Geographic Range
Cratogeomys castanops
occurs in a small area spanning the southern United States to northern Mexico, from
the Arkansas river drainage down to the Rio Grande River. In the United States, it
occupies regions in southeastern Colorado, Kansas, Oklahoma, eastern New Mexico and
western Texas. In Mexico, it occupies regions in northern Chihuahua, Coahuila, Durango
and Nuevo León.
Habitat
Cratogeomys castanops
usually inhabits deep soils with low to moderate amounts of sand, silt or clay, and
uncultivated short grass prairies. The distribution of individuals across an area
of land is usually clumped or randomly distributed, and they tend to localize in areas
of compact soils where preferred clay and sand content is approximately 20-25% of
the soil composition.
Cratogeomys castanops
lives in burrows that vary in depth, albeit deeper than most other pocket gophers,
and ranges from shallow for general movement, to deep burrows for food storage.
- Habitat Regions
- temperate
- Terrestrial Biomes
- desert or dune
- savanna or grassland
Physical Description
Cratogeomys castanops
is a medium sized pudgy-looking rodent with large eyes. Males are larger than females,
with body masses averaging 279 g and 248 g, respectively, and head-to-body lengths
of 271 mm and 263 mm, respectively. Adults can either be pale yellowish- or reddish-brown
in fur color, with the bases of the hairs usually pale brown or gray in pigmentation.
The hairs on the tops and backs of their heads are usually darker-tipped compared
to the rest of the pelage. Their ventral underbelly is buffy or whitish, lighter
colored than its dorsum. Juveniles have finer hairs which are pale yellowish-gray
or straw-colored. Like other pocket gophers, they have fur-lined cheek pouches on
the lateral sides of their mouth for storing food. Relative to other pocket gopher
species their forelimbs and front claws are shorter, and their jaw muscles are larger
so they can use their teeth for digging. Their basal metabolic rate is similar to
other species under the family Geomyidae, at approximately 0.70 cubic centimetres
of oxygen per gram, per hour. Several subspecies have been discovered, with two distinct
number of chromosomes depending on which regions they come from; Northern species
are 2n = 46, while Southern species are 2n = 42. There are no known external morphological
differences between subspecies.
The skull is medium sized (condylobasal length ranging from 48 to 57 mm) with a relatively
broad rostrum, and generally angular and rugose with few smooth surfaces. There is
also some "flatness" of the cranium (platycephaly), in that it is dorso-ventrally
compressed. The zygomatic arches are stout (breadth ranging from 30 to 40 mm), do
not twist, and have plate-like expansions at the anterolateral angles. The sagittal
crest is well-developed and blade-like, even more so in males. Upper incisors have
a single medial groove, the inner groove being absent from the anterior face of the
teeth. Enamel plates are absent on the posterior walls of P4, M1 and M2. The dental
formula is as follows: 1/1 0/0 4/2 1/1 = 6/4 = 20.
The middle ear of
Cratogeomys castanops
has a highly bullate and convex stapedial footplate, which has a width of 0.74 mm.
The auditory bullae themselves are thick-walled, and are composed of spongy bone,
while the external auditory meatus, extending laterally by about 4 mm, is composed
of compact bone. The length, width and depth of the bullae are approximately 16 mm,
8.5 mm and 9.1 mm, respectively. The tympanic membrane is circular in shape, and
has an average diameter of 4 mm.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- male larger
Reproduction
In
Cratogeomys castanops
, mating systems are polygynous, in which one male mates with more than one female
through random mating. Females do not mate with more than one male during a breeding
season. During breeding seasons, the effective sex ratio tends to skew towards females,
averaging three to four females for every one male.
- Mating System
- polygynous
Like many pocket gophers, individuals in a population of
Cratogeomys castanops
rarely share burrows, due to aggressive behaviors. During a breeding season, however,
burrows may be shared by mates. There are at least two intervals during the year
in which breeding occurs. Breeding seasons are from December to March, and from June
to August. In related species, male reproductive success varies, and adult sex ratios
during breeding seasons are skewed towards females. During copulation and mating,
males will communicate to females using low, guttural squeaks, and will bite into
the female when contact has been made. A female produces an average of two litters
per year, with two to three offspring per litter. Each newborn offspring weighs approximately
6 g, and takes one to two months to wean. After three months the young leave their
mother's burrow and are able to forage for food on their own.
- Key Reproductive Features
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
Offspring are altricial at birth, and need parental care as they are born blind and
naked. There is no paternal care. Females build maternal nests for themselves and
their offspring. During lactation, a female will sit on her haunches while the offspring
lie on their backs while grasping the nipple with their foreclaws to suckle. Occasionally
the female will adjust her position using her foreclaws, and groom the offspring with
her mouth. When juveniles are done suckling the mother pushes them away from the
nipples using her hindlimbs. When the offspring are old enough to leave their nest,
they will stay in the maternal burrow as a means to travel and forage for food, and
finally leave the burrow when they are about three months old and almost full-grown.
- Parental Investment
- altricial
- female parental care
Lifespan/Longevity
In the wild,
Cratogeomys castanops
has a short lifespan, with females living up to about 13 months, and males living
up to about 7 months. The oldest known individual was an 86 week old female (approximately
19 months).
Behavior
Cratogeomys castanops
forages for food using underground burrowing systems dug out by their claws. They
are also solitary animals, and will only interact with each other during breeding
seasons.
Cratogeomys castanops
are often parapatric from other pocket gophers, which include Botta's pocket gopher
(
Thomomys bottae
) and Plains pocket gopher (
Geomys bursarius
), via a zone of separation where habitat is usually unsuitable for all three pocket
gopher species. However, these species may interact and compete with one another
where their ranges overlap.
Cratogeomys castanops
has been known to kill a
Thomomys bottae
in captivity.
Home Range
The burrow systems of
Cratogeomys castanops
extends up to 32 m^2 for females, and as far as 59 m^2 for males. Juveniles and
male adults tend to move more frequently outside their home ranges.
Communication and Perception
Cratogeomys castanops communicates and perceives its environment using olfactory cues and sense of touch. During the breeding season, they communicate using squeaks.
- Communication Channels
- acoustic
Food Habits
Cratogeomys castanops
is herbivorous, and consumes a wide variety of plant material, including roots, stems
and leaves, using their burrow systems. One of their primary food sources are forbs
or flowering plants, preferring clovers (genus
Trifolium
). They also feed on
Agave lechuguilla
where it is present, such as in Texas. Food is stored in their cheek pouches, and
is transported and hoarded in designated areas in their burrows.
- Plant Foods
- leaves
- roots and tubers
- wood, bark, or stems
- flowers
- Foraging Behavior
- stores or caches food
Predation
Cratogeomys castanops
is consumed as prey by several animals, including weasels, rattlesnakes, and birds
of prey such as hawks, eagles and owls. They will retreat to their burrows to avoid
aerial predators, which include ferruginous hawks, Swainson's hawks, and golden eagles.
Ecosystem Roles
In areas where the land has been disturbed, populations of
Cratogeomys castanops
can increase as they build mounds and establish habitat, consuming the vegetation
in the area. By preventing forest re-growth, they can potentially change an ecosystem
to a grassland prairie.
Cratogeomys castanops
is used as a host by several parasite species, including mites and lice. The most
common mites found on
Cratogeomys castanops
, as well as other pocket gopher species, are
Echinonyssus femuralis
and
Androlaelaps geomys
.
Echinonyssus femuralis
is commonly found in the gopher's cheek pouches, and
Androlaelaps geomys
is found in many locations on the gopher's body. Both of these species suck blood
from the host.
- mites ( Echinonyssus femuralis )
- mites ( Androlaelaps geomys )
Economic Importance for Humans: Positive
Cratogeomys castanops
, among other pocket gopher species, are often used in ecological studies, as their
burrowing and foraging habits can give insight on how they affect their environment,
particularly important for wildlife conservation. For example, mound building by
pocket gophers can alter soil composition, and underground foraging can have a significant
effect on limiting forest growth.
- Positive Impacts
- research and education
Economic Importance for Humans: Negative
As Cratogeomys castanops inhabits the rich soils preferred by farmers, they can cause serious agricultural damage to farm crops, including orchards, gardens and potato fields.
- Negative Impacts
- crop pest
Conservation Status
As of 2008, Cratogeomys castanops is currently listed as "Least Concern" by the IUCN Red List.
Other Comments
Previously recognized as
Pappogeomys castanops
, genetic analyses have determined that the yellow-faced pocket gophers belongs in
the genus
Cratogeomys
. Conversion of land from silt and clay to cultivated and unstable land may affect
populations of pocket gophers and their distributions.
Additional Links
Contributors
Leanne Neufeld (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- desert or dunes
-
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- polygynous
-
having more than one female as a mate at one time
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- female parental care
-
parental care is carried out by females
- fossorial
-
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
- motile
-
having the capacity to move from one place to another.
- solitary
-
lives alone
- acoustic
-
uses sound to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- stores or caches food
-
places a food item in a special place to be eaten later. Also called "hoarding"
- herbivore
-
An animal that eats mainly plants or parts of plants.
- folivore
-
an animal that mainly eats leaves.
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
References
Birney, E., J. Jones, D. Mortimer. 1970. The Yellow-Faced Pocket Gopher, Pappogeomys castanops , in Kansas. Kansas Academy of Science (1903-) , 73/3: 368-375.
Davidow-Henry, B., J. Jones, R. Hollander. 1989. Cratogeomys castanops . Mammalian Species , 338: 1-6.
Ferguson, D. 1998. Effects of pocket gophers, bracken fern, and western coneflower on planted conifers in northern Idaho - an update and two more species. New Forests , 18/3: 199-217.
Giovanni, M., C. Boal, H. Whitlaw. 2007. Prey Use and Provisioning Rates of Breeding Ferruginous and Swainson's Hawks on the Southern Great Plains, USA. The Wilson Journal of Ornithology , 119/4: 558-569.
Giovanni, M., C. Taylor, G. Perry. 2005. Crotalus viridis viridis (Prairie rattlesnake). Diet. Herpetological Review , 36/3: 323.
Goetze, J., J. Knox Jones. 1992. Comments on distribution and natural history of pocket gophers on the Rolling Plains of west-central Texas. Occasional Papers Museum of Texas Tech University , 149: 1-12.
Hafner, D., M. Hafner, G. Hasty, T. Spradling, J. Demastes. 2008. Evolutionary Relationships of Pocket Gophers ( Cratogeomys castanops Species Group) of the Mexican Altiplano. Journal of Mammalogy , 89/1: 190-208.
Hegdal, P., A. Ward, A. Johnson, H. Tietjen. 1965. Notes on the Life History of the Mexican Pocket Gopher ( Cratogeomys castanops ). Journal of Mammalogy , 46/2: 334-335.
Hickman, G. 1975. The Maternal Behavior of a Mexican Pocket Gopher ( Pappogeomys castanops ). The Southwestern Naturalist , 20/1: 142-144.
Hoffman, J., J. Choate, R. Channell. 2007. Effects of Land Use and Soil Texture on Distributions of Pocket Gophers in Kansas. The Southwestern Naturalist , 52/2: 296-301.
Hoffman, J., J. Choate. 2008. Distribution and Status of the Yellow-faced Pocket Gopher in Kansas. Western North American Naturalist , 68/4: 483-492.
Hoffman, J. 2015. Habitat Characteristics within a Zone of Separation Between the Ranges of Two Species of Pocket Gophers. The American Midland Naturalist , 173/2: 253-266.
Mielke, H. 1977. Mound Building by Pocket Gophers (Geomyidae): Their Impact on Soils and Vegetation in North America. Journal of Biogeography , 4/2: 171-180.
Olendorff, R. 1976. The Food Habits of North American Golden Eagles. American Midland Naturalist , 95/1: 231-236.
Patton, J., M. Smith. 1993. Molecular evidence for mating asymmetry and female choice in a pocket gopher ( Thomomys ) hybrid zone. Molecular Ecology , 2/1: 3-8.
Pisani, G., B. Stephenson. 1991. Food Habits in Oklahoma Crotalus atrox in Fall and Early Spring. Transactions of the Kansas Academy of Science , 94/3-4: 137-141.
Reichman, O., T. Whitham, G. Ruffner. 1982. Adaptive Geometry of Burrow Spacing in Two Pocket Gopher Populations. Ecology , 63/3: 687-695.
Russell, R. 1968. Evolution and Classification of the Pocket Gophers of the Subfamily Geomyinae. University of Kansas Publications, Museum of Natural History , 16/6: 473-579.
Smolen, M., H. Genoways, R. Baker. 1980. Demographic and Reproductive Parameters of the Yellow-Cheeked Pocket Gopher ( Pappogeomys castanops ). Journal of Mammalogy , 61/2: 224-236.
Spradling, T., M. Hafner, J. Demastes. 2001. DIFFERENCES IN RATE OF CYTOCHROME-b EVOLUTION AMONG SPECIES OF RODENTS. Journal of Mammalogy , 82/1: 65-80.
Wilkins, K., J. Roberts, C. Roorda, J. Hawkins. 1999. Morphometrics and Functional Morphology of Middle Ears of Extant Pocket Gophers (Rodentia: Geomyidae). Journal of Mammalogy , 80/1: 180-198.
Wilkins, S., M. Houck. 2001. Parasitic mites of pocket gophers (Rodentia: Geomyidae) from Texas, USA. International Journal of Acarology , 27/4: 309-319.