The dropping of any animal is known as scat, but for otters, biologists and wildlife enthusiasts use the term “spraint.” Identifying spraint is a reliable method for determining the presence of otters in a specific aquatic environment. Analyzing these deposits provides valuable data, helping researchers track movements and understand the local ecology of these elusive mammals. The unique physical characteristics of spraint make it distinct from the scat of other riparian carnivores.
Visual Identification of Otter Spraint
Otter spraint typically appears as an elongated, cylindrical, or rope-like deposit, though it is often found broken into smaller, fragmented pieces. The diameter is generally small, ranging from 0.5 to 1 inch. Fresh spraint is usually a dark color—black, dark brown, or deep greenish-black—depending on the animal’s recent diet.
The color can vary significantly, becoming vibrant orange or pinkish if the otter has been consuming large amounts of crustaceans like crayfish. As the spraint ages and dries, the color fades considerably, often turning pale grey or nearly white.
The most defining visual feature is the presence of numerous undigested food materials embedded within the spraint. These visible inclusions are direct evidence of the otter’s diet because otters do not chew their food thoroughly before swallowing. Spraint is commonly packed with small fish scales, tiny bone fragments, or pieces of crustacean shells. This dense, fragmented texture gives the deposit a speckled or granular appearance, distinguishing it from the smoother scat of other species.
The Distinctive Smell and Consistency
The smell of otter spraint is often the most diagnostic feature for confirming identification, as it is markedly different from typical fecal odor. It is frequently described as having a strong, musky, or fishy scent, reflective of the otter’s aquatic, fish-heavy diet. This odor is generally not considered foul or repellent, unlike the scat of many terrestrial carnivores.
Some people have described the scent as surprisingly pleasant, comparing it to the aromas of freshly mown hay, sweet violets, or jasmine tea. This unique odor is due to specialized oily secretions from the otter’s anal glands, which are mixed with the feces.
When first deposited, spraint has a consistency that can be slimy, moist, or bound together by a tarry, dark mucus. This binding material helps hold the undigested bone and scale fragments together in a cohesive mass. As the deposit is exposed to air, it loses moisture and becomes chalky, crumbly, and brittle. The dried spraint breaks apart easily, leaving behind a small pile of fish scales and bone fragments.
Why Otters Use Spraint Sites
Otters use spraint primarily as a form of chemical communication, depositing it at specific, repeatedly used locations called spraint sites or latrines. These sites are strategically located on prominent natural features that maximize scent dispersal and visibility to other otters. Common locations include large rocks, exposed logs, grassy tussocks, and under bridges or culverts near the water’s edge.
The spraint serves as a sophisticated message board, conveying information to any otter that investigates the scent. The chemical signatures within the deposit allow otters to signal their presence, species identity, and social status. The spraint can also advertise an individual’s reproductive condition, communicating whether an otter is male or female and if a female is in estrus.
By regularly marking these sites, otters establish a network of communication points throughout their home range. This scent-marking behavior allows them to coordinate activities, maintain social spacing, and avoid conflict with other individuals. The repeated use of these visible spots ensures that the olfactory messages are current and easily discovered by neighboring otters.