Critical population status of the jaguar Panthera onca in the Argentine Chaco: camera-trap surveys suggest recent collapse and imminent regional extinction

摘要

The population of jaguars Panthera onca in the semi-arid Chaco Province is the least well-known in Argentina. Its status in the region is described only from interviews that confirmed its presence until 2003. To update information on the distribution and population density of this species we undertook three camera-trap surveys, combined with searches for sign, at sites across latitudinal and protection gradients, and 156 interviews with local inhabitants across three larger areas. The camera-trap sites were located in areas with the highest density of records in the Argentine Chaco: Copo National Park (1,204 trap days, 24 stations, 344 km of transects), Aborigen Reserve (1,993 trap days, 30 stations, 251 km of transects) and El Cantor (2,129 trap days, 35 stations, 297 km of transects). We did not obtain any photographs of jaguars. We recorded very few jaguar tracks, and only in the Aborigen Reserve (n = 3) and El Cantor (n = 1). The map of distribution points confirmed through interviews suggests that the jaguar range has not changed significantly in the past 10 years; however, the camera-trap and sign surveys suggest that densities are extremely low. Before our study the Chaco population was thought to be the largest in Argentina. This perception was incorrect: the Chaco jaguar population is the most threatened in the country. Systematic, intensive studies are essential to provide the necessary information for decision-making for the management and conservation of threatened species.