Wild Otter Acoustics is an organization researching the vocalizations and behaviors of North American river otters (Lontra canadensis) by comparing call repertoires of different populations in the wild and in human care. 

In the wild, otters are studied using audio and video capable trail cameras. To see footage of river otters and other animals recorded by WOA, visit Trail Camera Reports.
A pair of vocalizing river otters in Ward Pound Ridge Reservation
Mother otter and pups in Ward Pound Ridge Reservation