The eastern harvest mouse (''Reithrodontomys humulis'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

in the family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and h ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the

Southeastern United States The Southeastern United States, also referred to as the American Southeast or simply the Southeast, is a geographical region of the United States. It is located broadly on the eastern portion of the southern United States and the southern por ...

. Its natural

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s are subtropical or tropical seasonally wet or flooded lowland

grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...

, swamps, and pastureland.

Description

The eastern harvest mouse is characterized by brown pelage with a dark lateral line extending along its dorsal surface. The underbelly and ventral side of the tail are lighter colored than the rest of the body. The underbelly is a gray color that may be infused with some red character. The tail is bicolored with a dark brown coloration on the dorsal side and a white-gray coloration on ventral side. Females weigh more than males with increases in female weight being concordant with reproduction. They vary in length from 107–128 mm. The eastern harvest mouse is primarily nocturnal and has a life span of 9.5 weeks.

Habitat and distribution

The range of the eastern harvest mouse is wide across the North American continent. It reaches north to Delaware, south to the tip of Florida and as far west as Texas, Oklahoma and Ohio. They have been

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

from Maryland. They are found in open grassy areas such as abandoned fields, marshes or wet meadows. Eastern harvest mice prefer to live in open, damp grassy areas such as meadows or marshes. This species does not live in the forest and builds nests that it lives in year round. The nests are composed of dry weeds, grass or other plant material and are globular shaped. The home range of this species is estimated slightly below 1,000 meters².

Diet

The eastern harvest mouse diet is not well known. In laboratories, they feed on a variety of items from seeds to fruits and vegetables. It is believed that in the wild, these mice feed solely on seeds, weeds and small insects.

Reproduction

The eastern harvest mouse mates during spring and autumn. The males are always prepared to mate while the females will not mate during the summer period. The gestation period for pregnant females is ~21 days and they only need as little as 24 days to begin reproducing again. The litter size is usually between 2-4 offspring, however, it can range from 1-8 offspring. Female parents raise the offspring. The young will leave the mother after 30 days. At birth, the young will weigh 1.2 g and will have closed eyes for the first 7–10 days.

Development

Immediately after birth, the young do not have fur and their eyes are closed. During the first thirty days, the pelage grows, the young gain weight and the eyes open. The fastest growth period is the first week after birth. They will leave the protection of the nest by the second or third week of development. The offspring lactate from the mother until 4 weeks of age. After thirty days, the young will leave the nest after they weigh enough.

References

* Baillie, J. 1996.
Reithrodontomys humulis

2006 IUCN Red List of Threatened Species.
Downloaded on 20 July 2007. *Musser, G. G. and M. D. Carleton. 2005. Superfamily Muroidea. pp. 894–1531 ''in'' Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. {{Taxonbar, from=Q1767111 Reithrodontomys Mouse, eastern harvest Mouse, eastern harvest Mammals described in 1841 Taxonomy articles created by Polbot Taxa named by John James Audubon