Pacarana  (Dinomys branickii)

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

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).

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).

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

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).

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).

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).

View information on this species at the UNEP World Conservation Monitoring Centre.

To learn more about the Pacarana Conservation Project visit:

• Osbahr, K. (2004) Proposal: Pakarana (Dinomys branickii) Conservation Project. Fauna Research Group, UDCA, Bogotá. Available at:
  http://www.udca.edu.co/aplicaciones/veterinaria/PROPOSAL.pdf
• Zoological Society for the Conservation of Species and Populations (ZGAP):
  http://www.zgap.de/pacarana.html