Lemmiscus curtatussagebrush vole

Geographic Range

Lemmiscus curtatus is found in the western United States and Canada, primarily in the Great Basin and Great Plains regions. Its range extends from southern Saskatchewan and Alberta to northern Colorado, to the west coast of the United States. (Nowak, 1999)

Habitat

Sagebrush voles inhabit areas largely dominated by bunch grasses and sagebrush. Semi-arid prairies, brushy canyons, and rolling hills with loose soil are preferred habitats. (Nowak, 1999)

Physical Description

Pelage is pale gray and buff dorsally, with silver, white, and buff ventrally. Their fur is dense and is usually longer and softer than that of Microtus. Head and body length is usually 90 to130 mm, and tail length ranges from 16 to30 mm. Body weight is between 17 to 38 grams. Their body appears to be stocky. Adaptations for burrowing in loose soil are haired palms and soles, short tail, stout claws, and small ears. (Nowak, 1999)

  • Range mass
    17 to 38 g
    0.60 to 1.34 oz
  • Range length
    106 to 160 mm
    4.17 to 6.30 in

Development

See Reproduction.

Reproduction

Reports regarding the mating system of this species are variable. The weight of evidence seems to support the conclusion that sagebrush voles are monogamous.

Mullican and Keller (1986) reported that these animals live in male-female pairs in the wild, indicating a monogamous existence. One captive study confirmed that males and females share a single nest during the post-partum period, as is common for monogamous microtine rodents (Hofmann, et al., 1989). In species known to be polygynandrous, males inhabit separate nests. Also, in their breeding colony, pups often continued to inhabit the parental nest when another litter was born. This supports the notion that local concentrations of animals seen in the wild represent extended families, living in a somewhat colonial fashion.

However, not all of the data collected by Hofmann, et al (1989) were consistent with a monogamous breeding system. They also showed that males and females did not coordinate their activity to ensure that at least one parent was always with the pups, as has been reported for monogamous species. Further, males spent very little time caring for the pups, which is uncommon for monogamous species, and is very common in polygynous species. Further research is needed to clarify the mating system of this rodent.

Sagebrush voles breed year round, although in the northern portion of their range they generally breed only from March to early December. The estrous cycle of sagebrush voles is approximately 20 days, and within 24 hours after giving birth, a postpartum estrus occurs. A litter of 5 is average, with a range from 1 to 13. Gestation usually lasts between 24 to 25 days. Captive members of this species have been known to produce 14 litters in one year, but in the wild average 2 to 3 litters per year. Females in the wild may live together while raising young, or males and females may nest together.

Young are born naked and blind in an underground nest chamber composed of leaves, shredded sagebrush bark, and grass stems. At birth, young weigh approximately 1.5 grams. They open their eyes at 11 days, and by 21 days they are usually self-sufficient. (Brylski and Harris, 2001; Nowak, 1999)

Males may be aggressive, particularly during breeding. Sexual maturity for females is reached around 60 days, and for males between 60 and 75 days. (Brylski and Harris 2001; Hofmann et al. 1989; Nowak, 1999) (Brylski and Harris, 2001; Hofmann, et al., 1989; Nowak, 1999)

  • Breeding season
    Lemmiscus curtatus breeds throughout the year, although in the northern part of its range, breeding may be confined to the period between March and December.
  • Range number of offspring
    1 to 13
  • Average number of offspring
    5
  • Range gestation period
    24 to 25 days
  • Average weaning age
    21 days
  • Range age at sexual or reproductive maturity (female)
    60 to 75 days
  • Range age at sexual or reproductive maturity (male)
    60 to 75 days

The young are altricial. In captivity, both male and female care for the young. Because males and females have been reported to nest together in the wild (Mullican and Keller, 1986), this probably occurs in wild populations also. Hofmann, et al. (1989) showed that females generally spent more time alone in th nest than did males. They also groomed pups more frequently than did males. Frequency of grooming the pups decreased as the pups aged. (Hofmann, et al., 1989; Mullican and Keller, 1986)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • male
      • female

Lifespan/Longevity

Information on lifespan in L. curtatus is not available. However, other voles are known to live an average of less than one month (Microtus pennsylvanicus) to a maximum in captivity of nearly four years (M. guentheri). (Nowak, 1999)

Behavior

Sagebrush voles are active year round, and throughout the day. Their peak periods of activity are from 2-3 hours before sunset to 2-3 hours after complete darkness, and 1-2 hours before and after sunrise. They either occur in pairs or are solitary, and despite conflicting opinions, are not known to be colonial. They establish burrows in clusters that usually have 8-30 entrances each, and are often hidden by cover. Many short tunnels at depths of 80-460mm occur within the network of burrows, and a nest chamber can be 250mm in diameter. Tunnels abandoned by pocket gophers are often integrated into the network of burrows. Sagebrush voles use surface runways and short adjacent tunnels that act as escape holes. They often have a series of burrow networks and will switch networks depending on food availability. (Mullican and Keller, 1986; Nowak, 1999)

Communication and Perception

Food Habits

Sagebrush voles are herbivores, and feed upon the flowers and fleshy parts of vegetation, but not the seeds. Newly harvested vegetation may be piled before it is consumed, and it is often brought into burrows. There is no evidence of food caching in this species. They often forage under shrub canopy and grass cover, and may climb in to shrubs to feed. They are also known to steal from other individual’s food piles. (Brylski and Harris, 2001; Mullican and Keller, 1986; Nowak, 1999)

Predation

Predators include owls, hawks, snakes, coyotes, bobcats, and badgers. (Brylski and Harris, 2001)

Sagebrush voles may evade predators by burrowing, restricting activity to locations under vegetation, remaining cryptic, and by living in colonies or extended families.

Ecosystem Roles

Sagebrush voles are important food for a variety of predatory species.

Economic Importance for Humans: Positive

This species is not known to directly benefit humans. However, as a prey species, sagebrush voles provide food for charismatic megafauna.

Economic Importance for Humans: Negative

No negative interactions with humans have been reported in the literature.

Conservation Status

Population densities of 4-16 per hectare have been found in southeastern Idaho. Demographic patterns of Lemmiscus are different when compared to vole species that experience annual or multiannual population fluctuations. Much of the original range of sagebrush voles has been altered as a result of agriculture and overgrazing. (Brylski and Harris, 2001; Mullican and Keller, 1986; Nowak, 1999)

Contributors

Kasha Christopherson Baus (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.

Glossary

Nearctic

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.

World Map

altricial

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.

bilateral symmetry

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.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

endothermic

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.

folivore

an animal that mainly eats leaves.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

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).

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

solitary

lives alone

tactile

uses touch to communicate

temperate

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).

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Brylski, P., J. Harris. 2001. "Sagebrush Vole" (On-line). Accessed October 23, 2001 at http://www.dfg.ca.gov/whdab/html/M138.html.

Hofmann, J., B. McGuire, T. Pizzuto. 1989. Parental care in the sagebrush vole (*Lemmiscus curtatus*). Journal of Mammalogy, 70: 162-165.

Mullican, T., B. Keller. 1986. Ecology of the sagebrush vole (*Lemmiscus curtatus*) in southeastern Idaho. Canadian Journal of Zoology, 64: 1218-1223.

Nowak, R. 1999. Walker's Mammals of the World, 6th edition. Baltimore and London: Johns Hopkins University Press.