For River Otters:
* Large fish: Especially predatory fish like pike, bass, and catfish.
* Larger mammals: Like bears, wolves, coyotes, bobcats, and foxes.
* Birds of prey: Including eagles, hawks, and owls.
* Alligators and crocodiles: Especially in areas where they overlap.
For Sea Otters:
* Orcas (killer whales): The most significant predator.
* Great white sharks: They sometimes prey on sea otters, though not as frequently as orcas.
* Other sharks and large fish: Such as salmon sharks and halibut.
* Sea lions and seals: Occasionally prey on sea otters, particularly juveniles.
Other Predators:
* Domestic dogs: Can pose a threat to otters, especially in areas where they are common.
* Humans: Indirectly impact otter populations through habitat loss, pollution, and overfishing.
Factors affecting predation:
* Age and size: Young and smaller otters are more vulnerable to predators.
* Habitat: Otters living in areas with more predators are at higher risk.
* Time of year: Some predators are more active during certain seasons.
It's important to remember that otter populations are generally resilient and have adapted to dealing with predation. However, human activity and habitat loss pose significant threats to otter survival.