Pennsylvania’s river otter record is modest in number, 132 sightings across 43 counties, but wide in spread, and its center of gravity is the north country. Warren and Forest counties, along the Allegheny River drainage, lead the tally, with sign and sightings turning up in Allegheny National Forest, Susquehannock State Forest, and the Delaware Water Gap.
An athlete of the water
Few mammals are as thoroughly aquatic as the river otter. It swims with a tapered tail and webbed feet, hunts fish, crayfish, and frogs underwater, and can travel beneath winter ice between breathing holes. On land it moves between waters with an easy lope, and where a bank is snowy or muddy it leaves the giveaway: trough-like slides where an otter has tobogganed down on its belly, sometimes apparently for the fun of it.
Winter is when the sign shows
Otters do not hibernate, and Pennsylvania’s counts hold up through the cold months, with January, March, and April among the strongest. Snow records their slides and tracks, thin ice concentrates them at open water, and a family group fishing a pool is hard to miss, so the quietest season in the woods can be the liveliest one along the creeks.
Status in Pennsylvania
NatureServe ranks the river otter S4, Apparently Secure, in Pennsylvania, and the species is native to the state. Otters nearly vanished from most of the commonwealth by the early twentieth century under water pollution and unregulated trapping, a remnant holding on in the northeast, then returned with the help of reintroductions and cleaner rivers. USGS NAS does not list the species as nonindigenous here.
