Lagidium peruanumnorthern viscacha

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Geographic Range

Lagidium peruanum, one of several recognized species of "Mountain Viscachas," lives in the Andes Mountains of Peru at elevations ranging from approximately 3,000-5,000 meters. This corresponds to the area contained between the timber and snow lines. L. peruanum, while often locally abundant, exhibits a scattered distribution across its range. It is not uncommon to have dense populations separated from other such populations by over 10 kilometers. There is seemingly little or no difference in habitat structure between occupied areas and the unoccupied areas between populations.

Habitat

L. peruanum live in dry, rocky, habitats between the timber line and snow line of the Andes mountains. Vegetation is relatively sparse and characterized mainly by coarse grasses. L. peruanum are often found near water that offers more succulent vegetation than drier areas within their habitat. They occupy burrows among rocks and crevices.

Physical Description

L. peruanum, excluding their bushy tails which reach lengths of about 200-400mm, are approximately 300-450mm in length. They posess dense, soft fur on their bodies and long, coarse fur on the dorsal surface of their tails. Their pelage coloration varies from dark grey at low elevations to brown at higher elevations. The ventral portion of their fur is lighter, and can be white, yellowish, or light gray. The dorsally curled ends of their tails vary from rusty to black in color. L. peruanum have long, hair-covered ears. Females have only a single pair of mammae.

  • Range mass
    0.900 to 1.600 kg
    1.98 to 3.52 lb

Reproduction

Individuals reach sexual maturity after one year. The mating period ranges from October to December, in which all adult females become pregnant. Gestation lasts approximately 140 days and one offspring is produced. While females may undergo a post-partum estrus, it is unlikely that a second pregnancy in a given year will result given the length of the gestation period and the timing of the mating season. The offspring are precocious, and feed on a mixture of their mother's milk and vegetation. While females posess two ovaries and two uterine horns, only the right ovary and uterine horn are functional. If the right ovary is surgically removed, the left then becomes functional.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Range number of offspring
    1.000 (low)
  • Average number of offspring
    1.000
  • Average number of offspring
    1
    AnAge
  • Range gestation period
    104 to 140 days
  • Range weaning age
    30.000 (low) days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    365 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    365 days
    AnAge

Lifespan/Longevity

Behavior

L. peruanum live in large colonies of up to 80 individuals. These colonies are segregated into small family units of 2 to 5 individuals which occupy a single burrow. These animals are poor diggers, so their burrows consist of crevices among cliffs and rocks. They are not territorial and rarely aggressive. When the breeding season begins males are driven out of their family burrow by the female, at which point they disperse throughout the colony and exhibit some degree of promiscuity. Much of the day is spent basking and preening on exposed rocks. Feeding begins in the afternoon and lasts until after sunset, at which time individuals return to their burrows. L. peruanum are quick and agile, able to get from rock to rock with either short hops or leaps of over 2 meters, if alarmed. When alarmed they produce a high-pitched call to warn the colony of a potential threat. L. peruanum rarely stray more than 70 meters from shelter.

Communication and Perception

Food Habits

L. peruanum eat most of the sparse vegetable material they find in their habitats. This includes tough grasses, lichens, and moss. They feed primarily from late afternoon until after the sun sets.

Economic Importance for Humans: Positive

L. peruanum are used as a source of meat and fur, however their pelts are not in particularly high demand.

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

None.

Conservation Status

While their numbers have declined in some areas, L. peruanum, perhaps because they are the smallest of the Mountain Viscachas, are not particularly sought after for their fur or as a source of meat.

Contributors

Matthew Wund (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

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.

chemical

uses smells or other chemicals to communicate

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.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

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

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.

tactile

uses touch to communicate

young precocial

young are relatively well-developed when born

References

Matthews, H. 1971. The Life of Mammals. New York: Universe Books.

Nowak, R. 1991. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press.

Pearson, O. 1948. Life history of mountain viscachas in Peru. Journal of Mammology, 29: 345-374.