Thursday, July 19, 2012

Northern Pygmy-Owls

Favoring open forest of western mountains and foothills, northern pygmy-owls are found from southern Alaska to northern Mexico.  Among the smallest owls in North America, they resemble the elf owl of our Southwestern deserts but have darker plumage and a long, barred tail.  Like their desert cousin, they roost in cavities.

Northern pygmy-owls are crepuscular in their activity and are best observed at dawn or dusk.  Preferring to hunt from a perch, they may be spotted on the branch of a dead tree, atop a small conifer or on power lines along mountain roads.  Despite their small size, they are very aggressive raptors, often attacking prey twice their size; small mammals and songbirds are their primary victims but they also consume insects, lizards and small snakes.  Like many residents of mountain ecosystems, they cache food during the winter months and may descend to lower elevations if prey becomes scarce and their stock runs low.

Solitary for most of the year, northern pygmy-owls pair off in the spring and generally produce 3-4 young, nesting in natural or abandoned woodpecker cavities at least 10 feet above the ground; the family stays together until early autumn before dispersing.  Their natural predators include northern goshawks, larger owls, Cooper's hawks, merlins, ravens and snakes.  Unlike many owls, these mountain residents avoid consuming fur, feathers and scales; their pellets thus disintegrate quickly and are not helpful in locating their roost.  On the other hand, northern pygmy-owls are often mobbed by Steller's and gray jays, ravens and mixed flocks of mountain songbirds, calling the attention of hikers and birders to their presence.