Tytonidae
Encyclopedia
Barn-owls are one of the two families
of owls, the other being the true owls, Strigidae. They are medium to large sized owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerful talon
s. They also differ from Strigidae in structural details relating in particular to the sternum and feet.
The barn owls comprise two extant sub-families: the Tytoninae or Tyto owls (including the Common Barn Owl
) and the Phodilinae or bay-owls. The Sibley-Ahlquist taxonomy
unites the Caprimulgiformes
with the owl order
; here, the barn-owls are a subfamily Tytoninae. This is unsupported by more recent research (see Cypselomorphae
), but the relationships of the owls in general are still unresolved.
The barn owls are a wide ranging family, absent from northern North America
, Sahara
n Africa and large areas of Asia
. They live in a wide range of habitats from desert
s to forest
s, and from temperate
latitudes to the tropics
. The majority of the 16 living species of barn owls are poorly known. Some, like the Madagascar Red Owl
, have barely been seen or studied since their discovery, in contrast to the Common Barn Owl, which is one of the best known owl species in the world. However, some sub-species of the Common Barn Owl possibly deserve to be a separate species, but are very poorly known.
Five species of barn-owl are threatened, and some island species have gone extinct during the Holocene
or earlier (e.g. Tyto pollens
, known from the fossil record of Andros Island in the Bahamas, and possibly the basis for the Chickcharnie). The barn-owls are mostly nocturnal, and generally non-migratory
, living in pairs or singly.
, formed by stiff feather
s which serve to amplify and locate the source of sounds when hunting. Further adaptations in the wing feathers eliminate sound caused by flying, aiding both the hearing of the owl listening for hidden prey and keeping the prey unaware of the owl. Barn-owls overall are darker on the back than the front, usually an orange-brown colour, the front being a paler version of the back or mottled, although there is considerable variation even amongst species. The bay-owls closely resemble the Tyto owls but have a divided facial disc, ear tufts, and tend to be smaller.
, with the family eventually losing ground to the true owls after the radiation of rodent
s and owls during the Neogene
epoch. Two subfamilies are only known from the fossil record, the Necrobyinae and the Selenornithinae. Numerous extinct species of Tyto have been described; see the genus page for more information.
Genus Tyto
Lesser Sooty-owl
, T. multipunctata
Australian Masked Owl, T. novaehollandiae
Golden Masked Owl, T. aurantia
Lesser Masked Owl, T. sororcula
Manus Masked Owl
, T. manusi
Taliabu Masked Owl, T. nigrobrunnea
Minahassa Masked Owl, T. inexspectata
Sulawesi Owl
, T. rosenbergii
Barn Owl
, T. alba
Ashy-faced Owl
, T. glaucops
Madagascar Red Owl
T. soumagnei
African Grass Owl T. capensis
Australasian Grass Owl T. longimembris
Genus Phodilus
Fossil
genera
Placement unresolved
Placement of the Late Eocene/Early Oligocene genera Palaeotyto and Palaeobyas from Quercy (France) in this family is tentative; they might belong to the Sophiornithidae
instead.
The supposed "giant barn-owl" Basityto from the Early Eocene of Grafenmühle (Germany) was actually a crowned crane
(Balearica); the presumed "Easter Island Barn-owl", based on subfossil
bones found on Rapa Nui, has turned out to be some procellarid
(Steadman, 2006).
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of owls, the other being the true owls, Strigidae. They are medium to large sized owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerful talon
Talon
A talon is a sharp claw of an animal, especially a bird of prey, such as the eagle, hawk, falcon, owl, or buzzard. It may also refer to:Places:* Talon, Nièvre, a commune in the Nièvre département in France...
s. They also differ from Strigidae in structural details relating in particular to the sternum and feet.
The barn owls comprise two extant sub-families: the Tytoninae or Tyto owls (including the Common Barn Owl
Barn Owl
The Barn Owl is the most widely distributed species of owl, and one of the most widespread of all birds. It is also referred to as Common Barn Owl, to distinguish it from other species in the barn-owl family Tytonidae. These form one of two main lineages of living owls, the other being the typical...
) and the Phodilinae or bay-owls. The Sibley-Ahlquist taxonomy
Sibley-Ahlquist taxonomy
The Sibley-Ahlquist taxonomy is a bird taxonomy proposed by Charles Sibley and Jon Edward Ahlquist. It is based on DNA-DNA hybridization studies conducted in the late 1970s and throughout the 1980s....
unites the Caprimulgiformes
Caprimulgiformes
The Caprimulgiformes is an order of birds that includes a number of birds with global distribution . They are generally insectivorous and nocturnal...
with the owl order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
; here, the barn-owls are a subfamily Tytoninae. This is unsupported by more recent research (see Cypselomorphae
Cypselomorphae
Cypselomorphae is a clade of birds. It includes the living families and orders Caprimulgidae , Nyctibiidae , Apodiformes , as well as the Aegotheliformes whose distinctness was only recently realized...
), but the relationships of the owls in general are still unresolved.
The barn owls are a wide ranging family, absent from northern 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...
, Sahara
Sahara
The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...
n Africa and large areas of Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. They live in a wide range of habitats from desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
s to forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s, and from temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
latitudes to the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
. The majority of the 16 living species of barn owls are poorly known. Some, like the Madagascar Red Owl
Madagascar Red Owl
The Madagascar Red Owl, Tyto soumagnei, is an owl in the barn owl family Tytonidae. It is also known as the Madagascar Grass-owl and Soumange's Owl. It is a rare resident of Madagascar that was virtually unknown from its discovery in 1878 to its rediscovery by researchers from the World Wide Fund...
, have barely been seen or studied since their discovery, in contrast to the Common Barn Owl, which is one of the best known owl species in the world. However, some sub-species of the Common Barn Owl possibly deserve to be a separate species, but are very poorly known.
Five species of barn-owl are threatened, and some island species have gone extinct during the Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
or earlier (e.g. Tyto pollens
Tyto pollens
Tyto pollens, also known as Andros Island Barn Owl, Bahamian Barn Owl, Bahamian Great Owl, or "Chickcharnie," was a , flightless barn owl that lived in the old-growth pineyards of Andros Island...
, known from the fossil record of Andros Island in the Bahamas, and possibly the basis for the Chickcharnie). The barn-owls are mostly nocturnal, and generally non-migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, living in pairs or singly.
Description
The barn-owls' main characteristic is the heart-shaped facial discFacial disc
In ornithology, the facial disc is the concave collection of feathers on the face of some birds—most notably owls—surrounding the eyes. The concavity of the facial disc forms a circular paraboloid that collects sound waves and directs those waves towards the owl's ears...
, formed by stiff feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
s which serve to amplify and locate the source of sounds when hunting. Further adaptations in the wing feathers eliminate sound caused by flying, aiding both the hearing of the owl listening for hidden prey and keeping the prey unaware of the owl. Barn-owls overall are darker on the back than the front, usually an orange-brown colour, the front being a paler version of the back or mottled, although there is considerable variation even amongst species. The bay-owls closely resemble the Tyto owls but have a divided facial disc, ear tufts, and tend to be smaller.
Species
The fossil record of the barn-owls goes back to the EoceneEocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
, with the family eventually losing ground to the true owls after the radiation of rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s and owls during the Neogene
Neogene
The Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago...
epoch. Two subfamilies are only known from the fossil record, the Necrobyinae and the Selenornithinae. Numerous extinct species of Tyto have been described; see the genus page for more information.
Genus Tyto
Tyto
The genus Tyto includes all barn owls except for the bay owls - that is, the true barn owls, the grass owls and the masked owls collectively making up the subfamily Tytoninae...
- Greater Sooty-owl,
Lesser Sooty-owl
The Lesser Sooty Owl lives in the wet tropics region of Australia. Like other birds of prey the female is bigger than the male . The Lesser Sooty Owl is part of the masked group of owls an important part of the environment because they are efficient predators that keep down rodent populations...
,
- Cave-nesting Masked Owl,
- Buru Masked Owl,
Manus Masked Owl
The Manus Masked Owl is a barn owl endemic to Manus Island in Admiralty Islands, Papua New Guinea. Some authors consider it a subspecies of Australian Masked Owl ....
,
Sulawesi Owl
The Sulawesi Masked Owl is a species of owl in the Tytonidae family. It is endemic to Indonesia.-References:* BirdLife International 2004. . Downloaded on 24 July 2007....
,
- Peleng Masked Owl,
Barn Owl
The Barn Owl is the most widely distributed species of owl, and one of the most widespread of all birds. It is also referred to as Common Barn Owl, to distinguish it from other species in the barn-owl family Tytonidae. These form one of two main lineages of living owls, the other being the typical...
,
- Eastern Barn Owl,
Ashy-faced Owl
The Ashy-faced Owl is a species of owl in the Tytonidae family.It is found in the Dominican Republic and Haiti.Its natural habitats are subtropical or tropical dry shrubland, subtropical or tropical high-altitude shrubland, and heavily degraded former forest.- References :* BirdLife International...
,
Madagascar Red Owl
The Madagascar Red Owl, Tyto soumagnei, is an owl in the barn owl family Tytonidae. It is also known as the Madagascar Grass-owl and Soumange's Owl. It is a rare resident of Madagascar that was virtually unknown from its discovery in 1878 to its rediscovery by researchers from the World Wide Fund...
Genus Phodilus
Bay Owl
The bay owls are barn owls of the genus Phodilus, subfamily Phodilinae. Most classification schemes recognize two species in this genus: the Oriental Bay Owl and the Congo Bay Owl ....
- Oriental Bay OwlOriental Bay OwlThe Oriental Bay Owl is a type of owl, usually classified with barn owls. It is completely nocturnal, and can be found throughout Southeast Asia. It has several subspecies. It has a heart-shaped face with earlike extensions...
P. badius- Samar Bay Owl P. (badius) riverae
- Congo Bay OwlCongo Bay OwlThe Congo Bay-owl is a species of owl in the Tytonidae family. It is restricted to a small area in the east of the Democratic Republic of the Congo with possible records from Burundi and Rwanda....
, P. prigoginei - sometimes placed in Tyto
Fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
genera
- Nocturnavis (Late Eocene/Early Oligocene) - includes "Bubo" incertus
- Necrobyas (Late Eocene/Early Oligocene - Late Miocene) - includes "Bubo" arvernensis and Paratyto
- Selenornis (Late Eocene/Early Oligocene of Quercy, France) - includes "Asio" henrici
- Prosybris (Late Eocene/Early Oligocene of Quercy? - Early Miocene of France)
Placement unresolved
- Tytonidae gen. et sp. indet. "TMT 164" (Middle Miocene of Grive-Saint-Alban, France) - Prosybris?
Placement of the Late Eocene/Early Oligocene genera Palaeotyto and Palaeobyas from Quercy (France) in this family is tentative; they might belong to the Sophiornithidae
Sophiornithidae
Sophiornithidae , was a family of chicken-sized predatory birds that lived from the Paleocene to the Eocene periods of the Cenozoic, and were found primarily in Europe, and are thought to be primitive owls...
instead.
The supposed "giant barn-owl" Basityto from the Early Eocene of Grafenmühle (Germany) was actually a crowned crane
Crowned Crane
Crowned Crane may refer to:*Black Crowned Crane *Grey Crowned Crane *Red-crowned Crane or Japanese Crane...
(Balearica); the presumed "Easter Island Barn-owl", based on subfossil
Subfossil
Subfossil refers to remains whose fossilization process is not complete, either for lack of time or because the conditions in which they were buried were not optimal for fossilization....
bones found on Rapa Nui, has turned out to be some procellarid
Procellariidae
The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes , which also includes the albatrosses, the storm-petrels, and the diving petrels.The procellariids are...
(Steadman, 2006).
External links
- Barn-Owls on the Internet Bird Collection