The Eastern screech owl (Megascops asio) is a small owl found in woodlands across much of eastern North America. Though fairly common, its cryptic plumage and nocturnal habits often make it difficult to spot. However, the owl’s distinctive calls make Eastern screech owls much easier to identify by ear than by sight. The Eastern screech owl has several different vocalizations used for communicating different information. Learning to recognize these various screech owl calls can aid birders and naturalists in locating and identifying this widespread but often elusive species.
What does the Eastern screech owl look like?
The Eastern screech owl is a small owl, with adults reaching lengths of 19-24 cm (7.5-9.5 in) and weighing 140-250 g (5-9 oz). The species exhibits sexual dimorphism and occurs in two distinct color morphs. The gray morph is more common in the northern parts of the screech owl’s range, while the rufous or red morph is more prevalent in the south. Gray morph birds are gray with intricate barring on the underparts and faint streaks on the back and wings. The red morph is a warm rusty brown above with heavily streaked underparts. Both color types have dark horizontal barring on the chest. The Eastern screech owl has a rounded head without ear tufts, yellow eyes, and a yellowish bill.
What are the different calls of the Eastern screech owl?
Eastern screech owls have several different vocalizations that serve distinct functions in communication. These include:
Whinny Call
The whinny call is a tremolo or whinnying trill used by both male and female Eastern screech owls. It is produced year-round, most often given spontaneously at night but also in response to the calls of other screech owls. This call proclaims the owl’s territory and attracts potential mates. To human ears, the whinny call sounds like a descending whinny or rough, vibrating trill lasting 2-3 seconds.
Barking Calls
Screech owls produce a series of short, raspy barks when agitated or alarmed. Both sexes bark to defend nest sites and signal danger in the area. The barking increases in intensity as the perceived threat escalates. On rare occasions, screech owls may bark repeatedly for long periods at unknown threats.
Begging Calls
Young screech owls emit repetitive raspy begging calls when soliciting food from parents. These calls are easily heard at night in the vicinity of a nest. The begging calls grow stronger and more drawn-out as the nestlings mature.
Contact Calls
Screech owls use soft contact calls around the nest to communicate with their mate or offspring. These are quiet, warbled notes used for maintaining contact in the darkness. Both adults and young screech owls emit short contact calls when moving through dense vegetation.
Screams
When extremely alarmed, screech owls may emit a piercing scream or shriek. This vocalization is sharper and louder than the barking alarm call. Screams signal intense agitation and are often provoked by close encounters with potential predators.
When do screech owls call?
Eastern screech owls are primarily nocturnal and do most of their calling at night, particularly during the first few hours of darkness. However, they may call sporadically at any time of day or night. Calls are most frequent during the breeding season from late winter through mid-summer, when pairs are bonding, nesting, and rearing young. Cool temperatures, high winds, or heavy rain typically suppress calling activity.
Why do screech owls call?
Eastern screech owls call for the following key reasons:
- Attracting mates
- Defending territories
- Staying in contact with their mate or offspring
- Begging for food as nestlings
- Sounding alarms
Vocalizing allows screech owls to convey important information about their location, status, and level of alarm at all times of day or night. The different calls in their vocal repertoire help screech owls communicate effectively despite their solitary and nocturnal habits.
How can I identify Eastern screech owl calls?
Here are some tips for identifying the calls of the Eastern screech owl by ear:
- Learn the distinctive calls from audio recordings
- Focus on the call cadence, rhythm, pitch, and tone quality
- Note the context – is the call spontaneous or in response to other screech owl calls?
- Are multiple screech owls calling back and forth?
- Is the call coming from suitable screech owl habitat like woodland edges or riverine forests?
- Can you eliminate similar-sounding species like barn owls or barred owls?
- With practice, identification becomes easier as your ear becomes attuned to screech owl vocalizations
Where can I listen to examples of Eastern screech owl calls?
Here are some excellent online resources for listening to reference recordings of the various vocalizations of the Eastern screech owl:
- The Cornell Lab of Ornithology’s All About Birds site has examples of the whinny, barking, and begging calls.
- Xeno-canto is a community database of bird sounds from around the world, including many high-quality Eastern screech owl recordings.
- The Audubon Guide to North American Birds has clear audio of the whinny, bark, begging calls, and alarm screams.
- The online Macaulay Library from the Cornell Lab archives thousands of bird sound recordings, searchable by species.
With access to these kinds of reference materials, birders can become very adept at recognizing the unique vocalizations of the Eastern screech owl by ear.
Conclusion
The Eastern screech owl has a diverse repertoire of vocalizations that serve key communication functions related to breeding, territoriality, contact, and alarm. By learning the context and distinguishing characteristics of the whinny, barking, begging, contact, and alarm scream calls, birders can identify Eastern screech owls by sound alone. Paying attention to the owl’s habitat, time of day, call cadence, and interactions with other individuals provides helpful clues too. With practice listening to reference recordings, even novice birders can master the skill of identifying Eastern screech owls aurally. Screech owl vocalizations provide an exciting way to detect and study these cryptic birds of the night without even needing to see them.