Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported

摘要

Background: Guanacos ( ) are thought to have declined inPatagonia mainly as a result of hunting and sheep ranching. Currently accepted estimatesof total population size are extrapolated from densities obtained through strip transectsin local studies. We used road surveys (8,141 km) and distance sampling to estimateguanaco density and population size over major environmental gradients of Santa Cruz, alarge region in southern Patagonia. We also calculated the survey effort required todetect population trends in Santa Cruz.