A small (7-10 inches) owl, the Eastern Screech-Owl is most easily identified by its size, streaked breast, and ear-like feather tufts. This species has two color morphs, one with gray plumage and the other with rusty-red plumage. Male and female Eastern Screech-Owls are similar to one another in all seasons. The Eastern Screech Owl inhabits much of the eastern United States and southern Canada west to the eastern edge of the Rocky Mountains. This species also occurs in northern Mexico south to the Tropic of Cancer. Eastern Screech-Owls are non-migratory in all parts of their range. Eastern Screech-Owls inhabit a variety of deciduous, evergreen, or mixed woodland habitats. This species may also be found in more built-up areas, and can sometimes be found in large urban parks. Eastern Screech-Owls eat a variety of small animals, such as insects, songbirds, and rodents. Like most owls, the Eastern Screech-Owl hunts almost exclusively at night, making it difficult to observe. This owl may be more visible when it is active at dusk or just before sunrise, and birds roosting in trees may be seen during the day with the aid of binoculars. As its name suggests, the Eastern Screech-Owl produces a high-pitched hooting call which may be used to identify this species at night.

Threat Status: Least concern

Eastern screech-owls are found throughout much of eastern North America, from the Rocky Mountains in the West to the Atlantic coast and from Florida and southern Texas in the south as far north as southern Canada.

Biogeographic Regions: nearctic (Native )

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Resident from southern Saskatchewan (Adam 1987) and southern Manitoba east across southern Canada and northern U.S. to Maine, south through eastern U.S. to San Luis Potosi, southern Texas, Gulf Coast, and southern Florida, west to eastern Colorado.

The eastern screech-owl is found in eastern North America and
northeastern Mexico. Its range extends across southern Saskatchewan,
southern Manitoba, northern Minnesota, northern Michigan, southern
Ontario, southwestern Quebec, and Maine; south through eastern Montana,
eastern Colorado, and Texas to central Nuevo Leon, eastern San Luis
Potosi, and southern Tamaulipas; east to the Gulf Coast and southern
Florida [1,27]. At the western edges of its range, it appears to be
confined by the eastern front ranges of the Rocky Mountains in Wyoming,
Montana, and Colorado [1,13,22].

Distribution of subspecies is as follows:

Rocky Mountain screech-owl: Southeastern Saskatchewan, southern
Manitoba, eastern Montana, and the Dakotas south to eastern Wyoming,
western Nebraska, western Kansas, and northeastern Colorado. Possibly
also breeds in central Alberta, but these birds may be western screech-owl.

Hasbrouck's screech-owl: Central Kansas to Oklahoma and Texas.

Texas screech-owl: Lower Rio Grande to the southern border to Tamaulipas.

Southern screech-owl: Minnesota, peninsular Michigan, southern
Quebec, and southern Maine south to Missouri and northern parts of
Mississippi, Alabama, and Georgia.

Florida screech-owl: Florida and the Gulf Coast west at least to
Louisiana and north to Arkansas [18].

More info on this topic.

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

13 Rocky Mountain Piedmont
14 Great Plains
15 Black Hills Uplift
16 Upper Missouri Basin and Broken Lands

AL	AR	CO	CT	DE	FL	GA	IL	IN	IA
KS	KY	LA	ME	MD	MA	MI	MN	MS	MO
MT	NE	NH	NJ	NY	NC	ND	OH	OK	PA
RI	SC	SD	TN	TX	UT	VT	VA	WV	WI
WY	DC

MB

ON

PQ

SK

MEXICO

Eastern screech-owls are found throughout much of eastern North America, from the Rocky Mountains in the West to the Atlantic coast and from Florida and southern Texas in the south as far north as southern Canada.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Eastern screech-owls are small owls, from 16 to 25 cm in length. Females are generally larger than males, which is common in owls. Eastern screech-owls are dichromatic, they come in two distinct colors. They are either gray or reddish, with darker streaking on the body. Both color variations make these owls blend in with the color of surrounding tree bark. They have bold streaking on their breasts, yellow beaks and eyes, relatively large feet with feathered toes, and large "ear" tufts on either side of their head. These feather tufts really have nothing to do with the owl's ears, but they location on the side of the head makes them look like large, erect ears.

Range length: 16 to 25 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: female larger

Average mass: 164.1 g.

Average basal metabolic rate: 0.586 W.

Eastern screech-owls are small owls, from 16 to 25 cm in length. Females are generally larger than males, which is common in owls. Eastern screech-owls are dichromatic, they come in two distinct color morphs. They are either uniformly gray or uniformly rufous, with darker streaking on the body. Both color morphs make them very difficult to distinguish from surrounding tree bark. They have bold streaking on their breasts, yellow beaks and eyes, relatively large feet with feathered toes, and large "ear" tufts on either side of their head. Eastern screech-owls are distinguished from their close relative western screech-owls, by their yellow bill, descending trill call, and by the rufous coloration of some individuals.

Range length: 16 to 25 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: female larger

Average mass: 164.1 g.

Average basal metabolic rate: 0.586 W.

Length: 22 cm

Weight: 194 grams

More info for the term: natural

Nesting: Eastern screech-owls nest in natural cavities, woodpecker
holes, nest boxes, and other artificial structures [9]. Within the
oak-hickory forest region, maples, apples (Malus spp.), sycamores
(Platanus occidentalis) with natural cavities, and pines with woodpecker
holes are preferred [16]. In Louisiana eastern screech-owls chose nest
cavities in trees with lianas more often than expected according to
availability [24]. Mean minimum diameter of cavity trees is 12 inches
(30 cm) [10]. Eastern screech-owls usually choose cavities with
openings 3 to 5 inches (7.6-12.7 cm) in diameter. Typically, cavity
height is between 5 and 30 feet (1.5-9 m) above ground [5]. Nest
cavities are usually reused in successive years [11]. Nest boxes are
often reused by the same pair; one female was recorded using the same
box 8 years in a row [37].

Roosting: Eastern screech-owls prefer to roost in natural hollows
protected from rain and snow, and out of direct sunlight. They avoid
hollows used by fox squirrels (Sciurus niger) [7,19]. Roosting hollows
are typically 15 to 20 feet (4.5-6 m) and usually less than 40 feet (12
m) above the ground. Roosting cavity openings are about the same size
as nest cavity openings [7].

More info for the terms: cover, density, shrubs

Suitable eastern screech-owl habitat seems to be wherever nesting and
roosting cavities are near or adjacent to open areas with available
rodent prey [29]. Eastern screech-owls usually inhabit open woodlands
adjacent to meadows, marshes, or fields; forest clearings; old orchards;
and parks and other open areas in urban or suburban areas [10,9]. They
are more tolerant of human habitation and human activities than other
owls, and are found in or near barns, outbuildings, birdhouses,
hedgerows, and fencerows [19,29]. They are rarely found in swamps or
deep forest habitats [28].

Eastern screech-owls generally prefer areas with widely spaced trees
interspersed with grassy openings [10]. In Connecticut, red maple
woodlands, upland woodland, evergreen hedgerows, and edge habitats were
used by eastern screech-owl more often than expected if habitat choice
were random. Lawns, mixed woods, and evergreen woods were used less
often than would be expected if habitat choice were random. Although
lawns were not a selected habitat, they were a major component of all
monthly home ranges (a monthly home range is the amount of territory
used in the span of a month) [30]. In central Kentucky radio-tagged
eastern screech-owls used woodlots and edges more than expected based on
availability, and used pastures, old fields, and croplands less than
expected [32]. Lynch and Smith [38] reported that eastern screech-owl
abundance in Connecticut was positively related to the amount of natural
area within urban open space (examples include shrubs, old fields, and
marshes). There was also a positive relationship among eastern
screech-owl abundance, total habitat diversity, and the amount of linear
edge. Areas with mixtures of habitats including relatively high amounts
of undisturbed successional communities and edges tended to support many
owls [38]. In the southeastern states, eastern screech-owls are found
up to 4,500 feet (1,371 m) elevation (but are rare at the higher
elevations) [15].

Hunting: Eastern screech-owls usually hunt in grassy openings, fields,
meadows, and along wooded field margins and streams [10].

Home Range: In suburban areas most food gathering trips are less than
330 feet (100 m) round trip. In areas with lower prey density food
trips may be longer [14]. Home range size is related to prey
availability. Smith and Gilbert [30] estimated that the area traversed
in one night (the nightly range) for female eastern screech-owls was the
largest (38 acres [15.5 ha]) from November to February (when prey was
most scarce), was smallest during egg-laying and incubation (13 acres
[5.4 ha]) in March and April, and expanded again in June to 22 acres
(8.9 ha). The larger nightly ranges in winter were thought to reflect a
need to cover greater areas to obtain adequate food. The total home
range of one female was 323 acres (130.9 ha), but she typically hunted
only a small area each night and a larger cumulative portion each month.
Home range was largest while a female was selecting a nest site and
smallest during egg laying, incubation, and care of young. The actual
defended territory included only the area immediately around the nest
cavity [30]. Gehlbach [14] estimated Connecticut home ranges as 9.9 to
14.8 acres (4-6 ha) and Texas home ranges exceeding 74.1 acres (30 ha).

Estimated Population Density: In the Southeast, sampled breeding
density was listed as 2.8 pairs per 100 acres (2.8 pairs/40 ha) [15].
Lynch and Smith [38] observed a range of 1 to 18 eastern screech-owls
per square mile (1-7/sq km); an average of 6 birds per square mile
(2.3/sq km) occurred in 4 suburban areas in Connecticut.

More info for the term: hardwood

The eastern screech-owl occupies a wide variety of habitat types [29].
It is commonly associated with open woodlands of oaks (Quercus spp.),
maples (Acer spp.), and hickories (Carya spp.); it is also found in pine
(Pinus spp.) forests and plantations, mixed woodlands, orchards, and
forested wetlands [28]. At the northern and western edges of its range,
the eastern screech-owl occupies riparian woods dominated by hardwoods
including boxelder (Acer negundo), green ash (Fraxinus pennsylvanica),
and bur oak (Quercus macrocarpa) [23]. In South Dakota eastern
screech-owls were found in riparian woods dominated by eastern
cottonwood (Populus deltoides) and willows (Salix spp.), hardwoods
dominated by green ash, boxelder, American elm, and bur oak, and
shelterbelts. Siberian elm (Ulmus pumila) is a common shelterbelt tree
in South Dakota and is used by eastern screech-owls [12]. In Kansas
eastern screech-owls were also observed in shelterbelts [26]. In New
England, eastern screech-owls are found in aspen (Populus spp.), paper
birch (Betula papyrifera), northern hardwoods, red maple (Acer rubrum),
balsam fir (Abies balsamea), eastern hemlock (Tsuga canadensis),
northern red oak (Quercus rubra), eastern white pine (Pinus
strobus)-northern red oak-red maple, and eastern white pine communities
[11]. In South Carolina on the Coastal Plain, eastern screech-owls were
observed in pine and hardwood stands. The managed pine stands were
mostly longleaf pine (P. palustris) and loblolly pine (P. taeda).
Hardwood stands were dominated by gums (Nyssa spp.), baldcypress
(Taxodium distichum), oaks, or red maple [17]. In Louisiana eastern
screech-owls were found in mature mixed bottomland hardwoods dominated
by water oak (Q. nigra), pignut hickory (Carya glabra), American elm
(Ulmus americana), and sugarberry (Celtis laevigata). They also
inhabited cottonwood plantations and riverfront hardwoods dominated by
sweet pecan (Carya illinoiensis), water hickory (C. aquatica),
sugarberry, and waterlocust (Gleditsia aquatica) [24].

REFERENCES :
NO-ENTRY

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

1 Jack pine
5 Balsam fir
12 Black spruce
14 Northern pin oak
15 Red pine
20 White pine-northern red oak-red maple
21 Eastern white pine
22 White pine-hemlock
23 Eastern hemlock
24 Hemlock-yellow birch
25 Sugar maple-beech-yellow birch
26 Sugar maple-basswood
27 Sugar maple
28 Black cherry-maple
39 Black ash-American elm-red maple
40 Post oak-blackjack oak
42 Bur oak
43 Bear oak
44 Chestnut oak
45 Pitch pine
46 Eastern redcedar
50 Black locust
51 White pine-chestnut oak
52 White oak-black oak-northern red oak
53 White oak
55 Northern red oak
57 Yellow-poplar
58 Yellow-poplar-eastern hemlock
59 Yellow-poplar-white oak-northern red oak
60 Beech-sugar maple
61 River birch-sycamore
63 Cottonwood
64 Sassafras-persimmon
65 Pin oak-sweetgum
72 Southern scrub oak
87 Sweetgum-yellow-poplar
88 Willow oak-water oak-diamondleaf oak
89 Live oak
93 Sugarberry-American elm-green ash
94 Sycamore-sweetgum-American elm
95 Black willow
96 Overcup oak-water hickory
108 Red maple
109 Hawthorn
110 Black oak

More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

More info for the term: bog

K081 Oak savanna
K082 Mosaic of K074 and K100
K084 Cross Timbers
K089 Black Belt
K093 Great Lakes spruce-fir forest
K094 Conifer bog
K095 Great Lakes pine forest
K096 Northeastern spruce-fir forest
K097 Southeastern spruce-fir forest
K098 Northern floodplain forest
K099 Maple-basswood forest
K100 Oak-hickory forest
K101 Elm-ash forest
K102 Beech-maple forest
K103 Mixed mesophytic forest
K104 Appalachian oak forest
K106 Northern hardwoods
K107 Northern hardwoods-fir forest
K108 Northern hardwoods-spruce forest
K110 Northeastern oak-pine forest
K111 Oak-hickory-pine forest
K112 Southern mixed forest
K113 Southern floodplain forest
K114 Pocosin
K115 Sand pine scrub

More info on this topic.

This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES10 White-red-jack pine
FRES11 Spruce-fir
FRES12 Longleaf-slash pine
FRES13 Loblolly-shortleaf pine
FRES14 Oak-pine
FRES15 Oak-hickory
FRES16 Oak-gum-cypress
FRES17 Elm-ash-cottonwood
FRES18 Maple-beech-birch
FRES19 Aspen-birch

More info on this topic.

This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

810 Longleaf pine-turkey oak hills
811 South Florida flatwoods
812 North Florida flatwoods
813 Cutthroat seeps
820 Everglades flatwoods

Eastern screech-owls have the broadest ecological niche of any North American owl. They are found in virtually all kinds of habitats below about 1500 meters elevation, from urbanized surroundings to boreal forests. They are generally found in wooded areas but do well in urban and suburban areas and do well near humans, often using bird boxes for nesting. These birds are cavity nesters and use natural cavities or those created by other animals.

Range elevation: 1500 (high) m.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; forest ; scrub forest

Other Habitat Features: urban ; suburban

Systems

• Terrestrial

Eastern screech-owls have the broadest ecological niche of any North American owl. They are found in virtually all kinds of habitats below about 1500 meters elevation, from urbanized surroundings to boreal forests. They are generally found in wooded areas but do well in urban and suburban areas and acclimatize readily to human presence, often using bird boxes for nesting. These birds are cavity nesters and use natural cavities or those created by other animals.

Range elevation: 1500 (high) m.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; forest ; scrub forest

Other Habitat Features: urban ; suburban

Comments: Open woodland, deciduous forest, orchards, woodland/forest edge, swamps, parklands, residential areas in towns, scrub, and riparian woodland in drier regions. Evergreen woodland/ forest little used in northeastern U.S. Roosts in tree hollow, among foliage close to trunk, in rock crevice, old magpie nest, nest box, under eaves, or similar site.

Nests in natural cavity, old woodpecker hole, or bird box, often 1.5-9 m above ground; sites with opening of about 7-20 cm (Voous and Cameron 1989); in Kentucky avoided deep cavities (more than 60 cm) and shallow cavities, used cavities averaged 31 cm deep. In south-central Iowa, the highest use of nest boxes occurred in riparian sites (Iowa Bird Life, 1990).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Sedentary.

More info for the term: formation

The eastern screech-owl is an opportunistic feeder. Prey species are
primarily small rodents, but numerous other animals are consumed [10].
Norberg [25] stated that insects are the major portion of the diet of
Megascops owls, but since the eastern screech-owl is sedentary it switches to
mammalian and avian prey in winter [37]. The mammalian prey list
includes mice and rats (Muridae), shrews (Soricidae), moles (Talpidae),
flying squirrels (Glaucomys spp.), chipmunks (Tamias spp.), and bats
(Chiroptera). Avian prey includes songbirds, rock dove (Columbia
livia), northern bobwhite (Colinus virginianus), ruffed grouse (Bonasa
umbellus), American woodcock (Scolopax minor), common snipe (Gallinago
gallinago), American kestrel (Falco sparverius), and even other eastern
screech-owls [18]. Eastern screech-owls have killed domestic pigeons,
hens, and ducks with prandial intent [19]. Other vertebrate prey
includes snakes, lizards, frogs, toads, salamanders, and small fish.
Invertebrate prey includes many insects, snails, crayfish, spiders,
scorpions, millipedes, and earthworms [18].

Even though the prey lists are long, a few species form the main diet.
Favored prey includes meadow vole (Microtus pennsylvanicus),
white-footed mouse (Peromyscus leucopus), house mouse (Mus musculus),
and woodrats (Neotoma spp.) [19]. Snyder and Wiley [31] estimated that
year-round prey consumption by eastern screech-owls is 30.7 percent
invertebrates, 0.6 percent lower vertebrates, 65.6 percent mammals, and
3.3 percent birds.

Seasonal Diet: In Michigan pellet analysis during spring and summer
indicated a high proportion of meadow vole, white-footed mouse,
crayfish, and small birds in eastern screech-owl diets [7]. Pellet
analysis must be interpreted with caution, since many invertebrate prey
items do not contribute to pellet formation. In Ohio almost 65 percent
of the food items brought to nest boxes were birds, the majority of
which were migratory songbirds [37].

Craighead and Craighead's [7] analysis of pellets (Michigan study area)
indicated that meadow vole formed the bulk of the eastern screech-owl
winter diet. In a year when meadow vole numbers were lower than
average, a higher percentage of small birds appeared in pellets. In
both years, white-footed mouse were consumed in amounts comparable to
those of meadow voles. Other major pellet components were shrews and
moles [7]. In Ohio fall and winter diets contained 30 percent birds
[37].

Foraging Habits: Eastern screech-owls tend to follow approximately the
same hunting route within the territory, tending to visit previously
successful sites [5]. They usually forage in a perch-and-pounce manner,
taking short flights to capture already-spotted prey. Eastern
screech-owls have been observed to take a position near a bat colony and
capture bats as they leave the colony [39]. Insects are often caught in
flight. Eastern screech-owls also walk on the ground to forage for
insects, particularly night-dormant grasshoppers, and wade into shallow
water after fish and aquatic invertebrates [18,21,37,39].

Eastern screech-owls eat the most varied diet of any North American owl. Their diet includes large evening active insects, like Lepidoptera and Tettigoniidae, Malacostraca, Oligochaeta, amphibians, Squamata, small mammals, like Sigmodontinae and Vespertilionidae, and small Aves. These owls have symmetrical ears, which suggests that they hunt mainly by using their vision. (Ears that are not symmetrical give owls a better ability to pinpoint the location of prey using only hearing.) They do, however, have excellent hearing as they often capture prey hidden by leaf litter. They hunt by sitting on a tree branch and waiting to see or hear prey. Eastern screech-owls store prey in their nests to eat later or for their young to eat later.

Animal Foods: birds; mammals; amphibians; reptiles; insects; terrestrial non-insect arthropods; terrestrial worms

Foraging Behavior: stores or caches food

Eastern screech-owls eat the most varied diet of any North American owl. Their diet includes large evening active insects, like moths and katydids, crayfish, earthworms, amphibians, reptiles, small mammals, like mice and bats, and small birds. These owls have symmetrical ears, which suggests that they hunt primarily using their vision. They do, however, have excellent hearing as they often capture prey hidden by leaf litter. They hunt by sitting on a tree branch and waiting to see or hear prey. Eastern screech-owls cache prey in their nests for later consumption by adults or nestlings.

Animal Foods: birds; mammals; amphibians; reptiles; insects; terrestrial non-insect arthropods; terrestrial worms

Foraging Behavior: stores or caches food

Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)

Comments: Eats mainly mice, shrews, and insects, also other small vertebrates and invertebrates (Terres 1980). Opportunistic, takes whatever is readily available. Caches prey in tree holes and nest boxes.

Larger owls prey on eastern screech-owl; the primary predator is the
great horned owl (Bubo virginianus), but others include barred owl
(Strix varia), great gray owl (S. nebulosa), snowy owl (Nyctea
scandiaca), long-eared owl (Asio otus), short-eared owl (A. flammeus),
and common barn owl (Tyto alba). Large hawks also take eastern
screech-owl, but only rarely since hawks are largely diurnal. Other
predators include domestic cat (Felis catus), Mustelids (minks, weasels,
and skunks), northern river otter (Lutra canadensis), bobcat (Lynx
rufus), and domestic dogs (Canis familiaris). Snakes have killed adult
eastern screech-owls (usually because an eastern screech-owl attacked a
snake too large to capture easily) but are more commonly nest predators
[19].

Eastern screech-owls are sometimes the most abundant and important small predator in urban and suburban forested areas. They also deliberately bring live animals, such as Leptotyphlops dulcis into their nests. These animals feed on the ants, flies, and other insects that infest the nest cavity. Crematogaster lineolatus may inhabit the nest cavity of these owls and will repel intruders by spraying irritating secretions and biting.

Mutualist Species:

• Crematogaster lineolatus
• Leptotyphlops dulcis

Eastern screech-owls watch animal movements near their nest holes very carefully, they are always on the lookout for predators. They are preyed on as adults and fledglings by larger Strigiformes, Accipitridae, and other eastern screech-owls. Eggs and nestlings may be taken by Elaphe obsoleta, Didelphis virginiana, Procyon lotor, and Bassariscus astutus. Eastern screech-owls use alarm calls and will physically attack potential predators that approach their nestlings and fledglings. The colors of eastern screech-owls make them very difficult to see against a bark background, which protects them from predators as well.

Known Predators:

• owls (Strigiformes)
• hawks (Accipitridae)
• black rat snakes (Elaphe_obsoleta)
• Virginia opossums (Didelphis_virginiana)
• raccoons (Procyon_lotor)
• ringtails (Bassariscus_astutus)

Anti-predator Adaptations: cryptic

Eastern screech-owls are sometimes the most abundant and important small predator in urban and suburban forested areas. They also deliberately bring live animals, such as blind snakes into their nests. These animals feed on the ants, flies, and other insects that infest the nest cavity. Acrobat ants may inhabit the nest cavity of these owls and will repel intruders by spraying irritating secretions and biting.

Mutualist Species:

• acrobat ants
• blind snakes

Eastern screech-owls are extremely vigilant near their nest holes, perhaps in order to assess predator movements. They are preyed on as adults and fledglings by larger owls, hawks, and other eastern screech-owls. Eggs and nestlings may be taken by black ratsnakes, Virginia opossums, raccoons, and ringtails. Eastern screech-owls use alarm calls and will physically attack potential predators that approach their nestlings and fledglings. Their coloration also makes them cryptic.

Known Predators:

• owls (Strigiformes)
• hawks (Accipitridae)
• black rat snakes (Pantherophis obsoletus)
• Virginia opossums (Didelphis virginiana)
• raccoons (Procyon lotor)
• ringtails (Bassariscus astutus)

Anti-predator Adaptations: cryptic

Otus asio is prey of:
Strigiformes
Accipitridae
Elaphe obsoleta
Didelphis virginiana
Procyon lotor
Bassariscus astutus

This list may not be complete but is based on published studies.

Otus asio preys on:
non-insect arthropods
Annelida
Arthropoda
Insecta
Amphibia
Reptilia
Aves
Mammalia
Diadophis punctatus

This list may not be complete but is based on published studies.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

10,000 to >1,000,000 individuals

Comments: Guesstimated number of breeding pairs in Canada in the early 1990s was 10,000-50,000 (Kirk et al. 1995).

More info for the term: natural

Habitat related fire effects include loss of habitat, change in habitat
structure (which may affect both nesting and hunting), and effects on
the prey base. In the southeastern states a majority of small mammals
thrive in early- to mid-successional habitats which are maintained by
fire or other disturbance [41]. Prey vulnerability depends at least
partly on vegetation structure. Low, open vegetation makes prey easier
to spot, but eastern screech-owls require perches from which to hunt.
Fire-caused wounds may increase decay in large trees, making them more
likely to develop cavities (either natural or excavated).

More info for the terms: altricial, selection

Diurnal Activity: Eastern screech-owls are rarely active before dusk.
In Ithaca, New York, the earliest recorded time of initiation of feeding
activity was 8:25 p.m.; the latest time feeding ended was 4:15 a.m. [39].

Migration Status: Eastern screech-owls are resident throughout their
range; suggestions that some migration occurs at the northern edge of
the range have not been substantiated [18]. The large majority of adult
birds (87%) were recovered within 10 miles (16 km) of the banding site.
None had moved more than 40 miles (64 km) [37].

Pair Bond: Craighead and Craighead [7] stated that they had no data on
year-round pairing, but they observed birds that appeared to remain
loosely paired over the winter, using the same hunting areas and
roosting sites as during the breeding season. They delimited the
beginning of the breeding season by the selection of a nesting
territory; in Michigan this usually occurs around the end of February
[7].

Nesting: Peak nesting season, when young are in the nest, appears to
coincide with most passerine migration (a rich source of prey) [37]. In
the Southeast, nesting season is from mid-March to late May, peaking in
April [15]. In Michigan earliest egg date was April 18 (1942) [7]. In
New York and New England, egg dates ranged from April 12 to May 18. In
Pennsylvania and New Jersey eggs were present in nests from March 23 to
May 19, and in Florida, eggs were present from March 11 to May 18 [18].
The shortest time between eggs is 48 hours; the time between eggs is
often 72 hours and occasionally longer [19]. Typical clutch sizes are 3
to 5 eggs; clutch sizes range from 1 to 10 [18].

Incubation: Incubation is almost exclusively by the female; if she
leaves the nest to drink or bathe, the male will incubate until she
returns and pushes him away. The male brings food but the female eats
very little during incubation [19]. The incubation period is variable,
lasting from 26 to 32 days [37].

Development of Young: The altricial young are downy, with eyes closed
[19]. The young have been observed shivering almost constantly for the
first 2 weeks of life [5]. The eyes are usually open by the 20th day.
Flight feathers begin coming in around the 25th day. The average time
in the nest is 4 to 5 weeks [7,19]. Fledglings stay on branches near
the nest until full flight is achieved. Even after leaving the nest
tree, fledglings continue to be fed by the parents for up to 5 weeks
after fledging. By the ninth week, fledglings usually begin molting to
the first-winter plumage. In Ohio the overall nesting success rate
(the proportion of active nests that fledged at least one young) was
86.1 percent, and the overall breeding success rate (the proportion of
eggs that resulted in young fledged) was 73.8 percent [37].

Juvenile Dispersal: Family groups begin to split up by late August.
Dispersal, in an apparently random direction, occurs in early fall
[18,19]. In a Connecticut banding study, juvenile dispersal fell into
two groups; juveniles either travelled fewer than 20 miles (32 km) or
much greater distances (a minority). The longest distance recorded for
juvenile dispersal was 185 miles (300 km) [37].

Breeding Age and Longevity: One banding study indicated that at least
25 percent of eastern screech-owls bred as yearlings [37]. In the wild,
the average lifespan for eastern screech-owl in central Texas was
estimated as 3.6 years, although some individuals survived to at least 8
years of age [14]. Captive birds have lived more than 20 years [19].

Local population density in suitable habitat ranges from fewer than 1 to several per sq km (Johnsgard 1988). In Ohio, young dispersed an average of only 32 km by the spring following hatching; dispersal was much less in Texas and Kentucky (mean = 4.4 km) studies (Johnsgard 1988, Belthoff and Ritchison 1989). In Kentucky, juveniles settled 2-11 days after departing from natal areas; high mortality rate in juveniles (Belthoff and Ritchison 1989). Generally very sedentary. Home range size varies seasonally. Population fluctuations usually are minor, though die-offs may occur in far north when snow cover is deep and long-lasting (Voous and Cameron 1989).

Eastern screech-owls have keen senses of hearing and vision which help them to locate prey in dim light. They use a variety of calls to communicate with others. Nestlings and females call softly from within the nest cavity. Both males and females give the "trill" song, which may be used to advertise nest sites, in courting, when arriving at the nest with food, and females use it to ask nestlings to come out of the nest and try flying. Other calls are hoots, rasps, chuckle-rattles, barks, and screeches. These calls generally indicate some degree of alarm or anxiety.

Communication Channels: visual ; tactile ; acoustic

Eastern screech-owls have acute senses of hearing and vision which help them to locate prey in dim light. They use a variety of vocalizations. Nestlings and females call softly from within the nest cavity. Both males and females give the "trill" song, which may be used to advertise nest sites, in courting, when arriving at the nest with food, and to call nestlings out of the nest for fledging. Other calls are hoots, rasps, chuckle-rattles, barks, and screeches. These calls generally indicate some degree of alarm or anxiety.

Communication Channels: visual ; tactile ; acoustic

An eastern screech-owl lived in the wild for 14 years and 2 months, though most probably live for much less than this. It is estimated that only 30 to 50% of young from one year survive into the next year.

Range lifespan

Status: wild: 14 (high) years.

Average lifespan

Status: wild: 248 months.

An eastern screech-owl lived in the wild for 14 years and 2 months, though most probably live for much less than this. It is estimated that only 30 to 50% of young from one year survive into the next year.

Range lifespan

Status: wild: 14 (high) years.

Average lifespan

Status: wild: 248 months.

Maximum longevity: 20.7 years Observations: Animals in captivity may live up to 20 years. In the wild, the average longevity has been estimated at 3.6 years (http://www.fs.fed.us/database/feis/).

Most eastern screech-owls form pair bonds for life with individuals of the same age, although some males have more than one mate. Both males and females crouch and trill when their mate approaches.

Mating System: monogamous ; polygynous

Eastern screech-owl females lay eggs over a period of days to more than a week and do not begin full-time incubation until the last egg is laid. Because of this, eggs laid first also develop and hatch first. With larger broods, where newly hatched owlets may be up to 8 days behind their nestmates, younger nestlings tend to be killed accidentally or by their siblings. From 2 to 7 eggs, usually 3 or 4, are laid in a large nest cavity. They are incubated for 26 (eggs laid last) to 34 days (earlier eggs), with an average of 30 days of incubation.

Breeding interval: Breeding occurs once a year, usually, but a second clutch may be attempted in areas with dense resources.

Breeding season: Breeding occurs from February through March and perhaps later.

Range eggs per season: 2 to 7.

Average eggs per season: 3.5.

Range time to hatching: 26 to 34 days.

Range time to independence: 8 to 10 weeks.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization (Internal )

Average eggs per season: 4.

Average age at sexual or reproductive maturity (male)

Sex: male: 365 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 365 days.

Eastern screech-owl females incubate the eggs and brood the young. Males feed females and guard nest cavities during incubation and brooding. The young leave the nest at about 28 days old and remain with the parents until they are 8 to 10 weeks old. Both parents feed the young during this period.

Parental Investment: altricial ; male parental care ; female parental care

Most eastern screech-owls form pair bonds for life with individuals of the same age. Some mate switching occurs after unsuccessful nesting attempts and some males have been observed nesting simultaneously and sequentially with more than one female. Both males and females crouch and trill when their mate approaches.

Mating System: monogamous ; polygynous

Eastern screech-owl females lay eggs over a period of days to more than a week and generally do not begin full-time incubation until the last egg is laid. As a result, eggs laid first also develop and hatch first. With larger broods, where newly hatched young may be developmentally up to 8 days behind their nestmates, younger nestlings tend to be killed accidentally or by their siblings. From 2 to 7 eggs, usually 3 or 4, are laid in a large nest cavity. They are incubated for 26 (eggs laid last) to 34 days (earlier eggs), with an average of 30 days of incubation.

Breeding interval: Breeding occurs once a year, usually, but a second clutch may be attempted in areas with dense resources.

Breeding season: Breeding occurs from February through March and perhaps later.

Range eggs per season: 2 to 7.

Average eggs per season: 3.5.

Range time to hatching: 26 to 34 days.

Range time to independence: 8 to 10 weeks.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization (Internal )

Average eggs per season: 4.

Average age at sexual or reproductive maturity (male)

Sex: male: 365 days.

Average age at sexual or reproductive maturity (female)

Sex: female: 365 days.

Eastern screech-owl females incubate the eggs and brood the young. Males feed females and guard nest cavities during incubation and brooding. The young leave the nest at about 28 days old and remain with the parents until they are 8 to 10 weeks old. Both parents feed the young during this period.

Parental Investment: altricial ; male parental care ; female parental care

Eggs: March-May (April-May in north). Clutch size usually is 4-5 in north, 3 in Florida; increases south to north, and east to west. Incubation is mainly/entirely by female, 3-4 weeks. Young are tended by both parents, leave nest at 30-32 days; usually one or both parents roost with young for several weeks after fledging. Most breed in first year. In Kentucky, juveniles dispersed in mid-July, an average of 55 days after fledging (Belthoff and Ritchison 1989).

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There are 10 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.


Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 13
Specimens with Barcodes: 16
Species With Barcodes: 1

The eastern screech-owl is listed as a species of special concern on the
American Ornithologists' Union Blue List. It was first blue-listed in
1981, and was listed again in 1982 and 1986. Numbers of eastern
screech-owls have been reported as declining on the Hudson-Delaware,
southern Atlantic Coast, and in Appalachian and mid-western prairie
regions [34].

Eastern screech-owls may suffer as a result of deforestation and the loss of appropriate nesting cavities and prey populations. They are relatively common throughout their range, though, and are not currently threatened.

IUCN Red List of Threatened Species: least concern

US Migratory Bird Act: no special status

US Federal List: no special status

CITES: appendix ii

State of Michigan List: no special status

Eastern screech-owls may suffer as a result of deforestation and the loss of appropriate nesting cavities and prey populations. They are relatively common throughout their range, though, and are not currently threatened.

US Migratory Bird Act: no special status

US Federal List: no special status

CITES: appendix ii

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Species is abundant and widespread.

Degree of Threat: D : Unthreatened throughout its range, communities may be threatened in minor portions of the range or degree of variation falls within natural variation

More info for the terms: natural, presence

Population Status: Census of eastern screech-owl by song playback
provides a quick and relatively easy method to obtain accurate numbers
[29]. Eastern screech-owl is common in the eastern United States, where
it is often the most common raptor [10,29]. Eastern screech-owl
population densities vary with the relative proportion of woodland cover
in an area [29]. In Connecticut long-term survey data indicated a
decline in eastern screech-owl populations in the 1970's and 1980's,
possibly as a result of increased habitat fragmentation and conversion
of open woods to residential areas [38]. In Ohio the eastern
screech-owl population fluctuated during the 30 years prior to 1975, but
no long-term trend was apparent in owls studied in suitable habitat.
The estimated annual recruitment needed to maintain population size is
2.21 fledglings per nesting pair. Eastern screech-owls have probably
increased with the opening up of dense forest but may be threatened by
increasing conversion of woods to residential areas [37]. The increase
in early successional forest area in the latter half of the twentieth
century, largely due to abandonment of agricultural lands, may benefit
eastern screech-owls. Management considerations for maintenance of
populations include provision of natural and artificial cavities and
preservation of woodlots in suburban areas [38]. Recommended size for
eastern screech-owl nest boxes: floor 8 inches by 8 inches (20 cm X 20
cm), cavity depth 8 to 10 inches (20-24 cm), and an entrance hole 3
inches (7.5 cm) in diameter [16].

Pesticide Accumulation: In the early 1970's eggshell thinning and DDE
and PCB levels in eggs were found to be relatively low for eastern
screech-owls. It was suggested that the consumption of rodents (lower
trophic levels) prior to egg-laying contributed to the relatively low
pesticide loads in eggs. Consumption of birds (higher trophic levels)
increased after eggs were incubated, and thus did not contribute to egg
pesticide loads [37]. Other pesticides have not been investigated in
relationship to eastern screech-owl.

Predator-Prey Relationships: As a general rule, predators that are
specialized on small rodents tend to destabilize rodent population
cycles, whereas generalized predators tend to have a stabilizing effect,
sometimes suppressing cycles altogether. The eastern screech-owl is
more generalist in its effects on rodent populations [25]. Even though
eastern screech-owls sometimes prey heavily on songbirds, they are more
likely to help keep rodent and insect populations in check [19].
Orchard owners reported that putting up nest boxes for screech-owls
resulted in a decrease in rodent damage to orchard trees [5]. Eastern
screech-owls commonly nest in boxes put up for wood ducks (Aix sponsa),
American kestrels, squirrels, and purple martins (Progne subis) and will
even attempt to nest in mailboxes. Wood ducks often use nest boxes
after eastern screech-owls have left the nest; VanCamp and Henny [37]
suggested that wood duck nesting success is enhanced by eastern
screech-owl presence because owls discourage the usurpation of nest
boxes by European starlings (Sternus vulgaris).

Mortality Rates and Causes of Mortality: Mortality rate for the eastern
screech-owl was estimated as 69.5 percent the first year; eastern
screech-owls over 1 year old experience approximately 34 percent annual
mortality [37]. Predation accounts for substantial adult mortality
[37]. Collision with motor vehicles is also a major cause of mortality.
Other causes include shooting (which has become less frequent since
legal protection of raptors was enacted), electrocution, collision with
windows, or entrapment in buildings, and drowning (apparently these owls
take many baths and can become waterlogged and drown in rain barrels)
[18]. There is a small amount of sibling cannibalism, usually after
accidental injury to a nestling [19]. In Michigan nest loss due to fox
squirrels (Sciurus niger), which usually then appropriate the nest
hollow, has been observed [7].

REFERENCES :
NO-ENTRY

Global Protection: Unknown whether any occurrences are appropriately protected and managed

Comments: Probably abundant in many managed areas, no details.

Needs: None.

There are no negative effects of eastern screech-owls on humans.

Eastern screech-owls may help to control the populations of potential pests such as mice and some insects.

Positive Impacts: controls pest population

There are no negative effects of eastern screech-owls on humans.

Eastern screech-owls may help to control the populations of potential pests such as mice and some insects.

Positive Impacts: controls pest population

Comments: Formerly treated as a subgenus within Otus (Marshall and King in Amadon and Bull 1988), but mitochondrial DNA and vocal differences with Old World species indicate that generic status is warranted (Konig et al. 1999).

Formerly considered conspecific with western O. kennicottii and Mexican and Middle American O. seductus and O. cooperi. Mixed pairs and overlap of Asio and kennicottii in se. Colorado and s. Texas attributed to long-distance dispersal in marginally poor habitat. Sympatry without interbreeding with kennicottii reported for w. Edwards Plateau (Dixon 1989).