True owl or Typical owl (family Strigidae) are one of the two generally accepted families of Owls, the other being the barn owls (Tytonidae). The Sibley-Ahlquist taxonomy unites the Caprimulgiformes with the owl order; here, the typical owls are a subfamily Strigidae. This is unsupported by more recent research (see Cypselomorphae for details), but the relationships of the owls in general are still unresolved. This large family comprises around 189 living species in 25 genera. The typical owls have a cosmopolitan distribution and are found on every continent except Antarctica.
Cross sectioned Great Grey Owl specim
en showing the extent of the body
plumage, Zoological Museum, Copenhagen
While typical owls (hereafter referred to simply as owls) vary greatly in size, with the smallest species, the Elf Owl, being a hundred times smaller than the largest, the Eurasian Eagle-Owl and
Blakiston's Fish Owl, owls generally share an extremely similar body plan.[1] They tend to have large heads, short tails, cryptic plumage and round facial discs around the eyes. The family is generally arboreal (with a few exceptions like the Burrowing Owl) and obtain their food on the wing. The wings are large, broad, rounded and long. Like other birds of prey many owl species exhibit reverse sexual dimorphism in size, where females are larger than males (as opposed to the more typical situation in birds where males are larger).[2]
Because of their nocturnal habits they tend not to exhibit sexual dimorphism in their plumage. The feathers are soft and the base of each is downy, allowing for silent flight. The toes and tarsus are feathered in some species, and more so in species at higher latitudes.[3] Numerous species of owl in the genus Glaucidium and the Northern Hawk-Owl have eye patches on the backs of their heads, apparently to convince other birds they are being watched at all times. Numerous nocturnal species have ear-tufts, feathers on the sides of the head that are thought to have a camouflage function, breaking up the outline of a roosting bird. The feathers of the facial disc are arranged in order to increase sound delivered to the ears. Hearing in owls is highly sensitive and the ears are asymmetrical allowing the owl to localise a sound. In addition to hearing owls have massive eyes relative to their body size. Contrary to popular belief, however, owls cannot see well in extreme dark and are able to see fine in the day.[1]
Owls are generally nocturnal
and spend much of the day roosting. They
are often perceived as tame since they will allow people to approach quite closely before taking flight, but they are instead attempting to avoid detection. The cryptic plumage and inconspicuous locations adopted are an effort to avoid predators and mobbing by small birds.
Skeleton of Strigidae. Note the incorrect orientation of the toes; although most birds perch with three toes forward and one back, owls do not. They perch with two toes forward and two back. Mus?um de Toulouse
The nearly 200 extant species are assigned to a number of genera, which are in taxonomic order:
Genus Megascops: screech-owls
, some 20 species
Genus
Otus: scops-owls; probably paraphyletic, about 45 species
Genus Pyrroglaux - Palau Owl
Genus Gymnoglaux - Bare-legged Owl or Cuban Screech-owl
Genus Ptilopsis - white-faced owls, 2 species
Genus Mimizuku - Giant Scops-owl or Mindanao Eagle-owl
Genus Bubo - horned owls, eagle-owls and fish-owls; paraphyletic with Nyctea, Ketupa and Scotopelia, some 25 species
Genus Strix - earless owls, some 15 species
Genus Ciccaba - 4 species
Genus Lophostrix - Crested Owl
Genus Jubula - Maned Owl
Genus Pulsatrix - spectacled owls, 3 species
Genus Surnia - Northern Hawk-Owl
Tawny Owl
Genus Glaucidium - pygmy owls, about 30-35 species
Genus Xenoglaux - Long-whiskered Owlet
Genus Micrathene - Elf Owl
Genus Athene - 2-4 species (depending on whether Speotyto and Heteroglaux are included or not)
Genus Aegolius - saw-whet owls, 4 species
Genus Ninox - Australasian hawk-owls, some 20 species
Genus Uroglaux - Papuan Hawk-owl
Genus Pseudoscops - Jamaican Owl and possibly Striped Owl
Genus Asio - eared owls, 6-7 species
Genus Nesasio - Fearful Owl
Recently extinct
Genus Mascarenotus - Mascarene owls, 3 species (extinct c.1850)
Genus Sceloglaux - Laughing Owl (extinct 1914?)
Late Quaternary prehistoric extinctions
Genus Grallistrix - Stilt-owls, 4 species
Kaua?i Stilt-owl,
Grallistrix auceps
Maui Stilt-owl, Grallistrix erdmani
Moloka?i Stilt-owl, Grallistrix geleches
O?ahu Stilt-owl, Grallistrix orion
Genus Ornimegalonyx - Caribbean giant owls, 1-2 species
Cuban Giant Owl, Ornimegalonxy oteroi
Ornimegalonyx sp. - probably subspecies of O. oteroi
Fossil record
Mioglaux (Late Oligocene? - Early Miocene of WC Europe) - includes "Bubo" poirreiri
Intutula (Early/Middle Miocene of WC Europe) - includes "Strix/Ninox" brevis
Alasio (Middle Miocene of Vieux-Collonges, France) - includes "Strix" collongensis
Placement unresolved:
"Otus/Strix" wintershofensis - fossil (Early/Middle Miocene of Wintershof West, Germany) - may be close to extant genus Ninox (Olson 1985:131)
"Strix" edwardsi - fossil
(Middle Miocene of Grive-Saint-Alban, France)
"Asio" pygmaeus - fossil (Early Pliocene of Odessa, Ukraine)
Strigidae gen. et sp. indet. UMMP V31030 (Rexroad Late Pliocene of Kansas, USA) - Strix/Bubo? (Feduccia 1970)
Ibiza Owl, Strigidae gen. et sp. indet. - prehistoric (Late Pleistocene/Holocene of Es Pou?s, Ibiza) - see S?nchez Marco 2004
The supposed fossil heron "Ardea" lignitum (Late Pliocene of Germany) was apparently a strigid owl, possibly close to Bubo (Olson 1985:167). The Early?Middle Eocene genus Palaeoglaux from west-central Europe is sometimes placed here, but given its age it is probably better considered its own family for the time being.
ctioned Great Grey Owl specimen showing the extent of the body plumage, Zoological Museum, Copenhagen
While typical owls (hereafter referred to simply as owls) vary greatly in size, with the smallest species, the Elf Owl, being a
hundred times smaller than the largest, the Eurasian Eagle-Owl and Blakiston's
Fish Owl, owls generally share an extremely similar body plan.[1] They tend to have large heads, short tails, cryptic plumage and round facial discs around the eyes. The family is generally arboreal (with a few exceptions like the Burrowing Owl) and obtain their food on the wing. The wings are large, broad, rounded and long. Like other birds of prey many owl species exhibit reverse sexual dimorphism in size, where females are larger than males (as opposed to the more typical situation in birds where males are larger).[2]
Because of their nocturnal habits they tend not to exhibit sexual dimorphism in their plumage. The feathers are soft and the base of each is downy, allowing for silent flight. The toes and tarsus are feathered in some species, and more so in species at higher latitudes.[3] Numerous species of owl in the genus Glaucidium and the Northern Hawk-Owl have eye patches on the backs of their heads, apparently to convince other birds they are being watched at all times. Numerous nocturnal species have ear-tufts, feathers on the sides of the head that are thought to have a camouflage function, breaking up the outline of a roosting bird. The feathers of the facial disc are arranged in order to increase sound delivered to the ears. Hearing in owls is highly sensitive and the ears are asymmetrical allowing the owl to localise a sound. In addition to hearing owls have massive eyes relative to their body size. Contrary to popular belief, however, owls cannot see well in extreme dark and are able to see fine in the day.[1]
Owls are generally nocturnal and spend much of the day roostin
g. They are often perceived as tame since
they will allow people to approach quite closely before taking flight, but they are instead attempting to avoid detection. The cryptic plumage and inconspicuous locations adopted are an effort to avoid predators and mobbing by small birds.
Skeleton of Strigidae. Note the incorrect orientation of the toes; although most birds perch with three toes forward and one back, owls do not. They perch with two toes forward and two back. Mus?um de Toulouse
The nearly 200 extant species are assigned to a number of genera, which are in taxonomic order:
Genus Megascops: screech-owls, some 20 species
Genus Otus: scops-owls; probably
paraphyletic, about 45 species
Genus Pyrroglaux - Palau Owl
Genus Gymnoglaux - Bare-legged Owl or Cuban Screech-owl
Genus Ptilopsis - white-faced owls, 2 species
Genus Mimizuku - Giant Scops-owl or Mindanao Eagle-owl
Genus Bubo - horned owls, eagle-owls and fish-owls; paraphyletic with Nyctea, Ketupa and Scotopelia, some 25 species
Genus Strix - earless owls, some 15 species
Genus Ciccaba - 4 species
Genus Lophostrix - Crested Owl
Genus Jubula - Maned Owl
Genus Pulsatrix - spectacled owls, 3 species
Genus Surnia - Northern Hawk-Owl
Tawny
Owl
Genus Glaucidium - pygmy owls, about 30-35 species
Genus Xenoglaux - Long-whiskered Owlet
Genus Micrathene - Elf Owl
Genus Athene - 2-4 species (depending on whether Speotyto and Heteroglaux are included or not)
Genus Aegolius - saw-whet owls, 4 species
Genus Ninox - Australasian hawk-owls, some 20 species
Genus Uroglaux - Papuan Hawk-owl
Genus Pseudoscops - Jamaican Owl and possibly Striped Owl
Genus Asio - eared owls, 6-7 species
Genus Nesasio - Fearful Owl
Recently extinct
Genus Mascarenotus - Mascarene owls, 3 species (extinct c.1850)
Genus Sceloglaux - Laughing Owl (extinct 1914?)
Late Quaternary prehistoric extinctions
Genus Grallistrix - Stilt-owls, 4 species
Kaua?i Stilt-owl, Grallistrix
auceps
Maui Stilt-owl, Grallistrix erdmani
Moloka?i Stilt-owl, Grallistrix geleches
O?ahu Stilt-owl, Grallistrix orion
Genus Ornimegalonyx - Caribbean giant owls, 1-2 species
Cuban Giant Owl, Ornimegalonxy oteroi
Ornimegalonyx sp. - probably subspecies of O. oteroi
Fossil record
Mioglaux (Late Oligocene? - Early Miocene of WC Europe) - includes "Bubo" poirreiri
Intutula (Early/Middle Miocene of WC Europe) - includes "Strix/Ninox" brevis
Alasio (Middle Miocene of Vieux-Collonges, France) - includes "Strix" collongensis
Placement unresolved:
"Otus/Strix" wintershofensis - fossil (Early/Middle Miocene of Wintershof West, Germany) - may be close to extant genus Ninox (Olson 1985:131)
"Strix" edwardsi - fossil (Middle Miocene of
Grive-Saint-Alban, France)
"Asio" pygmaeus - fossil (Early Pliocene of Odessa, Ukraine)
Strigidae gen. et sp. indet. UMMP V31030 (Rexroad Late Pliocene of Kansas, USA) - Strix/Bubo? (Feduccia 1970)
Ibiza Owl, Strigidae gen. et sp. indet. - prehistoric (Late Pleistocene/Holocene of Es Pou?s, Ibiza) - see S?nchez Marco 2004
The supposed fossil heron "Ardea" lignitum (Late Pliocene of Germany) was apparently a strigid owl, possibly close to Bubo (Olson 1985:167). The Early?Middle Eocene genus Palaeoglaux from west-central Europe is sometimes placed here, but given its age it is probably better considered its own family for the time being.
^ ab J. S. Marks, R. J. Cannings
& H. Mikkola (1999) "Family Strigidae (Typical Owls)". In del Hoyo, J.; Elliot, A. & Sargatal, J. (editors). (1999). Handbook of the Birds of the World. Volume 5: Barn-Owls to Hummingbirds. Lynx Edicions. ISBN 84-87334-25-3
^ Caroline M. Earhart and Ned K. Johnson (1970) "Size Dimorphism and Food Habits of North American Owls" Condor72 (3): 251-264
^ Kelso L & Kelso E (1936) "The Relation of Feathering of Feet of American Owls to Humidity of Environment and to Life Zones" Auk53 (1): 51-56
Feduccia, J. Alan (1970): Some birds of prey from the Upper Pliocene of Kansas. Auk87(4): 795-797. PDF fulltext
Olson, Storrs L. (1985): The fossil record of birds. In: Farner, D.S.; King, J.R. & Parkes,
Kenneth C. (eds.): Avian Biology8: 79-238. Academic Press, New York.
S?nchez Marco, Antonio (2004): Avian zoogeographical patterns during the Quaternary in the Mediterranean region and paleoclimatic interpretation. Ardeola51(1): 91-132. PDF fulltext
Aegolius is a small genus of owls. Three of the species are restricted to the New World, but th Boreal Owl has a circumpolar range through North America, Eurasia, the Alps and the Rockies. [more]
Asio
Asio is a genus of typical owls, or true owls, in family Strigidae. The genus Asio contains the eared owls, which are characterised by feather tufts on the head which have the appearance of ears. This group has representatives over most of the planet, and the Short-eared Owl is one of the most widespread of all bird species, breeding in Europe, Asia, North and South America, the Caribbean, Hawaii and the Gal?pagos Islands. Its geographic range extends to all continents except Antarctica and Australia. [more]
Athene
In Greek religion and mythology, Athena or Athene ( or /?'?i?ni?/; Attic: ?????, Athena or ????a?a, Athenaia; Epic: ????a??, Athenaie; Ionic: ?????, Athene; Doric: ????a, Athana), also referred to as Pallas Athena/Athene ( /'p?l?s/; ?a???? ?????; ?a???? ?????), is the goddess of wisdom, courage, inspiration, civilization, law and justice, just warfare, mathematics, strength, strategy, the arts, crafts, and skill. Minerva, Athena's Roman incarnation, embodies similar attributes. Athena is also a shrewd companion of heroes and is the goddess of heroic endeavour. She is the virgin patron of Athens. The Athenians founded the Parthenon on the Acropolis of her namesake city, Athens (Athena Parthenos), in her honour. [more]
Athenes
Athens (; Modern Greek: ????a, Ath?na, IPA: [a'?ina], Katharevousa: ????a?, Athine, Ancient Greek: ????a?, Athenai), is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, as its recorded history spans around 3,400 years. Classical Athens was a powerful city-state. A centre for the arts, learning and philosophy, home of Plato's Academy and Aristotle's Lyceum, it is widely referred to as the cradle of Western civilization and the birthplace of democracy, largely due to the impact of its cultural and political achievements during the 5th and 4th centuries BC on the rest of the then known European continent. Today a cosmopolitan metropolis, modern Athens is central to economic, financial, industrial, political and cultural life in Greece. In 2008, Athens was ranked the world's 32nd richest city by purchasing power and the 25th most expensive in a UBS study. [more]
The Bare-legged Owl or Cuban Screech Owl (Gymnoglaux lawrencii) is a species of owl in the Strigidae family that is endemic to Cuba. It belongs to the monotypic genus Gymnoglaux. Its natural habitats are dry forests, lowland moist forests, and heavily degraded former forest. It lives in the canopy of the forests where it does most of its foraging. [more]
Ketupa is a genus of owls in the Strigidae family. The genus should arguably be merged with Bubo.They are fishing owls. [more]
Lophostrix
The Crested Owl (Lophostrix cristata) is a species of owl in the family Strigidae. It is the only species (monotypic), in the genus Lophostrix. [more]
Mascarenotus
The Mascarene owls form a distinct (Mascarenotus) of owls. The three species, the Réunion Owl, Mauritius Owl, and Rodrigues Owl, are all extinct. [more]
Megascops
Screech owls or Screech-owls are typical owls (Strigidae) 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. For most of the 20th century, this genus was merged with the Old World scops owls in Otus, but nowadays it is again considered separate based on a range of behavioral, biogeographical, morphological and DNA sequence data. [more]
Micrathene
The Elf Owl (Micrathene whitneyi) is a member of the owl family Strigidae that breeds in the southwestern United States and Mexico. It is the world's lightest owl, although the Long-whiskered Owlet and the Tamaulipas Pygmy Owl are of a similarly diminutive length. The mean body weight of this species is 40 grams (1.4 oz). These tiny owls are 12.5 to 14.5 cm (4.7-5.5 in) long and have a wingspan of about 27 cm (10.6 in). Their primary projection extends nearly past their tail. They have fairly long legs and often appear bow-legged. They can often be heard calling to one another just after dusk or at sunset. Their call is a high-pitched whinny or chuckle. The male and female dart around trees and call back and forth. [more]
The Giant Scops Owl, Lesser Eagle-Owl, or Mindanao Eagle-Owl (Mimizuku gurneyi) is a species of owl in the Strigidae family. Originally described as Pseudoptynx gurneyi, it is now a only species in the genus Mimizuku. [more]
Nesasio
The Fearful Owl (Nesasio solomonensis) is a medium-sized owl endemic to the Solomon Islands and Bougainville in Papua New Guinea. It is generally seen no more than 800 meters above sea level, where it is found in tall lowland or hill forests. It nests in tree holes and cracks. [more]
Ninox
Ninox is a genus of owls comprising about 20 species found in Asia and Australasia. Many species are known as hawk owls or boobooks. Note that the Northern Hawk-Owl Surnia ulula is not a member of this genus. [more]
The Snowy Owl (Bubo scandiacus) 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 White Owl or Harfang. Until recently, it was regarded as the sole member of a distinct genus, as Nyctea scandiaca, but mtDNA cytochrome b sequence data (Olsen et al. 2002) shows that it is very closely related to the horned owls in the genus Bubo. The Snowy Owl is the official bird of Quebec. [more]
The Jamaican Owl (Pseudoscops grammicus) is a medium-sized tawny colored that is endemic to the island of Jamaica. It is considered by some the only member if its genus Pseudoscops, while other authorities include in it the Striped Owl. It has dark brown barring, flecking and streaks and its amber facial disk is rimmed in black-flecked white. It has hazel eyes, long ear tufts and a grayish-yellow bill. It mainly uses open habitats with scattered clumps of trees, generally in lowlands. It is nocturnal and eats mainly large insects, spiders, amphibians, lizards, birds and rodents. It lays its eggs in tree cavities. This species is common and widespread throughout its limited range, but some populations are at risk from habitat loss. [more]
Ptilopsis
Ptilopsis is a genus of African owls. Its members are: [more]
Pulsatrix
Pulsatrix is a genus of in the Strigidae family. They are called spectacled owls because of their prominent facial pattern. [more]
The Laughing Owl (Sceloglaux albifacies), also known as Whekau or the White-faced Owl, was an endemic owl found in New Zealand, but is now extinct. It was plentiful when European settlers arrived in New Zealand in 1840. Specimens were sent to the British Museum, where a scientific description was published in 1845. The species belongs to the monotypic genus Sceloglaux ("scoundrel owl", probably because of the mischievous-sounding calls). [more]
The Papuan Hawk Owl, Uroglaux dimorpha is a medium-sized, sleek with a porportionately small head, long tail, and short, rounded wings. Its white facial disk is small and indistinct, with black streaks, and white eyebrows. It has buff colored upperparts and barred black and brown underparts. Its eyes are bright yellow, and it has a gray to black bill. [more]
Xenoglaux
The Long-whiskered Owlet (Xenoglaux loweryi) is a tiny owl that is endemic to a small area in the Andean mountains in Amazonas and San Mart?n in northern Peru. It is restricted to cloud forests with dense undergrowth and epiphytes at about 1890?2200 meters (6200?7220 ft) above sea level. [more]
More info about the Genus Xenoglaux may be found here.
^ ab J. S. Marks, R. J. Cannings & H. Mikkola (1999) "Family Strigidae (Typical Owls)". In del Hoyo, J.; Elliot, A. & Sargatal, J. (editors). (1999). Handbook of the Birds of the World. Volume 5: Barn-Owls to Hummingbirds. Lynx Edicions. ISBN 84-87334-25-3
^ Caroline M. Earhart and Ned K. Johnson (1970) "Size Dimorphism and Food Habits of North American Owls" Condor72 (3): 251-264
^ Kelso L & Kelso E (1936) "The Relation of Feathering of Feet of American Owls to Humidity of Environment and to Life Zones" Auk53 (1): 51-56
/'p?l?s/; ?a???? ?????; ?a???? ?????), is the goddess of wisdom, courage, inspiration, civilization, law and justice, just warfare, mathematics, strength, strategy, the arts, crafts, and skill. Minerva, Athena's Roman incarnation, embodies similar attributes. Athena is also a shrewd companion of heroes and is the goddess of heroic endeavour. She is the virgin patron of Athens. The Athenians founded the Parthenon on the Acropolis of her namesake city, Athens (Athena Parthenos), in her honour.