Otters are semi-aquatic mammals known for their playful nature and sleek appearance. A common question concerns their diet. Otters are not herbivores; they are primarily carnivores. They belong to the Mustelidae family, which includes weasels and badgers, and their diet consists of animal matter.
What Otters Eat
The diet of otters is diverse, varying by species, habitat, and prey availability. Their primary food source is fish, which they actively hunt in aquatic environments. Beyond fish, otters consume other aquatic animals like crustaceans (crayfish, crabs) and mollusks (mussels, clams, snails).
Amphibians such as frogs and toads are also part of their diet. Some species occasionally prey on small mammals or birds. Sea otters, in particular, have a diet rich in marine invertebrates, including sea urchins and abalones. Their high metabolic rate requires them to consume a substantial amount of food, with some otters eating 15% to 30% of their body weight daily to maintain energy levels.
Why Otters Are Not Herbivores
Herbivores primarily consume plant material, possessing digestive systems adapted to break down tough plant fibers. In contrast, otters are carnivores. While some otters might occasionally ingest small amounts of plant material, these offer limited nutritional value and are not a significant part of their diet. Their digestive system is designed for processing animal protein, characterized by a high metabolic rate and rapid food transit time.
Otters possess teeth and jaws suited for capturing and consuming prey, including strong jaws and blunt teeth capable of crushing shells. This physiological adaptation for a meat diet, along with their active hunting behaviors, distinguishes them from herbivores. Their reliance on animal matter for energy and growth confirms their carnivorous nature.
How Otters Hunt and Forage
Otters are highly skilled hunters, well-adapted to aquatic environments. They exhibit remarkable agility in water, allowing them to pursue and capture fast-moving prey. Many species, such as river otters and giant otters, use their sensitive whiskers, known as vibrissae, to detect movements and disturbances in the water, locating prey even in murky conditions. Their vision also works well underwater, aiding their pursuit.
Once prey is located, otters typically grasp it with their teeth, though some species use their forepaws to manipulate and secure food. Sea otters are known for using tools, such as rocks, to crack open the hard shells of mollusks and crustaceans, often balancing the tool on their chest while floating on their backs. This intelligent foraging behavior, combined with their powerful physical adaptations, makes them effective predators in their diverse habitats.