The domesticated llama (Lama glama) and alpaca (Vicugna pacos) are the best known South American camelids (or New World camelids, as distinguished from their Old World relatives camels). As a family, the Camelidae actually originated in the North American continent, migrating outward. The guanaco (Lama guanicoe) and vicuña (Vicugna vicugna)—wild counterparts of the llama and alpaca—face major conservation threats. Of the camelid species, the vicuña population is the smallest. The vicuña lives in Peru and Argentina, typically at high elevations and often in tundra marshes. The vicuña has an extraordinary luxury fiber coat, softer than cashmere and finer than silk, and has been overhunted to near-extinction despite being protected throughout most of South America. Guanaco inhabit a large range in South America, from northern Peru to southern Chile, and prefer semi-arid shrub and grasslands. Guanaco face overhunting and loss of habitat. See table: Comparison of Vicuña and Guanaco (The Two Wild Species of South American Camelids) Comparison of Vicuña and Guanaco (The Two Wild Species of South American Camelids)
New World camelids have lived in conjunction with humans for more than 5,000 years, the longest-known animal-human relationship. In South America, camelids are used for meat, fiber, as pack animals, and for religious ceremonies. In North America, they are also used for sporting events, such as driving and agility, as well as for trekking in environmentally fragile areas, because their soft foot pads are less damaging to substrate than the hard feet (or metal shoes) of horses. Llamas can carry up to 60 kg of weight on their backs, although they are seldom loaded with more than 20 kg. Alpacas produce a rapidly growing, luxury fiber that can be sheared annually. Both llamas and alpacas are also used as guard animals for small flocks and herds of sheep and goats. They can be very fierce if threatened and will bray, spit, charge, kick, and bite.
Although vicuña and guanaco are always light brown or tan, alpacas and guanacos come in a variety of fiber colors, some of which are highly prized. The genetics of coat colors are complex; counter-intuitively, breeding non-white animals can produce white offspring. Coat colors and patterns in camelids are not explained by simple Mendelian genetics but involve complex gene linkages that determine color, hue, fiber quality, and distribution. Coat color has been shown to be related to eye color, and white fur with blue eyes can be associated with deafness.
All camelids have 74 chromosomes. New World camelids can interbreed, producing fertile F1 progeny. New World camelids can also interbreed with Old World camels, although this is uncommonly done, requires artificial insemination, and results in peculiar-looking offspring. The most common naturally occurring cross is a male llama-female alpaca breeding, producing a huarizo that is intermediate in size and fiber quality between the two species. Offspring of male vicuña and female alpacas are called pacovicuña. Sexually intact male llamas and alpacas are called studs (machos in Spanish), whereas castrated males are referred to as geldings. Females are called hembras in Spanish. The neonates and young up to 6 months of age are called crias, whereas juveniles are called tuis in the local Quechua language. This term is not commonly used outside of South America. See table: Comparison of Llamas and Alpacas Comparison of Llamas and Alpacas