Northern Pygmy Owls have also been called Pygmy Owl, Rocky Mountain Pygmy Owl, Vancouver Pygmy Owl, California Pygmy Owl, and Dwarf Owl.
Description: The Northern Pygmy Owl is a tiny, woodland, diurnal Owl that is most active between dawn and dusk. They have greyish or brownish or reddish (3 morphs) upperparts and light belly that is boldly streaked with brown. The head and nape are liberally sprinkled with whitish dots (more cinnamon or buff on red morph). On the nape are 2 distinctive, vertical black patches that resemble an extra pair of eyes. The relatively long tail is distinctly barred with 6 to 7 light stripes. Eyes are yellow, bill is yellowish-horn, and the toes are greyish-yellow.
Juveniles are similar to adults but with unspotted and greyer heads, and fluffy plumage.
Size: Length females 18.5cm (7.3″), males 16.5cm (6.5″) average. Wingspan 380mm (15″) average.
Weight females 73g (2.6 oz), males 62g (2.2 oz) average.
Habits: Northern Pygmy Owls are very secretive and tend to perch and roost in thickets where it is safe from predators. At times, one will sit atop the highest spire of a tree. At rest, a Northern Pygmy Owl sits with its tail cocked away from vertical, and often twitches its tail when excited. A Northern Pygmy Owl’s flight between perches is short and rapid – plummeting downwards as it leaves a perch before levelling off, and swooping up to the next. If the next perch is a tree, it will tend to land low, then moves up through the tree to a higher perch. Flight is relatively noisy for an owl, and resembles a shrike, with rapid wing beats and rounded wing tips.
Despite their small size, Northern Pygmy Owls are quite fierce, and will attack prey or drive off intruders several times their own size. When one of these owls is threatened, it will puff up its feathers and spread its tail to make itself look larger. When hiding, it tries to look thin, faces the danger, and closes its eyes into slits.
Voice: The primary call of the male is a series of repetitive, whistled hoots “too-too-too-too-too-too-too” at intervals of 1 to 2 seconds, although it is reported that this can vary from 0.5 seconds, all the way up to 4 seconds. This call is territorial in nature and is usually given in the early evening and before dawn, and may be heard year-round. The male gives a high whinnying sound when bringing food to his mate. The female calls much less often and it has a cackling quality. Other calls include an ascending staccato series of whistles. When excited, they may emit a high-pitched trill (8 notes/second).
Hunting & Food: Northern Pygmy Owls are “sit and wait” predators, that hunt mainly by vision, diving down onto prey on the ground and driving the talons into the prey’s throat. they will also attack birds in shrubs, crashing into the hapless victims. Most prey is carried off in the feet to feeding sites. Birds are usually plucked before being consumed. They often eat only the brains of birds and the soft abdomen of insects! One of these little owls can carry prey weighing up to 3 times its own weight.
The Northern Pygmy Owl feeds on a wide range of small prey including small mammals, birds, and reptiles and amphibians. Voles make up the bulk of their diet, with birds comprising most of the rest (mainly songbirds, but as large as a California Quail). Other small mammals include shrews, mice, chipmunks, bats, moles, young rabbits, and weasels. Insects may be very important when they are most abundant. Other prey taken are toads, frogs and small lizards and snakes.
During winter, surplus prey is cached in a cavity, often in large quantities. These caches help small owls like these meet their metabolic needs during very cold winter periods. Summer caches are usually much smaller.
Pellets are very small, averaging about 3cm (1.2″) long. They are formed only occasionally as these owls don’t consume large amounts of fur, feathers, or bone. The pellets tend to fall apart shortly after ejection.
Breeding: Northern Pygmy Owls are unsociable birds, remaining solitary much of the year. During courtship both sexes call to each other with their mating trill. They also pass food to each other and snuggle closely.
Northern Pygmy Owls are almost entirely dependent on old woodpecker cavities for nest sites. They will also nest in natural tree cavities. Nest trees are usually dead and are usually coniferous in the boreal forest and deciduous in more southern areas. Nest cavities range from 3 to 23 metres (10 to 75 feet) above ground, averaging 6 to 7 meters (20 to 23 feet). Eggs are laid between April and June, with clutch size ranging from 3 to 7 (3 – 4 average; may increase from south to north). The female does the incubating and brooding while the male brings food and defends the nest. The incubation period is about 29 days. Unlike all other North American owls, The Northern Pygmy Owl begins incubation only after the clutch is complete, so that young tend to hatch over a period of 1 to 2 days, rather than one every 1 to 2 days. Young grow quickly, reaching 60% of adult size after 2 weeks. They fledge at about 30 days, when they are capable of flight. Fledglings are then fed and defended by their parents for a further 20 to 30 days. Family groups tend to break up in late Summer or Autumn. Northern Pygmy Owls are single-brooded. It is not known if replacement clutches are laid. Nest cavities may be used for several consecutive years by the same birds.
There is no information on territory size, but the similar Eurasian Pygmy Owl has territories from 200 to 1700 hectares (500 to 4200 acres), and the Northern Pygmy Owl likely has similar-sized territories.
Mortality: No information on longevity or mortality currently available. Potential predators of these owls are other owls, jays, crows, ravens, snakes, and weasels.
Habitat: Northern Pygmy Owls inhabit open coniferous and mixed forests from valley bottoms up to treeline. They do not inhabit dense, continuous forest. In all areas they use forest clearings for hunting – along the edges of meadows, fields, wetlands, and roadsides, and through old burns and logged areas. For roosting they prefer quiet, shady alder thickets. During the breeding season they inhabit open forests with a selection of snags with old woodpecker cavities.
Distribution: West North America, from British Columbia and southern Alaska south through the Rock Mountains to California and Arizona, and possibly also to the mountains far north Mexico.
Northern Pygmy Owls are essentially sedentary, except for altitudinal movements downslope in winter. Southward irruptions during winter may occur in years of food shortage.