The Eastern Screech-Owl (Megascops asio) is a small owl found throughout eastern North America. Identifying this species can be tricky since they can vary greatly in coloration. However, there are some key features to look and listen for when trying to identify an Eastern Screech-Owl.
Size and Shape
Eastern Screech-Owls are relatively small owls, measuring between 6.3-9.8 inches in length with wingspans of 18-24 inches. They have large heads and almost no neck. Their body shape is stocky and rounded. They have short tails that are often bobbed up and down. Overall, their silhouette is round and plump.
Color Variations
Eastern Screech-Owls can be either gray or rufous (reddish-brown) in color. The gray morph is more common in the northern parts of the range, while the rufous morph is more prevalent in the south. However, both color morphs can be found throughout the range.
Gray morph birds are mottled gray and brown above with streaking on the underparts. The feathers often have fine black barring. Rufous morphs are bright reddish-brown above with heavily streaked underparts. The two color morphs can mate and produce offspring of either color.
Facial Disk
All screech-owls have a rounded facial disk that surrounds their eyes and billows out to their ears. The disk has grayish-green feathers with white margins that help direct sound waves towards the owl’s ears. The ear tufts of the Eastern Screech-Owl are made up of 6-7 feathers compared to the Western Screech-Owl’s 5 or fewer ear tuft feathers.
Eyes and Bill
Eastern Screech-Owls have large yellow eyes. The eyes of young birds are initially gray before changing over to yellow as they mature. The eyes are surrounded by black-ish “eyebrows” and dark marks along the sides of the face.
The bill is dark gray or black. It is short and hooked like most raptors. Unlike many owls, Eastern Screech-Owls lack the feathering on the bill and legs that some species like Great Horned Owls exhibit.
Plumage Details
When observed closely, Eastern Screech-Owls have some finer plumage details:
- Fine barring or streaking on the breast and belly
- Horizontal barring on the flanks
- Dark vertical streaks on the throat
- Fine white spots on the wings and back when perched
- Dark bands on the tail
Flight and Behavior
In flight, Eastern Screech-Owls have relatively small and rounded wings compared to other owls. The wingbeats are quick and chopped. The flight itself is rather weak and fluttering with occasional short glides. The small size and erratic movement make them resemble a large moth in flight.
Screech-owls are primarily nocturnal, so they are most active at night. However, they are occasionally observed hunting at dusk or even during the daytime. They perch in cavities or obscured locations and remain motionless for long periods as they scan for prey. They frequently bob their tail up and down while perched.
Vocalizations
As the name implies, Eastern Screech-Owls are named for their eerie vocalizations. They produce a shivering, whinnying call that descends in pitch. The call has an unsettling tremolo quality. Listen for a series of short, wavering notes that drop in frequency.
At close range, individuals may produce a quickly repeated series of short, whistled notes. When interacting at the nest, mated pairs make soft moans or barking notes.
Range and Habitat
Eastern Screech-Owls are year-round residents throughout the Eastern United States and Canada. They range from southeastern Minnesota east to the Atlantic Coast and south to central Texas and Florida.
These adaptable owls occupy a wide variety of wooded habitats including deciduous, coniferous, and mixed forests. They also utilize wooded parks, suburbs, riparian areas, and other woodlands near human settlement provided adequate nesting cavities are available.
Preferred Habitats:
- Deciduous forests
- Riparian woodlands
- Pine and mixed forests
- Orchards
- Wooded suburban areas
Nest Sites
Eastern Screech-Owls are cavity nesters, using natural holes and abandoned woodpecker holes. They also readily use nest boxes provided for them. Nest sites are typically found in large trees, snags, or cacti and are usually between 10-30 feet above the ground. The female alone chooses the nest site and completes most of the incubation of the 3-4 white eggs.
Prey
Eastern Screech-Owls hunt from perches in areas with some dense cover and take prey on the ground or low in vegetation. They primarily eat small rodents such as mice and voles, but also take small birds, reptiles, amphibians, and invertebrates. Their hunting is aided by their excellent low-light vision and hearing. Prey is captured with the owl’s sharp talons and then consumed whole.
Key Identification Features
Use this checklist when identifying a potential Eastern Screech-Owl:
Feature | Description |
---|---|
Size | Small owl, 6.3-9.8 in long with 18-24 in wingspan |
Shape | Stocky, plump, and rounded with almost no neck |
Color | Gray or rufous morphs throughout range |
Facial Disk | Prominent grayish-green facial disk with white margins |
Eyes | Large yellow eyes, black brow “eyebrows” |
Bill | Dark gray, short and hooked |
Plumage | Heavily streaked and barred below, spotted above |
Flight | Fluttering and moth-like |
Call | Whinnying, trembling call that drops in pitch |
Range | Year-round in eastern North America |
Habitat | Woodlands near open areas for hunting |
Conclusion
The Eastern Screech-Owl’s small size, stocky shape, ear tufts, and mournful whinny are all helpful clues in identifying this owl. Look and listen for them in woodland areas at night when they are most active. With some practice, birders can learn to recognize these vocal and endearing little owls.