About Lama glama (Linnaeus, 1758)
A full-grown llama (Lama glama) reaches 1.7 to 1.8 m (5 ft 7 in to 5 ft 11 in) in height measured at the top of the head, and weighs between 130 and 272 kg (287 and 600 lb). At maturity, average weights differ by sex: males weigh 94.74 kg, while females weigh 102.27 kg. A newborn llama, called a cria, weighs 9 to 14 kg (20 to 31 lb) at birth. Llamas typically live 15 to 25 years, with some individuals living 30 years or longer. Adult llamas have a dental formula of 1/3 incisors, 1/1 canines, 2/2 premolars, and 3/3 molars, for a total of 32 teeth. In the upper jaw, a compressed, sharp, pointed laniariform incisor sits near the rear edge of the premaxilla. This is followed, at least in males, by a moderately sized, pointed, curved true canine in the anterior portion of the maxilla. Llamas do not have the isolated canine-like premolar found in camels. The connected teeth of the molar series are made up of two very small premolars (the first nearly rudimentary) and three broad molars, built generally like those of the Camelus genus. In the lower jaw, the three incisors are long, spatulate, and procumbent, with the outer incisors being the smallest. Next to the incisors is a curved, suberect canine, followed after a gap by an isolated, tiny, often deciduous, simple conical premolar. After that comes a connected series of one premolar and three molars, which differ from Camelus molars in having a small accessory column at the anterior outer edge. The llama skull generally resembles that of Camelus, but has a larger brain cavity and eye sockets, with less developed cranial ridges due to the llama's smaller overall size. The nasal bones are shorter and broader, and are joined by the premaxilla. Llama vertebrae count: 7 cervical, 12 dorsal, 7 lumbar, 4 sacral, and 15 to 20 caudal vertebrae. Llama ears are moderately long, slightly curved inward, and are characteristically described as "banana" shaped. Llamas do not have a dorsal hump. Their feet are narrow, with toes more separated than camel toes, and each toe has a distinct plantar pad. The llama tail is short, and its fiber is long, woolly, and soft. All members of the Lama genus are very similar in core structural traits, general appearance, and habits, so whether they should be classified as one, two, or more species remains a matter of debate among naturalists. This debate is complicated because most observed individuals are either fully or partially domesticated, and many are descended from already domesticated ancestors. Domesticated status tends to create more variation from the original wild type. South American inhabitants commonly distinguish four forms, which are often recognized as separate species, though defining their unique traits is difficult. These four forms are: the llama (Lama glama (Linnaeus)), the alpaca (Lama pacos (Linnaeus)), the guanaco (Quechua huanaco, Lama guanicoe (Müller)), and the vicuña (Lama vicugna (Molina)). The llama and alpaca are only known in domesticated states, vary in size, and come in many colors: they are often white, brown, or piebald, with some individuals grey or black. The guanaco and vicuña are wild. The guanaco is endangered, has a nearly uniform light-brown color that fades to white on its lower body. The guanaco and vicuña are clearly distinct: the vicuña is smaller, more slender in proportion, and has a shorter head than the guanaco. The vicuña lives in herds on exposed, high-elevation parts of mountain ranges near perpetual snow, among rocks and cliffs, across suitable habitats throughout Peru, southern Ecuador, and as far south as central Bolivia. Its behavior closely resembles that of the European Alps chamois; it is equally vigilant, wild, and timid. Vicuña fiber is extremely fine and soft, and highly valued for weaving, but each animal produces only a small amount. Domesticated alpacas descend primarily from wild vicuña ancestors, while domesticated llamas descend primarily from wild guanaco ancestors, though a large amount of hybridization between the two species has occurred. Key differences between llamas and alpacas include the llama's larger size, longer head, and curved ears. Alpaca fiber is generally more expensive, though not always more valuable. Alpacas typically have a more consistent body color. The clearest visible difference between llamas and camels is that camels have humps while llamas do not. Llamas are not ruminants, pseudo-ruminants, or modified ruminants. They have a complex three-compartment stomach that lets them digest lower-quality, high-cellulose foods: the stomach compartments allow fermentation of hard-to-digest materials, followed by regurgitation and re-chewing. Unlike ruminants such as cows, sheep, and goats, which have four stomach compartments, llamas have three: the rumen, omasum, and abomasum. Llamas (and other camelids) also have an extremely long and complex large intestine (colon). The large intestine's function in digestion is to reabsorb water, vitamins, and electrolytes from food waste passing through the organ. The length of the llama's colon lets it survive on much less water than many other animals, which is a major advantage in the arid climates where llamas live. Llamas have an unusual reproductive cycle for a large animal. Female llamas are induced ovulators: mating triggers the female to release an egg, and fertilization often occurs on the first attempt. Female llamas do not go into estrus ("heat"). Like humans, male and female llamas reach sexual maturity at different rates. Females reach puberty at around 12 months old, while males do not become sexually mature until approximately three years of age. Doctors and researchers have found that llamas have antibodies well suited to treating certain diseases. Scientists have studied how llamas may contribute to fighting coronaviruses, including MERS and SARS-CoV-2, the virus that causes COVID-19.
