A river otter took a selfie in Ridley Creek, ending a 100-year absence for ‘the most elusive aquatic animal in Pa.’

The river otter ogled the camera, posing for an inadvertent selfie on a chilly winter night. The adult critter explored its surroundings for 45 minutes before slipping off into the darkness, ever elusive.

The unexpected December cameo marked the first known presence of a river otter along the Ridley Creek watershed in Chester County for 100 years, signifying that the revival of the animal, once nearly extirpated from Southeastern Pennsylvania, continues throughout the region.

“We haven’t caught much else by way of footage, but a homeowner has reported seeing it swim in their pond just few weeks ago, which is a good sign that it’s hanging out in the area,” said Lauren McGrath, director of the watershed protection program for the Willistown Conservation Trust, a nonprofit in Chester County.

McGrath’s team installed a game camera on private property to monitor beaver on private land near where the trust recently acquired 90 acres of the 218-acre Kirkwood Farm at Plumstock and Providence Roads in Willistown.

Kirkwood Farm was purchased in March 2023 by movie director M. Night Shyamalan. He sold 90 acres of the farm to the trust in January for $9 million, according to the deed. The trust renamed the preserved land Kestrel Hill Preserve and plans to open it to the public in the future.

The American river otter (Lontra canadensis) was found on land close to what would have still been Shyamalan’s property at the time. It was caught on camera along Okehocking Run, a small tributary to Ridley Creek, and near Plumsock Road and Route 3 (West Chester Pike).

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Trust officials credit cleaner waterways and nearby preservation efforts with providing a new, safe habitat for the river otter. They waited to announce that the otter had been sighted until the footage could be verified and they could attempt more pictures, which turned out to be unsuccessful. But they did capture audio of noises it made while hunting. The sounds, McGrath said, were like a cross between a “pig and a dog.”

“If that property had been developed, it would have been devastating to that habitat,” said Kate Etherington, executive director of the trust, adding that the otters are “certainly benefiting from the adjacent open space.”

Though never completely gone, river otters were once nearly eradicated from Pennsylvania in the 19th century because of water pollution, over-trapping, and deforestation. The Pennsylvania River Otter Reintroduction project that ran from 1982 to 2004 successfully reintroduced 153 river otters into state waterways.

Over time, they gradually emerged in Southeastern Pennsylvania, including the Delaware River watershed, and have grown more numerous over the past decade. According to the Pennsylvania Game Commission, the river otter is “the most elusive aquatic mammal in Pennsylvania.” The otter belongs to the mustelid or weasel family.

River otters are curious and playful. They gracefully slide on ice, snow and muddy banks. They play with sticks and one another. But it’s rare to catch a glimpse of one.

A mature male weighs 10 to 25 pounds and measures 30 to 40 inches long. Females are about 25% smaller. They are muscular, with a long tapered tail, a broad face, and slightly protruding eyes. They navigate underwater for up to a quarter-mile without coming up for air, able to stay submerged up to four minutes.

Pennsylvania issues licenses for river otter trapping each February, though none of the licenses is issued in the Philadelphia region because numbers are too low. New Jersey also has a river otter trapping program.

River otters dine on diverse array of prey, including minnows, sunfish, suckers, carp, trout, frogs, turtles, snails, mussels, crayfish, snakes and snake eggs. They feast on insects and aquatic plants and roots.

Conservation efforts, including the Clean Water Act of the 1970s and land preservation programs, contributed to a remarkable recovery, according to Tom Keller, a furbearer biologist with the Game Commission. Otters, which have few natural enemies, are susceptible to water pollution such as heavy metals, polychlorinated biphenyls, and other chemicals. Their comeback indicates cleaner waterways.

“Through those protections, the otter started to make a comeback,“ Keller said. “We continue to see numbers of otters increase, particularly in areas where we haven’t seen them for some time.”

Notably, otters have been seen in recent years in the Delaware and Schuylkill Rivers, as well as their larger tributaries. They inhabit the Brandywine Creek, as well.