Coastal Otter Research

River Otters
Between July 2009 and September 2011, we conducted the first monitoring and research project on coastal river otters (Lontra canadensis) inhabiting Martha’s Vineyard (MV). With sponsorship from Sheriff’s Meadow Foundation, a grant from the Edey Foundation, and private donor funding, we surveyed ponds, wetlands, and shoreline for otter tracks, scat, and trails to gather baseline data on the distribution of this top predator in our watersheds.
We are grateful to many private landowners as well as to The Martha’s Vineyard Land Bank, Mass Audubon at Felix Neck, The Nature Conservancy, Sheriff’s Meadow Foundation, The Trustees of Reservations, Vineyard Conservation Society, and Vineyard Open Land Foundation for opening their properties for otter mapping and monitoring.

Our wildlife cameras sometimes capture beautiful photos of otters such as this one!

Otter at DawnCoastal River Otter at Edgartown Great Pond

We have an entire gallery of photos and videos from our wildlife cameras available in a picasa web gallery here

Monitoring and Mapping

We monitored sites once per month to document the amount of otter activity (scat, tracks, scent mounds) at each site and to collect scat for diet analysis. We mapped 150 sites with otter activity on the Island, and we will continue with mapping of overland trails that connect many of these sites during winter 2012/2013.

Otter latrine site on Edgartown Great Pond

We selected 30 latrine sites and 19 trails as baseline sites for future monitoring.

An otter trail from Katama Bay leading inland on Chappaquiddick Island








Otter Diet Analysis

We collected over 300 otter scat samples and used a sub-set of these to create a guide to otter diet analysis for the region that was distributed to several Island science teachers. Identification of prey in the remaining samples will be complete in fall of 2012.  Otters in southeastern Massachusetts eat a variety of fish and crustaceans.  Most surprising to us, was the relative abundance of small fish species in otter scat.  Some of these species include Mummichog and Golden Shiner:

Otter with Mummichog – photo by Jeff Bernier

Golden Shiner scale








For coastal otter biology and behavior information, click here.

Coastal Otters

Edgartown Great Pond otter with pups – photo by Anne Mazar