Eastern Screech Owl
Encyclopedia
The Eastern Screech Owl or Eastern Screech-Owl (Megascops asio) is a small owl
that is relatively common in Eastern North America
, from Mexico
to Canada
.
with streaking on the underparts. Mid-sized by screech-owl
standards, these birds are stocky, short-tailed and broad-winged. They have a large round head with prominent ear tufts, yellow eyes and a yellowish bill. Rusty birds are more common in the southern parts of the range; pairings of the two color variants do occur. A pale gray variation also exists in western Canada
and the north-central United States
. The color variations are referred to as "red morph
" and "gray morph" by bird watchers
and ornithologists
.
or mixed woods in eastern North America
. Usually solitary, they nest in a tree cavity, either natural or excavated by a woodpecker
; they will also use nesting boxes. The bird doesn't actually build a nest; instead, females lay their eggs directly on the layer of fur and feathers left over from previous meals that lines the bottom of its den. Breeding pairs often return to the same nest year after year.
Eggs are laid every two days and incubation begins after laying of the first egg. The incubation period is about 26 days and the fledging period about 31 days. Females do most of the incubating but males will assist. The male provides most of the food while the female broods the young, and will stockpile food during early stages. Eastern Screech Owls are single brooded, but may re-nest if the first clutch is lost. When the young are small the female tears the food up for them.
with a descending, whinny-like quality.
, weasel
s, raccoon
s, skunk
s, snake
s, crow
s, and blue jay
s. Adults have fewer predators but larger species of owl 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
s, Barred Owl
s, Long-eared Owl
s, Great Gray Owls, Short-eared Owl
s and Snowy Owl
s.
The eastern screech owl's sense of hearing is so acute that it can even locate mammals under heavy vegetation or snow. The bird's ears 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.
For the better part of the year, large insect
s are favored in their diet, with invertebrate
s often comprising more than half of the owls' diet. Some regularly eaten insects include beetle
s, moth
s, cricket
s, grasshopper
s and cicada
s. Also taken are crayfish
, snail
s, spider
s, earthworm
s, scorpion
s, and centipede
s. Small mammal
s, ranging in size from shrew
s to rabbit
s, are regular prey and often become the owl's primary prey during winter. Small rodents such as microtine rodents
and mice
comprise about 67% of mammals taken, although rodents of a similar weight to the owl, such as rat
s and squirrel
s are also taken. Small birds such as chickadee
s, sparrow
s and warbler
s are the most common avian prey and such species are normally caught directly off of their nocturnal perches or during nocturnal migration. However, much larger avian prey is sometimes caught, including rock pigeon
s, northern bobwhite and even ruffed grouse
(which are heavier than the screech owls). Irregularly, small fish
, small snake
s, lizard
s, baby soft-shelled turtles, small frog
s, toad
s, and salamander
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.
and Plasmodium gundersi
.
:
Typical owl
True owl or Typical owl are one of the two generally accepted families of Owls, the other being the barn owls . The Sibley-Ahlquist taxonomy unites the Caprimulgiformes with the owl order; here, the typical owls are a subfamily Strigidae...
that is relatively common in Eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, from Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
to Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
Description
Adults range from 16 to 25 cm (6.3–10 in) in length and weigh 121-244 grams (4.3-8.6 oz). They have either rusty or dark gray intricately patterned plumagePlumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
with streaking on the underparts. Mid-sized by screech-owl
Screech-owl
Screech owls or Screech-owls are typical owls belonging to the genus Megascops. Twenty-one living species are known at present, but new ones are frequently recognized and unknown ones are still being discovered on a regular basis, especially in the Andes...
standards, these birds are stocky, short-tailed and broad-winged. They have a large round head with prominent ear tufts, yellow eyes and a yellowish bill. Rusty birds are more common in the southern parts of the range; pairings of the two color variants do occur. A pale gray variation also exists in western Canada
Western Canada
Western Canada, also referred to as the Western provinces and commonly as the West, is a region of Canada that includes the four provinces west of the province of Ontario.- Provinces :...
and the north-central United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The color variations are referred to as "red morph
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
" and "gray morph" by bird watchers
Birdwatching
Birdwatching or birding is the observation of birds as a recreational activity. It can be done with the naked eye, through a visual enhancement device like binoculars and telescopes, or by listening for bird sounds. Birding often involves a significant auditory component, as many bird species are...
and ornithologists
Ornithology
Ornithology is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds...
.
Breeding
Their breeding habitat is deciduousDeciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
or mixed woods in eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. Usually solitary, they nest in a tree cavity, either natural or excavated by a woodpecker
Woodpecker
Woodpeckers are near passerine birds of the order Piciformes. They are one subfamily in the family Picidae, which also includes the piculets and wrynecks. They are found worldwide and include about 180 species....
; they will also use nesting boxes. The bird doesn't actually build a nest; instead, females lay their eggs directly on the layer of fur and feathers left over from previous meals that lines the bottom of its den. Breeding pairs often return to the same nest year after year.
Eggs are laid every two days and incubation begins after laying of the first egg. The incubation period is about 26 days and the fledging period about 31 days. Females do most of the incubating but males will assist. The male provides most of the food while the female broods the young, and will stockpile food during early stages. Eastern Screech Owls are single brooded, but may re-nest if the first clutch is lost. When the young are small the female tears the food up for them.
Behavior
They 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. Though they generally go unnoticed, these owls are frequently heard calling at night, especially during their spring breeding season. Despite their name, this owl (nor most "screech-owls") doesn't truly screech. The Eastern Screech-Owl's call is a haunting tremoloTremolo
Tremolo, or tremolando, is a musical term that describes various trembling effects, falling roughly into two types. The first is a rapid reiteration...
with a descending, whinny-like quality.
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 predatation. Common predators at screech owl nests including minkMink
There are two living species referred to as "mink": the European Mink and the American Mink. The extinct Sea Mink is related to the American Mink, but was much larger. All three species are dark-colored, semi-aquatic, carnivorous mammals of the family Mustelidae, which also includes the weasels and...
, weasel
Weasel
Weasels are mammals forming the genus Mustela of the Mustelidae family. They are small, active predators, long and slender with short legs....
s, raccoon
Raccoon
Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...
s, skunk
Skunk
Skunks are mammals best known for their ability to secrete a liquid with a strong, foul odor. General appearance varies from species to species, from black-and-white to brown or cream colored. Skunks belong to the family Mephitidae and to the order Carnivora...
s, snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s, crow
Crow
Crows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
s, and blue jay
Blue Jay
The Blue Jay is a passerine bird in the family Corvidae, native to North America. It is resident through most of eastern and central United States and southern Canada, although western populations may be migratory. It breeds in both deciduous and coniferous forests, and is common near and in...
s. Adults have fewer predators but larger species of owl 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
Great Horned Owl
The Great Horned Owl, , also known as the Tiger Owl, is a large owl native to the Americas. It is an adaptable bird with a vast range and is the most widely distributed true owl in the Americas.-Description:...
s, Barred Owl
Barred Owl
The Barred Owl is a large typical owl. It goes by many other names, including eight hooter, rain owl, wood owl, and striped owl, but is probably best known as the hoot owl.-Description:...
s, Long-eared Owl
Long-eared Owl
The Long-eared Owl - Asio otus is a species of owl which breeds in Europe, Asia, and North America. This species is a part of the larger grouping of owls known as typical owls, family Strigidae, which contains most species of owl...
s, Great Gray Owls, Short-eared Owl
Short-eared Owl
The Short-eared Owl is a species of typical owl . In Scotland this species of owl is often referred to as a cataface, grass owl or short-horned hootlet. 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 may...
s and Snowy Owl
Snowy Owl
The Snowy Owl is a large owl of the typical owl family Strigidae. The Snowy Owl was first classified in 1758 by Carolus Linnaeus, the Swedish naturalist who developed binomial nomenclature to classify and organize plants and animals. The bird is also known in North America as the Arctic Owl, Great...
s.
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 Owls. These 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 behind loose boards on buildings, boxcars, or water tanks. They will also roost in dense foliage of trees, usually on a branch next to the trunk, or in dense scrubby brush.Feeding habits
Like most predators, Eastern Screech-Owls are opportunistic hunters. They 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, occasionally hovering 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 will usually be 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 will tend 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 that it can even locate mammals under heavy vegetation or snow. The bird's ears 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.
For the better part of the year, large insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s are favored in their diet, with invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s often comprising more than half of the owls' diet. Some regularly eaten insects include beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
s, cricket
Cricket
Cricket is a bat-and-ball game played between two teams of 11 players on an oval-shaped field, at the centre of which is a rectangular 22-yard long pitch. One team bats, trying to score as many runs as possible while the other team bowls and fields, trying to dismiss the batsmen and thus limit the...
s, grasshopper
Grasshopper
The grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...
s and cicada
Cicada
A cicada is an insect of the order Hemiptera, suborder Auchenorrhyncha , in the superfamily Cicadoidea, with large eyes wide apart on the head and usually transparent, well-veined wings. There are about 2,500 species of cicada around the world, and many of them remain unclassified...
s. Also taken are crayfish
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...
, snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s, spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
s, scorpion
Scorpion
Scorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. They have eight legs and are easily recognized by the pair of grasping claws and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger...
s, and centipede
Centipede
Centipedes are arthropods belonging to the class Chilopoda of the subphylum Myriapoda. They are elongated metameric animals with one pair of legs per body segment. Despite the name, centipedes can have a varying number of legs from under 20 to over 300. Centipedes have an odd number of pairs of...
s. Small mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, ranging in size from shrew
Shrew
A shrew or shrew mouse is a small molelike mammal classified in the order Soricomorpha. True shrews are also not to be confused with West Indies shrews, treeshrews, otter shrews, or elephant shrews, which belong to different families or orders.Although its external appearance is generally that of...
s to rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s, are regular prey and often become the owl's primary prey during winter. Small rodents such as microtine rodents
Arvicolinae
The Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae . Some authorities place the subfamily Arvicolinae in the family Muridae along with all other members of the superfamily Muroidea...
and mice
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
comprise about 67% of mammals taken, although rodents of a similar weight to the owl, such as rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s and squirrel
Squirrel
Squirrels belong to a large family of small or medium-sized rodents called the Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots , flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and Africa and have been introduced to Australia...
s are also taken. Small birds such as chickadee
Chickadee
Chickadee is a group of birds in the Paridae familyChickadee may also refer to:* USS Chickadee , a minesweeper in the United States Navy* Chickadee , a Canadian children's magazine-See also:* Black-capped Chickadee...
s, sparrow
Sparrow
The sparrows are a family of small passerine birds, Passeridae. They are also known as true sparrows, or Old World sparrows, names also used for a genus of the family, Passer...
s and warbler
Warbler
There are a number of Passeriformes called "warblers". They are not particularly closely related, but share some characteristics, such as being fairly small, vocal and insectivorous....
s are the most common avian prey and such species are normally caught directly off of their nocturnal perches or during nocturnal migration. However, much larger avian prey is sometimes caught, including rock pigeon
Rock Pigeon
The Rock Dove or Rock Pigeon, is a member of the bird family Columbidae . In common usage, this bird is often simply referred to as the "pigeon"....
s, northern bobwhite and even ruffed grouse
Ruffed Grouse
The Ruffed Grouse is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is non-migratory.The Ruffed Grouse is frequently referred to as a "partridge"...
(which are heavier than the screech owls). Irregularly, small fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, small snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s, lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s, baby soft-shelled turtles, small frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, toad
Toad
A toad is any of a number of species of amphibians in the order Anura characterized by dry, leathery skin , short legs, and snoat-like parotoid glands...
s, and salamander
Salamander
Salamander is a common name of approximately 500 species of amphibians. They are typically characterized by a superficially lizard-like appearance, with their slender bodies, short noses, and long tails. All known fossils and extinct species fall under the order Caudata, while sometimes the extant...
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.
Parasites
This species is infected by several parasites including Plasmodium elongatum, Plasmodium forresteriPlasmodium 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:...
and Plasmodium gundersi
Plasmodium gundersi
Plasmodium gundersi is a parasite of the genus Plasmodium subgenus Giovannolaia.Like all Plasmodium species P. gundersi has both vertebrate and insect hosts. The vertebrate hosts for this parasite are birds....
.
Subspecies
There are 5 recognized subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
:
- Megascops asio asio (Linnaeus, 1758)
- Megascops asio floridanus (Ridgway, 1874)
- Megascops asio hasbroucki (Ridgway, 1914)
- Megascops asio maxwelliae (Ridgway, 1877)
- Megascops asio mccallii (Cassin, 1854)
In popular culture
The 1992 comedy My Cousin Vinny starring Joe Pesci and Marisa Tomei has a scene with a Screech Owl. During the scene, the owl disturbs the main characters' sleep with its call. The bird's call is not realistically portrayed in the movie; the movie audio has the call as a loud, abrasive "screech".General references
- Owlpages.com description of the eastern screech owl with a map of its range and recordings of its calls
- USGS page for the eastern screech owl
External links
- Eastern Screech Owl - Otus asio - USGS Patuxent Bird Identification InfoCenter
- Eastern Screech Owl Species Account - Cornell Lab of Ornithology
- Eastern Screech Owl - eNature.com
- Eastern Screech Owl Information and Photos - South Dakota Birds and Birding
- Eastern Screech Owl videos, photos & sounds on the Internet Bird Collection
- Eastern Screech-Owl - The Peregrine Fund
- Eastern Screech-Owl - Megascops (Otus) asio
- Eastern Screech-Owl Bird Sound