Identifying spatial conservation priorities for the giant otter (Pteronura brasiliensis)

The giant otter (Pteronura brasiliensis) is a charismatic, South American, social carnivore, and the largest otter species in the world. Historically, giant otters were almost extirpated due to the wildlife skin trade and are currently considered as Endangered. Using the Range Wide Priority Setting methodology, we (a group of 33 giant otter experts) updated the species’ historical range (9,021,590 km2), modelled an adjusted and more conservative aquatic historical range of 2,813,539 km2, systematized 5,593 giant otter distribution points across the range, and identified geographic areas for which there was expert knowledge (63%), including areas where giant otters no longer occur (19%), and geographic areas where giant otter presence is uncertain due to a lack of expert knowledge (37%). To prioritize conservation actions into the future and identify existing giant otter population strongholds, we used expert knowledge to identify 22 of the most important areas for the conservation of the species (i.e., Giant Otter Priority Conservation Units [GOPCUs]) that cover 29% of the historical range, and range in size from 1,367 km2 to 829,152 km2. In general, GOPCUs were relatively large and approximately 35% of the total GOPCU area is already designated as protected areas. Using the Range Wide Priority Setting results, we make a series of recommendations towards the long-term conservation of this iconic aquatic species.