Pocket Gophers (Geomyidae)

views updated

Pocket gophers

(Geomyidae)

Class Mammalia

Order Rodentia

Suborder Sciurognathi

Family Geomyidae


Thumbnail description
Small- to medium-sized herbivores, characterized by a tube-shaped body, small eyes and ears, short tail, short but stout forelimbs, and small hindlimbs

Size
5–14 in (13–36 cm); 0.13–3.1 lb (60–1,400 g)

Number of genera, species
6 genera; 36 species

Habitat
Meadows, prairies, woodlands, and deserts

Conservation status
Critically Endangered: 2 species; Endangered: 1 species; Vulnerable: 2 species; Lower Risk/Near Threatened: 10 species

Distribution
North, central, and northwestern North America

Evolution and systematics

Pocket gophers have an extensive fossil record that dates back to the late Oligocene or early Miocene of North America, approximately 25 million years ago. The closest living relatives to pocket gophers are members of the rodent family Heteromyidae, which includes kangaroo rats (Dipodomys) and pocket mice (Chaetodipus and Perognathus).

Living pocket gophers comprise two major lineages, one of which contains only a single living genus, Thomomys, the other containing the living genera Geomys, Cratogeomys, Orthogeomys, Pappogeomys, and Zygogeomys. Molecular analyses of DNA sequences support this basic subdivision within the family Geomyidae. Pocket gophers are most diverse in Mexico, where representatives of all six genera (and 22 of the 36 species) can be found.

Evolutionary relationships among species of pocket gophers have been compared to the relationships among species of chewing lice that live in the pocket gopher's fur. Surprisingly, the louse relationships almost exactly mirror the relationships among their hosts (a phenomenon known as "cospeciation"), which suggests that lice and pocket gophers have been living together for many millions of years.

Physical characteristics

Pocket gophers are extraordinarily well adapted for life in subterranean tunnels. Their body is tubular in shape, which permits them to travel rapidly both forwards and backwards in tunnels. Their eyes and external ears (pinnae) are reduced in size, and numerous hairs around the eyes and ears prevent the entry of soil. Pocket gophers have relatively short limbs and a short, almost hairless tail. Most digging is accomplished using the claws of the powerful forefeet, but the large, procumbent, and blade-like incisor teeth also are used on occasion for digging. While digging, the pocket gopher's lips can be closed behind the incisors to prevent soil from entering the mouth. Although short, the forelegs are stout, with

broad hands and long, curved claws. These powerful digging appendages can also be used to push large quantities of earth within the burrow.

Pocket gophers have cheek pouches that open external to the mouth and extend from the mouth region to the animal's shoulders (hence the common name "pocket" gopher). These commodious pouches are lined with fur and are used to transport food and nest material (but not soil) within the burrow system. When full, the pouches make the pocket gopher's head appear almost twice its natural size. The fur of pocket gophers is generally short and may be very sparse in species living in hot, tropical environments. Fur color varies widely, even within a species, and tends to match the color of freshly excavated soil (generally light brown to almost black). This camouflage appears to be an adaptation to hide the animal from aerial predators such as hawks when the pocket gopher is pushing excavated soil onto the surface.

Distribution

Pocket gophers are found only in the Western Hemisphere, where their range extends from southern Canada through western North America, southward to northwestern Colombia in South America. One isolated species, Geomys

pinetis, occurs in the southeastern United States (Alabama, Georgia, and Florida).

Habitat

Pocket gophers live in almost any habitat that contains friable soil and does not flood. They are known from meadows, prairies, woodlands, alpine forests, valleys, deserts, rainforests, and agricultural fields. Neither elevation nor temperature seem to limit pocket gopher distibution—they are known from hot desert habitats at sea level and also from cold, high-elevation habitats near timberline. Pocket gophers live in a wide variety of plant communities where they feed on the roots and tubers of many species of plants. They are especially abundant in agricultural fields and seem to prefer alfalfa, potato, banana, and sugar cane crops.

Behavior

Pocket gophers are extremely asocial mammals that generally live alone in their burrow systems. The population density of pocket gophers tends to vary widely among habitats, depending on the availability of food resources. Numbers of individuals may be fewer than 50 to as many as several hundred individuals per acre (0.4 ha). Their burrow systems are easily recognized by the characteristic mounds of earth (generally five to 20 per burrow system) that have rounded rather

than conical tops. Burrow entrances are usually plugged with soil when not in use. Where gophers occur in high numbers, the spacing of individual burrow systems is highly uniform, producing a buffer zone between burrows. This pattern is evident even in areas that differ widely in food availability, which suggests that the buffer zones are related to social interactions among pocket gophers, rather than food availability. Although pocket gophers live in almost continual darkness, they are generally crepuscular (active mainly at dawn and dusk), and some species are nocturnal. Pocket gophers are active all year and do not hibernate.

Pocket gophers display a remarkable amount of burrowing activity, and they, like beavers, have caused numerous changes in the landscape. Estimates of the amount of soil moved by pocket gophers in a single year range from 4.4–74.5 cubic yd (3.4–57 cubic m) per acre (0.4 ha). The disturbance resulting from this burrowing activity alters both physical and biotic processes in the local environment. Although pocket gophers eat voraciously, the net long-term effect of their presence is an increase in plant biomass, probably because of the effect of their excavations on soil nutrients. Pocket gophers also spread roots,

tubers, and other plant parts as a result of their burrowing activities, and thus they contribute to the distribution of plant life in their communities. The energetic cost of the subterranean lifestyle is extraordinarily high. Thus, the advantages of living in a subterranean burrow system—including protection from predators and extreme climatic fluctuations—must be very important to pocket gopher survival.

Feeding ecology and diet

Most mammals that burrow into the earth do so simply for shelter or dens. Pocket gophers, however, actually forage through the earth in search of food, and they leave behind them a complex network of tunnels, which they also use for shelter and nesting. Pocket gophers are strict herbivores that feed on the underground parts of plants, especially the succulent parts such as bulbs and tubers. Occasionally, pocket gophers will eat the aboveground stems and leaves of forbs located near their burrow entrances. The horizontal feeding tunnels produced by pocket gophers are usually dug at the depth of greatest root density, approximately 2–8 in (6–20 cm) below the surface. In contrast, their nest and food storage chambers may be as deep as 4.9–6.5 ft (1.5–2 m).

Reproductive biology

Pocket gophers generally breed only once per year (usually in spring), although some species are capable of producing two litters per year (spring and fall) if conditions permit. During the breeding season, reproductively mature females will allow males to enter their burrow systems for brief mating encounters. The gestation period ranges from 18 days in smaller species to more than a month in the larger species. Litter size varies widely among pocket gopher species, ranging from one to 10 young per litter, with an average of three to five young. Young pocket gophers remain in their mother's burrow for one to two months, at which time they disperse in search of a place to dig their own burrow system. Some species reach reproductive maturity at only three months of age, whereas others do not breed until they are nine to 12 months of age. Adult body size is usually attained at an age of five to nine months.

Conservation status

Fifteen species of pocket gophers are listed on the World Conservation Union (IUCN) Red List. These include two species listed as Critically Endangered (Cratogeomys neglectus and Orthogeomys cuniculus), one species listed as Endangered (Zygogeomys trichopus), two listed as Vulnerable (Geomys tropicalis and Pappogeomys alcorni), and 10 additional species listed as Lower Risk/Near Threatened.

Most of the threatened species of pocket gophers occur naturally in low abundance within restricted habitats. Current threats to these pocket gophers include competition from other gopher species and, in the case of Geomys tropicalis, loss of habitat caused by urban expansion of humans.

Significance to humans

Pocket gophers are widely considered to be agricultural pests. In tropical areas, a single pocket gopher can destroy a family's garden in less than a month. Commercial agriculturalists regularly trap or poison pocket gophers to limit loss of crops. Early Native Americans are known to have consumed pocket gophers, and it is reported that in some areas of Latin America local people regard the meat of pocket gophers as a delicacy.

Species accounts

List of Species

Valley pocket gopher
Plains pocket gopher
Michoacán pocket gopher
Large pocket gopher
Yellow-faced pocket gopher
Querétaro pocket gopher
Buller's pocket gopher

Valley pocket gopher

Thomomys bottae

taxonomy

Thomomys bottae (Eydoux and Gervais, 1836), coast of California, United States. One hundred ninety-one subspecies.

other common names

English: Smooth-toothed pocket gopher, western pocket gopher; Spanish: Tuza, topo.

physical characteristics

Head and body length 6–13 in (15–33 cm); weight 1.6–21 oz (45–600 g). Color ranges from pale gray to russet to black.

distribution

Western United States into northern Mexico. Sea level to approximately 10,000 ft (3,000 m).

habitat

Common in valleys, woodlands, deserts, and agricultural fields.

behavior

Lives singly in subterranean burrow system; asocial and aggressive toward individuals of same species, except during breeding season when brief mating encounters occur.

feeding ecology and diet

Herbivorous; burrows through the soil in search of roots and tubers. Occasionally feeds on surface vegetation near entrance to burrow.

reproductive biology

Polygamous. Breeds once, sometimes twice per year (spring and fall); generally two to four young per litter.

conservation status

Not threatened.

significance to humans

Common lawn, garden, and agricultural pest in some regions.


Plains pocket gopher

Geomys bursarius

taxonomy

Geomys bursarius (Shaw, 1800), upper Mississippi Valley, United States. Twenty-one subspecies.

other common names

English: Eastern pocket gopher.

physical characteristics

Head and body length 6–13 in (15–36 cm); weight 7–21 oz (200–600 g). Color ranges from pale brown to black.

distribution

Extreme southern Manitoba, Canada through southern Texas.

habitat

Common in plains, valleys, woodlands, and agricultural fields.

behavior

Lives singly in subterranean burrow system; asocial and aggressive toward individuals of same species, except during breeding season when brief mating encounters occur.

feeding ecology and diet

Herbivorous; burrows through the soil in search of roots and tubers. Occasionally feeds on surface vegetation near entrance to burrow.

reproductive biology

Polygamous. Breeds once, sometimes twice per year (spring and fall); generally one to three young per litter.

conservation status

Not threatened.

significance to humans

Common lawn, garden, and agricultural pest in some regions.


Michoacán pocket gopher

Zygogeomys trichopus

taxonomy

Zygogeomys trichopus Merriam, 1895, Michoacán, Mexico. Two subspecies.

other common names

None known.

physical characteristics

Head and body length 10–13 in (26–36 cm); weight 7–21 oz (200–600 g).

distribution

Known only from four isolated localities in central Michoacán, Mexico.

habitat

Small clearings in pine, spruce, and alder forests between approximately 3,000–10,000 ft (900–3,000 m).

behavior

Lives singly in subterranean burrow system; asocial, but less aggressive than other species of pocket gopher; surface mounds are tall and conical, unlike those of all other species.

feeding ecology and diet

Herbivorous; burrows through the soil in search of roots and tubers. Unlike all other pocket gopher species, Zygogeomys trichopus is not known to feed on surface vegetation near the entrance to its burrow.

reproductive biology

Unknown; probably breeds once per year; a pregnant female with a single embryo was captured in the month of December.

conservation status

Listed on the IUCN Red List as Endangered; known only from small, isolated populations that may be threatened by competition from other species of pocket gophers and habitat destruction by humans.

significance to humans

None at present, although human populations are expanding into the high-elevation habitat characteristic of this species.


Large pocket gopher

Orthogeomys grandis

taxonomy

Orthogeomys grandis (Thomas, 1893), Dueñas, Guatemala. Sixteen subspecies.

other common names

English: Giant pocket gopher.

physical characteristics

Head and body length 12–18 in (31–44 cm); weight 18–34 oz (500–950 g). Color is dark brown or black above and paler below.

distribution

Western regions of southern Mexico, Guatemala, El Salvador, and Honduras.

habitat

Variable, from arid tropical lowlands to moist tropical forests at higher elevations. Sea level to approximately 10,000 ft (3,000 m).

behavior

Lives singly in subterranean burrow system; primarily nocturnal and less active than most other species.

feeding ecology and diet

Herbivorous; burrows through the soil in search of roots and tubers. Diet also includes the roots of cultivated plants, including banana trees and sugar cane.

reproductive biology

Unknown; may breed throughout the year, as do other species in this genus.

conservation status

Not threatened.

significance to humans

This species is considered a major agricultural pest, and in many areas of Latin America, professional tuceros (pocket gopher catchers) charge farmers a small price to remove pocket gophers from their land. Many Mexican villages have a tucero, and it is said that the job is respected and passed from father to son. In some areas of Latin America, local people regard the meat of Orthogeomys grandis as a delicacy.


Yellow-faced pocket gopher

Cratogeomys castanops

taxonomy

Cratogeomys castanops (Baird, 1852), Colorado, United States. Twenty-five subspecies.

other common names

None known.

physical characteristics

Head and body length 8–16 in (20–40 cm); weight 8–53 oz (230–1,500 g). Color is yellowish brown and paler below.

distribution

Western United States (Colorado and Kansas) southward through northcentral Mexico.

habitat

Common in grassy plains, deserts, tropical lowland forests, montane forests, and agricultural fields. Sea level to approximately 12,000 ft (3,700 m).

behavior

Lives singly in subterranean burrow system; asocial and aggressive toward individuals of same species, except during breeding season when brief mating encounters occur.

feeding ecology and diet

Herbivorous; burrows through the soil in search of roots and tubers. Occasionally feeds on surface vegetation near entrance to burrow. Occurs commonly in agricultural areas, especially alfalfa, banana, corn, and sugar cane fields.

reproductive biology

Polygamous. May breed only once per year (spring) in the north and throughout the year in the south; generally one to three young per litter.

conservation status

Not threatened.

significance to humans

Common lawn, garden, and agricultural pest in some regions.


Querétaro pocket gopher

Cratogeomys neglectus

taxonomy

Cratogeomys neglectus (Merriam, 1902), Querétaro, Mexico. No subspecies recognized.

other common names

None known.

physical characteristics

Head and body length 9–14 in (22–37 cm); weight 7–18 oz (200–500 g). Color is yellow, brown, or blackish and paler below.

distribution

Known only from one isolated region near the town of Pinal de Amoles, Querétaro, Mexico.

habitat

Locally common in mountain valleys where oak woodlands meet higher–elevation pine forests. Also occur in agricultural fields (corn, potatoes, and apples). Approximately 8,600–9,600 ft (2,600–2,900 m).

behavior

Lives singly in subterranean burrow system; asocial and aggressive toward individuals of same species, except during breeding season when brief mating encounters occur.

feeding ecology and diet

Herbivorous; burrows through the soil in search of roots and tubers. Occasionally feeds on surface vegetation near entrance to burrow. Also feeds on corn and potato crops and the roots of apple trees.

reproductive biology

Little is known; may breed only once per year (spring); probably only one to three young per litter. Assumed polygamous.

conservation status

Listed on the IUCN Red List as Critically Endangered. The major threat to this species comes from encroachment of human agriculture into its natural range.

significance to humans

Common agricultural pest throughout its limited range.


Buller's pocket gopher

Pappogeomys bulleri

taxonomy

Pappogeomys bulleri (Thomas, 1892), near Talpa, Jalisco, Mexico. Eight subspecies.

other common names

None known.

physical characteristics

Head and body length 7–10 in (18–27 cm); weight 3–9 oz (80–250 g). Color is orange-cinnamon to dark brown and paler below.

distribution

Western Mexico (Colima, Jalisco, and Nayarit).

habitat

Mountain slopes and plains at elevations between 3,000 and 10,000 ft (900–3,000 m).

behavior

Lives singly in subterranean burrow system; asocial and aggressive toward individuals of same species, except during breeding season when brief mating encounters occur. Assumed polygamous.

feeding ecology and diet

Herbivorous; burrows through the soil in search of roots and tubers. Occasionally feeds on surface vegetation near entrance to burrow. Occurs commonly in agricultural areas, especially corn and bean fields.

reproductive biology

Nothing is known.

conservation status

Not threatened.

significance to humans

Common agricultural pest in some parts of its range.

Common name / Scientific namePhysical characteristicsHabitat and behaviorDistributionDietConservation status
Northern pocket gopher Thomomys talpoidesVariable in color from yellowish brown to pale gray above and paler below. Outer face of each upper incisor smooth (without grooves). Small pocket gopher: length 6–10 in (15–27 cm); weight 3–9 oz (80–250 g).Found generally in cool, montane meadows, often near pine forests. Behavior typical of pocket gophers: fossorial and asocial.South-central Canada through western United States.Plant roots, bulbs, and tubers, as typical for the family.Not threatened
Mazama pocket gopher Thomomys mazamaVariable in color from reddish brown to black above and paler below. Outer face of each upper incisor smooth (without grooves). Small pocket gopher: length 6–10 in (15–27 cm); weight 3–9 oz (80–250 g).Found generally in cool, montane meadows, often near pine forests. Behavior typical of pocket gophers: fossorial and asocial.Western Washington, western Oregon, and northern California, United States.Plant roots, bulbs, and tubers.Lower Risk/Near Threatened
Southern pocket gopher Thomomys umbrinusHighly variable in color from nearly white to black above and somewhat paler below. Outer face of each upper incisor smooth (without grooves). Small pocket gopher: length 6–10 in (15–27 cm); weight 3–9 oz (80–250 g).Found a variety of habitats, including grasslands, woodlands, and pine forests from sea level to more than 12,000 ft (3,600 m). Behavior typical of pocket gophers: fossorial and asocial.Southern Arizona, United States, through central Mexico.Plant roots, bulbs, and tubers.Not threatened
Mountain pocket gopher Thomomys monticolaDark brown above and somewhat paler below; ears pointed, rather than rounded, as in most pocket gophers. Outer face of each upper incisor smooth (without grooves). Small pocket gopher: length 7–9 in (19–22 cm); weight 3–6 oz (80–180 g).Found in or near pine forests in mountainous areas. Behavior typical of pocket gophers: fossorial and asocial.Sierra Nevada of California, United States.Plant roots, bulbs, and tubers.Not threatened
Camas pocket gopher Thomomys bulbivorusLarge for genus; dark sooty brown above and somewhat paler below. Outer face of each upper incisor smooth (without grooves). Medium-sized pocket gopher: length 9–12 in (24–30 cm); weight 8–19 oz (230–550 g).Found mainly in open valleys and grasslands. Behavior typical of pocket gophers: fossorial and asocial.Restricted to the Willamette Valley of Oregon, United States.Plant roots, bulbs, and tubers.Not threatened
Desert pocket gopher Geomys arenariusVery light brown to almost white above and somewhat paler below. Has two longitudinal grooves on outer face of each upper incisor. Medium-sized pocket gopher: length 9–11 in (24–28 cm); weight 8–14 oz (230–400 g).Found in arid and sandy desert habitats. Behavior typical of pocket gophers: fossorial and asocial.Southern New Mexico, extreme western Texas, (United States) and northern Chihuihui, Mexico.Plant roots, bulbs, and tubers.Lower Risk/Near Threatened
Texas pocket gopher Geomys personatusLight brown to grayish drab above and somewhat paler below. Has two longitudinal grooves on outer face of each upper incisor. Medium-sized pocket gopher: length 9–11 in (24–28 cm); weight 8–14 oz (230–400 g).Found in areas with deep, sandy soils. Behavior typical of pocket gophers: fossorial and asocial.Extreme southern Texas, United States, and nearby Padre and Mustang Islands.Plant roots, bulbs, and tubers.Lower Risk/Near Threatened
Tropical pocket gopher Geomys tropicalisLight brown above and somewhat paler below. Has two longitudinal grooves on outer face of each upper incisor. Medium-sized pocket gopher: length 9–1 in (24–28 cm); weight 8–14 oz (230–400 g).Found in coastal areas with deep, sandy soils. Behavior typical of pocket gophers: fossorial and asocial.Restricted to vicinity immediately north of Tampico, Tamaulipas, Mexico.Plant roots, bulbs, and tubers.Vulnerable
Southeastern pocket gopher Geomys pinetisLight brown above and somewhat paler below. Has two longitudinal grooves on outer face of each upper incisor. Medium-sized pocket gopher: length 9–12 in (24–30 cm); weight 8–14 oz (230–400 g).Generally found in areas with deep, sandy soils, including open grasslands and low-elevation pine forests. Behavior typical of pocket gophers: fossorial and asocial.Southern Alabama, southern Georgia, and northern Florida, United States.Plant roots, bulbs, and tubers.Not threatened
Common name / Scientific namePhysical characteristicsHabitat and behaviorDistributionDietConservation status
Hispid pocket gopher Orthogeomys hispidusPelage very sparse and stiff above and almost naked below; grayish to black above and paler below. Has one longitudinal groove on outer face of each upper incisor. Large pocket gopher: length 12–18 in (31–44 cm); weight 18–33 oz (500–950 g).Found in humid lowland habitats and low-elevation pine forests up to approximately 5,000 ft (1,500 m). Behavior typical of pocket gophers: fossorial and asocial.Coastal regions of southeastern Mexico, Yucatán Peninsula, Belize, Guatemala, and northwestern Honduras.Plant roots, bulbs, and tubers.Not threatened
Big pocket gopher Orthogeomys laniusPelage soft and woolly; grayish brown above and paler below. Has one longitudinal groove on outer face of each upper incisor. Large pocket gopher: length 12–18 in (31–44 cm); weight 18–33 oz (500–950 g).Found in meadows adjacent to pine forests. Behavior typical of pocket gophers: fossorial and asocial.Known only from the vicinity of Xuchil, Veracruz, Mexico.Plant roots, bulbs, and tubers.Not threatened
Variable pocket gopher Orthogeomys heterodusPelage soft and dense; blackish above and paler below. Has one longitudinal groove on outer face of each upper incisor. Large pocket gopher: length 12–19 in (31–49 cm); weight 18–34 oz (500–950 g).Found in open grasslands and tropical forests in high-land habitats up to 8,000 ft (2,500 m). Behavior typical of pocket gophers: fossorial and asocial.Central highlands of Costa Rica.Plant roots, bulbs, and tubers.Lower Risk/Near Threatened
Chiriquá pocket gopher Orthogeomys cavatorPelage soft and dense; dark brown to almost blackish above and paler below. Has one longitudinal groove on outer face of each upper incisor. Large pocket gopher: length 12–19 in (31–49 cm); weight 18–34 oz (500–950 g).Found in tropical forests in highland habitats up to 8,000 ft (2,500 m). Behavior typical of pocket gophers: fossorial and asocial.Mountains of south-eastern Costa Rica and northwestern Panama.Plant roots, bulbs, and tubers.Not threatened
Darién pocket gopher Orthogeomys dariensisPelage soft and dense; dull brown to almost blackish above and paler below. Has one longitudinal groove on outer face of each upper incisor. Large pocket gopher: length 12–19 in (31–49 cm); weight 18–34 oz (500–950 g).Found in small clearings in humid tropical forests at elevations between 1,600 and 5,000 ft (500–1,500 m). Behavior typical of pocket gophers: fossorial and asocial.Mountains of south-eastern Panama.Plant roots, bulbs, and tubers.Not threatened
Underwood's pocket gopher Orthogeomys underwoodiPelage generally short and sparse; blackish above with white transverse belt 0.5–1.5 in (1.3–3.8 cm) wide encircling the lumbar region; paler below. A few specimens known to lack transverse belt. Has one longitudinal groove on outer face of each upper incisor. Medium-sized pocket gopher: length 9–12 in (24–30 cm); weight 8–14 oz (230–400 g).Found in coastal tropical and semi-arid forests. Behavior typical of pocket gophers: fossorial and asocial.Pacific coast of Costa Rica.Plant roots, bulbs, and tubers.Not threatened
Cherrie's pocket gopher Orthogeomys cherrieiPelage generally short and sparse; dark brown to blackish above with large, triangle-shaped white spot on forehead; paler below. Has one longitudinal groove on outer face of each upper incisor. Medium-sized pocket gopher: length 9–12 in (24–30 cm); weight 8–14 oz (230–400 g).Found in low-elevation tropical and semi-arid forests. Behavior typical of pocket gophers: fossorial and asocial.Pacific and Atlantic coastal plains and adjacent foothills of northwestern Costa Rica.Plant roots, bulbs, and tubers.Lower Risk/Near Threatened
Nicaraguan pocket gopher Orthogeomys matagalpaePelage generally short and sparse; dark brown to blackish above with large, triangle-shaped white spot on forehead; paler below. Has one longitudinal groove on outer face of each upper incisor. Medium-sized pocket gopher: length 9–12 in (24–30 cm); weight 8–14 oz (230–400 g).Found in low-elevation tropical and semi-arid forests. Behavior typical of pocket gophers: fossorial and asocial.South-central Nicaragua and east-central Honduras.Plant roots, bulbs, and tubers.Not threatened
Common name / Scientific namePhysical characteristicsHabitat and behaviorDistributionDietConservation status
Merriam's pocket gopher Cratogeomys merriamiPelage generally short and sometimes sparse; color variable, from yellowish buff to glossy black above; paler below. Has one longitudinal groove on outer face of each upper incisor. Medium-sized pocket gopher: length 9–16 in (24–40 cm); weight 10–21 oz (300– 600 g).Found in semi-arid grass-lands, and nearby forests between 5,000 and 12,500 ft (1,500–3,800 m). Behavior typical of pocket gophers: fossorial and asocial.East-central Mexico (Hidalgo, Puebla, and Veracruz).Plant roots, bulbs, and tubers.Not threatened
Smoky pocket gopher Cratogeomys fumosusPelage generally coarse and bristly; dark grayish brown above, paler below. Has one longitudinal groove on outer face of each upper incisor. Medium-sized pocket gopher: length 9–16 in (24–40 cm); weight 10–21 oz (300–600 g).Found in semi-arid lowland habitats. Behavior typical of pocket gophers: fossorial and asocial.Known from one small region in Colima, Mexico.Plant roots, bulbs, and tubers.Lower Risk/Near Threatened
Zinser's pocket gopher Cratogeomys zinseriPelage soft and lax; dark grayish brown above, paler below. Has one longitudinal groove on outer face of each upper incisor. Medium-sized pocket gopher: length 9–16 in (24–40 cm); weight 10–21 oz (300–600 g).Found in semi-arid habitats with deep, sandy soils. Behavior typical of pocket gophers: fossorial and asocial.Known from one small region near Lagos de Moreno, Jalisco, Mexico.Plant roots, bulbs, and tubers.Lower Risk/Near Threatened

Resources

Books

Hafner, M. S., J. W. Demastes, T. A. Spradling, and D. L. Reed. "Cophylogeny Between Pocket Gophers and Chewing Lice." In Tangled Trees: Phylogeny, Cospeciation, and Coevolution, edited by R. D. M. Page. Chicago: The University of Chicago Press, 2002.

Hall, E. R. The Mammals of North America. 2nd ed. New York: John Wiley & Sons, 1981.

Nowak, R. M. Walker's Mammals of the World. 6th ed. Baltimore: Johns Hopkins University Press, 1999.

Periodicals

Demastes, J. W., T. A. Spradling, M. S. Hafner, D. J. Hafner, and D. L. Reed. "Systematics and Phylogeography of Pocket Gophers in the Genera Cratogeomys and Pappogeomys." Molecular Phylogenetics and Evolution 22, no. 1 (2002): 144–154.

Hovey, K., and D. Rissolo. "The Process and Sociocultural Significance of Gopher Trapping in a Modern Yucatec Maya Community." Journal of Ethnobiology 19, no. 2 (1999): 261–276.

Reichman, O. J., and E. W. Seabloom. "The Role of Pocket Gophers as Subterranean Ecosystem Engineers." Trends in Ecology & Evolution 17, no. 1 (2002): 44–49.

Mark S. Hafner, PhD

More From encyclopedia.com