INVESTIGADORES
TRAVAINI Alejandro
congresos y reuniones científicas
Título:
Assessing the importance of natural and human factors in predictive models of Guanaco in southern Patagonia.
Autor/es:
JULIETA PEDRANA; ANTOINE GUISAN; JAVIER BUSTAMANTE; ALEJANDRO RODRIGUEZ; ALEJANDRO TRAVAINI
Lugar:
Mendoza
Reunión:
Congreso; The 10th International Mammalogical Congress; 2009
Institución organizadora:
Sociedad Argentina para el Estudio de los Mamíferos
Resumen:
Predictive models have become a useful tool for identifying conflicts between human activities and biodiversity conservation. Human activities such as sheep ranching and hunting have been regarded as the main cause of contraction in the geographic range of guanaco (Lama guanicoe) during the last century. Since a combination of natural and human predictors seem to influence guanaco distribution, our aim was to assess the relative importance of these factors using predictive models. We present a procedure that classifies guanaco habitat in four categories, hypothetically related with different population dynamics. We performed guanaco censuses from vehicles across Santa Cruz province, Argentina. To analyze the relationship between guanaco occurrence and predictors, we built GAMs using a binomial error. The AUC of the ROC plot was computed to assess the predictive power of the models. We generated two separate models, one with natural factors and another with human factors as explanatory variables. Predictions of these models were translated into spatial probability maps and simplified into two classes: the human model was split up into low and high human disturbance, and the natural model into favorable and unfavorable habitat. The combination of predictions in the resulting maps were hypothesized to delineate the spatial boundaries of areas where guanacos could exhibit four types of dynamics: source (favorable habitats with low human disturbance), sink (unfavorable habitats with high human disturbance), attractive sink (favorable habitats with high human disturbance), and refuge (unfavorable habitats with low human disturbance). We found that potential sinks for guanaco populations were predominated in the north and west of Santa Cruz, associated mainly with cities. Attractive sinks occur in the south, related with more productive areas that are devoted to sheep ranching. Potential sources were scattered through the province associated with the Andean slopes in the west, and with productive valleys in the center.