Food Chain
Last Review/Updated: May 31, 2002
All owls are predators, which means they depend on other animals for food. But very few predators feed on owls. In fact, owls often eat other predators, such as weasels, bats, shrews and insect-eating birds. Therefore, owls hold a position at the top of the food chain. Like many predators, they feed from more than one link on the chain or web.
Because most species hunt at night, owls feed upon a different group of prey species than raptors that hunt by day. Hares, weasels and many species of mice are more active at night and are exposed to predation at that time. Hawks, eagles and falcons may occasionally take these species in the early mornings or late evenings, but spend most of their time hunting squirrels, grouse, songbirds and other diurnal animals.
As with most wildlife, numbers are largely dependent upon the amount of food available, particularly when young are being raised. Since most owls feed upon a variety of animals, owl abundance is not limited by the rise and fall in numbers of any one prey species. If a preferred prey species should become scarce, owls will switch to others. However, the snowy owl is dependent upon lemmings for its steady diet when it is raising young on the Arctic tundra in spring and summer. In years when lemmings are scarce, snowy owls will actually reduce the number of eggs laid, or not nest at all.
Like all predators, including people, owls play an important role in nature by removing individuals surplus to prey populations. Most wildlife populations produce more offspring than their habitats can support. These surplus individuals must eventually die of starvation, disease, or predation. Although starvation and disease may affect individuals throughout the population, predators tend to remove the weaker members of a population that are easiest to catch and least able to cope with the rigors of their environment. In so doing, predators help maintain the health and viability of prey populations.
