Bird of the Month: Short-eared Owl
By Andy McCormick
PC: Mick Thompson (Short-eared Owl)
Scientific Name: Asio flammeus
Length 15 in
Wingspan 38 in
Weight 12 oz (350 g)
AOU Band code SEOW
The Short-eared Owl is an open country, ground-nesting species and one of the world’s most widely distributed owls. One of the ten subspecies worldwide is Pueo (Pu-a’-o), the Hawaiian Short-eared Owl A. f. sandwichensis. In Hawaiian mythology Pueo is The Protector and is among the oldest physical manifestations of the aumakua, the ancestral guardians of Hawaiian families. The saying, “A no lani, a no honua,” says that Pueo is the guardian owl that belongs to both heaven and earth (Schweitzer).
Worldwide this owl prefers grasslands and marshes and is most frequently a winter visitor to Western Washington, but in 2010 birders were treated to many days of early evening spring viewing of an actively hunting owl at Marymoor Park in Redmond, WA. The Short-eared Owl has a buoyant, moth-like flight. It is a diurnal owl which is generally more active in the early evening. On the breeding grounds in the spring the males exhibit a dramatic courtship display of high altitude gain and a sudden shallow stoop with audible wing clapping under their body as they descend.
The Short-eared is a close relative of the Long-eared Owl and shares the genus Asio from the Latin Axio, the little horned owl, but is not closely related to the Great Horned Owl Bubo virginianus. What ear tufts that are present rise from the center of the forehead and are so small they are rarely seen and not useful for identification. The species name flammeus also from the Latin for flaming, or flame colored, refers to the tawny plumage. Owl is a derivative of the Anglo-Saxon ule (Holloway). Females are generally larger and darker colored than males.
The color of Short-eared Owls resembles dried grass with mottled brown and rust on the head, back and upper wings. The breast is heavily streaked and the under wing and belly are lighter colored with a clear black carpal (“wrist”) mark. The head is large and round and frames the facial disk containing yellow eyes in dark patches. It flies low over fields which it shares with the Northern Harrier which can rob the owl of its prey (Alderfer).
Unlike many owls Short-eareds build their own nest which is usually a shallow depression on the ground lined with grass and feathers. Anywhere from three to eleven eggs can be deposited with 6-8 the usual number. Incubation varies from three to five weeks. The eggs hatch asynchronously usually in the order of laying, so the earliest hatched have an advantage for survival. The nestlings start walking from the nest in about two weeks after hatching. This pre-fledging dispersal from the nest saves some nestlings from predation by mammals (Kaufman). First flights begin in another four to five weeks.
The population of Short-eared Owls fluctuates with the population of small rodents which comprise the bulk of their diet. They will range long distances in search of prey and typically require long stretches of grasslands. Being sensitive to habitat loss some populations have fallen where habitat has become fragmented and native prairies have been converted to agricultural use (Wiggins, et al). Nevertheless, the Short-eared Owl, the Hawaiian bird of power, is doing well.