quality of plant material (food) present.
Pocket gophers expel the soil they excavate from the burrow in a fan shape radiating away from the burrow opening. They will use both their claws and teeth while digging, pushing the soil and debris behind them with hind claws, then flip over in a somersault motion and push the material out of the burrow with their forefeet and chest.
Breeding
Depending on the species and local conditions, pocket gophers may have a specific annual breeding season, or may breed repeatedly through the year. Each litter typically consists of 2 to 5 young, although this may be much higher in some species. The young are born blind and helpless, and are weaned at around 40 days. Pocket gophers reach sexual maturity about 1 year of age and can live up to 3 years.
Positive Actions – The Purpose of a Gopher
What is the real purpose of gophers? No one really knows, but here are a few observations researchers have noted so far.
Gophers mix and aerate the soil, bringing deeper layers of soil to the surface when they create the soil mounds, where, over time, the effects of light, water and wind, make those soil minerals available to plants. Thus soil fertility is increased. Aerating the soil adds oxygen, which aids the growth of certain plant species. The activities of gophers increase plant diversity, as different species of plants grow on those soil mounds, plants whose germination and growth were inhibited in the surrounding soil. The mounds of soil they push to the surface in the process of digging their tunnels actually reduce erosion on steep slopes. Scientists have speculated that gophers may help to prevent the extinction of certain ruderal/early successional plant species (whose seeds may only have a certain life span), by periodically providing the perfect growing conditions for their germination and growth, in a natural plant community, such as a forest.
When a gopher leaves the area and moves to a new spot with fresh plant material, the burrow system that the gopher has abandoned becomes a home for a toad, snake, etc.
Predators
Main predators of this species include coyotes, long-tailed weasels and snakes, but other predators include skunks, owls, bobcats, and hawks.
References
Botta’s pocket gopher, from Wikipedia, the free encyclopedia
Pocket gopher, from Wikipedia, the free encyclopedia
Pocket Gophers (Thomomys bottae), www.laspilitas.com/animals/thomomys/thomomys-bottae.htm
How to Manage Pests; Pests in Gardens and Landscapes; Pocket Gophers; University of California Agriculture & Natural Resources, UC IPM Online, Statewide Integrated Pest Management Program
www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7433.html
Pocket Gophers and Pocket Gopher Control;
