Estimating effective population size of guanacos in Patagonia: an integrative approach for wildlife conservation

By the mid-1900s the guanaco (Lama guanicoe) approached extinction in southern South America due to habitat destruction and hunting. In order to maintain the ecological prominence of this iconic species, as well as assist in the management of populations that are emerging economically while increasing in conservation value, accurate and potentially rapid estimates of effective population size (Ne) (demographic and/or genetic) are essential. Estimates of Ne generally focus on the genetic effective population size; however, we posited that both parameters may be necessary to provide more accurate and timely estimates. Therefore, we examined the performance of three demographic and four genetic estimators of Ne of guanacos in Torres del Paine National Park, Chile, at different years and time intervals between 1987 and 1997. We compared our estimates with census estimates of the adult population size (Nac) during the same time period. Average Ne/Nac ratios of demographic estimates varied be...