Otters are aquatic carnivores belonging to the Mustelid family, which also includes weasels, badgers, and mink. These highly adapted mammals spend a significant portion of their lives hunting in or around water. The direct answer to the question of whether otters kill ducks is yes, they can and sometimes do predate on waterfowl. This behavior is not a daily occurrence across all otter populations but is highly dependent on local circumstances and the availability of their preferred food sources.
Otter Primary Food Sources
The baseline diet for most otters, particularly the North American River Otter (Lontra canadensis) and the Eurasian Otter (Lutra lutra), is predominantly aquatic. These animals are generalist carnivores, meaning they consume a wide variety of prey rather than specializing in one type of food. Fish form the largest part of the diet, often supplemented by other slow-moving aquatic organisms. Common secondary food sources include crustaceans, such as crayfish and crabs, and amphibians like frogs and salamanders.
Otters also consume small mammals that live near the water’s edge and various insects throughout the warmer months. Because of their high metabolism, a river otter must consume between 15% and 20% of its body weight daily to maintain its energy levels. This constant need for sustenance drives them to be opportunistic hunters, which occasionally brings waterfowl into their prey selection.
Why Waterfowl Become Prey
An otter targets a duck not as part of a dedicated hunting strategy but typically under specific conditions that make the bird an easy or necessary meal. Predation most often occurs when the otter attacks the duck from beneath the water’s surface. The otter rapidly surfaces, grabs the duck by the legs or the underside, and then pulls it under to drown it before bringing the carcass to shore for consumption.
Vulnerable Targets
This hunting technique is particularly effective against ducks that are young, injured, or molting, as these individuals cannot take flight or dive quickly enough to escape the ambush. The vulnerability of birds during the molting season, when they are temporarily flightless, makes them far simpler targets than healthy fish. If primary prey, like fish, is scarce, the otter may substitute birds to meet its daily energy requirements.
Other Factors
While freshwater river otters are the species most commonly observed preying on ducks due to shared habitat, marine otters have also been documented killing seabirds. Evidence suggests that some predation may not be solely for food but related to territorial behavior or practice hunting. When a high concentration of naive waterfowl is present, the otter may kill multiple birds in an opportunistic frenzy, sometimes leaving uneaten remains.
How Common Is Duck Predation?
Predation on waterfowl, while dramatic and widely publicized in anecdotal reports, does not usually constitute a major portion of the otter’s overall diet. Scientific analyses of otter scat, known as spraint, consistently show that fish, crustaceans, and amphibians dominate their food intake. In some environmental studies, bird remains were found in as little as 3.1% of all spraints, confirming that birds are generally a peripheral food source. This evidence suggests that birds are only consumed when primary aquatic prey is unavailable or difficult to catch.
The frequency of duck predation is highly variable and localized, often rising only when specific environmental factors align. For instance, high local availability of vulnerable waterfowl, such as a large colony of breeding birds, or a poor local fish population can temporarily increase the incidence of bird consumption. The numerous viral videos and anecdotal accounts often exaggerate the prevalence of this behavior, but their impact on most wild duck populations is generally considered sustainable within the natural ecosystem.