By Matthew Wund
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.
Biogeographic Regions:
neotropical
(native
).
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.
Terrestrial Biomes:
mountains
.
Physical Description
(1.98 to 3.52 lbs; avg. 2.75 lbs)
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.
Some key physical features:
endothermic
; bilateral symmetry
.
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
.
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.
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: Negative
None.
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.
Ways that people benefit from these animals:
food
.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special 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.
Phil Myers (editor), Museum of Zoology, University of Michigan.

