Fulvous harvest mouse
|Fulvous harvest mouse|
About seventeen subspecies of Reithrodontomys fulvescens are recognised and they vary in both colouring and in size. The total length ranges from about 134 to 189 mm (5.3 to 7.4 in) with a tail of between 73 and 116 mm (2.9 and 4.6 in). The yellowish-buff or tawny fur is relatively coarse and has a streaked or speckled effect caused by the mixture of black guard hairs and the paler, banded hairs of the undercoat. There is often a dark stripe running along the spine. The underparts are grayish-white, sometimes tinged with buff. This mouse can be distinguished from the rather larger hairy harvest mouse (Reithrodontomys hirsutus) by its pelage and skull characteristics, the pale underside of the tail and the whitish or buff color of the hind feet.
Distribution and habitat
The fulvous harvest mouse has a widespread distribution with a range extending from Honduras, Guatemala and El Salvador northwards through Mexico to the southwestern United States where it is present in Arizona, Texas, Oklahoma, Kansas, Missouri, Arkansas and Mississippi. Its typical habitat is grassy areas containing some shrubs, especially in areas with mesquite or pine/grass ecozones.
The fulvous harvest mouse is nocturnal. In Arkansas, animals began to deposit fat in their tissues in November and this peaks in January and then the fat reserves are steadily used up by April. Other adaptations to winter include a lengthening of the animal's hair and a possible daily reduction of its body temperature during sleep in the daytime. The animal quickly recovers from hypothermia and resumes activity when it warms up. A nest is built in vegetation just off the ground and consists of a ball of grasses and sedges about 75 millimetres (3.0 in) in diameter. It is usually occupied by a pair of mice which may be a pair-bonded male and female. When the mice are inside, the entrance, or pair of entrances, is plugged. When the animals move about outside, much of their time is spent off the ground in low vegetation.
The diet of the fulvous harvest mouse varies seasonally, but in milder climates consists primarily of insects and other invertebrates throughout the year whereas in colder regions, invertebrates predominate in the spring, and seeds in the fall and winter. A small proportion of green leafy and other plant food is also eaten. Predators of this mouse include barn owls (Tyto alba) and red-tailed hawks (Buteo jamaicensis).
In Mexico, breeding seems to take place throughout the year, but in Texas there are usually two breeding peaks, one in late spring and the second a few months later. The litter size is usually two to four offspring but may be more. The young are blind, naked and helpless at birth, their eyes open between the ninth and twelfth days and weaning takes place between the thirteenth and sixteenth. Life expectancy is up to fifteen months for males and up to twelve months for females.
- Linzey, A.V. & Timm, R. (2008). "Reithrodontomys fulvescens". IUCN Red List of Threatened Species. Version 2014.2. International Union for Conservation of Nature. Retrieved 18 September 2014.
- Musser, G. G.; Carleton, M. D. (2005). "Superfamily Muroidea". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 1081–1082. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Spencer, Stephen R.; Cameron, Guy N. (1982). "Reithrodontomys fulvescens". Mammalian Species 174: 1–7. doi:10.2307/3503795. JSTOR 3503795.