The U.S.-headquartered conservation organization said the guanaco -- a wild cousin of the llama -- once roamed in vast herds from the Andean Plateau to the steppes of Patagonia. Today, the guanaco population has dwindled to about half a million animals that live in highly fragmented populations due to habitat loss and competition from domesticated livestock.

Tierra del Fuego, especially Karukinka, holds the largest wild population of Chilean guanacos. Donated to the WCS by Goldman Sachs in 2004, Karukinka consists of 740,000 acres of wilderness, including the world's southernmost old-growth forest. Goldman Sachs is providing key funding for the guanaco study.

"This study is pivotal in understanding the ecological importance of the guanaco and ultimately conserving them as a species," said Steven Sanderson, president of the Wildlife Conservation Society.

A team of WCS researchers have successfully equipped eight guanacos with radio collars to better understand their current movements. Researchers are particularly interested in how guanacos adapt to seasonal changes and how they are affected by livestock grazing and other human factors outside the reserve.