River otters making a comeback on the North Fork

In the early morning of April 16, Mike Bottini received a call about a dead animal in the turning lane on Route 58 in Riverhead, between Pulaski Street and Osborn Avenue.

That animal turned out to be a river otter, a species once thought not to inhabit Long Island at all but which has been seen in the area increasingly in recent years.  The dead animal in the road was as good an indication as any that the otters have indeed moved out to the North Fork.

The State Department of Environmental Conservation picked up the otter carcass and took it to a veterinarian for an autopsy. It was determined to be a sub-adult male, most likely two to three years old. It was 40 inches long, with a 14-inch tail, and weighed about 13 pounds.

“River otters have a really large home range, so we can’t necessarily say that there’s an increase in numbers because they can travel quite far,” said Leslie Lupo, wildlife biologist for the DEC.

Ms. Lupo added that there have been two road kill incidents involving otters recently, including another in Cold Spring Harbor, although they are not very common otherwise. 

Mr. Bottini has studied and worked with river otters since the 1980s. He came to Long Island in 1988 to work for the Group for the East End and started the Long Island River Otter Project in 2008. He found that river otters were populating the north shore of Nassau County and a small portion of western Suffolk County, most likely coming from Westchester County and western Connecticut. The road kill incident in Riverhead reinforced his belief that otters are heading out to the East End.

“They have expanded their range in the last decade so now they’re all along the North Shore of Long Island,” he said.

River otters have very thick skin, so although it did not immediately appear to have sustained many injuries, the autopsy made it clear the dead animal had been run over at least two or three times. The otter had broken ribs and a crushed pelvis. The DEC archived sample tissue to be used for research and identification. 

“It’s a really unfortunate thing, but at least we can salvage some information from the death,” Mr. Bottini said.

He believes the otter was trying to make it to one of the four ponds on the north side of Osborn Avenue off Route 58. He investigated the area and found at least eight otter latrines, areas where otters leave their scent and scat. This indicated that the otter was trying to get from the pond to the Peconic River or vice versa.

“When otters are living in developed areas, they tend to move around in the middle of the night when there are less people around,” Mr. Bottini said. “This helps them out a lot when it comes to expanding because we don’t have as many road kills.”

Mr. Bottini said he’s also seen signs of river otters in Swan Lake, Cranberry Bog Preserve, Orient Point State Park in Southold and some parts of Wading River and Baiting Hollow. 

He raise the possibility of installing a culvert, a large-diameter pipe, underneath Route 58 to prevent future otter deaths, but acknowledged that it is an expensive solution.

Mr. Bottini said he wants to make his otter studies a community project and hosts free workshops at different watersheds, teaching people how to locate potential otter latrines from aerial photographs, how to identify other otter signs and how to help monitor sites in the Long Island River Otter Project. This Saturday, May 5, he will be at Arshamomaque Preserve in Greenport from 9 to 11 a.m.

“The otter is a charismatic wildlife species that people get really excited about,” Mr. Bottini said.

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Photo caption: A river otter was spotted at Marion Lake in East Marion.  (Carolyn Bunn photo)