Little is known about the life history of the pacarana in the wild, therefore most information about this enigmatic rodent comes from studies of captive animals (2) (4). Mostly active at night, the pacarana can generally be found moving along the forest floor with a slow, ungainly, waddling gait (2). With relatively poor eyesight, this species mostly relies on smell, taste and touch to locate the fruits, leaves and tender stems that comprise the majority of its diet (2) (5). During feeding, the pacarana displays surprising dexterity, grasping food in its front paws and inspecting it, while sitting upright on its hind limbs (2). During the day, wild pacaranas are believed to shelter in natural crevices, which they enlarge using their powerful claws. However, captive specimens have never been observed to dig, and prefer to shelter in trees which, in contrast to their ungainly locomotion on the ground, they climb with remarkable agility. Several different species prey on the pacarana, including ocelots, coatis and humans (2). In response to threats, the pacarana's main defence involves backing its vulnerable hindquarters up against a rock or into a burrow, while making a low, guttural growl, and attacking using its powerful incisors and claws (2) (4). Communication between pacaranas is believed to be facilitated through urination and defection at communal sites, by wiping whitish secretions from glands around the eye on vegetation, and by gnawing branches. During social encounters pacaranas display a variety of behaviours, including foot stamping with forepaws, tooth chattering, whimpers, whines, songs, and hisses. Such vocalisations are especially useful for attracting a mate, with the male making a complex series of calls in an attempt to locate a female, followed by a courtship song which may last over two minutes (4). Following a gestation period of around 223 to 283 days, the female gives birth to one or two well-developed offspring (2). The newborn pacaranas are quickly active, exploring and trying solid food at just two days old, although suckling may continue for an extended period (4).

Resembling a gigantic guinea pig, the pacarana is the third largest rodent worldwide, and is the only living species of its genus. The pacarana has a large head with small eyes, short rounded ears, a blunt snout and long whiskers (2) (3). The coarse fur is mostly brown or blackish, with two well-defined rows of white spots running parallel to the spine, merging towards the neck and head into broad stripes. Two rows of white spots also run along the flanks, but are more diffuse. The limbs are short, and end in broad four-toed feet, equipped with long, powerful claws, while the tail is short, thick, and completely covered with dark hair (2).

This species occurs in Venezuela, Colombia, Ecuador, Peru, Brazil, and Bolivia (Woods and Kilpatrick, 2005). It is found in Colombia from 300 to 3,400 m (Alberico et al., 2000). In the Bolivian yungas it is known from 1,000 to 1,600 m; there are few records in Bolivia (Anderson, 1997; J. Vargas pers. comm.).

Pacaranas are distributed throughout Western South American from Colombia to Bolivia (Anderson 1984 and White 1992).

Biogeographic Regions: neotropical (Native )

The pacarana has a large distribution extending from the Venezuelan Andes, southwards through western Colombia, Ecuador, Peru and eastern Brazil, as far as eastern and north-eastern Bolivia (1).

Pacaranas are the third largest living rodent with a head and body length ranging from 730-790mm and a tail length of about 190mm (Anderson 1984). Pacaranas have upper parts that are typically dark brown or blackish with two discontinuous white stripes along the back and a few rows of white spots down each side (Burton 1987, Anderson 1984). The ears are relatively short and curved, the upper lip has a deep cleft, and pacaranas have many long, greyish whiskers. The feet are plantigrade and there are four digits on each foot, each with a long and powerful claw (Grzimek 1975 and White 1992).

Range mass: 10.000 to 15.000 kg.

Habitat and Ecology

Systems

• Terrestrial

Pacaranas inhabit the slopes and valleys of rainforests in the Andes mountains. They are thought to be extremely rare, although some scientists speculate that this might be due to a lack of information about the animal's true habitat (White 1992 and Matthews 1971).

Terrestrial Biomes: forest

The pacarana is found in rainforest covered valleys and mountain slopes, from elevations of 240 to 3,400 metres (1) (2).

Pacaranas mainly feed on fruits, leaves, and stems of plants (Matthews 1971).

Primary Diet: herbivore (Folivore , Frugivore , Lignivore)

Average lifespan

Status: captivity: 9.4 years.

Average lifespan

Status: captivity: 9.0 years.

Maximum longevity: 12.8 years (captivity) Observations: One captive specimen lived for 12.8 years (Richard Weigl 2005).

Little is known about the reproductive characteristics of this species. Pacaranas in captivity have a gestation period of 222-283 days, and the female usually gives birth to no more than two young (Grzimek 1975). Each young weighs about 900g and shows considerable activity and curiosity about its environment within just a few days of birth (White 1992). Weaning period and age of sexual maturity are not known, but the life span of captive pacaranas can be over nine years. It also seems that pacaranas "cry" in the breeding season to attract sexual partners, and males approach females in a bipedal position during courtship (Anderson 1984).

Range number of offspring: 1.000 to 4.000.

Average number of offspring: 2.400.

Range gestation period: 223 to 283 days.

Average birth mass: 900 g.

Average number of offspring: 2.

Parental Investment: precocial

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Pacaranas are classified as threatened and possibly on the verge being classified as endangered (Bailie 1996). The classification is mostly due to the animal's rareness. They are probably not significantly affected by deforestation. The most important challenge is to learn more about the pacarana's life history in the wild and its habitat range (Burton 1987 and White 1992).

CITES: no special status

IUCN Red List of Threatened Species: vulnerable

Classified as Vulnerable (VU) on the IUCN Red List (1).

Population

Population Trend

Major Threats

Despite an overall large range, the pacarana appears to have a patchy distribution and a relatively small population, which is estimated to have declined by over 30 percent in the last decade. As an easily hunted species, one of the chief threats to this species is overexploitation, coupled with the ongoing habitat destruction and degradation occurring throughout its range (1).

Conservation Actions

The Universidad De Ciencias Aplicadas Y Ambientales, in Bogotá, Colombia, is working extensively to conserve the pacarana. The university's Fauna Research Group has implemented a comprehensive Pacarana Conservation Project, which involves international collaboration with the European Association of Zoos and Aquaria (EAZA) and the Zoological Society for the Conservation of Species and Populations (ZGAP). Through captive breeding programmes in Colombia, as well as at several European zoos, the project aims to develop a large, healthy captive population, which can be used to strengthen wild populations through reintroductions. In addition, the project will provide educational initiatives, and research into the pacarana's biology and ecology, so that a conservation management plan can be developed (6). In addition to this specific conservation action, the pacarana is recorded in several protected areas throughout its range, including Cotapata National Park in Bolivia (1).

Although rare, natives hunt pacaranas for food (Matthews 1971). Scientist believe the biggest enemy to pacaranas is the human (Grzimek 1975).