River Otter Scat and Tracks: How to Identify Them (Lontra canadensis)

River Otter sign: scat size, shape and contents, track size, toes and gait, and how to tell it from American Mink and Beaver, quoted from state wildlife agencies, the National Park Service and the CDC.

Do not handle droppings bare-handed and do not sniff or dry-sweep them; several of the animals here carry parasites or viruses that spread through scat and dust. These pages report what wildlife agencies and the CDC say; they are not medical advice.

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At a glance

Scientific name: Lontra canadensis
Scat: Contents/color: Dark in color when fresh, containing fish scales and bones or other food remains; once broken down, fish scales and crayfish remains are commonly visible · Where: Often left in a conspicuous spot near water (such as on a log or rock); the same spraint site may be reused repeatedly by multiple otters
Tracks: Front: About 2.5 inches long, 5 toes · Hind: About 2.5-3 inches long, 5 toes · Toes: 5 toes on each foot with webbing between them; the webbing often registers in soft mud · Claws usually show · Gait: Moves with a loping gait on land; on snow or ice it often moves by bounding and sliding, leaving slide marks 10-20 feet long

Reading River Otter sign: start here

Carnivore scat is tubular, often twisted and tapered at one end, and full of hair, bone fragments, berries or seeds depending on the season. Dog-family tracks show four toes with claw marks and an X drawn between the pads; cat-family tracks show four toes with no claws and a three-lobed heel pad. Many carnivores leave scat on trails, rocks and junctions on purpose, so where it sits is a clue in itself. The measurements below for River Otter are quoted from the wildlife agencies linked at the bottom of the page.

River Otter scat: what it looks like

Contents/color: Dark in color when fresh, containing fish scales and bones or other food remains; once broken down, fish scales and crayfish remains are commonly visible
Where: Often left in a conspicuous spot near water (such as on a log or rock); the same spraint site may be reused repeatedly by multiple otters

River Otter tracks

Front: About 2.5 inches long, 5 toes
Hind: About 2.5-3 inches long, 5 toes
Toes: 5 toes on each foot with webbing between them; the webbing often registers in soft mud
Claws usually show
Gait: Moves with a loping gait on land; on snow or ice it often moves by bounding and sliding, leaving slide marks 10-20 feet long

Other sign to look for

Slides: Leaves long slide marks over 8 inches wide on muddy or snowy riverbank slopes
Uses a burrow abandoned by another animal: River Otters do not dig their own burrows; they often take over abandoned Beaver burrows

River Otter vs American Mink

The American Mink is smaller (no more than 27 inches total length), nearly all brown, and its tail does not noticeably thicken at the base, is not flattened underneath, and does not taper markedly from body to tip

River Otter vs Beaver

River Otters can be distinguished from Muskrats and Beavers by their thick, tapering, furred tail The Beaver page has its own sign list.

How to photograph sign for identification

Put something of known size next to it (a coin, a pen, a boot) and shoot straight down in soft light; low side light brings out the shape of tracks in mud or snow. For scat, photograph the whole deposit and one close-up showing contents. Note where it was: on a log, in the open, on a trail, near water. The app suggests the likely animal; confirm with the size and shape notes above.

FAQ

What does River Otter poop look like?

Contents/color: Dark in color when fresh, containing fish scales and bones or other food remains; once broken down, fish scales and crayfish remains are commonly visible. Where: Often left in a conspicuous spot near water (such as on a log or rock); the same spraint site may be reused repeatedly by multiple otters.

What do River Otter tracks look like?

Front: About 2.5 inches long, 5 toes. Hind: About 2.5-3 inches long, 5 toes. Toes: 5 toes on each foot with webbing between them; the webbing often registers in soft mud. Claws usually show. Gait: Moves with a loping gait on land; on snow or ice it often moves by bounding and sliding, leaving slide marks 10-20 feet long.

How do I tell River Otter sign from American Mink?

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Start with a single photo.