Defining conservation status using limited information: The case of Patagonian otters Lontra provocax in Argentina

The Southern river otter or huillín Lontra provocax has been classified as 'endangered', with the loss of riparian forest identified as the main threat to its survival. We used new information on distribution from Argentina to define their status. There are no data on the huillin's population structure and dynamics, and no estimate of its abundance or population trends at a relevant scale. Our survey teams covered 435 locations in lakes, rivers and coastal sites using a standard and repeatable methodology of 600 m survey transects as adopted for otter surveys across Europe. We found that its present geographic range in Argentina is slightly larger than is characteristic of a species at risk of extinction at the national level, although its contemporary distribution is still radically contracted in comparison to its historical distribution. © 2010 Springer Science+Business Media B.V.