A relative of the now-domesticated llama, the guanaco -- Patagonia's largest land vertebrate -- roams the plains of Torres del Paine. Guanacos live in groups, usually a single dominant male accompanied by up to 10 females and their young. Though elegantly formed creatures, guanacos exhibit a number of seemingly incongruous habits. When they greet, for example, the animals exchange a turkey-like gobble and then, on occasion, vomit a wad of semi-masticated grasses.

Female guanacos give birth every other year, mating in August and September. They bear only a single offspring, called a chulengo, which learns to walk within minutes of being born. Male chulengos are driven from the herd after a year, when they are no longer reliant on their mothers. These young males form a separate pack, and challenge the older males for the privilege of leading familial herds.