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. (Davidow-Henry, et al., 1989)
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. (Birney, et al., 1970; Davidow-Henry, et al., 1989; Goetze and Knox Jones, 1992; Hoffman and Choate, 2008; Hoffman, 2015)
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. (Davidow-Henry, et al., 1989; Hafner, et al., 2008; Hegdal, et al., 1965; Hoffman, 2015; Russell, 1968; Smolen, et al., 1980)
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. (Davidow-Henry, et al., 1989; Russell, 1968)
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. (Wilkins, et al., 1999)
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. (Hegdal, et al., 1965; Smolen, et al., 1980)
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. (Birney, et al., 1970; Goetze and Knox Jones, 1992; Hegdal, et al., 1965; Patton and Smith, 1993; Reichman, et al., 1982; Smolen, et al., 1980)
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. (Davidow-Henry, et al., 1989; Hickman, 1975)
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). (Smolen, et al., 1980)
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. (Goetze and Knox Jones, 1992; Hoffman and Choate, 2008; Hoffman, 2015)
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. (Smolen, et al., 1980)
Cratogeomys castanops communicates and perceives its environment using olfactory cues and sense of touch. During the breeding season, they communicate using squeaks.
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. (Davidow-Henry, et al., 1989; Hegdal, et al., 1965)
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. (Giovanni, et al., 2007; Giovanni, et al., 2005; Olendorff, 1976; Pisani and Stephenson, 1991)
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. (Mielke, 1977; Wilkins and Houck, 2001)
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. (Ferguson, 1998; Mielke, 1977)
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.
As of 2008, Cratogeomys castanops is currently listed as "Least Concern" by the IUCN Red List.
Previously recognized as Cratogeomys 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. (Goetze and Knox Jones, 1992; Hoffman, et al., 2007)
Leanne Neufeld (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.
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.
uses sound to communicate
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.
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.
uses smells or other chemicals to communicate
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.
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.
parental care is carried out by females
an animal that mainly eats leaves.
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
An animal that eats mainly plants or parts of plants.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
having more than one female as a mate at one time
reproduction that includes combining the genetic contribution of two individuals, a male and a female
places a food item in a special place to be eaten later. Also called "hoarding"
uses touch to communicate
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).
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.
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.
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.
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