Short Eared Owl

A skilled hunter, the short-eared owl is most active during the morning, late afternoon and night, when it can be seen flying low above the ground searching for prey (2) (4). The structure of the wings and feathers give this species impressive aerial agility, and make its flight almost entirely silent. This is a very useful adaptation, as this species mainly hunts by sound, and also means that prey are not alerted to its presence. The short-eared owl feeds upon small mammals up to the size of hares, but will also take birds. Feeding is a rather gruesome affair, and involves the owl decapitating its prey, before pulling out the entrails, or, in the case of birds, pulling off the wings and swallowing them whole (2). In order to attract a mate, the male short-eared owl carries out a dramatic aerial display, involving rising quickly, hovering and descending with exaggerated wing beats, along with singing and wing-clapping (2) (4). Breeding pairs generally remain together for a single breeding season, although it is possible that breeding with multiple partners may also occur. Egg-laying takes place between March and June in the northern hemisphere, while in the southern hemisphere it commences in September. The female constructs a nest comprising a scraped out bowl in the ground lined with grasses and downy feathers. A clutch of between 5 and 10 eggs is laid and incubated by the female for 26 to 29 days, while the male brings food and defends the nest. At 12 to 18 days after hatching the young leave the nest, but are unable to fly and so hide in vegetation. This behaviour serves to minimise time spent in the nest, where predation is most likely to occur. The short-eared owl reaches sexual maturity at 1 year or less and may live for around 13 years (2). Although in the southern parts of its range the short-eared owl generally remains in the same location throughout the year, northern populations are highly migratory and make long-distance journeys to find food. Interestingly, if this species finds a wintering area with an abundant food supply it may remain there permanently (2).

Several state offices of the United States bird conservation organisation Audubon have initiated grassland protection and restoration initiatives, which should help to counteract the decline that this species is experiencing in some parts of its range (5).

The short-eared owl's scientific name flammeus, meaning “fiery”, is a reference to its boldly streaked plumage, which provides excellent camouflage when concealed amongst vegetation (4). This species has a large round head, with a white-bordered facial disc, and striking yellow eyes framed with black. The plumage is mostly mottled brown and buff on the upperparts, with black bars on the wings and tail feathers, while the breast is whitish or pale buff, with dense vertical streaking. The underwing is buffish-white, with a black tip, and a distinctive ochre patch just beyond the mid-wing, on the leading edge. The female short-eared owl is slightly larger than the male, with heavier streaking and browner upperparts, while the juvenile is darker still, with a brownish-black facial disc. There are ten recognised subspecies of short-eared owl, which vary in terms of location and colouration. Perhaps the most distinctive of these subspecies is Asio flammeus galapagoensis, which has extremely dark plumage and larger black regions around the eyes (2).

The short-eared owl is mostly found in open country, occupying tundra, marshland, grassland, savanna, sand dunes and moorland from sea level to elevations as high as 4,000 metres in the Andes (2). It requires sufficient vegetation to provide cover for nesting, as well as an abundance of small mammal prey (2) (4).

One of the most widespread owl species, the short-eared owl's range extends throughout the Americas, Europe and Asia (5). Subspecies Asio flammeus flammeus has the widest distribution and is known to breed in Iceland, the British Isles and much of Europe and Asia, as far east as the Kamchatka Peninsula and the Commander Islands, and south as far as Spain and north-east China. This subspecies is also found in North America from western and northern Alaska, east through Canada and south to central USA. The other subspecies have smaller ranges: Asio flammeus ponapensis occurs on Pohnpei Island in the East Caroline Island Group; Asio flammeus sandwichenis inhabits several Hawaiian Islands; Asio flammeus domingensis occupiesHispaniola and Cuba; Asio flammeus portoricensis is found on Puerto Rico; Asio flammeus pallidicaudus inhabitsnorthern Venezuela and Guyana; Asio flammeus bogotensis occurs in Colombia, Ecuador and north-west Peru; Asio flammeus galapagoensis is only found on theGalapagos Islands; Asio flammeus suinda inhabits southern Peru, western-central Bolivia, Paraguay, south-east Brazil, south to Tierra del Fuego; and Asio flammeus sanfordi is restricted to the Falkland Islands (2).

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (3).

With its expansive range, and accordingly large population, on a global scale the short-eared owl is far from threatened (1) (2). Nevertheless, in many parts central Europe, Russia and the USA, this species is in decline, and is considered to be the rarest and most threatened owl in north-east USA. Some of the main reasons for this appear to be intensification of agriculture, urban expansion and the use of rodent poisons and other pesticides (2).