Date of Award

Spring 2020

Degree Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair

Hans Stadthagen-Gonzalez

Committee Chair School


Committee Member 2

Heidi Lyn

Committee Member 3

Richard Mohn

Committee Member 3 School


Committee Member 4

Carla Almonte


This study focuses on the vocalization repertoires of wild North American river otters (Lontra canadensis) in New York and California. Although they are the same species, these two established populations of river otters are separated by a significant distance and are distinct from one another. River otters are semi-aquatic social predators that can be found throughout North America. This is the first study to examine the vocalizations of wild river otters, and results are compared across field sites in the different regions. River otter vocalizations and behaviors in New York were recorded using Bushnell Aggressor trail cameras that were placed in areas of moderate to high river otter activity. The River Otter Ecology Project, a nonprofit organization studying river otter populations in Marin County, provided the otter videos from California. Recorded vocalizations were separated into categories based on their appearance on a spectrogram and parameters including frequency and duration were measured for each call. Behaviors were identified in all New York videos and during vocalizations in both New York and California videos. Four call types (chuckle, hah, chirp, and whine) were recorded in both California and New York otters. An additional call (chirpwhine) was recorded only in the California population. Otters in both populations produced chuckles while traveling, scentmarking, and investigating. Hahs were produced during disturbance, food, play, and rub behaviors. Otters were most likely to produce chirps when they were stationary and alone. Hahs were most likely to occur in pairs, and chuckles and whines were more likely to occur among groups of 3 or more otters. This study not only contributes to the limited knowledge that exists on the North American river otter vocalization repertoire, but also bridges the gap between animal acoustics and behaviors, providing behavioral context for this elusive species’ most common call types in the wild.