gophers are burrowing rodents with stocky bodies, small ears and eyes,
and a sparsely-haired tail. They are adapted to an existence that
is almost entirely below-ground. Typically, pocket gophers appear
above ground to excavate soil to the surface or to disperse to new
areas. They are named for the large external fur-lined cheek pouches
that carry food or bedding material to underground caches or nests.
The lips of pocket gophers close behind the large incisors, giving
them a bucktoothed appearance. Powerful front shoulders and limbs
end in long claws that are adapted for excavating and moving hundreds
of pounds of soil in a year.
gopher is found throughout the country, particularly in alfalfa, pastures,
rangelands, and roadside areas. The smaller northern pocket gopher
is found in clay soils north of the Pine Ridge in northwestern Nebraska.
pocket gophers range in size from 1/3 to 1 pound . Larger animals
are about one-foot long, including a four-inch tail. Their short fur
ranges in color from a dark chocolate brown to a sandy brown. Pocket
gophers are not protected by law.
gophers usually live alone within their burrows, except during their
breeding season in late winter to spring. A single litter of three
to four young are born between March and May. Young leave their mother's
burrow during late summer and may travel above ground before digging
their own burrow. Each adult pocket gopher occupies its own burrow
system most of the year but animals in neighboring burrows can quickly
reoccupy a vacant burrow. Populations of pocket gophers may exist
at densities of one to eight animals per acre.
gophers usually forage below ground, feeding on roots and even pulling
plants down into their burrows and feeding on stems and leaves. Pocket
gophers prefer succulent forbs (prickly pear, dandelion) and legumes
(alfalfa) to grasses and will eat many kinds of plants, including
the roots of trees and garden vegetables. Pocket gophers deposit soil
castes under snow. These are deposits of excavated soil placed into
tunnels that are dug through the snow. The castes are seen in spring
when the snow melts. A single pocket gopher may exist within an extensive
system of feeding tunnels and chambers.
Pocket gophers create extensive burrow systems. The depth of their
feeding tunnels are typically 8 to 18 inches deep while their nest
chambers may be several feet below the surface of the soil. Tunnels
remain open throughout the year. During winter, the animals slow their
activity and periodically travel through existing tunnels to feed
on caches of roots, stems and leaves. Pocket gophers do most of their
mound-building in early spring and fall or in periods of wetter soil
conditions. Each pocket gopher can create dozens of mounds, sometimes
within a span of a few days. The burrow system of a pocket gopher
may cover more than one acre.
gophers excavate soil through newly opened lateral burrows that run
45 degrees to the soil surface. Mounds are fan- or bean-shaped, in
contrast to the conical shape of mounds of moles. Mounds of pocket
gophers may contain up to a bushel of soil whereas mole mounds are
Immediately after a mound
is made, the gopher plugs the burrow with soil to a depth of several
inches. Occasionally a lateral burrow is plugged without soil being
excavated or a mound created. Below and offset to the lateral burrows
lie the feeding burrows in which pocket gophers eat roots and pull
down plants through quarter-size holes.
gophers can cause extensive damage to native range, pasture, and hay
fields. They can also damage trees and shrubs in windbreaks, orchards,
and backyards, damage root crops in gardens, and create mounds that
damage turf in backyards, public parks, and golf courses. Through
their digging they can affect the integrity of airport runways, roadbeds,
dikes, canals, and other earthen structures. Gophers also gnaw into
buried utility cables and irrigation pipes. Their mounds damage or
slow hay harvesting equipment.
gophers adversely affect crops by directly feeding on roots, stems
and leaves, and by exposing plant roots to drying through their burrowing.
Gophers also cover growing plants with excavated soil. Pocket gophers
have reduced forage yield on some rangelands by 21 to 49 percent and
on hay meadows by as much as 30 percent. In irrigated alfalfa, yields
have been reduced as much as 17 percent and in dryland alfalfa as
much as 35 percent in those areas within fields that were occupied
by pocket gophers.
Pocket gophers girdle
the stems of young trees, chew or sever tree roots that are up to
6 inches in diameter, and can damage up to 10-year-old trees. Gophers
are particularly troublesome when they move through tunnels created
by tree-planting machines in windbreaks and eat the roots of young
trees. Occasionally, pocket gophers burrow through snow and damage
young tree trunks. Signs of gophers include a smooth gnawed surface,
with 1/8-inch-wide tooth marks, or deeply gnawed wood on stems that
leaves a sculptured effect. Mounds created by pocket gophers also
dull and plug hay harvesting equipment. Harvest operations are slowed
and labor and equipment costs rise when pocket gopher mounds are
Skunks, fox, bobcat,
weasels, hawks, owls, and bull-snakes feed on pocket gophers but
these predators have minimal affect on gopher numbers. This is probably
because gophers are rarely exposed above ground and plug their tunnels
immediately after excavating a mound. Pocket gophers also readily
block attempts by predators to dig into their tunnels by fending
them off with their strong teeth and claws, by retreating into their
extensive burrow system, or by pushing soil between them and would-be
predators. Pocket gophers play an important role in burrowing and
excavating soil that promotes the vertical cycling and mixing of
One objective in controlling damage caused by pocket gophers is to
reduce the population to a level where losses could be tolerated.
In forest plantations, research suggests that reducing populations
to two pocket gophers per acre is an economic level. No comparable
information is available for other crops or rangelands. Reduction
of pocket gopher numbers may be an appropriate objective for preventing
damage to high value cash crops when the manager does not have control
over adjacent areas that contain perennial populations of pocket gophers.
Another objective in managing damage is to eliminate populations entirely
within an area or a portion of a field where immigration of pocket
gophers in not a perennial problem. In this case, 100-foot buffers
surrounding the treated field should also receive control.
to Maintenance. Community Effort. Control and maintenance of pocket
gophers should be a community effort. Neighboring fields of perennial
grasses, like those in native rangelands, pastures, land enrolled
in the Conservation Reserve Program, and even roadside rights-of-way
contain pocket gophers that will immigrate into your protected fields.
Enlist the help of neighbors to develop a community-wide control program
to limit gopher populations in these source areas. Consider mowing,
cultivating or burning the source areas at the end of the growing
season to allow for better detection of mounds and subsequent control
of pocket gophers.
Patrols. Whether you use traps, concussion systems, toxic baits or
cultural methods, new animals will immigrate into your protected fields.
Mounds will most likely appear first near the edge of the field. Mounds
also appear near bales, loaves, or stacks of hay where the gopher
seeks warmth and food in the soil below. Once the initial control
program is complete, you should patrol the 100 feet outside of the
field perimeter at least three times during the growing season. To
maintain a 100-acre field, you will likely spend as little as one
hour (hand baiting) to six hours (trapping) three times each growing
Trapping requires much labor in both setting and checking the traps.
Trapping is best employed in fields up to 20 acres, in larger fields
that are sparsely or sporadically inhabited by pocket gophers, or
as a follow-up control with toxic baits. Trapping also can be used
as a substitute for chemical control in areas that are near surface
water or where there is a high water table. Labor costs for trapping
are about 35 percent higher than for baiting methods.
of traps are available for controlling pocket gophers .Three lethal
types are clutch-jawed, choker-loop, and box traps. Trap sizes vary
among models or brands. Select traps that relate to the average size
of pocket gophers in the local population.
technique, two traps are seated on the floor of the main burrow, pointing
in opposite directions. In another technique, a single trap is seated
on the floor of the lateral burrow. Some trappers prefer to close
the burrow entrance after setting traps while others leave the burrow
entrance open. The latter technique presumes that the gopher returns
to the trap site because of the light and air movement associated
with the opening. One caution in using this method is that pocket
gophers respond by pushing soil in front of them to close the opening.
Traps may be tripped by the soil rather than by the animal. Pocket
gophers quickly bury, and may even create new mounds, over top of
tripped traps. Always secure traps with a wire that leads to a stake
at the soil surface. This helps in retrieving either a buried trap
or one in which there is a wounded animal. Pocket gophers can inflict
painful bites, and extreme caution should be used in handling them.
may be used when placing two traps in the main burrow and when burrow
entrances are closed. Young carrots, tomatoes, and fresh alfalfa leaves
and roots have been used as bait.
Baits. Toxic baits can be applied belowground to pocket gopher burrows
in three ways: 1) hand baiting through opened mounds, 2) hand baiting
through holes opened above burrows and 3) machine baiting. Applying
bait aboveground for pocket gopher control is both ineffective and
baits have varying levels of effectiveness, ranging from 10 to 90
percent. As of February 2003, the only products registered for use
on pocket gophers include:
0.5% strychnine-treated grain baits
2% zinc phosphide-treated pellets and grain baits
63% concentrate powder of zinc phosphide
0.005% chlorophacinone pellets and grain baits
0.005% diphacinone bait bars
Both strychnine and zinc phosphide are single-dose poisons. Quantities
over 5 pounds of strychnine-treated bait and zinc-phosphide-treated
bait are Restricted Use Pesticides. Individuals that purchase or apply
the baits as commercial applicators must be certified by the U.S.
Environmental Protection Agency and licensed by the Nebraska Department
of Agriculture. Zinc phosphide should be rotated with other toxic
materials in a baiting program so that pocket gophers do not develop
a taste aversion to it.
and diphacinone act as an anticoagulant. Gophers must eat repeated
applications of bait for it to have a lethal effect. Both chlorophacinone
and diphacinone are General Use Pesticides. Check for current registrations
with the Department of Agriculture and follow all pesticide label
instructions before purchasing or applying toxic baits.
a) two-foot length of stiff wire or a long-handled screwdriver for
probing, b) long-handled spade or spoon or a hand trowel for digging,
c) a funnel for dispensing bait, and d) a flag for marking mounds.
Several tools may be useful for hand baiting (Figure 5). To place
bait into a pocket gopher's burrow, dig through the mound and soil
plug or use a probe to directly enter the burrow from above. To dig,
choose a freshly excavated mound that is small and bean- or fan-shaped.
recently excavated mounds generally are at the perimeter of the burrow
system. Use a 2-foot length of 9-gauge wire or a long screwdriver
blade to probe through the mound on the concave side or at the apex
of the fan to locate the soil plug and the open burrow below (Figure
Figure 6. Probing through the soil plug.
Use a hand trowel or small shovel to excavate through the plug. Place
a quantity of bait specified by the label (usually a teaspoonful)
deep into the burrow using a long-handled spoon. Bait bars also can
be applied using this technique. To probe and enter a burrow from
above, use a pointed 3/8-inch diameter metal rod to probe about 12
to 18 inches from the concave side of the mound. The burrow will typically
lie from 8 to 18 inches below the surface. The probe will accelerate
as you enter the burrow. Apply bait through the opening made by the
results when hand baiting, apply baits to all freshly excavated mounds.
A pocket gopher may excavate several mounds at different areas of
its tunnel system. Apply bait at two to five locations within a single
tunnel system so the animal quickly consumes the bait. Baits that
remain in the tunnel will be consumed by gophers that subsequently
enter the system.
Baiting. Machine baiting can be done by using a tractor-drawn burrow-building
machine or "gopher getter" to create tunnels in which bait
is applied. Gophers enter the tunnels created by the machine during
their normal digging activities and find the bait. Several models
of burrow builders are available. Custom rates for burrow builder
operations usually start at about $5.00 per acre at 2003 prices. For
detailed information see your Cooperative Extension office near you.
and Time of Baiting. Regardless of the application method, toxic baits
can be of most benefit when applied during early March or April, when
pocket gophers are most active and their populations are at their
lowest. Toxic baits are effective at any time of year when applied
in tunnels below new mounds. In hand or probe-applied baiting, if
new mounds appear within three to seven days, apply toxic baits again.
Burrow builders are typically used in alfalfa before spring growth
and after the last harvest of the crop. New mounds may appear for
10 to 14 days after burrow builders are used because it usually takes
time for the pocket gophers to find the baits in the machine-made
Generally, fumigants are not effective in controlling pocket gophers.
The effects of fumigants are reduced when pocket gophers respond to
the gases by blocking the tunnels, Fumigants are unlikely to spread
through the extensive burrow system, particularly if they are not
similar in weight to the air that exists within the burrows.
fumigants are registered for controlling pocket gophers: tablets or
pellets of 55 percent - 60 percent aluminum phosphide, and gas cartridges
with various active ingredients. Products that contain aluminum phosphide
are Restricted Use Pesticides. Gas cartridges are General Use Pesticides
and are commonly sold at discount stores and lawn, garden, or farm
supply stores. Aluminum phosphide slowly releases a toxic gas over
a period of hours while gas cartridges are ignited and burn quickly
while eliminating the oxygen within the burrow. Fumigants are applied
into the burrow as in the procedure for hand baiting. The burrow entrance
is then closed with soil, being careful not to cover the pellet, tablet,
or burning cartridge. Low soil moisture can reduce the effect of aluminum
phosphide or of gas cartridges.
ranch managers, orchardists, and others, can do a more thorough evaluation
by flagging at least 25 mounds in separate burrow systems within the
treatment area. Open each burrow with a hand trowel and revisit the
opened holes about 24 to 48 hours later. When using anticoagulant
baits, wait at least two weeks to open holes and evaluate your success.
If machine baiting with burrow builders, wait at least one week to
Mounds. Hand or tractor-drawn implements can be used to scrape or
rake the mounds to spread the soil over the surface. You can then
examine a field for any new mounds that may appear in the days following
treatment . You can also reduce the damage caused by mounds during
harvest operation by spreading the soil away from the mounds.
Underground cable or pipe can be protected by backfilling the trench
with 6 inches of large gravel 1-inch or greater in diameter to surround
the pipe. Cable companies use steel armor or spaced wire basket protectors
around the cable to protect them from gophers.
that is greater than 2.1 inches in diameter for underground water
lines or conduit. They are much less likely to be gnawed than pipes
of a smaller diameter because pocket gophers cannot gain a purchase
with their teeth.
Methods. Eliminate weeds and other broad-leaved plants in grasslands
by hand digging or by using herbicides. Alfalfa that borders range,
pastures, or other perennial crops is more susceptible to pocket gopher
damage than alfalfa that borders weed-free, clean-tilled row crops.
Small grain crops can also serve as buffers around alfalfa or tree
crop rotations, row crops used in two successive years with alfalfa
can reduce pocket gopher populations. Also, try varieties of alfalfa
that are less susceptible to damage from pocket gophers. Use varieties
with fibrous roots rather than a single taproot or with crowns that
are broad and positioned close to the soil surface, instead of those
with crowns that are small and partially elevated.
Work. Repellents, like moth balls, and others do not work because
the animal may likely close and reroute its burrows, even if the odor
or taste is obnoxious to them. Plants, like chrysanthemum, castor
bean (Ricinus), and "gopher" spurge (Euphorbia) have not
been proven as repelling to pocket gophers.
like capsaicin, have been used to reduce gnawing on buried cable,
but no products are currently registered for use against pocket gophers.
Electronic, magnetic, and vibrating devices have not been proven as
effective. Barn owl nest boxes and perch poles have been used to promote
owl predation but there is no evidence that this reduces damage by