The critically endangered Giant River Otter (Pteronura brasiliensis) is restricted to the drainages of the Orinoco and Amazon river basins in South America and among the largest of the aquatic mammals to inhabit these neotropical rainforests.  The giant otter measures approximately 2 meters from snout to the tip of its tail. They have been observed eating caiman and anacondas in Peru, but prefer fish, eating them bones and all.  With keen vision, underwater sensing whiskers and powerful webbed feet, these are formidable semi-aquatic predators.  They are stealthy animals that appear suddenly and often vanish just as quickly.  They are sometimes seen eating their fish or resting on uprooted trees cast against the riverbank.  Individual otters can be recognized by the patterns on their throats.

I joined a Ecuadorian friend and fellow zoologist  in Yasuní National Park who had been studying the local family of giant otters for over a year, but still had not been able to identify each member of the family.  During my second week in the park, I heard the “barking” sound of a single otter near the entrance to a lagoon.  Hoping it might enter the lagoon with the entire family, I took a position near a fallen tree which extended out from the shore.   I anticipated correctly.   The otter photographed above “spyhopped” just long enough to check me out.

The research team was jubilant tot learn that I had successfully photographed the group during their brief topside appearance.  From those images, I  created the series of drawings shown here which allowed the team to confirm the size of the otter family and identify each member.   The ability to identify individual animals is key to tracking movement, surveying habitat use and recording behavioral observations of endangered wildlife.  These are important baseline data from which to assess potential impacts and make conservation recommendations.

Which drawing depicts the spyhopping otter in the photograph?