page_title: Aegolius
section_title: Vocalizations
hierarchical_section_title: Aegolius / Mating system / Mate choice / Vocalizations
caption_attribution_description: Tengmalms owl (Aegolius funereus), nest with eggs and food store. Picture taken in the Etelä-Pohjanmaa region (Finland), close to Kauhava.
context_page_description: Aegolius is a genus of small true owls. The genus name is from Latin; aegolius is a type of screech owl thought to be a bird of ill omen.
  Aegolius owls are small, dumpy, short-tailed, and broad-winged, with large, round facial discs. The species varies from 18–27 cm in length. These owls take mainly rodents and other small mammals as their prey, but also feed on birds, bats, insects, and other invertebrates according to what is available. They are dark brown or black above, and whitish or buff below, marked with streaks or spots in the two northern forms. The head is large, with yellow eyes and a well-defined facial disc. The flight is strong, agile, and direct. They breed in tree holes, laying several eggs. They have repetitive whistling calls in the breeding season.
  Three of the extant species are restricted to the New World, but the boreal owl has a circumpolar range through North America, Eurasia, the Alps, and the Rockies. Essentially nocturnal woodland owls of temperate or colder climates; the two northern species breed in North America's coniferous forests, and the unspotted saw-whet owl and buff-fronted owl are species of mountain, cloud, or oak forests.
context_section_description: Mate choice in this genus is largely related to auditory vocalizations (a form of sensory exploitation). A quiet species through most of the year, the northern saw-whet owl male produces a bell-like or “series song” advertisement call. Generally, it can be heard early morning or on bright nights from March – May (the breeding season) to attract females. The calls are believed to be relatively different between individuals, suggesting they may play a role in individual identification by the females. After pairing with a mate, vocalizations are very limited and appear to be related to territory or offspring defence.
  In contrast, the boreal owl produces a “staccato song” starting around dusk, and ending around midnight in the late winter and early spring. The call serves to attract females and becomes increasingly persistent as time without a mate passes. Some research suggests that unlike the Northern saw-whet owl, a variation of the mall call persists after mating throughout the reproductive cycle for defense, aggression, or to convey information about prey. This suggests that vocalization may be used in this species beyond mate attraction and possibly as a contact call.
caption: Typical boreal owl (A. funereus) nest
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