The Eurasian Pygmy Owl (Glaucidium passerinum) is Europe's smallest owl, barely larger than a starling, yet an effective predator of tits and small mammals in the coniferous forest, often active by day unlike most owls. It is compact and round-headed, lacking the ear tufts of larger owls such as the Long-eared Owl or Eagle-Owl, with dark brown, white-spotted upperparts, a white, brown-streaked underside, a round face with yellow eyes and no distinct facial disc, and a dark tail crossed by narrow white bars. The female is roughly 15% larger and heavier than the male, though the sexes look alike.
Its autumn call, given September–October, is a rising series of whistles, "pyü-pyü-pyü-pyü", used to establish winter territory, while the spring call in March–April is a monotonous, evenly spaced "pyü … pyü … pyü" audible hundreds of metres away. Breeding throughout the coniferous forest belt of Sweden — from Dalarna and Norrland south to Värmland and Uppland, more sparsely in Götaland — with a population of 8,000–12,000 pairs, it depends on old woodpecker holes in mature spruce and mixed forest for nesting, since it cannot excavate its own cavity; it will also take a nest box sized to a woodpecker hole. The female lays 4–7 white eggs and incubates alone for 28–29 days, with young fledging after 28–34 days. Small birds — tits, kinglets, chaffinches, treecreepers — make up 50–70% of its diet, taken in fast strikes through the branches, supplemented by voles and mice caught on the ground; remarkably, it caches up to 30–50 dead prey items in tree holes and bark crevices as a winter larder, a habit that helps this largely sedentary species survive the coldest months.
Read about this species in Swedish →