Owlet-nightjar
Encyclopedia
Owlet-nightjars are small nocturnal bird
s related to the nightjar
s and frogmouth
s. Most are native to New Guinea
, but some species extend to Australia
, the Moluccas, and New Caledonia
. A New Zealand
species is extinct. There is a single monotypic
family
Aegothelidae with the genus
Aegotheles.
Owlet-nightjars are insectivore
s which hunt mostly in the air but sometimes on the ground; their soft plumage is a crypic mixture of browns and paler shades, they have fairly small, weak feet (but larger and stronger than those of a frogmouth or a nightjar), a tiny bill that opens extraordinarily wide, surrounded by prominent whiskers. The wings are short, with 10 primaries and about 11 secondaries; the tail long and rounded.
Cytochrome b
and ATPase
subunit 8 suggests that 11 living species of owlet-nightjar should be recognized, plus one that went extinct early in the second millennium AD.
The relationship between the owlet-nightjars and the (traditional) Caprimulgiformes
has long been controversial and obscure and remains so today: in the 19th century they were regarded as a subfamily of the frogmouth
s, and they are still generally considered to be related to the frogmouths and/or the nightjar
s. It appears though that that they are not so closely related to either as previously thought, and that the owlet-nightjars share a more recent common ancestor with the Apodiformes
. As has been suggested on occasion since morphological
studies of the cranium in the 1960s, they are thus considered a distinct order
, Aegotheliformes. This, the caprimulgiform lineage(s), and the Apodiformes, are postulated to form a clade
called Cypselomorphae
, with the owlet-nightjars and the Apodiformes forming the clade Daedalornithes.
In form and habits, however, they are very similar to both caprimulgiform group - or, at first glance, to small owl
s with huge eyes. Interestingly, the ancestors of the swifts and hummingbirds, two groups of birds which are morphologically very specialized, seem to have looked very similar to a small owlet-nightjar, possessing strong legs and a wide gape, while the legs and feet are very reduced in today's swifts and hummingbirds, and the bill is narrow in the latter.
They are an exclusively Australasian group, but close relatives apparently occurred all over Eurasia
in the late Paleogene
.
A fossil
proximal right tarsometatarsus
(MNZ S42800) was found at the Manuherikia River
in Otago
, New Zealand
. Dating from the Early to Middle Miocene
(Awamoan to Lillburnian, 19-16 million years ago), it seems to be of an owlet-nightjar ancestral to A. novaezealandiae.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s related to the nightjar
Nightjar
Nightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats . Some New World species are named as nighthawks...
s and frogmouth
Frogmouth
The frogmouths are a group of nocturnal birds related to the nightjars. They are found from India across southern Asia to Australia.They are named for their large flattened hooked bills and huge frog-like gape, which they use to capture insects. Their flight is weak.They rest horizontally on...
s. Most are native to New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, but some species extend to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, the Moluccas, and New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
. A New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
species is extinct. There is a single monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
family
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...
Aegothelidae with the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Aegotheles.
Owlet-nightjars are insectivore
Insectivore
An insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures. An alternate term is entomophage, which also refers to the human practice of eating insects....
s which hunt mostly in the air but sometimes on the ground; their soft plumage is a crypic mixture of browns and paler shades, they have fairly small, weak feet (but larger and stronger than those of a frogmouth or a nightjar), a tiny bill that opens extraordinarily wide, surrounded by prominent whiskers. The wings are short, with 10 primaries and about 11 secondaries; the tail long and rounded.
Systematics
The comprehensive 2003 study analyzing mtDNA sequencesDNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
Cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...
and ATPase
ATPase
ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur...
subunit 8 suggests that 11 living species of owlet-nightjar should be recognized, plus one that went extinct early in the second millennium AD.
The relationship between the owlet-nightjars and the (traditional) Caprimulgiformes
Caprimulgiformes
The Caprimulgiformes is an order of birds that includes a number of birds with global distribution . They are generally insectivorous and nocturnal...
has long been controversial and obscure and remains so today: in the 19th century they were regarded as a subfamily of the frogmouth
Frogmouth
The frogmouths are a group of nocturnal birds related to the nightjars. They are found from India across southern Asia to Australia.They are named for their large flattened hooked bills and huge frog-like gape, which they use to capture insects. Their flight is weak.They rest horizontally on...
s, and they are still generally considered to be related to the frogmouths and/or the nightjar
Nightjar
Nightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats . Some New World species are named as nighthawks...
s. It appears though that that they are not so closely related to either as previously thought, and that the owlet-nightjars share a more recent common ancestor with the Apodiformes
Apodiformes
Traditionally, the bird order Apodiformes contained three living families: the swifts , the tree swifts , and the hummingbirds . In the Sibley-Ahlquist taxonomy, this order is raised to a superorder Apodimorphae in which hummingbirds are separated as a new order, Trochiliformes...
. As has been suggested on occasion since morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
studies of the cranium in the 1960s, they are thus considered a distinct 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...
, Aegotheliformes. This, the caprimulgiform lineage(s), and the Apodiformes, are postulated to form a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
called 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...
, with the owlet-nightjars and the Apodiformes forming the clade Daedalornithes.
In form and habits, however, they are very similar to both caprimulgiform group - or, at first glance, to small owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s with huge eyes. Interestingly, the ancestors of the swifts and hummingbirds, two groups of birds which are morphologically very specialized, seem to have looked very similar to a small owlet-nightjar, possessing strong legs and a wide gape, while the legs and feet are very reduced in today's swifts and hummingbirds, and the bill is narrow in the latter.
They are an exclusively Australasian group, but close relatives apparently occurred all over Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
in the late Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
.
Species
FAMILY: AEGOTHELIDAE- Genus Quipollornis (fossilFossilFossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
; Early/Middle Miocene of New South Wales) - Genus Aegotheles
- New Zealand Owlet-nightjarNew Zealand Owlet-nightjarThe New Zealand Owlet-nightjar, Aegotheles novazelandiae, was a large species of owlet-nightjar formerly endemic to the islands of New Zealand. Fossil remains indicate the species was once widespread across both North Island and South Island...
, Aegotheles novaezealandiae (prehistoricLate Quaternary prehistoric birdsPrehistoric birds are various taxa of birds that became extinct before recorded history, or more precisely, before they could be studied alive by bird scientists...
; formerly Megaegotheles) - New Caledonian Owlet-nightjarNew Caledonian Owlet-nightjarThe New Caledonian Owlet-nightjar Aegotheles savesi, also known as the Enigmatic Owlet-nightjar, is a large owlet-nightjar with vermiculated grey-brown and black plumage. It has a long, slightly rounded tail, short, rounded wings, and long, stout legs. Its voice is unknown but similar birds make...
, Aegotheles savesi - Feline Owlet-nightjarFeline Owlet-nightjarThe Feline Owlet-nightjar is a species of bird in the Aegothelidae family.It is found in Indonesia and Papua New Guinea.Its natural habitat is subtropical or tropical moist montanes.-References:...
, Aegotheles insignis - Starry Owlet-nightjarStarry Owlet-nightjarThe Spangled Owlet-Nightjar , also known as the Starry Owlet-nightjar, is a species of bird in the Aegothelidae family. It is endemic to Papua New Guinea. Its natural habitat is subtropical or tropical moist lowland forests It is threatened by habitat loss.-Source:* BirdLife International 2004. ...
or Spangled Owlet-nightjar, Aegotheles tatei - Long-whiskered Owlet-nightjarLong-whiskered Owlet-nightjarThe Moluccan Owlet-nightjar , also known as the Long-whiskered Owlet-nightjar, is a species of bird in the Aegothelidae family. It is endemic to Indonesia....
or Moluccan Owlet-nightjar, Aegotheles crinifrons - Australian Owlet-nightjarAustralian Owlet-nightjarThe Australian Owlet-nightjar, Aegotheles cristatus, is a nocturnal bird found in open woodland across Australia and in southern New Guinea. It is colloquially known as "Moth Owl". It is the most common of the owlet-nightjars, and the best known of this secretive family...
, Aegotheles cristatus - Barred Owlet-nightjarBarred Owlet-nightjarThe Barred Owlet-nightjar is a species of bird in the Aegothelidae family.It is found in Indonesia and Papua New Guinea.Its natural habitat is subtropical or tropical moist lowland forests.It has a spotted belly....
, Aegotheles bennettii- Upland Barred Owlet-nightjar, Aegotheles (bennettii) affinis
- Wallace's Owlet-nightjarWallace's Owlet-nightjarThe Wallace's Owlet-nightjar is a species of bird in the Aegothelidae family.It is found in Indonesia and Papua New Guinea.-Source:* BirdLife International 2004. . Downloaded on 24 July 2007....
, Aegotheles wallacii - Archbold's Owlet-nightjarArchbold's Owlet-nightjarThe Archbold's Owlet-nightjar is a species of bird in the Aegothelidae family. It is found in West Papua, Indonesia and Papua New Guinea....
, Aegotheles archboldi - Mountain Owlet-nightjarMountain Owlet-nightjarThe Mountain Owlet-nightjar is a species of bird in the Aegothelidae family.It is found in Indonesia and Papua New Guinea.Its natural habitat is subtropical or tropical moist montanes.-References:...
, Aegotheles albertisi- Salvadori's Owlet-nightjar, Aegotheles (albertisi) salvadorii
- New Zealand Owlet-nightjar
A fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
proximal right tarsometatarsus
Tarsometatarsus
The tarsometatarsus is a bone that is found in the lower leg of certain tetrapods, namely birds.It is formed from the fusion of several bones found in other types of animals, and homologous to the mammalian tarsal and metatarsal bones...
(MNZ S42800) was found at the Manuherikia River
Manuherikia River
The Manuherikia River is located in Otago in the South Island of New Zealand. It rises in the far north of the Maniototo, flowing southwest for 85 kilometres before its confluence with the Clutha River at Alexandra. During the 1860s the Manuherikia was one of the centres of the Central Otago Gold...
in Otago
Otago
Otago is a region of New Zealand in the south of the South Island. The region covers an area of approximately making it the country's second largest region. The population of Otago is...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. Dating from the Early to Middle Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
(Awamoan to Lillburnian, 19-16 million years ago), it seems to be of an owlet-nightjar ancestral to A. novaezealandiae.