  Pocket
Gophers | |
Geomyidae
Members
of family Geomyidae, the pocket gophers, are fossorial (burrowing) rodents
and spend most of their time below ground. They do not hibernate, but rather
they store food in underground chambers for use in the winter. During the
winter, they are able to expand their range by burrowing into the snow at
the surface of thin layers of soil that are too shallow to burrow in during
the summer and feed on vegetation. They are named "pocket gophers" because
of the external, fur-lined pouches on each side of their cheeks. They carry
food and nesting materials in these pouches and literally squeeze the material
out with their forepaws.
Pocket
gophers are well adapted to a fossorial
existence. Their bodies
are tube-shaped with very small eyes, and ears and short and smooth fur that
allows them to easily move forward or backward in cramped tunnels underground.
They have a short, nearly hairless tail. Their lips close behind their incisors,
a useful adaptation for gnawing and nipping roots underground without getting
a mouthful of soil. They have long claws on their forepaws which allows them
to dig and move soil very efficiently.
They may be very important ecologically in Idaho. They are known to excavate vast amounts of soil. A study in Yellowstone National Park estimated that one pocket gopher may excavate as much as 5 tons of soil each year. Consider what it would be like to excavate that much soil with two teaspoons, and you get the idea that they are very efficient diggers. This excavation occurs because they dig very extensive burrow systems. They typically have two tunnel systems, one near the surface of the ground for foraging for food, and a much deeper one that seems to serve primarily for nesting and shelter, as a nursery for female gophers, and perhaps for storing food. Their underground tunnels have been found to be up to 500 feet in length. This extensive digging activity allows rainfall and snowmelt to more effectively permeate the soil, which is important in Idaho since much of our state has limited rainfall. Research has show that their digging activity influences moisture retention in the soil and plant distribution. Additionally, one study in Colorado documented that at least 22 species of vertebrates utilized pocket gopher burrows including snakes, lizards, ground squirrels, mice and others. Their food storing habits have provided an important food source for grizzly bears where grizzlies are found in Idaho. Grizzlies dig up pocket gopher burrows to get at their storage chambers which contain roots, bulbs and other plant parts, which is great food for bears.