Sounds

Literature scant for North America (but see Clark 1975), better for Europe (Cramp 1985). May be more vocal than previously reported (DWH).

Development

Nestlings give high pitched cheep calls from within the egg, and from hatching to about 7 d (DWH); may be food begging calls or perhaps discomfort. Clark (1975) reported a different food begging call, Pssssss-sip to begin at 3–4 d of age, and a chitter (Psseee) given by young within the nest. Vocal pitch changes at about 7 d; by about 10 d hisses and lower Pssssss-sip call given (DWH). Unknown when adult-like calls and song are learned; likely by first breeding season. A captive adult gave courtship song when 1–yr–old, suggesting vocal repertoire is innate (Clark 1975).

Vocal Array

Adult and 1st year birds generally silent but intraspecific Keee-ow heard during winter (Clark 1975, DWH). Same call and variations of it (including a bark-like call) directed at human territorial intruders any time of year; bark call perhaps most frequently heard call (DWH). May also function in male/female contact and solicitation (Cramp 1985).

Winter calls give way to territorial courtship songs in late Feb to Mar (DWH). Primary song given by male during courtship flight (see Behavior: sexual; DuBois 1924, Clark 1975, DWH). Song may also be given from ground or elevated perch. DuBois estimated 16 to 18 tooting calls during male display. Clark (1975) reported the song to be Voo-hoo-hoo-hoo-hoo (Fig. 3), generally lasting about 3 s. Holt (1985) described the flight song as hoo-hoo-hoo-hoo-hoo-hoo, given 13 to 16 times/bout, similar to that from Palearctic region (Cramp 1985). Females vocalize little during male flight display; occasional Keeee-yow or keeeyup calls (Clark 1975, DWH). Mikkola (1983) stated that females Keeee-ow call is monosyllabic and males disyllabic.

Most vocal around nest. Female said to give cuk call similar to chicken (Gallus domesticus) when calling to experimental nestlings (DuBois 1923, see Breeding: parental care). Both males and females bark, scream, whine, and give broken wing distraction displays (DWH) when defending nests and young from potential threats. Adults in hand also hiss and bill snap.

Sexual Differences

In several species of North American owls, syrinx of males generally larger, leading to tonal differences; with some males having lower pitched songs and calls (Miller 1934). Male Short-eared Owls appear to have lower pitched voice than females, but this is difficult to detect unless both sexes call simultaneously (DWH).

Development

Not known.

Vocal Array

Bill-snapping by adults and young; latter begin when 7–d–old. Sound produced by snapping maxilla and mandible together. Appears defensive, e.g., given when approached by humans. May also be used against predators and in intraspecific encounters. Adults wing-clap during courtship flights and nest defense (see Behavior: sexual). Wings brought below trunk of body and clapped together (Fig. 3); sounds like slapping hands alternately against thighs as rapidly as possible.