Scat might seem like something to avoid, but it's actually very interesting. Scat can tell scientist not only what animal came by, but how healthy it is, and what it's diet is like. In fact, by examining scat, researchers have discovered how eating patterns for the same species change with the seasons. A bear, for example, might eat mostly fish in the fall, but berries in the spring. Researchers have also realized that similar species in the same habitat occupy different ecological niches because of their differing eating patterns. For instance, foxes eat significantly more insects and significantly less mammals than coyotes. All that from scat!
Identifying Scat
It is hard to identify scat visually. For instance, the scat of different carnivore species can look very similar. It is true that larger carnivores leave larger droppings. However, there is enough variation within species, and enough overlap among species, that scat size cannot be used to positively determine a species any more than scat shape can. Visually examining scat alone can lead to mistakes 1/3 to 1/2 of the time!
Researchers often rely on more sophisticated clues, like the pH (acidity) of herbivore scat or the bile acids or carnivores to positively identify a species. That does not mean people need a sophisticated lab to figure out which animal left its mark. But it does mean people should also rely on other clues-- like habitat, tracks, chewed vegetation, or borrows-- when identifying a species.
- Shape is the most important clue to identifying scat. Carnivores have large, cylindrical scat, often with tapered ends. Herbivores, meanwhile, have smaller, roundish scat. A small, slightly flattened sphere was probably left by a rabbit or hare, while mice have scat the size and shape of a grain of rice. Deer typically have clusters of dimpled round scat, but that changes when their diet is rich in moisture -- then their droppings more closely resemble "cow pies".
- Some animals like rodents, rabbits, and shrews have two types of scat. One is the typical kind -- waste that is left behind. The other, however, is dark and rich in vitamins. Just like cows regurgitate and chew cud to get more nutrients from their hard-to-digest diet, some animals eat this special scat.
- The color of scat can help determine the animal's diet. Dark scat means lots of meat for carnivores, and moist plants for herbivores. White scat is often dried out. Blue scat means berries, whereas grey carnivore scat usually indicates the presence of fur.
- Some animals, like deer, leave scat as they walk. But other species, particularly those with dens, have a latrine area so they can keep things tidy. Just like pet cats, wild cats try to bury their scat. And some animals, like mountain lions, use scat as territorial markings.
- Birds, reptiles, and amphibians sometimes combine their scat and urine. A white nitrogenous deposit on scat means it didn't come from a mammal. However, just because there is no whitish layer on the scat doesn't mean it didn't come from a bird.
- Bird pellets, also known as cough pellets or casting, aren't scat, but they are similar: pellets are the undigested remains of meals that birds regurgitate from their gizzards. Raptors like eagles and owls and corvids like ravens and crows, as well as other birds cast pellets, including herons, gulls, and kingfishers. Pellets are often found near roosting or nesting sites, though some birds will cast pellets were they ate. In them, you can find hair, bones, beaks, claws, and other clues as to what a bird’s last meal was.
Estela Kennen - Estela is a doctoral student in Public Administration and a freelance writer and editor.
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