February 2017

Vol. 45, No. 1

Front Cover: February 2017

Long-eared Owl by John Sill

Long-eared Owl by John Sill. © Massachusetts Audubon Society. Courtesy of the Museum of American Bird Art.

John Sill is a freelance wildlife artist living in the mountains of North Carolina. He was the illustrator for the Bird Identification Calendar for Mass Audubon for many years. His work has appeared in Birds In Art at the Leigh-Yawkey Woodson Art Museum, Wausau, Wisconsin, and in Art of the Animal Kingdom at the Bennington Center for the Arts in Vermont. He continues to illustrate the “About” and “About Habitats” series of natural history books for children written by his wife Cathryn.

Long-eared Owl

The Long-eared Owl (Asio otus) is a medium-sized owl that is notably reclusive, hunting mostly at night and perching motionless in dense foliage during the day. It is indeed a delight to find a winter roost of these elegant birds. This predominantly buff and brown owl, barred and streaked with brown below, has densely-feathered buff-colored legs. It has a round, rich buff facial disk, highlighted with white eyebrows and eyes with bright yellow irises. The facial disks are topped by two prominent ear tufts that are fairly close together and usually held upright. Females are larger and more brightly colored than males. Six subspecies are recognized, with A. o. wilsonianus found in eastern North America. Similar species include the Great Horned Owl, which is much larger than the Long-eared Owl; and the Short-eared Owl, which is lighter in color, lacks the ventral barring, and has much smaller ear tufts.

The Long-eared Owl’s breeding range in North America stretches across Canada east of Alaska. It dips south through western United States to the Mexican border and then heads northeast from New Mexico through the Great Lakes across the northern New England states and Canada to Nova Scotia. On the West Coast, the owls breed only in a few local areas in California, Baja California, and British Colombia. They also breed sparingly along the Appalachian Mountains. In Eurasia they breed from England to Japan, and south to North and East Africa. Migration patterns of this owl are poorly known, partly because they exhibit a tendency to nomadism in response to fluctuating prey availability. Most Long-eared Owls winter within the breeding range of the species. In Massachusetts, the Long-eared Owl is considered a rare breeder and is almost certainly overlooked because of its retiring nature. In some years they are uncommon to sometimes fairly common at winter roosts. Their poorly-documented migration pattern suggests that spring migration occurs from mid-March to mid-April, and in fall from October through November.

Long-eared Owls are usually monogamous but occasionally they may be polygamous. They produce a single brood and occasionally may nest in loose colonies. The male’s advertising song consists of a series of low hoo notes given about three seconds apart, from an elevated perch. These calls may function for both mate attraction and territorial advertisement. The male also has a zigzag display flight. Pair formation occurs while the birds are still at their winter roosts. Long-eared Owls are fairly tolerant of conspecifics, but often give threat displays to predators (including humans) by crouching with head lowered, wings drooped, and feathers ruffled. They will defend the area near their nest.

Long-eared Owls tend to nest in coniferous or mixed deciduous forests or woodlands adjacent to the open fields, grasslands, and meadows where they prefer to hunt. They nest in old stick nests of other species and usually do not add new material to the nest or even line it. Only the female develops a brood patch and she alone incubates the clutch of five to six white eggs for the four weeks until hatching. The male brings food to the female throughout the incubation period. If the nest is approached, the owls may utter alarm calls and perform distraction displays. At hatching the young owls are covered with down and have closed eyes. They leave the nest in about three weeks and can fly at about five weeks of age. Initially, the male does most of the hunting for both the chicks and the female, but eventually she joins the hunting. Females tend to desert the nest after seven to eight weeks, but the male continues to feed the young for several more weeks until they are able to hunt on their own.

Long-eared Owls forage mostly at night. They fly silently, aided by the usual owl wing-feather adaptations that mute sound in flight. They typically alternate rapid wingbeats and glide about one-to-six feet from the ground. They also occasionally hover. Their hearing is excellent because their asymmetrical ear openings facilitate pinpointing the location of sounds by triangulation. They probably locate most prey by ear. Their prey is mostly small mammals and birds which are taken from the ground, or roosting birds taken from perches. They often swallow small mammal prey whole, but birds are picked apart and the wings discarded. Most prey species have been identified from bones found in regurgitated pellets.

If flushed in the daytime, Long-eared Owls are subject to attack by hawks, falcons, and larger owls. They also are subject to nest predation by raccoons, but little else is known about nest predation. Brood reduction also may occur in years of food shortage. Long-eared Owls are not listed federally, although they appear to have experienced declines in many states. However, declines are hard to document because of the species’ nomadic proclivities. Habitat alteration is also a threat that is not well documented. The extensive range of Long-eared Owls worldwide should offer them some protection so that we can continue to enjoy the thrill of seeing them at a winter roost.

William E. Davis, Jr.

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