Guanacoes, the llama's ancestor
Here we discuss the guanaco, the wild ancestor of the llama, a domesticated animal. The guanaco resides in South America, distributed from Tierra del Fuego to the Andes. Until recently, it has been an endangered species.
General information about guanacoes
The following information is taken from the book, Medicine and Surgery of South American Camelids (Llama, Alpaca, Vicuna, Guanaco) by Dr. Murray E. Fowler. The first chapter, as well as other sections, of this book deals with general biology and evolution of camelids, and thus touches on guanacos, which are physiologically almost indistinquishable from llamas.
All camelids are similar, in having 37 pairs of chromosomes. All of the New World camelids can be crossed to each other to produce fertile offspring.
Despite some major differences in size, all of the camelids are basically similar in structure. Because camelids evolved in a semi-desert environment, they have developed sophisticated physiological adaptations for coping with both heat and dehydration.
All camelids have a complex, 3-compartmented stomach. Although they are not considered ruminants, they do regurgitate and rechew ingested forage. In fact, they are more efficient at feed conversion than are ruminants in extracting protein and energy from poor quality forages.
All of the camelids evolved in North America. Although the ancestors of the lamas and camels appear to have diverged sometime in the Eocene epoch, they weren't completely separated from each other until the Pleistocene, when the ancestors of the camels migrated across the Bering Strait (temporary) land bridge to Asia. Lamas migrated to South American, and all camelids died out in North America.
The original migrants to South America were longer legged, as they were adapted to a plains ecology, but genera evolved in the Andes that were shorter legged, a better mode for mountainous terrain. The guanaco has the broadest distribution of the four camelids, from the tip of Tierra del Fuego to the Andes.
They are are somewhat smaller than llamas, but are otherwise very similar. They have a different ear shape from that of the llama and all have a similar color pattern, although the intensity of the pattern varies with the region. They have a brownish upper body and neck, with the fronts of the limbs colored brown, and the backs of the limbs, chest, belly, anal region whitish to cream. This white area usually extends quite high into the flanks, as high as the point of the hip. The head is usually greyish to black.
Llamas were domesticated from the guanaco by about 4000 B.C. The guanaco is wild and endangered in much of its range, although attempts are now being made to protect them, especially in Argentina.
The guanaco is both a grazer and a browser, and is quite adaptable. Some guanacos live in one of the driest deserts in the world (the Atacama in Chile) while others live in the wet archipelago of Tierra del Fuego, where rain falls year round.
Dr. William Franklin (Iowa State) has concentrated his research on the guanaco for many years, and has collaborated with the National Geographic Society to produce some spectacular videos about guanacos. If you are interested in these animals, try to get hold of one of these tapes.