Guanaco

The guanaco is flexible in its feeding habits, foraging mainly on grasses and shrubs (2) (3) (9), but also taking lichens, cacti and succulent plants when other food sources are scarce (1) (8). The guanaco is surprisingly graceful in its movements, and is capable of running at speeds of up to 56 kilometres per hour. Its blood is able to carry more oxygen than other mammals, enabling it to function well at high altitudes (2). Groups of up to 30 female guanacos and their young live on feeding territories defended by a single adult male, the boundaries of the territory being marked by communal dung heaps, known as latrines. Young and non-territorial males are found either alone or in all-male groups, although groups of all ages and sexes may form in migratory populations during winter (2) (6) (9). The female guanaco gives birth to a single offspring each year, in spring, after a gestation of 345 to 360 days (2) (3) (9). The long gestation period and the often harsh environment mean that the female has to be ready to mate again within two weeks of giving birth (3). The newborn is able to run and follow the female almost immediately after birth, and remains with the group until around 13 to 15 months old, when it is usually forced out by the adult male (2) (3). Sexual maturity is reached at 12 to 24 months, and captive guanacos may live up to 28 years (2). After leaving the family group, young male guanacos spend three to four years in all-male bachelor groups, practicing fighting skills and competing for dominance with other males, in readiness to challenge territorial males for control of a group of females. Rivals are fought with neck wrestling and chest ramming, often accompanied by a high-pitched scream and low growl (2).

Although still relatively numerous and widely distributed, and occurring in a number of protected areas, the guanaco is thought to be dependent on effective conservation measures for its long-term survival (1) (6). The species is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in the guanaco and its products should be carefully regulated (4). Although protected under various legislation over much of its range, illegal hunting and trade still persist, and lack of adequate funds, difficulties in enforcing legislation, and few incentives for local people to participate in guanaco conservation often make effective protection difficult (1) (6) (9). Conservation priorities for the guanaco include accurate population surveys, adequate habitat protection and management, regulation of hunting quotas and better control of poaching, as well as increased public awareness. Without urgent action it is thought that the guanaco may soon be lost from parts of its range (1) (6) (9). Sustainable use of wild guanaco populations may offer some hope for the species, and may also provide an alternative to traditional agricultural practices in some areas, helping to reduce the risk of overgrazing, and contributing to rural development (6). Such sustainable use programmes often take the form of live-shearing initiatives, whereby wild guanacos are caught, sheared for their wool, and then released. However, although the process itself may not cause high mortality, the long-term effects on guanaco populations are still unknown (1) (9) (12).

Described by Charles Darwin as “an elegant animal, with a long, slender neck and fine legs” (5), the guanaco is the largest wild member of the camelid family in South America (6), and is believed to be the ancestor of the domestic llama (6) (7). The woolly coat is a light fawn brown on top, with white undersides and a gray to black head (2) (3) (6), and the area around the lips, the edges of the ears and the insides of the legs are also white (6). Like other camelids, the guanaco walks on enlarged sole pads, with only the tips of the hooves touching the ground; in the guanaco these pads are moveable and help give grip on rocky and gravelly terrain (2) (3). Four subspecies of guanaco have been described in the past, based on differences in skull measurements, coat colouration and body size (2) (6) (8). However, recent genetic studies recognise only two subspecies, Lama guanicoe guanicoe and the more northerly Lama guanicoe cacsilensis (8) (9).

Inhabiting a range of arid and semiarid habitats, including desert grassland, savanna, shrubland, and sometimes forest, the guanaco can be found at elevations from sea-level to over 4,500 metres (3) (6) (9). While some populations are sedentary, others make seasonal migrations, including moving to lower altitudes, to avoid snow cover or drought (2) (3) (9).

The guanaco has a wide but fragmented distribution across much of South America, from the north of Peru to southern Chile, including Argentina, Bolivia and Paraguay, and on the islands of Tierra del Fuego and Navarino (1) (3) (9). Feral populations also exist in the Falkland Islands (3).

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (4).

Thought to number up to 50 million when Europeans first arrived in South America (2) (3) (9), the guanaco has since undergone a steep decline, particularly during the last century, and now numbers fewer than 600,000 individuals, 90 percent of which are found in Argentina (1) (9). Although still relatively widely distributed, the guanaco now occupies only 40 percent of its original range, and has become fragmented into often small and relatively isolated populations, increasing the risk of local extinctions in some areas (1) (9). L. g. cacsilensis is the more threatened subspecies, numbering perhaps fewer than 3,000 individuals, in small, isolated populations (9). Major threats to the guanaco include overhunting, for skins, meat and wool, as well as poaching, habitat degradation, and the fragmentation and isolation of its populations due to development and the use of barbed wire fences. Overgrazing and drought, possibly linked to climate change, pose further threats to its habitat (1) (6) (9). The large decline in guanaco numbers in the last century is thought to largely result from the introduction of domestic sheep, which monopolise the best feeding areas and compete with the guanaco for food (1) (9) (10). Sheep breeders often kill the guanaco, viewing it as a competitor with sheep and a possible source of disease transmission (2) (6) (9), although it has been suggested that the diseases of domestic livestock are likely to threaten the guanaco rather than the other way around (1) (11).