Owlet-nightjars are small

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylig ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

s related to the

nightjar Nightjars are medium-sized nocturnal or crepuscular birds in the family Caprimulgidae and order Caprimulgiformes, characterised by long wings, short legs, and very short bills. They are sometimes called goatsuckers, due to the ancient folk ta ...

s and

frogmouth The frogmouths are a group of nocturnal birds related to owlet-nightjars, swifts, and hummingbirds. Species in the group are distributed in the Indomalayan and Australasian realms. Biology They are named for their large flattened hooked bill and ...

s. Most are native to

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

, but some species extend to

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, the

Moluccas The Maluku Islands (; Indonesian: ''Kepulauan Maluku'') or the Moluccas () are an archipelago in the east of Indonesia. Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone. Geographically they are located eas ...

, and

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. A

flightless Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species, including the well known ratites (ostriches, emu, cassowaries, rheas, and kiwi) and penguins. The smallest flightless bird is the ...

species from

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

is extinct. There is a single

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Aegothelidae with the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Aegotheles''. Owlet-nightjars are

insectivore A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores wer ...

s which hunt mostly in the air but sometimes on the ground; their soft plumage is a cryptic 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

A comprehensive 2003 study analyzing

mtDNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA ...

sequences In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called t ...

Cytochrome b Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes. F ...

and

ATPase ATPases (, Adenosine 5'-TriPhosphatase, adenylpyrophosphatase, ATP monophosphatase, triphosphatase, SV40 T-antigen, ATP hydrolase, complex V (mitochondrial electron transport), (Ca2+ + Mg2+)-ATPase, HCO3−-ATPase, adenosine triphosphatase) are ...

subunit 8 suggests that 11 living species of owlet-nightjar should be recognized, as well as another that became extinct early in the second millennium AD. The relationship between the owlet-nightjars and the (traditional)

Caprimulgiformes Nightjars are medium-sized nocturnal or crepuscular birds in the family Caprimulgidae and order Caprimulgiformes, characterised by long wings, short legs, and very short bills. They are sometimes called goatsuckers, due to the ancient folk tal ...

has long been controversial and obscure and remains so today: in the 19th century they were regarded as a subfamily of the

s, and they are still generally considered to be related to the frogmouths and/or the

s. It appears though that they are not as closely related to either as previously thought, and that the owlet-nightjars share a more recent common ancestor with the

Apodiformes Traditionally, the bird order Apodiformes contained three living families: the swifts (Apodidae), the treeswifts (Hemiprocnidae), and the hummingbirds (Trochilidae). In the Sibley-Ahlquist taxonomy, this order is raised to a superorder Apodi ...

. As has been suggested on occasion since morphological studies of the

cranium The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

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 A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

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 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 ...

s with huge eyes. The ancestors of the swifts and

hummingbirds Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics aro ...

, 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. Owlet-nightjars are an exclusively Australasian group, but close relatives apparently thrived all over

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...

in the late

Paleogene The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

Taxonomy

Family Aegothelidae * Genus '' Quipollornis'' Rich & McEvey 1977 (Early/Middle Miocene of New South Wales) ** †'' Quipollornis koniberi'' Rich & McEvey 1977 * Genus ''Aegotheles'' ** † New Zealand owlet-nightjar, ''Aegotheles novaezealandiae'' (Scarlett 1968) (

prehistoric Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...

; formerly ''Megaegotheles'') **

New Caledonian owlet-nightjar The New Caledonian owlet-nightjar (''Aegotheles savesi''), also known as the enigmatic owlet-nightjar, is a large owlet-nightjar Owlet-nightjars are small crepuscular birds related to the nightjars and frogmouths. Most are native to New Guinea ...

, ''Aegotheles savesi'' Layard & Layard 1881 ** Feline owlet-nightjar, ''Aegotheles insignis'' Salvadori 1876 ** Starry owlet-nightjar or spangled owlet-nightjar, ''Aegotheles tatei'' Rand 1941 ** Moluccan owlet-nightjar or long-whiskered owlet-nightjar, ''Aegotheles crinifrons'' (Bonaparte 1850) ** Australian owlet-nightjar, ''Aegotheles cristatus'' (Shaw 1790) *** ''A. c. cristatus'' (Shaw 1790) *** ''A. c. tasmanicus'' Mathews 1918 ** Vogelkop owlet-nightjar, ''Aegotheles affinis'' Salvadori 1876 ** Barred owlet-nightjar, ''Aegotheles bennettii'' Salvadori & Albertis 1875 *** ''A. b. bennettii'' Salvadori & Albertis 1875 *** ''A. b. plumifer'' Ramsay 1883 *** ''A. b. terborghi'' Diamond 1967 *** ''A. b. wiedenfeldi'' Laubmann 1914 ** Wallace's owlet-nightjar, ''Aegotheles wallacii'' Gray 1859 *** ''A. w. gigas'' Rothschild 1931 *** ''A. w. manni'' Diamond 1969 *** ''A. w. wallacii'' Gray 1859 ** Mountain owlet-nightjar, ''Aegotheles albertisi'' Sclater 1874 *** ''A. a. albertisi'' Sclater 1874 (Arfak owlet-nightjar) *** ''A. a. wondiwoi'' Mayr & Rand 1936 *** ''A. a. salvadorii'' (Hartert 1892) (Salvadori's owlet-nightjar) A

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

proximal Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

right tarsometatarsus ( MNZ S42800) was found at the

Bannockburn Formation The Manuherikia Group is a fluvial-lacustrine sedimentary fill in the Central Otago area of New Zealand, at the site of the prehistoric Lake Manuherikia. The area consists of a valley and ridge topography, with a series of schist-greywacke mount ...

of the

Manuherikia Group The Manuherikia Group is a fluvial- lacustrine sedimentary fill in the Central Otago area of New Zealand, at the site of the prehistoric Lake Manuherikia. The area consists of a valley and ridge topography, with a series of schist-greywacke mountai ...

near the

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, with the West Branch draining the eastern side of the St Bathans Range, and the East Branch draining the western flanks of t ...

Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...

. Dating from the Early to Middle

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

( Altonian, 19-16

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

), it seems to represent an owlet-nightjar ancestral to ''A. novaezealandiae''. In 2022, an additional specimen from the same locality was described by Worthy ''et al''. as a new extinct species of ''Aeotheles'', ''A. zealandivetus''. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen is NMNZ S.52917, a distal right tarsometatarsus.

Footnotes

References

* Dumbacher, John P. ; Pratt, Thane K. & Fleischer, Robert C. (2003): Phylogeny of the owlet-nightjars (Aves: Aegothelidae) based on mitochondrial DNA sequence. '' Mol. Phylogenet. Evol.'' 29(3): 540–549.
PDF fulltext
* Mayr, Gerald (2002): Osteological evidence for paraphyly of the avian order Caprimulgiformes (nightjars and allies). '' J. Ornithol.'' 143(1): 82–97. PDF fulltext
* Simonetta, A.M. (1967): Cinesi e morfologia del cranio negli Uccelli non passeriformi. Studio su varie tendenze evolutive. Part II – Striges, Caprimulgiformes ed Apodiformes Cranial kinesis and morphology of non-passerine birds. Study of various evolutionary tendencies. Part II – Striges, Caprimulgiformes and Apodiformes" n Italian''Archivio Zoologico Italiano'' 52: 1–35. * Worthy, Trevor H.; Tennyson, A.J.D.; Jones, C.; McNamara, J.A. & Douglas, B.J. (2007): Miocene waterfowl and other birds from central Otago, New Zealand. '' J. Syst. Palaeontol.'' 5(1): 1–39. (HTML abstract) {{Taxonbar, from=Q575930 Aegotheliformes Nightjars Taxa named by Nicholas Aylward Vigors