Ochrotomys nuttalli lives throughout the southern United States from northern Kentucky to central Florida and from eastern Texas to the Atlantic Ocean. (Dietz et al., 1992)

Biogeographic Regions: nearctic (Native )

endemic to a single nation

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Southeastern U.S., from southeastern Missouri to West Virginia and southern Virginia, south to eastern Texas, Gulf coast, and central Florida.

The body length of O. nuttalli ranges from 51 to 115 mm. The prehensile tail is from 50 to 97 mm in length, generally the same length as the body of the mouse to which it belongs. Golden mice receive their common name from the thick and soft golden fur that covers the upper body. However, the feet and undersides are white and its tail have a cream coloring.

Male golden mice have a baculum tipped with cartilage. Females have six mammae.

The cheek teeth of golden mice contain thick folds of enamel. As in other members of Muridae, these mice have an infraorbital foramen with a distinct keyhole shape. Neither canines nor premolars are present. Incisors are sharp and long, separated from the cheek teeth by a diastema. (Grosvenor et al., 1987; Hall, 1981; Myers, 1997; Nowak, 1993)

Range mass: 15 to 30 g.

Range length: 51 to 115 mm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Average basal metabolic rate: 0.151 W.

Length: 19 cm

Weight: 93 grams

• Terrestrial

Golden mice, O. nuttalli, live in thick woodlands, swampy areas, among vines, and within small trees and shrubs. These animals especially like to live where honeysuckle, greenbrier, and red cedar grow. Golden mice in the south-central region of the United States inhabit climates that are hot and wet in the summer and dry in the winter.

Their nests may be located in the trees or on the ground. Ground nests, frequently located near leaf litter, may be fabricated within sunken areas of the soil or beneath logs. Ground nests have both advantages and disadvantages. Floods or wet soil may force golden mice to leave their ground nests and relocate into the trees. However, if the ground nest is undisturbed, it can lower the risk for predation for the following reasons: the nest is well hidden, a mouse on the ground is more likely to escape a predator, and less energy is required to build a nest on the ground since the mouse doesn't have to keep running up and down a tree with nesting materials.

Golden mice have been known to remodel old bird nests into homes for themselves. Otherwise these animals create a nest 100 to 200 mm in size, from scratch using different elements, depending on what materials are locally available.

The inner lining of a nest consists of soft materials such as milkweed, cotton, feathers, or fur. A thick layer of woven fibers surrounds this fluffy layer. The protective, surface material contains leaves, grass, and bark. The nest usually has one entrance, although up to three have been noted.

Home ranges, which overlap with one another, are from 0.053ha to 0.627ha. (Dietz, 1992; Frank, 1992; Grosvenor, 1987; Nowak, 1991)

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest

Comments: Prefers moist thickets, forests, field borders; generally uses early and mid-successional habitats with thickets and vines, may range short distance into adjacent fields with sparse redcedars, may cross dirt roads (Morzillo et al. 2003). Builds nests and feeding platforms on the ground and above ground in the understory. Young are born in nests that usually are a few inches to 15 feet above ground in bushes and vines. In south-central Florida, nearly all daytime refuges were on the ground under leaf litter; a few were aboveground in shrubs (Frank and Layne 1992).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

In Illinois, home range size of radio-collared individuals was less than 3 ha (average about 1.3 ha or less, depending on the sex and calculation method) (Morzillo et al. 2003).

Golden mice are granivorous, eating mostly seeds. They prefer sumac seeds, but also consume honeysuckle and other seeds as well. Sumac seeds are poor quality food because they contain tannin, which reduces the efficiency of enzymes in the mouse's digestive pathway. Studies have shown that females fed year-old seeds, which have more calories, have significantly higher mean ingestion and assimilation rates than females that eat freshly matured seeds.

Flooding is a problem for golden mice because the water causes the seeds to be unobtainable, to sprout, or to spoil. (Jewell et al., 1991; Peles et al., 1995; Rose et al., 1988)

Plant Foods: seeds, grains, and nuts

Primary Diet: herbivore (Granivore )

Comments: Eats seeds, nuts, and insects. Forages in trees.

Gregarious; lives in loose communities. Average home range is less than an acre. Population densities range from less than one per acre to 3 per acre (Shadowan 1963).

Comments: Primarily nocturnal and crepuscular. Peak activity is 3-4 hours before dawn.

Average lifespan

Sex: female

Status: captivity: 8.4 years.

Golden mice reproduce all year long. However, the reproductive season varies geographically. The majority of O. nuttalli reproduce from September to spring in Texas but from March to October in Kentucky and Tennessee. Golden mice in captivity tend to reproduce most frequently during the early spring and late summer. Because the gestation period is only about 30 days, females can produce many litters in one year. Captive mothers have been known to produce up to seventeen litters in an eighteen month period. A litter of golden mice typically consists of two or three young, but ranges from one to four. Aside from the mother, all other adults leave the nest when the litter is born. (Grosvenor et al., 1987; Nowak, 1991; Rose et al., 1988)

Breeding interval: These mice are capable of breeding monthly, producing litters up to twelve times per year.

Breeding season: The breeding season varies geographically.

Range number of offspring: 1 to 4.

Average gestation period: 30 days.

Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average birth mass: 2.7 g.

Average gestation period: 30 days.

Average number of offspring: 2.7.

Breeds April-October. Gestation lasts 25-30 days. Produces several litters of 1-4 (average 2-3) young per year.

Golden mice are presently threatened to be endangered in the state of Illinois. The Department of Zoology at Southern Illinois University is presently studying the nesting sites of this rodent. (  http://dnr.state.il.us/ILDNR/OFFICES/PUBAFFRS/news/small97.html)

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Comments: Originally diagnosed as a subgenus of Peromyscus; full generic status has been supported by several studies (see Musser and Carleton, in Wilson and Reeder 1993, 2005). Packard (1969) presented a subspecific classification, but Whitaker and Hamilton 1998 saw no basis for recognizing any subspecies.