The Short Eared Owl (Asio flammeus) is a species owl belonging to genus Asio. They are known as the ‘eared owls’, as they have tufts of feathers resembling ears like mammals. Their ear tufts are sometimes visible and sometime not. These owls usually display their tufts when in a defensive pose. The Short Eared Owl is found in open country and grasslands.
The Short Eared Owl is a medium sized owl averaging 34 – 43 centimetres (13 to 17 inches) in length and weighing 206 – 475 grams (11 to 13 ounces). It has large eyes, big heads, short necks and broad wings. Its beak is short, strong, hooked and black. Its plumage is mottled tawny to brown with a barred tail and wings. The upper breast is significantly streaked.
Short Eared Owl wingspans range from 85 to 103 centimetres (38 to 44 inches). Females are slightly larger than males. The yellow-orange eyes are exaggerated by black rings encircling each eye and large, whitish disks of plumage surrounding the eyes like a mask.
The Short Eared Owl can be found on all continents except Antarctica and Australia. It has one of the largest distributions of any bird. The Short Eared Owl breeds in Europe, Asia, North and South America, the Caribbean, Hawaii and the Galápagos Islands. The Short Eared Owl is partially migratory, moving south in winter from the northern parts of its range. The Short Eared Owl is known to relocate to areas of higher rodent populations. The Short Eared Owl nests on the ground in prairie, tundra, savanna, or meadow habitats.
Nests are concealed by low vegetation and may be lightly lined by weeds, grass or feathers. Around 4 to 7 white eggs are found in a typical clutch, but clutch size can reach up to a dozen eggs in years when voles are abundant. There is one brood per year. The eggs are incubated mostly by the female for 21 – 37 days. Offspring fledge at a little over four weeks. This owl is known to lure predators away from its nest by appearing to have a crippled wing.
Sexual maturity of the Short Eared Owl is attained at one year. Breeding season in the northern hemisphere lasts from March to June, peaking in April. During this time these owls may gather in flocks.
During breeding season, the males make great spectacles of themselves in flight to attract females. The male swoops down over the nest flapping its wings in a courtship display. These owls are generally monogamous (having only one mate in a relationship).
Hunting occurs mostly at night, but this owl is diurnal (active during the daytime and resting at night) and crepuscular (primarily active during the twilight) as well as nocturnal (sleeping during the daytime and being active at night). It tends to fly only feet above the ground in open fields and grasslands until swooping down upon its prey feet-first.
Several owls may hunt over the same open area. Its food consists mainly of rodents, especially voles, but it will eat other small mammals and some large insects. Sometimes it even tends to eat smaller birds. Its flight is characteristically floppy due to its irregular wingbeats.
Short Eared Owls have a scratchy bark-like call. Raspy ‘waowk, waowk, waowk’ or ‘toot-toot-toot-toot-toot’ sounds are common. A loud ‘eeee-yerp’ is also heard on breeding grounds. However, Short Eared Owls are silent on the wintering grounds.