Camels, guanacos, llamas, alpacas, and vicuñas

(Camelidae)

Class: Mammalia

Order: Artiodactyla

Suborder: Tylopoda

Family: Camelidae

Thumbnail description
Medium-to large-sized mammals with a long and thin neck, small head, and a slender snout with a cleft upper lip; they bend their legs beneath the body and rest on the stomach, the toes bear nails rather than hooves, and there are no hornlike structures on their low and elongated skull

Size
Bactrian and dromedary camels: average height 6–7.5 ft (183–229 cm); 1,000–1,800 lb (454–816 kg); vicuñas, guanacos, llamas, and alpacas: average height 3–4.3 ft (90–130 cm);88.8–265.5 lb (40–120 kg)

Number of genera, species
3 genera; 6 species

Habitat
Semiarid to arid plains, grasslands, and deserts

Conservation status
Critically Endangered: 1 species; Vulnerable: 2 species

Distribution
Bactrian camels and dromedaries found in the arid plains and hills of Africa, Asia, and Australia; vicuñas, guanacos, llamas and alpacas located in the Andean high plateau and the arid plains of western and southern South America

Evolution and systematics

The family Camelidae originated in North America during the Eocene period, 45 million years ago. At the end of this period, camelids migrated to Africa and Asia through the Bering Strait, where after successive changes they evolved into the Camelini tribe, which includes the Bactrian, or twohumped camel, and the dromedary, or one-humped camel. The population also spread into South America through the Panama Isthmus, where it evolved into the Lamini tribe that gave way to the species now known as vicuña, guanaco, llama, and alpaca.

The camelidae family developed in North America from the late Eocene to the late Pleistocene, while in Europe it was present from the mid Pliocene to the Pleistocene. After many migrations and transformations, camelids became extinct in both. Members of the family are still present, however, in North Africa, where the family has developed from the late Pliocene until Recent in Asia, which it inhabits since the mid Pliocene until Recent, and in South America, where it has developed since the Pleistocene until Recent. There are currently six camelid species throughout these regions.

Two species belong to the genus Camelus (Camelus bactri-anus and Camelus dromedarius); and three species to the genus Lama (Lama guanicoe, Lama glama, and Lama pacos). Only one species belongs to the genus Vicugna (Vicugna vicugna). Some authors place Camelus under the species Camelus ferus bactrianus and Camelus ferus dromedarius, but this taxonomic classification is no longer in use. Both species of the genus Camelus have been domesticated. Although there is still some controversy among several authors regarding when domestication started, it is estimated that it began some 6,000 or 5,000 years ago. The only known wild ancestor of Camelus bactrianus is a very small population found in the western Gobi Desert. However, taxonomists still hold the same genus and species for both wild and domestic populations in all its range. No wild ancestor is known for Camelus dromedarius.

The members of the Camelidae family found in South America include the wild guanaco (Lama guanicoe) and vicuña (Vicugna vicugna) as well as the domestic llama (Lama glama) and alpaca (Lama pacos). The origins of the alpaca are somewhat confusing, mainly due to a high level of hybridization and the lack of genetic analyses. However, recently, Kadwell et al. confirmed through mitochondrial and microsatellite DNA analysis that vicuña is the wild ancestor of alpaca. Therefore, this domestic species should be reclassified as Vicugna pacos. According to Kadwell et al., the domestication of this South American camelid began approximately some 7,000 to 6,000 years ago.

A similar situation occurred with the llama, which originated from the domestication of the guanaco, according to osteological remains from Andean archaeological sites approximately 6,000 years old.

Physical characteristics

There is a great difference in size between the genus Camelus in Africa and Asia, and Lama and Vicugna in South America. However, all three genera are characterized by a long and thin neck, a small head, and a slender snout with a cleft upper lip. Their mouths are tough, in order to allow them to eat thick grasses and thorny desert plants without hurting themselves.

The skull is long and elongated, and there are no horns or antlers. The usual dental formula in Camelus is: (I1/3, C1/1, P3/2, M3/3) × 2 = 34. In Lama and Vicugna, it is: (I1/3, C1/1, P2/1, M3/3) × 2 = 30. However, there is some variation depending on their age. The premaxilary bones of the skull bear the full number of upper incisors in the young, but only the outer incisors in the adult.

The hind part of the body is contracted and all of their limbs are long. The forelimbs have naked callosities in the guanaco, and prominent kneepads are present in Camelus, since they bend their legs beneath the body and rest on the stomach. In Vicugna, the knee joint is low in position, because of the long femur and its vertical placement. All camelids run with a swinging stride, as the front and hind legs move in unison on each side of the body.

Each foot has only two digits (the third and fourth). The proximal digital bones are expanded apart from the center. The other digital bones are small, not flattened on the inner surface, and not encased in hooves, bearing nails on the upper surface only. The digits are spread nearly flat on the ground. The feet are broad in Camelus and slender in Lama and Vicugna.

Both Camelus species have humps that help them survive in the desert, since they serve to store fat as a source of energy in times of need. When they are well fed, the hump is erect and plump, but when they do not have adequate food, the hump shrinks and often leans to one side. Dromedaries have only one hump, while Bactrian camels have two.

All Camelidae species have thick coats to protect them from the cold, but only the species of the genus Camelus shed their hair when temperatures rise. Both Bactrians and dromedaries have special muscles that allow them to close their nostrils and lips tightly for long periods, in order to avoid breathing large amounts of sand or snow.

Distribution

Camelidae are found in the wild since ancient times, from the Arabian Peninsula to Mongolia and in western and southern South America. There has been a drastic reduction in the range of wild camelids, but domesticated members of the family have spread over much of the world.

The distribution of the wild Bactrian camel (Camelus bactrianus) in historic times extended from about the great bend of the Yellow River at 110°E westward across the deserts of southern Mongolia and northwestern China to central Kazakhstan. Populations of wild Bactrians are currently restricted to three reduced areas in Mongolia and China: the Taklimakan Desert, the deserts surrounding Lop Nur, and the region in and around Great Gobi Strict Protected Area.

The domesticated dromedary (Camelus dromedarius) is mainly found in the Sahara Desert, but its presence is also common in arid regions of the Middle East through northern India. In central Australia, there is a population composed of individuals that were introduced into the dry and arid regions and live in feral state.

The vicuña is distributed throughout the southern Andes of South America. In Peru, it is found in the Ancash, Ayacucho, and Arequipa Departments. In Chile, the species is located in the Tarapaca, Antofagasta, and Atacama regions. In Bolivia, vicuñas inhabit the La Paz, Oruro, Potosi, and Tarija Departments. In Argentina, the species is found in the San Juan, La Rioja, Catamarca, Salta, and Jujuy Provinces.

The llama is distributed in Argentina from the northeast, southward through the Pampa, to as far as Tierra del Fuego. In Chile, the species is irregularly distributed in the northern regions of Tarapaca, Copiapo, and La Serena, and the cen-Guanacos tral O'Higgins region. However, the largest population is found in the southernmost areas of the Magallanes region. In Peru, the population is represented by small numbers in the departments of La Libertad, Arequipa, and Ayacucho. In Bolivia, individuals are located on the Mochara Range and in the Chaco region. In Paraguay, a small population is found in the northern section of the boreal Chaco in the Paulo Lagerenza area.

Alpacas and llamas are found throughout the southern Andes of South America, where they are kept in herds by the Andean local people. A significant number of both alpacas and llamas has been taken to the United States and Australia to be traded as pets.

Habitat

Wild camelids inhabit desert and semi-arid environments covered by sparse vegetation, some drought-resistant shrubs, and with a rigorous climate presenting a long dry season and a short rainy season.

The habitat of wild Bactrians is located in the arid continental areas in the temperate zone, where summer is hot and winter is severely cold, with large daily differences in temperature. Annual precipitation is less than 3.9 in (100 mm), and most of the distribution area presents aridity.

The dromedary inhabits desert environments where thorny plants, dry grasses, and saltbush are found.

The guanaco inhabits both warm and cold grasslands and shrublands, from sea level to approximately 13,120 ft (4,000 m). In some areas, the species inhabits forests during the winter.

The vicuña is more specific in its habitat and only occupies the grasslands of the Andes above 11,482 ft (3,500 m).

Behavior

All species are diurnal, adapted to harsh climates, and may spit, or occasionally kick, when threatened.

In the Gobi desert wild herds of Bactrians move widely in search of water. The animals tend to concentrate in and around the mountain areas where there are springs and snow on the slopes, which can provide the only moisture in winter. They also move to areas where a local shower has created a green spot. During October and November, large concentrations of Bactrians occur near the mountains. Most of them gather in herds of up to 30 individuals, while a few individuals of both sexes remain solitary.

In the Sahara, the domestic dromedary is left on its own for four or five months each year, coinciding with the mating season. The dromedaries form three types of herds during that time: bachelor males; adult females with their newborns; and up to 30 adult females, along with their one-and two-yearold offspring, each group led by a single adult male. Rival males that approach one another first employ dominance displays, including defacating, urinating, and slapping their tails on their backs. If neither male retreats from the display, the two animals fight by biting and thrashing with their forefeet.

The vicuña is a social animal. Territorial males maintain family groups consisting of the male adult and subadults, females, and young less than one year old. Adult males without territories form non-reproductive groups. Membership in these groups is limited to subadult males one to four years old, which have been expelled from their family groups, and of aging males, which have lost their territories.

There are three social groups in guanaco populations: family groups, male groups, and solitary males. Family groups consist of an adult male and one or several females with their year's offspring; young females may also be present. The number of animals found in this group may vary from a minimum of two to a maximum of 30 members. Male groups are entirely formed by males, both young and adult, whose number may amount to 50 individuals, but usually ranges from 5–20 animals. Solitary males are physically and sexually mature males prepared to form a family group and control a territory, or old, sick, or wounded males.

Alpaca and llama are raised as domestic stock and, as such, have lost their sense of social structure.

Feeding ecology and diet

Camelidae are grazers that feed on many kinds of grass and need very little water. They thrive on salty plants that are rejected by other grazing animals and need to eat halophytes, because although they are adapted for conservation of water, and since they hardly sweat or urinate, they will lose weight and strength if they go for long periods without drinking water. Dromedaries and guanacos have been seen drinking salty water, which no other animal could tolerate.

Both Camelus species eat practically any vegetation that grows in the desert or semiarid regions and are able to convert thorny desert shrubs and salty plants into highly nutritious food. They do not chew their food completely before swallowing it. After eating, they bring up the partly digested food, and then they re-chew it, swallow it again, and digest it.

Contrary to what is commonly believed, there is no evidence that Camelus store water in the stomach or in the humps. Humps are really masses of fat that nourish the animals when food is scarce. With this energy supply on their backs, they can go several days without eating. Both camel species can store up to 80 lb (36 kg) of fat in their humps. As camels use this fat, their humps shrink.

Reproductive biology

Females of the genus Camelus give birth to only one offspring after approximately 12–13 months of pregnancy. The newborn can stand shortly after its birth and can walk within a few hours. It stays with its mother until it is almost two years old, but it is not full-grown until the age of five.

Females of the genera Lama and Vicugna give birth to a single young after a gestation period of approximately 11 months. The offspring stay with their mothers until they are about one year old.

Because of their long gestation period and the high mortality rate of their newborns, females of all Camelidae species have an early estrous period that begins approximately one or two weeks after giving birth. Guanacos are polygamous, but the mating system for domesticated species is not well known.

Conservation status

The population of wild Bactrian camels has been reduced in Mongolia since the 1960s, due to heavy hunting and competition with domestic animals for water and grasses. This species is currently classified as Critically Endangered by the IUCN Red List.

Vicuña has shown a remarkable recuperation since its precarious existence during the 1960s, and guanaco shows the most stable population of all wild camelids. At present, the IUCN Red List has placed both species in the Vulnerable category.

Domestic Bactrian camel, dromedary, alpaca, and llama are not given a conservation status because they are grazing domestic animals, and unlikely to need protection.

Significance to humans

Camelids have been used for transportation as well as to obtain meat and fiber for clothes since approximately 7,000– 6,000 years ago until today. Ancient civilizations in the Arabian Peninsula, Mongolia, and the South American Andes flourished thanks to these animals.

It is estimated that both bactrian and dromedary were domesticated at approximately the same time, some 6,000 years ago, in Mongolia and Arabia. This brought about an increase in trade that linked the Indus Valley civilization with Mesopotamian city-states along the Tigris and Euphrates rivers and even reached the waters of the Indian Ocean.

Human populations living in the hot deserts of North Africa and Asia have especially benefited from these species, using them to travel in caravans, since they may travel about 100 mi (161 km) without water and keep up a steady pace despite the heavy burdens they carry. Some desert peoples measure wealth by the number of camels a person owns. These species also provide their owners with food, clothing, and fuel. Camelus milk is thick and rich, and people sometimes eat camel meat. The fat contained in their humps can be melted and used for cooking. Also, when the animals shed their coats, their owners gather up the woolly hair and weave it into clothing, blankets, and tents.

Llama and alpaca domestication began thousands of years ago before the Inca Empire. Nevertheless, detailed knowledge of llama and alpaca breeding and pastoralism is available only from the Inca period, when the ownership of these animals was a symbol of wealth. Therefore, herds were owned by the state, the priests, the community, and certain individuals. The animals that were part of community herds pastured freely and mingled. To identify their owner, they were marked with a piece of wool tied to their ears, a practice that still exists today in the Andes.

Pastoralism specialists, who constituted a well-identified social level, controlled the herds belonging to the state and the priests and concentrated on the reproduction of animals of certain colors, which were later sacrificed to specific deities.

Unlike the llama and alpaca, the use of vicuña was limited to specific ritual practices. This restriction was very strict in the Inca Empire, therefore specialists improved upon a method of capturing animals, which had been used long before the Empire. This method was known as chaku, and consisted in rounding up the vicuñas toward the end of ravines or mountain slopes where there were stone corrals with enough space to capture a large number of animals without injuring them. Several hundred people participated in this ancestral management technique. After the animals were captured, they were sheared. Only a few were sacrificed in rituals, and the rest were set free to be used later on.

The guanaco's wide distribution allowed its existence without domestication. Many cultures in the southernmost areas of South America benefited from this species to obtain meat for food, hides for clothing and shelter, bezoar stones for medical purposes, fibers for sewing, domesticated juveniles for entertainment, a stimulus for the creation of myths, and several words to designate age, sex, color, etc.

Species accounts

Resources

Bonavia, D. Los Camélidos Sudamericanos (Una introducción a su estudio). Lima, Peru: IFEA, UCH, Conservation International. 1996.

Gilmore, R. Fauna and Ethnozoology of South America. Handbook of South American Indian. Washington, DC: Smithsonian Institution, 1955.

Schaller, G. B. Wildlife of the Tibetan Steppe. Chicago: University of Chicago Press, 1998.

Tan, B. J. Into the Wild—The Rare and Endangered Species of China. Beijing, China: New World Press, 1996.

Torres, H. South American Camelids. An Action Plan for their Conservation. Gland, Switzerland: IUCN, 1992. ——. Distribution and Conservation of the Guanaco. Cambridge, Cambridge, UK: University Press, 1985. ——. Distribution and Conservation of the Vicuña. Gland, Switzerland: IUCN, 1983.

Afshar, A. "Camels at Persepolis." Antiquity LII (November 1978).

Kadwell, M., et al. "Genetic Analysis Reveals the Wild Ancestors of the Llama and the Alpaca." The Royal Society Journal 268 (2001): 2575–2584.

Wheeler, J., A. Russel, and H. Reden. "Llamas and Alpacas: Pre-conquest Breeds and Post-conquest Hybrids." Journal of Archaeological Science 22 (1995): 833–840.

Zarius, J. "The Camel in Ancient Arabia: A Further Note." Antiquity LII (March 1978).

[Article by: Hernán Torres, PhD]