Eastern Screech Owl
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The eastern screech owl (''Megascops asio'') or eastern screech-owl, is a small
owl Owls are birds from the order Strigiformes (), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers a ...
that is relatively common in Eastern
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, from
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to
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. This species resides in most types of woodland habitats across its range, and is relatively adaptable to urban and developed areas compared to other owls. Although it often lives in close proximity to humans, the eastern screech owl frequently avoids detection due to its strictly nocturnal habits.


Taxonomy

The eastern screech owl was
formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...
in 1758 by the Swedish naturalist
Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
in the
tenth edition Tenth may refer to: Numbers * 10th, the ordinal form of the number ten * One tenth, , or 0.1, a fraction, one part of a unit divided equally into ten parts. ** the SI prefix deci- ** tithe, a one-tenth part of something * 1/10 of any unit of me ...
of his ''
Systema Naturae ' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...
''. He placed it with all the other owls in the
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
'' Strix'' and coined the
binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...
''Strix asio''. Linnaeus based his account on the "little owl" that had been described and illustrated by the English naturalist
Mark Catesby Mark Catesby (24 March 1683 – 23 December 1749) was an English natural history, naturalist who studied the flora and fauna of the New World. Between 1729 and 1747, Catesby published his ''Natural History of Carolina, Florida and the Bahama ...
in his book ''The Natural History of Carolina, Florida and the Bahama Islands''. The specific epithet is the
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
word for a type of eared owl. The eastern screech owl is now one of 22 screech owls placed in the genus ''
Megascops Screech owls are typical owls (Strigidae) belonging to the genus ''Megascops'' with 22 living species. For most of the 20th century, this genus was merged with the Old World scops owls in ''Otus'', but nowadays it is again considered separat ...
'' that was introduced in 1848 by the German naturalist Johann Kaup. Five
subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
are typically recognised for the eastern screech owl, but the taxonomy in the species is considered "muddled". Much of the variation may be considered clinal, as predictably, the size tends to decrease from north to south and much of the color variation is explainable by adaptation to habitat. *''M. a. asio'' (Linnaeus, 1758) includes previously described races no longer considered valid such as ''M. a. carolinensis'', ''M. a. naevius'' and ''M. a. striatus''. It is resident from eastern
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to southwestern
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and southern
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south to
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,
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, and northern
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. Dorsal color is cold gray; the red morph is common (about 39% of overall population). The nominate's markings are coarse and sparse and its toes are densely feathered. Its primary song has a terminal, tremulous whinny. This is a medium-to-large race, measuring in wing chord length. The owls of southern
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are on the larger end of the scale, of similar size to the relatively big owls of
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and
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. *''M. a. maxwelliae'' ( Ridgway, 1877). Includes ''M. a. swenki''. Resident from central
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, southeastern
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, and southern
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south to western
Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...
. This race is similar to ''M. a. asio'' but dorsal color tends to be a paler gray, the ventrum being whiter and less heavily marked and red morphs tending to paler and rarer (~7% of population). With a wing chord length of , this is the largest race in average linear measurements. This subspecies was named in honor of
Martha Maxwell Martha Ann Maxwell (née Dartt 21 July 1831 – 31 May 1881) was an American naturalist, artist and taxidermist. She helped found modern taxidermy. Maxwell's pioneering diorama displays are said to have influenced major figures in taxidermy histor ...
by ornithologist
Robert Ridgway Robert Ridgway (July 2, 1850 – March 25, 1929) was an American ornithologist specializing in systematics. He was appointed in 1880 by Spencer Fullerton Baird, secretary of the Smithsonian Institution, to be the first full-time curator of birds ...
of the
Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase a ...
. *''M. a. hasbroucki'' (Ridgway, 1914). Replacement name for the formerly described ''M. a. trichopsis''. This subspecies is a resident from
Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...
panhandle and southern
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south to
Edwards Plateau The Edwards Plateau is a geographic region forming the crossroads of Central, South and West Texas, United States. It is named in honor of Haden Edwards. It is bounded by the Balcones Fault to the south and east; the Llano Uplift and the Lla ...
of central
Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
. This subspecies is also similar to ''M. a. asio'' but the dorsal color is buffy gray, the red morph being rare (~5% of population), and markings coarse and dense. This race averages at a similar size as the first two, at in wing chord length. *''M. a. mccallii'' ( Cassin, 1854) includes previously described races such as ''M. a. enano'' and ''M. a. semplei''. Resident from southern
Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
( Big Bend to lower
Rio Grande Valley Lower Rio Grande Valley (), often referred to as the Rio Grande Valley (RGV) of South Texas, is a region located in the southernmost part of Texas, along the northern bank of the Rio Grande. It is also known locally as the Valley or the 956 (the ...
) and northwestern Chihuahua and northern
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southeast to eastern
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, this race is similar to ''M. a. hasbroucki'', but its markings are fine and dense so the dorsum looks heavily mottled, with red morphs being rare (apparently entirely absent in South Texas). Its body size is smaller to the northern races, with a wing chord length of . Unlike other subspecies, the primary song of ''M. a. mccallii'' lacks a terminal whinny. * ''M. a. floridanus'' (Ridgway, 1873) is resident in Florida and southern
Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...
west through
Gulf Coast The Gulf Coast of the United States, also known as the Gulf South or the South Coast, is the coastline along the Southern United States where they meet the Gulf of Mexico. The coastal states that have a shoreline on the Gulf of Mexico are Tex ...
states to western
Louisiana Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...
and north in the
Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...
valley to southeastern
Arkansas Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...
. This race's dorsal color is often rusty-brown (red morph equally common), with fine and dense markings. As described above, this subspecies may occur in a true "brown morph". It is the smallest race of eastern screech owl, ranging in wing chord length from .


Description

Adults range from in length and weigh . Among the differently sized races, length can average from . The wingspan can range from . In
Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...
, male owls average and females while in central
Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
, they average and , respectively. They have either rusty or dark gray intricately patterned
plumage Plumage () is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can b ...
with streaking on the underparts. Midsized by
screech-owl Screech owls are typical owls (Strigidae) belonging to the genus ''Megascops'' with 22 living species. For most of the 20th century, this genus was merged with the Old World scops owls in ''Otus'', but nowadays it is again considered separat ...
standards, these birds are stocky, short-tailed (tail averages from in length) and broad-winged ( wing chord averages from in length) as is typical of the genus. They have a large, round head with prominent ear tufts, yellow eyes, and a yellowish beak, which measures on average in length. The feet are relatively large and powerful compared to more southern screech owls and are typically feathered down to the toes, although the southernmost populations only have remnant bristles rather than full feathering on the legs and feet. The eastern screech owl (and its western counterpart) are actually some of the heaviest screech owls; the largest tropical screech owls do not exceed them in average or maximal weight, but (due to the eastern screech owls' relatively short tails) they are surpassed in length by Balsas (''M. seductus''), long-tufted (''M. sanctaecatarinae''), white-throated (''M. albogularis''), and
rufescent Rufous () is a color that may be described as reddish-brown or brownish-red, as of rust or oxidised iron. The first recorded use of ''rufous'' as a color name in English was in 1782. However, the color is also recorded earlier in 1527 as a dia ...
owls (''M. seductus''), in roughly increasing order.''CRC Handbook of Avian Body Masses, 2nd Edition'' by John B. Dunning Jr. (Editor). CRC Press (2008), . Two color variations are referred to as " red or rufous morphs" and "gray morphs" by
bird watchers Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device such as binoculars or a telescope, ...
and
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. Rusty birds are more common in the southern parts of the range; pairings of the two color variants do occur. While the gray morph provides remarkably effective camouflage amongst the bark of hardwood trees, red morphs may find security in certain pine trees and the colorful leaves of changing deciduous trees. The highest percentage of red morphs is known from
Tennessee Tennessee (, ), officially the State of Tennessee, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Kentucky to the north, Virginia to the northeast, North Carolina t ...
(79% of population) and
Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...
(78% of population). A rarer "brown morph" is known, recorded exclusively in the south (i.e.
Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
), which may be the occasional product of hybridation between the morphs. In Florida, brown morphs are typically reported in the more humid portions of the state, whereas they appear to be generally absent in the northern and northwestern parts of the state. A paler gray variation (sometimes bordering on a washed-out, whitish look) also exists in
western Canada Western Canada, also referred to as the Western provinces, Canadian West, or Western provinces of Canada, and commonly known within Canada as the West, is a list of regions of Canada, Canadian region that includes the four western provinces and t ...
and the north-central
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.


Confusion with other species

In the closely related
western screech owl The western screech owl (''Megascops kennicottii'') is a small owl native to North and Central America, closely related to the eastern screech owl. The scientific name commemorates the American naturalist Robert Kennicott. Description Length ...
(''Megascops kennicottii''), no color morphs are known; all owls of the western species are gray. Besides coloration, the western screech owl is of almost exactly the same general appearance and size as the eastern. The only reliable distinguishing feature is the bill color, which is considerably darker (often a black-gray) in the western and olive-yellow in the eastern; their voices also differ. The eastern and western screech owls overlap in the range in the
Rio Grande The Rio Grande ( or ) in the United States or the Río Bravo (del Norte) in Mexico (), also known as Tó Ba'áadi in Navajo language, Navajo, is one of the principal rivers (along with the Colorado River) in the Southwestern United States a ...
valley at the
Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
–
Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
border and the riparian woods of the Cimarron tributary of the
Arkansas River The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in Colorado, specifically ...
on the edge of southern
Great Plains The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...
. Other somewhat similar species that may abut the eastern screech owl's range in its western and southernmost distribution, like the Middle American screech owl (''Megascops guatemalae''; formerly called "vermiculated screech owl"),
whiskered screech owl The whiskered screech owl (''Megascops trichopsis'') is a small screech owl found in North and Central America. Description Adults occur in 2 color morphs, in either brown or dark grey plumage. They have a round head with ear tufts, yellow eyes ...
(''Megascops trichopsis''), and the
flammulated owl The flammulated owl (''Psiloscops flammeolus'') is a small migratory North American owl in the family Strigidae. It is the only species placed in the genus ''Psiloscops''. Taxonomy The flammulated owl was formally described in 1852 by the Germa ...
(''Psiloscops flammeolus''), are distinguished by their increasingly smaller body and foot size, different streaking pattern on breast (bolder on the whiskered, weaker on the others), different bare part coloration, and distinctive voices. Through much of the eastern United States, eastern screech owls are essentially physically unmistakable, because other owls with ear tufts are much larger and differently colored and the only other small owl, the
northern saw-whet owl The northern saw-whet owl (''Aegolius acadicus'') is a species of small true owl, owl in the Family (biology), family Strigidae. The species is native to North America. Saw-whet owls of the genus ''Aegolius'' are some of the smallest owl species ...
(''Aegolius acadius'') is even smaller, with no ear tufts, a more defined facial disc, and browner overall color.


Plumage polymorphism

Eastern screech owls exhibit a similar polymorphism as
tawny owl The tawny owl (''Strix aluco''), also called the brown owl, is a stocky, medium-sized owl in the family Strigidae. It is commonly found in woodlands across Europe, as well as western Siberia, and has seven recognized subspecies. The tawny owl' ...
s, whose plumage ranges from rufous to gray. The inheritance of morph in owls is likely complex, but rufous plumage may be controlled by a dominant allele and gray plumage alleles are recessive. There are latitudinal clines in screech owl polymorphism, with northern latitudes containing mostly gray individuals and southern latitudes containing primarily rufous individuals. This cline may be driven by higher metabolic rates in rufous individuals compared to gray individuals. Evidence of higher metabolic rates was shown by a higher proportion of gray morphs in the rural areas surrounding Waco, TX compared to the warmer suburban areas. Rufous screech owls also had higher mortality during cold winters.


Distribution and habitat

Eastern screech owls inhabit open mixed woodlands, deciduous forests, parklands, wooded suburban areas, riparian woods along streams and wetlands (especially in drier areas), mature orchards, and woodlands near marshes, meadows, and fields. They try to avoid areas known to have regular activity of larger owls, especially
great horned owl The great horned owl (''Bubo virginianus''), also known as the tiger owl (originally derived from early naturalists' description as the "winged tiger" or "tiger of the air") or the hoot owl, is a large owl native to the Americas. It is an extreme ...
s (''Bubo virginianus''). Their ability to live in heavily developed areas outranks even the great horned and certainly the
barred owl The barred owl (''Strix varia''), also known as the northern barred owl, striped owl or, more informally, hoot owl or eight-hooter owl, is a North American large species of owl. A member of the true owl family, Strigidae, they belong to the genus ...
(''Strix varia''); screech owls also are considerably more successful in the face of urbanization than
barn owl The barn owls, owls in the genus '' Tyto'', are the most widely distributed genus of owls in the world. They are medium-sized owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerful talons. The ter ...
s (''Tyto alba'') following the conversion of what was once farmland. Due to the introduction of open woodland and cultivated strips in the
Great Plains The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...
, the range of eastern screech owls there has expanded. Eastern screech owls have been reported living and nesting in spots such as along the border of a busy highway and on the top of a street light in the middle of a busy town square. They often nest in trees in neighborhoods and urban yards inhabited by humans. In such urban environments, they often meet their dietary needs via introduced species that live close to humans such as
house sparrow The house sparrow (''Passer domesticus'') is a bird of the Old World sparrow, sparrow family Passeridae, found in most parts of the world. It is a small bird that has a typical length of and a mass of . Females and young birds are coloured pa ...
s (''Passer domesticus'') and
house mice The house mouse (''Mus musculus'') is a small mammal of the rodent family Muridae, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus '' Mus''. A ...
(''Mus musculus''). They also consume anole lizards and large insects such as cicadas. They occupy the greatest range of habitats of any owl east of the Rockies. Eastern screech owls roost mainly in natural cavities in large trees, including cavities open to the sky during dry weather. In suburban and rural areas, they may roost in manmade locations such as behind loose boards on buildings, in boxcars, or on water tanks. They also roost in dense foliage of trees, usually on a branch next to the trunk, or in dense, scrubby brush. The distribution of the species is largely concurrent with the distribution of eastern deciduous woodlands, probably discontinuing at the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...
in the west and in northern Mexico in the south due to the occupation of similar niches by other screech owls and discontinuing at the start of true
boreal forest Taiga or tayga ( ; , ), also known as boreal forest or snow forest, is a biome characterized by pinophyta, coniferous forests consisting mostly of pines, spruces, and larches. The taiga, or boreal forest, is the world's largest land biome. I ...
because of the occupation of a similar niche by other small owls (especially
boreal owl The boreal owl (''Aegolius funereus'') or Tengmalm's owl is a small owl in the "true owl" family Strigidae. It is known as the boreal owl in North America and as Tengmalm's owl in Europe after Swedish naturalist Peter Gustaf Tengmalm or, more r ...
s (''Aegolius funereus''). Eastern screech owls may be found from sea level up to in elevation in the eastern
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...
and up to in the eastern
Sierra Madre Oriental Mountains The Sierra Madre Oriental () is a mountain range in northeastern Mexico. The Sierra Madre Oriental is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that f ...
, although their altitudinal limits in the
Appalachian Mountains The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...
, near the heart of their distribution, is not currently known.


Behavior

Eastern screech owls are strictly nocturnal, roosting during the day in cavities or next to tree trunks. They are quite common, and can often be found in residential areas. However, due to their small size and camouflage, they are much more frequently heard than actually seen. These owls are frequently heard calling at night, especially during their spring breeding season. Despite their name, this owl does not truly screech. The eastern screech owl's call is a
tremolo In music, ''tremolo'' (), or ''tremolando'' (), is a trembling effect. There are multiple types of tremolo: a rapid repetition of a note, an alternation between two different notes, or a variation in volume. Tremolos may be either ''measured'' ...
with a descending, whinny-like quality, like that of a miniature horse. They also produce a monotone purring trill lasting 3–5 seconds. Their voices are unmistakable and follow a noticeably different phrasing than that of the western screech owl. The lugubrious nature of the eastern screech owl's call has warranted description such as, "A most solemn graveyard ditty, the mutual consolation of suicide lovers remembering the pangs and delights of the supernal love in the infernal groves, ''Oh-o-o-o-o that I never had been bor-r-r-r-n!''.


Breeding

Their breeding habitat is
deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...
or mixed woods in eastern
North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
. Usually solitary, they nest in a tree cavity, either natural or excavated by a
woodpecker Woodpeckers are part of the bird family (biology), family Picidae, which also includes the piculets, wrynecks and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar and the extreme ...
. Holes must have a entrance to accommodate this owl. Usually, they fit only in the holes excavated by
northern flicker The northern flicker or common flicker (''Colaptes auratus'') is a medium-sized bird of the woodpecker family. It is native to most of North America, parts of Central America, Cuba, and the Cayman Islands, and is one of the few woodpecker specie ...
s (''Colaptes auratus'') or
pileated woodpecker The pileated woodpecker ( ; ''Dryocopus pileatus'') is a large, crow-sized woodpecker with a prominent red crest, white neck stripe, and a mostly black body. These woodpeckers are native to North America, where it is the largest confirmed extant ...
s (''Dryocopus pileatus''), as apparently the midsized red-bellied woodpecker (''Melanerpes carolinensis'') make holes that are not large enough to accommodate them.
Orchard An orchard is an intentional plantation of trees or shrubs that is maintained for food production. Orchards comprise fruit tree, fruit- or nut (fruit), nut-producing trees that are generally grown for commercial production. Orchards are also so ...
s, which often have trees with crevices and holes, as well as
meadow vole The eastern meadow vole (''Microtus pennsylvanicus''), sometimes called the field mouse or meadow mouse, is a North American vole found in eastern Canada and the United States. Its range extends farther south along the Atlantic coast. The weste ...
s (''Microtus pennsylvanicus''), a dietary favorite, are often preferred nesting habitats. Eastern screech owls also use nesting boxes erected by humans. Although some people put up nest boxes meant for screech owls, the owls also take over nest boxes meant for others, such as those for
wood duck The wood duck or Carolina duck (''Aix sponsa'') is a partially migratory species of perching duck found in North America. The male is one of the most colorful North American waterfowls. Taxonomy The wood duck was Species description, formal ...
s (''Aix sponsa''), houses erected for
purple martin The purple martin (''Progne subis'') is a passerine bird in the swallow family Hirundinidae. It is the largest swallow in North America. Despite its name, the purple martin is not truly purple. The dark blackish-blue feathers have an iridescent ...
s (''Progne subis''), and dovecotes put up for
rock dove The rock dove (''Columba livia''), also sometimes known as "rock pigeon" or "common pigeon", is a member of the bird family Columbidae (doves and pigeons). In common usage, it is often simply referred to as the "pigeon", although the rock dov ...
s (''Columba livia''), occasionally killing and consuming at least the latter two in the process of taking over the nest box. A 9-year study comparing the breeding success of eastern screech owls nesting in natural cavities and nesting in nest boxes showed that the fledging rate was essentially the same, although in some years, up to 10% more success occurred in the natural cavities. Depending on the origins of the hole being used, eastern screech owl nests have been recorded from off the ground. Like all owls, these birds do not actually build a nest; instead, females lay their eggs directly on the bare floor of the nest hole or on the layer of fur and feathers left over from previous meals that line the bottom of its den. Breeding pairs often return to the same nest year after year. This species commences egg laying on average about two months after great horned owls, but about two weeks before
American kestrel The American kestrel (''Falco sparverius'') is the smallest and most common falcon in North America. Though it has been called the American sparrowhawk, this common name is a misnomer; the American kestrel is a true falcon, while neither th ...
s (''Falco sparveius'') and almost throughout the range lays its first egg at some point in April. Eggs are laid at two-day intervals and incubation begins after laying of the first egg. Eggs vary in size in synch with their ultimate body size, ranging from an average of in the Northern Rockies to in south Texas. From one to six eggs have been recorded per clutch, with an average of 4.4 in
Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...
, 3.0 in Florida, and 4.56 in the north-central United States. The incubation period is about 26 days, and the young reach the fledging stage at about 31 days old. Females do most of the incubating and brooding, but males also occasionally take shifts. As is the typical division of labor in owls, the male provides most of the food while the female primarily broods the young, and they stockpile food during the early stages of nesting, although the male tends to work hard nightly because many nestlings often appear to live almost entirely on freshly caught insects and invertebrates. The male's smaller size make it superior in its nimbleness, which allows it to catch insects and other swift prey. Eastern screech owls are single-brooded, but may renest if the first clutch is lost, especially towards the southern end of its range. When the young are small, the female tears the food apart for them. The female, with her larger size and harder strike, takes on the duty of defending the nest from potential threats, and even humans may be aggressively attacked, sometimes resulting in them drawing blood from the head and shoulders of human passers-by.


Feeding habits

Like most predators, eastern screech owls are opportunistic hunters. Due to the ferocity and versatility of their hunting style, early authors nicknamed eastern screech owls "feathered wildcats".Bent, A.C. (1938). ''Life histories of North American Birds of Prey, Vol. 2''. Dover, New York. In terms of ecological niche, they have no easy ecological equivalent in Europe, perhaps the closest being the
little owl The little owl (''Athene noctua''), also known as the owl of Athena or owl of Minerva, is a bird that inhabits much of the temperate and warmer parts of Europe, the Palearctic east to Korea, and North Africa. It was introduced into Britain at t ...
(''Athene noctua''), the similar looking
Eurasian scops owl The Eurasian scops owl (''Otus scops''), also known as the European scops owl, common scops owl or just scops owl, is a small owl in the typical owl family Strigidae. Its breeding range extends from southern Europe eastwards to southern Siberia a ...
(''Otus scops'') being smaller and weaker and the
long-eared owl The long-eared owl (''Asio otus''), also known as the northern long-eared owlOlsen, P.D. & Marks, J.S. (2019). ''Northern Long-eared Owl (Asio otus)''. In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook o ...
(''Asio otus'') more fully dependent on rodents. The success of eastern screech (and western screech) owls in North America may be the reason long-eared owls are much more restricted to limited northern forest habitat in North America than they are in Europe. Eastern screech owls hunt from dusk to dawn, with most hunting being done during the first four hours of darkness. A combination of sharp hearing and vision is used for prey location. These owls hunt mainly from perches, dropping down onto prey. Occasionally, they also hunt by scanning through the treetops in brief flights or hover to catch prey. This owl mainly hunts in open woodlands, along the edges of open fields or wetlands, or makes short forays into open fields. When prey is spotted, the owl dives quickly and seizes it in its talons. Small prey usually is swallowed whole on the spot, while larger prey is carried in the bill to a perch and then torn into pieces. An eastern screech owl tends to frequent areas in its home range where it hunted successfully on previous nights. The eastern screech owl's sense of hearing is so acute, it can even locate mammals under heavy vegetation or snow. The bird's ears (as opposed to its ear tufts) are placed asymmetrically on its head, enabling it to use the differences between each ear's perception of sound to home in on prey. Additionally, the feathers the eastern screech owl uses to fly are serrated at their tips. This muffles the noise the bird makes when it flaps its wings, enabling it to sneak up on prey quietly. Both the specialized ear placement and wing feathers are a feature shared by most living owl species to aid them in hunting in darkness. During the breeding season, large
insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...
s are favored in their diet, with
invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...
s often composing more than half of the owls' diet. Some regularly eaten insects include
beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...
s,
moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...
s,
crickets Crickets are orthopteran insects which are related to bush crickets and more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 886 ...
,
grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grassh ...
s,
katydid Insects in the family Tettigoniidae are commonly called katydids (especially in North America) or bush crickets. They have previously been known as "long-horned grasshoppers". More than 8,000 species are known. Part of the suborder Ensifera, the ...
s, and
cicada The cicadas () are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into two ...
s, although they likely consume any commonly available flying insect. Also taken are
crayfish Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some spe ...
,
snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...
s,
spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...
s,
earthworm An earthworm is a soil-dwelling terrestrial invertebrate that belongs to the phylum Annelida. The term is the common name for the largest members of the class (or subclass, depending on the author) Oligochaeta. In classical systems, they we ...
s,
scorpion Scorpions are predatory arachnids of the Order (biology), order Scorpiones. They have eight legs and are easily recognized by a pair of Chela (organ), grasping pincers and a narrow, segmented tail, often carried in a characteristic forward cur ...
s,
leech Leeches are segmented parasitism, parasitic or Predation, predatory worms that comprise the Class (biology), subclass Hirudinea within the phylum Annelida. They are closely related to the Oligochaeta, oligochaetes, which include the earthwor ...
es,
millipede Millipedes (originating from the Latin , "thousand", and , "foot") are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derive ...
s, and
centipede Centipedes (from Neo-Latin , "hundred", and Latin , "foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', "lip", and Neo-Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, ...
s. Small
mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
s, ranging in size from
shrew Shrews ( family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to dif ...
s to young
rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...
s (''
Sylvilagus Cottontail rabbits are in the ''Sylvilagus'' genus, which is in the family Leporidae. They are found in the Americas. Most ''Sylvilagus'' species have stub tails with white undersides that show when they retreat, giving them their characteris ...
'' ssp.), are regular prey and almost always become the owl's primary food during winter. Small rodents such as microtine rodents and
mice A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
account for about 67% of mammals taken, although rodents of a similar weight to the owl, such as
rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include '' Neotoma'' (pack rats), '' Bandicota'' (bandicoo ...
s and
squirrel Squirrels are members of the family Sciuridae (), a family that includes small or medium-sized rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrel ...
s, especially the
red squirrel The red squirrel (''Sciurus vulgaris''), also called Eurasian red squirrel, is a species of tree squirrel in the genus ''Sciurus''. It is an arboreal and primarily herbivorous rodent and common throughout Eurasia. Taxonomy There have been ...
(''Tamiasciurus hudsonicus''), are also taken.
Jumping mice Zapodidae, the jumping mice, is a family of mouse-like rodents in North America and China. Although mouse-like in general appearance, these rodents are distinguished by their elongated hind limbs, and, typically, by the presence of four pairs o ...
(''Zapus'' ssp.),
chipmunk Chipmunks are small, striped rodents of subtribe Tamiina. Chipmunks are found in North America, with the exception of the Siberian chipmunk which is found primarily in Asia. Taxonomy and systematics Chipmunks are classified as four genera: '' ...
s,
mole Mole (or Molé) may refer to: Animals * Mole (animal) or "true mole" * Golden mole, southern African mammals * Marsupial mole Marsupial moles, the Notoryctidae family, are two species of highly specialized marsupial mammals that are found i ...
s, and
bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...
s (especially the
little brown bat The little brown bat or little brown myotis (''Myotis lucifugus'') is an endangered species of mouse-eared bat, mouse-eared microbat found in North America. It has a small body size and glossy brown fur. It is similar in appearance to several ...
(''Myotis lucifugus'') may be taken occasionally. Small birds such as
chickadee The chickadees are a group of North American birds in the family Paridae included in the genus '' Poecile''. Species found in North America are referred to as chickadees; species found elsewhere in the world are called tits. They are small-si ...
s (''Poecile'' ssp.),
swallow The swallows, martins, and saw-wings, or Hirundinidae are a family of passerine songbirds found around the world on all continents, including occasionally in Antarctica. Highly adapted to aerial feeding, they have a distinctive appearance. The ...
s, sparrows,
finch The true finches are small to medium-sized passerine birds in the family Fringillidae. Finches generally have stout conical bills adapted for eating seeds and nuts and often have colourful plumage. They occupy a great range of habitats where the ...
es, flycatchers, and
warbler Various Passeriformes (perching birds) are commonly referred to as warblers. They are not necessarily closely related to one another, but share some characteristics, such as being fairly small, vocal, and insectivorous. Sylvioid warblers T ...
s are the most common avian prey, and such species are normally caught directly from their nocturnal perches or during nocturnal migration. In Ohio, the most commonly reported avian prey species, and most commonly stored food items behind meadow voles, were
yellow-rumped warbler The yellow-rumped warbler (''Setophaga coronata'') is a regular North American bird species that can be commonly observed all across the continent. Its extensive range connects both the Pacific and Atlantic coasts of the U.S. as well as Canada an ...
s (''Setophaga coronata'') and
white-throated sparrow The white-throated sparrow (''Zonotrichia albicollis'') is a passerine bird of the New World sparrow family Passerellidae. It breeds in northern North America and winters in the southern United States. Taxonomy In 1760 the English naturalist ...
s (''Zonotrichus albicollis''). Abundant midsized avian or largish passerine prey are also not uncommon foods, such as
mourning dove The mourning dove (''Zenaida macroura'') is a member of the dove Family (biology), family, Columbidae. The bird is also known as the American mourning dove, the rain dove, the chueybird, colloquially as the turtle dove, and it was once known a ...
s (''Zenaida macroura''),
downy woodpecker The downy woodpecker (''Dryobates pubescens'') is a species of woodpecker, the smallest in North America. Length ranges from . Downy woodpeckers primarily live in forested areas throughout the United States and Canada, with the exception of desert ...
s (''Picoides pubescens''),
northern flicker The northern flicker or common flicker (''Colaptes auratus'') is a medium-sized bird of the woodpecker family. It is native to most of North America, parts of Central America, Cuba, and the Cayman Islands, and is one of the few woodpecker specie ...
s,
blue jay The blue jay (''Cyanocitta cristata'') is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations ar ...
s (''Cyanocitta cristata''),
American robin The American robin (''Turdus migratorius'') is a migratory bird of the true thrush genus and Turdidae, the wider thrush family. It is named after the European robin because of its reddish-orange breast, though the two species are not clos ...
s (''Turdus migratorius''),
European starling The common starling (''Sturnus vulgaris''), also known simply as the starling in Great Britain and Ireland, and as European starling in North America, is a medium-sized passerine bird in the starling family, Sturnidae. It is about long and ha ...
(''Sturnus vulgaris''),
red-winged blackbird The red-winged blackbird (''Agelaius phoeniceus'') is a passerine bird of the family Icteridae found in most of North America and much of Central America. It breeds from Alaska and Newfoundland south to Florida, the Gulf of Mexico, Mexico, and ...
s (''Agelaius phoeniceus''), and
common grackle The common grackle (''Quiscalus quiscula'') is a species of large icterid bird found in large numbers through much of North America. First described in 1758 by Carl Linnaeus, the common grackle has three subspecies. Adult common grackles have a ...
s (''Quiscalus quiscula''). However, larger avian prey are sometimes caught, including
northern bobwhite The northern bobwhite (''Colinus virginianus''), also known as the Virginia quail or (in its home range) bobwhite quail, is a ground-dwelling bird native to Canada, the United States, Mexico, and Cuba, with introduced populations elsewhere in th ...
(''Colinus virginianus'') and
American woodcock The American woodcock (''Scolopax minor''), sometimes colloquially referred to as the timberdoodle, mudbat, bogsucker, night partridge, or Labrador twister is a small shorebird species found primarily in the eastern half of North America. Woodco ...
s (''Scolopax minor'') and even
feral pigeon Feral pigeons are birds derived from domesticated populations of the rock dove ''Columba livia'', descendants that have escaped and are living independently from (and often unwanted by) humans, having gone "feral". They are sometimes given the ...
s and
ruffed grouse The ruffed grouse (''Bonasa umbellus'') is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is the most widely distributed game bird in North America. It is non-migratory. It is the only spe ...
(''Bonasa umbellus''), most likely young or fledgling aged birds, but all of which are likely to be heavier than the screech owls themselves. All told, more than 100 species of bird have been hunted by eastern screech owls. Irregularly, small
fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
, small
snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...
s (i.e. ''
Heterodon ''Heterodon'' is a genus of harmless colubrid snakes endemic to North America.Platt, Dwight R. 1983. Heterodon'. Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles, 351: 1-2. They are stout with upt ...
'' ssp.),
lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...
s, baby
soft-shelled turtle Trionychidae is a family (biology), family of turtles, Common name, commonly known as softshell turtles or simply softshells. The family was described by Leopold Fitzinger in 1826. Softshells include some of the world's largest freshwater turtles ...
s (''Apalone'' ssp.), small
frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...
s such as
tree frog A tree frog (or treefrog) is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia suborder have given rise to treefrogs, although they are not clos ...
s and
northern leopard frog ''Lithobates pipiens''Integrated Taxonomic Information System nternet2012''Lithobates pipiens'' pdated 2012 Sept; cited 2012 Dec 26Available from: www.itis.gov/ formerly ''Rana pipiens'', commonly known as the northern leopard frog, is a s ...
s (''Lithobates pipiens''),
toad Toad (also known as a hoptoad) is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands. In popular culture (folk taxonomy ...
s,
newt A newt is a salamander in the subfamily Pleurodelinae. The terrestrial juvenile phase is called an eft. Unlike other members of the family Salamandridae, newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aqua ...
s, and
salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...
s are also preyed upon. They have even been observed hunting for fish at fishing holes made by people or cracks in ice at bodies of water during winter. The most commonly reported fish prey in Ohio were
American gizzard shad The American gizzard shad (''Dorosoma cepedianum''), also known as the mud shad, is a member of the Clupeidae, herring family of fish and is native to large swaths of fresh and brackish waters in the United States of America, as well as portions ...
(''Dorosoma cepedianum'') and
green sunfish The green sunfish (''Lepomis cyanellus'') is a species of aggressive freshwater fish in the sunfish family ( Centrarchidae) of order Centrarchiformes. The green sunfish does not always grow large enough to be an appealing target for anglers, ...
(''Lepomis cyanellus'').
Brown bullhead The brown bullhead (''Ameiurus nebulosus'') is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (''Ameiurus melas'') and yellow bullhead (' ...
s (''Ameiurus nebulosus'') have been captured by eastern screech owls along coastal areas during winter. From hundreds of prey remains from Ohio, 41% were found to be mammals (23% of which were mice or voles), 18% were birds, and 41% were insects and other assorted invertebrates. Of vertebrates taken in the nesting season, 65% were birds (of about 54 species), 30% were mammals (11% meadow voles; 8% each of
house mice The house mouse (''Mus musculus'') is a small mammal of the rodent family Muridae, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus '' Mus''. A ...
and
deermice ''Peromyscus'' is a genus of rodents. They are commonly referred to as deer mice or deermice, not to be confused with the chevrotain or "mouse deer". They are New World mice only distantly related to the common house and laboratory mouse, ''Mu ...
of the genus ''Peromyscus''), 3% were fish, and less than 2% were reptiles and amphibians. In
Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...
, among winter foods, 45–50% were meadow voles, 45% were
white-footed mice The white-footed mouse (''Peromyscus leucopus'') is a rodent native to North America from southern Canada to the southwestern United States and Mexico. It is a species of the genus ''Peromyscus'', a closely related group of New World mice often ...
(''Peromyscus leucopus'') and 1–10% were birds; during the summer, these respective numbers changed to 30, 23, and 19%, with as much as 28% of the food in summer being
crayfish Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some spe ...
(''
Cambarus ''Cambarus'' is a large and diverse genus of crayfish from the United States and Canada. The adults range in size from about up to approximately . Description The genus ''Cambarus'' is the second largest freshwater crayfish genus inhabiting t ...
'' ssp.). Due to meeting the needs of their nestlings, eastern screech owls frequently consume less per day during summer than they do during winter. Five owls captured in April, averaging about in males and in females, gained on average when captured in fall (October–December) and when captured in winter (January–February). In Michigan, screech owls consumed about 25% of their own weight per day during winter against 16% of their weight in summer. The average weight of vertebrate prey for screech owls in Michigan is In
Wisconsin Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...
, the average weight of vertebrate prey is . While much of their insect prey can weigh only a fraction of a gram, their largest prey, such as adult rats and pigeons and juvenile rabbits and gamebirds, can weigh up to at least .


Urban/suburban vs. rural behavior

Eastern screech owls are known for their ability to live in close proximity to humans. There is previous information pointing to potential behavioral adaptations of urban and suburban eastern screech owls from their rural counterparts. There have been previous studies that found suburban eastern screech owls breed no differently in man-made nest boxes than in natural tree cavities. Climate, food sources, and predator presence are some potential factors that impact the behaviors of suburban and rural eastern screech owls. Living in suburbia can have some additional impacts on eastern screech owl behavior such as secondary poisoning, vehicles, and more predation and competition from raccoon, opossum and squirrels. Previous research has shown that male eastern screech owls find and defend two to three potential nesting sites (man-made and natural) in order to have backups for failed first nesting attempts. However, in a study by Gehlbach it was found that suburban eastern screech owls had fewer alternative nesting sites due to humans cutting down trees with natural cavities, pruning the trees, or filling in the natural cavities with cement. Gehlbach also found that nesting sites close to houses and with fewer surrounding shrubs were some of the most used. Additionally, older eastern screech owls were found to be more likely to habituate to human disturbances compared to younger eastern screech owls. A study by Artuso found that there were larger average brood sizes and earlier average fledging dates of eastern screech owls shown in moderate and high-density suburban areas than in low-density suburban and rural areas. Urban and suburban populations of eastern screech owls are more dense and productive than their rural counterparts. There are various differences in habitat that have impacts on the nesting behaviors of eastern screech owls. Eastern screech owl feeding behaviors have also been shown through previous research to be impacted by whether the owl lived in a rural or suburban area. In a previous study, prey diversity for eastern screech owls peaked in low-density suburban areas. The owl's feeding habits changed based on the habitat type—owls in low-density suburban sites consumed almost double the amount of birds in non-breeding season as owls in high-density sites and triple that of owls in rural sites. Rural owls generally consumed more
invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...
s and fewer caterpillars and earthworms. It is already known that eastern screech owl diets vary throughout the breeding and non-breeding season, but now there is more research describing habitat's role in feeding behaviors as well. The climate within urban or suburban and rural areas differ as well which in turn impacts eastern screech owl behavior. Suburban climate is typically warmer than rural climate due to the "heat island effect". A previous study showed that as suburban climates got warmer over the course of a few years, eastern screech owls started nesting an average of 4.5 days earlier annually. There were also more avian prey and a 93% success rate in annual nests. Bird baths and feeders located in the suburban habitats were also noted as being likely factors in enhancing residence successes.  


Mortality

While eastern screech owls have lived for over 20 years in captivity, wild birds seldom, if ever, live that long. Mortality rates of young and nestling owls may be as high as 70% (usually significantly less in adult screech owls). Many losses are due to predation. Common predators at screech owl nests including
Virginia opossum The Virginia opossum (''Didelphis virginiana''), also known as the North American opossum, is a member of the opossum family found from southern Canada to northern Costa Rica, making it the northernmost marsupial in the world and the only marsup ...
s (''Didelphis virginiana''),
American mink The American mink (''Neogale vison'') is a semiaquatic species of Mustelidae, mustelid native to North America, though human introduction has expanded its range to many parts of Europe, Asia, and South America. Because of range expansion, the Am ...
s (''Neogale vison''),
weasel Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets, and European mink. Members of this genus are small, active predators, with long and slend ...
s (''Mustela'' and ''Neogale'' sp.),
raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...
s (''Procyon lotor''),
ringtail The ringtail (''Bassariscus astutus'') is a mammal of the raccoon family native to arid regions of North America. It is widely distributed and well-adapted to its distributed areas. It has been legally trapped for its fur. Globally, it is list ...
s (''Bassariscus astutus''),
skunk Skunks are mammals in the family Mephitidae. They are known for their ability to spray a liquid with a strong, unpleasant scent from their anal glands. Different species of skunk vary in appearance from black-and-white to brown, cream or gi ...
s (''Mephitis'' and ''Spilogale'' sp.),
snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...
s,
crow A crow is a bird of the genus ''Corvus'', or more broadly, a synonym for all of ''Corvus''. The word "crow" is used as part of the common name of many species. The related term "raven" is not linked scientifically to any certain trait but is rathe ...
s (''Corvus'' sp.), and
blue jay The blue jay (''Cyanocitta cristata'') is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations ar ...
s (''Cyanocitta cristata'').
Eastern fox squirrel The fox squirrel (''Sciurus niger''), also known as the eastern fox squirrel or Bryant's fox squirrel, is the largest species of tree squirrel native to North America. It is sometimes mistaken for the American red squirrel or eastern gray squirr ...
s (''Sciurus niger'') may raid the tree holes being used by eastern screech owls, not only destroying or consuming the eggs, but also displacing the adult owls from the hole to use the hole for themselves. Adults have fewer predators, but larger species of owls do take them, since they have similar periods of activity. Larger owls known to have preyed on eastern screech owls have included
great horned owl The great horned owl (''Bubo virginianus''), also known as the tiger owl (originally derived from early naturalists' description as the "winged tiger" or "tiger of the air") or the hoot owl, is a large owl native to the Americas. It is an extreme ...
s (''Bubo virginianus''),
barred owl The barred owl (''Strix varia''), also known as the northern barred owl, striped owl or, more informally, hoot owl or eight-hooter owl, is a North American large species of owl. A member of the true owl family, Strigidae, they belong to the genus ...
s (''Strix varia''),
spotted owl The spotted owl (''Strix occidentalis'') is a species of true owl. It is a resident species of old-growth forests in western North America, where it nests in tree hollows, old bird of prey nests, or rock crevices. Nests can be between high a ...
s (''Strix occidentalis''),
long-eared owl The long-eared owl (''Asio otus''), also known as the northern long-eared owlOlsen, P.D. & Marks, J.S. (2019). ''Northern Long-eared Owl (Asio otus)''. In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook o ...
s (''Asio otus''),
short-eared owl The short-eared owl (''Asio flammeus'') is a widespread grassland species in the family Strigidae. Owls belonging to genus ''Asio'' are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or ...
s (''Asio flammeus''), and
snowy owl The snowy owl (''Bubo scandiacus''), also known as the polar owl, the white owl and the Arctic owl, is a large, white owl of the true owl family. Snowy owls are native to the Arctic regions of both North America and the Palearctic, breeding mo ...
s (''Bubo scandianus''). Diurnal birds of prey may also kill and eat them, including
Cooper's hawk Cooper's hawk (''Astur cooperii'') is a medium-sized hawk native to the North American continent and found from southern Canada to Mexico. This species was formerly placed in the genus ''Accipiter''. As in many birds of prey, the male is small ...
s (''Accipiter cooperii''),
northern harrier The northern harrier (''Circus hudsonius''), also known as the marsh hawk or ring-tailed hawk, is a bird of prey. It breeds throughout the northern parts of the northern hemisphere in Canada and the northernmost United States, USA. The northern ...
s (''Circus cyaenus''),
red-tailed hawk The red-tailed hawk (''Buteo jamaicensis'') is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members of ...
s (''Buteo jamaicensis''),
red-shouldered hawk The red-shouldered hawk (''Buteo lineatus'') is a medium-sized buteo. Its breeding range spans eastern North America and along the coast of California and northern to northeastern-central Mexico. It is a permanent resident throughout most of its ...
(''Buteo lineatus'') and
rough-legged hawk The rough-legged buzzard (Europe) or rough-legged hawk (North America) (''Buteo lagopus'') is a medium-large bird of prey. It is found in arctic and subarctic regions of North America, Europe, and Asia during the breeding season, and migrates s ...
s (''Buteo lagopus''). Most prolific by far of the eastern screech owl's avian predators is the great horned owl, which can destroy up to 78% of a local population, but locally, Cooper's hawks and barred owls are almost as serious of a threat. A most dramatic case illustrating the owl food chain involved a barred owl, which upon examination after being shot in
New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...
, contained a long-eared owl in its stomach that, in its own stomach, contained an eastern screech owl. All other common owls in this species range also live on similar rodent prey, but direct competition is obviously disadvantageous to the screech owl. One exception is the even smaller
northern saw-whet owl The northern saw-whet owl (''Aegolius acadicus'') is a species of small true owl, owl in the Family (biology), family Strigidae. The species is native to North America. Saw-whet owls of the genus ''Aegolius'' are some of the smallest owl species ...
, on which eastern screech owls have been known to prey. In rural
Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...
, 9 different species of owls and diurnal raptors including the screech owl fed primarily on the same four species of small rodents from the ''
Peromyscus ''Peromyscus'' is a genus of rodents. They are commonly referred to as deer mice or deermice, not to be confused with the chevrotain or "mouse deer". They are New World mice only distantly related to the common house and laboratory mouse, ''M ...
'' and ''
Microtus ''Microtus'' is a genus of voles found in North America, Europe and northern Asia. The genus name refers to the small ears of these animals. They are stout rodents with short ears, legs and tails. They eat green vegetation such as grasses and se ...
'' genera. Eastern screech owls have had nesting attempts fail due to
biocide A biocide is defined in the European legislation as a chemical substance or microorganism intended to destroy, deter, render harmless, or exert a controlling effect on any harmful organism. The US Environmental Protection Agency (EPA) uses a sli ...
poisoning, which causes the thinning of eggs and failure of nests, but seemingly not to the overall detriment of the species. Collisions with cars, trains, and windowpanes kill many screech owls, the earlier especially while feeding on road-side rodents and road kills.


Parasites

This species has the potential to be infected by several parasites, including ''
Plasmodium elongatum ''Plasmodium elongatum'' is a malaria parasite discovered by Hartman and first disclosed in Hartman 1927. Study of it has been fundamental to understanding the lifecycle of malaria along with study of '' P. gallinaceum'', also a malaria para ...
'', ''
Plasmodium forresteri ''Plasmodium forresteri'' is a parasite of the genus ''Plasmodium''. Like all ''Plasmodium'' species ''P. forresteri'' has both vertebrate and insect hosts. The vertebrate hosts for this parasite are birds. Description The parasite was first de ...
'', and ''
Plasmodium gundersi ''Plasmodium'' is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of ''Plasmodium'' species involve development in a blood-feeding insect host which then injects parasites into a verteb ...
''.


Image gallery

EasternScreechOwl23.jpg, Gray morph screechowl23.jpg, Gray morph EasternScreechOwlBillWaller.jpg, Red morph Eastern Screech-Owl (Megascops asio) RWD.jpg, Red morph Eastern Screech Owl RWD1 at CRC.jpg, Red morph and gray morph at a raptor center Eastern Screech Owl-red-phase2.jpg, Red morph Eastern screech owl rehabilitated after eye injury (44333).jpg, Rescued after an eye injury


References


External links


Eastern Screech-owl – ''Otus asio''
– USGS Patuxent Bird Identification InfoCenter
Eastern Screech-Owl Species Account
– Cornell Lab of Ornithology
Eastern Screech-owl
â€
eNature.com
*
''Otus asio'' species account
at
Animal Diversity Web The Animal Diversity Web (ADW) is a non-profit group that hosts an online database site that collects natural history, classification, species characteristics, conservation biology, and distribution information on species of animals. The website ...

Eastern Screech Owl profile – The Peregrine Fund

Eastern Screech-Owl – Megascops (Otus) asio
a
owling.com

Eastern Screech Owl – ''Megascops asio''
a
owlpages.com
* {{Authority control
eastern screech owl The eastern screech owl (''Megascops asio'') or eastern screech-owl, is a small typical owl, owl that is relatively common in Eastern North America, from Mexico to Canada. This species resides in most types of woodland habitats across its range, ...
Native birds of Eastern Canada Native birds of the Eastern United States Birds of Mexico
eastern screech owl The eastern screech owl (''Megascops asio'') or eastern screech-owl, is a small typical owl, owl that is relatively common in Eastern North America, from Mexico to Canada. This species resides in most types of woodland habitats across its range, ...
eastern screech owl The eastern screech owl (''Megascops asio'') or eastern screech-owl, is a small typical owl, owl that is relatively common in Eastern North America, from Mexico to Canada. This species resides in most types of woodland habitats across its range, ...
eastern screech owl The eastern screech owl (''Megascops asio'') or eastern screech-owl, is a small typical owl, owl that is relatively common in Eastern North America, from Mexico to Canada. This species resides in most types of woodland habitats across its range, ...
Extant Late Pleistocene first appearances