River otters once again making Long Island home

With the birth of river otter pups at the Long Island Aquarium and possible sightings of otters at Marion Pond in East Marion, interest in river otters on the East End has increased. Once extirpated from almost all of New York State, these elusive animals have made a remarkable comeback. 

“On the North Fork, there are otters in most of the main waterways, ponds and creeks, from Orient west to East Marion. There are a few missing that are in the very western part of Southold, until you get to the tributaries of the Peconic in Riverhead,” said Mike Bottini, wildlife biologist at Seatuck Environmental Association. “Wading River and Baiting Hollow are both occupied by otters.”

The population on the East End most likely migrated from Connecticut via the archipelago of islands off Orient, starting with Fishers Island, where an established population is breeding. As juveniles mature, they move outward from their parents’ home range to the other islands in the chain- first Plum Island, then Great Gull and Little Gull, and finally the North Fork.

“They have very large home ranges, and they’re not territorial, so they share watersheds with other otters. The males will do cooperative hunting. They could be unrelated males, [and] they’ll travel together and drive fish into shallow water where they’re easier to hunt,” said Mr. Bottini.

One otter captured on a series of trail cameras had a range that ran from Greenport to Shelter Island and across to East Hampton, a distance of more than 15 miles. 

“In the literature … the linear miles of waterways otters will occupy in coastal areas was easily 20 miles, 12 linear miles or greater. So [when] we draw that out on a map of the North Fork, it covers a lot of different ponds and creeks,” said Mr. Bottini.

Because otters are social animals and do not like to be alone, juveniles will often make a stop at a pond and then continue on in search of a range with other otters already in residence.

“Otters are so gregarious and so social, they’re not real loaners. Even an ideal habitat, if there are no other otters there, they don’t really want to stick around. They’re not into the solitary life like mountain lions and other species,” said Mr. Bottini.

Unfortunately, the most common way to see wild otters on Long Island is when they are forced out onto a roadway and killed by traffic.

“The otters have to get out of the water to get around a lot of dams, even really low dams, and in doing that here, a lot of times there’s a road over the dam, or very close to the dam. So they have to move onto to a roadway to get from the freshwater pond to the tidal creek, and then they get hit by cars. That’s the major source of mortality here,” said Mr. Bottini.

While otters do travel over land between waterways, they spend most of their time in the riparian environment, which is the shoreline surrounding the water body or water way. 

“The last road-killed otter was two months ago in Sag Harbor. That otter didn’t use the culvert, because it was clogged, I guess, and so it got out of the stream bed and tried to go up the road and got hit,” said Mr. Bottini. 

A simple solution is to build cinder block ladders for the otters to traverse the dam. 

“We can put these simple ladders up,” said Mr. Bottini. “It might take you half an hour to put these cinder blocks, so they can run up and get over the dam, or swim up to the dam and go down the stairway.” 

Trail cameras set up at these sites have captured otters and muskrats using the ladders.

“At one site in Flanders, we actually have a female with two pups using it, so that was kind of cool,” said Mr. Bottini. “There’s less roadkill [there]. It’s nice that there’s a viable option that they’re taking.”

Mr. Bottini hopes the increased interest in otters will lead to a greater interest in all the species under threat on Long Island.

“Otters are kind of a charismatic species, an unusual species. It’s hard for [the public] to ignore the situation,” said Mr. Bottini.