cholla and prickly pear cactus. Using cacti and other large desert plants as an anchor, builds an extensive home using pieces of cacti, cow chips, sticks, bones, and any other found items, including garbage left by humans. It is known for its large and complex shelters. Averaging 8 feet in diameter and 2 to 3 feet in height, its shelters contain several chambers and underground tunnels which are used to escape predators. Each shelter also includes a small underground nest that serves as a retreat from daytime heat and as a place for females to raise their young. The size of the nest averages about 8 inches in diameter. It consists of soft materials such as grasses or shredded fibers. The average density of shelters in heavily populated areas is between 5 to 15 per acre, but densities vary depending on resource availability. is a solitary species and houses are never cohabited by adults. (Brown, 1968; Hoffmeister, 1986; Macedo and Mares, 1988; Olsen, 1971)appears in a wide range of habitats including forest edges, scrubland forests, and low deserts, and can be found from 2135 m to 76 m in elevation. It occasionally builds dens in the caves of rocky hills, but more commonly prefers areas of extensive
Mating the only time that (Macedo and Mares, 1988)engages in social behavior with adults conspecifics. Foot thumping often precedes copulation, although the purpose is unknown. During copulation, males and females have limited tactile contact and males do not clasp the female. The average copulatory lock lasts 30.1 seconds. It is hypothesized that this short lock has evolved to minimize predation risk as copulation can create vulnerability to attack. Mate selection behavior is not well understood. is promiscuous and no bonding occurs between mates after copulation.
Reports on the breeding season of (Macedo and Mares, 1988)vary greatly. Some observations suggest year-round breeding, while others identify a period between January and September as breeding season. This discrepancy may be a result of differences in breeding seasons among the different regions occupied and/or subspecies. However, all sources agree that breeding slows during the hottest months of the year and that the majority of breeding takes place between January and June. can produce multiple litters per season, and females are sometimes found with offspring of two different ages in their dens. Average gestation lasts 38 days, however, gestation periods short as 30 days have been recorded. Litters range from 1 to 4 offspring, with an average of 2 offspring per litter. Average birth mass is 10.9 grams. Weaning occurs between 62 and 72 days, at which point offspring have already begun practicing shelter construction and consuming cacti, berries, and vegetation. In the wild, reaches sexual maturity at around 180 days. In captivity, instances of reaching sexual maturity as young as 80 days in females and 101 days in males have been documented.
Little is known on the lifespan of (Zeng and Brown, 1989). The few existing data suggests that members of this species can live between 3 and 5 years. Longest known lifespan in the wild is 6 years.
Nest construction involves collecting many different items. (Macedo and Mares, 1988)constructs large nests that integrate cacti, sticks, animal bones, cow chips and man-made materials. Members of this species appear to have a particular affinity for collecting man-made objects for incorporation into the nest. See Habitat section for additional information.
White-throated woodrats use scent to communicate with conspecifics. Males have specialized midventral glands that they use to scent mark selected locations. In females, this gland is poorly developed. Pheromones are used in social situations involving courtship, sexual, agonistic, hierarchical, and possibly territorial interactions. Pheromones present in feces are used to determine the sex of den occupants, thereby avoiding agonistic encounters between males. White-throated woodrats rely upon scent and visual cues to warn them of danger from predators. Altricial infants with unopened eyes cannot distinguish a predator by scent alone. (Macedo and Mares, 1988)
In desert habitats, cholla and prickly pear cactus. is not an obligate drinker and acquires most of its water from cactus. Some observations estimate that the diet of consists of up to 44% cacti. During periods of exceptionally high temperatures, can eat upwards of 60% of its body mass in cacti per day. While this species prefers cacti, it is considered a generalist herbivore. Other important food items includes the beans and bark of mesquite plants, juniper branches and berries, various flowers, and yucca leaves. has also been observed consuming insects, small reptiles and mice, however, such observations are uncommon. is known to store food throughout its large shelter. (Macedo and Mares, 1988; Olsen, 1971; Zeng and Brown, 1989; Zeveloff, 1988)feeds primarily on
Predators of mustelids such as weasels, skunks, and badgers. Additional mammalian predators include racoons, red fox, gray fox, bobcats, coyotes, and ringtails. Other important predators of include snakes and Great-horned Owls (Davis, 1960; Hoffmeister, 1986; Macedo and Mares, 1988; Olsen, 1971; Prakash and Ghosh, 1975)include a number of
Altricial young are unable to identify predators by smell alone and treat predators as inanimate objects. Once their eyes are open, visual clues play an important role in predator detection for individuals as young as 26 days. In predatory experiments, the reaction of bird species and other diurnal predators. The coloration of likely helps camouflage them from potential predators as well. (Davis, 1960; Hoffmeister, 1986; Macedo and Mares, 1988; Olsen, 1971; Prakash and Ghosh, 1975)to predatory stimuli occurs in three steps: awareness of threat, foot thumping and increased agitation, and fast and random direction running. Structural adaptations to predation are thought to have lead to extensive tunnels and chambers in and around the habitation structures of . Tunnels appear to function as a means of escape when faced with a potential threat in or near the nest. A large proportion of 's shelter is constructed from pieces of cacti. These spiny additions act as a deterrent for predators, without inhibiting the mobility of . Nocturnal behavior likely reduces risk of predation. By remaining inside during the day, avoids many predators including many
There are no known positive effects of (Macedo and Mares, 1988)on humans, however, there have been rare reports of humans consuming .
is widespread and abundant throughout its geographic range. As a result, this species is classified as "least concern" on the IUCN's Red List of Threatened Species.
Another common term for the white-throated woodrat is "packrat". This term refers to its tendency to cache man-made objects.
Maria Brym (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, John Berini (editor), Animal Diversity Web Staff.
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
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
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.
A substance that provides both nutrients and energy to a living thing.
an animal that mainly eats fruit
an animal that mainly eats seeds
An animal that eats mainly plants or parts of plants.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
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.
active during the night
chemicals released into air or water that are detected by and responded to by other animals of the same species
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
scrub forests develop in areas that experience dry seasons.
breeding is confined to a particular season
remains in the same area
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).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
breeding takes place throughout the year
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