Flightless bird
Flightless birds are
Many domesticated birds, such as the
Flightlessness has evolved in many different birds independently, demonstrating repeated convergent evolution.
History
Origins of flightlessness
Divergences and losses of flight within ratite lineage occurred right after the K-Pg extinction event wiped out all non-avian dinosaurs and large vertebrates 66 million years ago.[6] The immediate evacuation of niches following the mass extinction provided opportunities for Palaeognathes to distribute and occupy novel environments. New ecological influences selectively pressured different taxa to converge on flightless modes of existence by altering them morphologically and behaviorally. The successful acquisition and protection of a claimed territory selected for large size and cursoriality in Tertiary ancestors of ratites.[7] Temperate rainforests dried out throughout the Miocene and transformed into semiarid deserts, causing habitats to be widely spread across the growingly disparate landmasses. Cursoriality was an economic means of traveling long distances to acquire food that was usually low-lying vegetation, more easily accessed by walking.[7] Traces of these events are reflected in ratite distribution throughout semiarid grasslands and deserts today.[8]
Gigantism is not a requirement for flightlessness. The kiwi do not exhibit gigantism, along with tinamous, even though they coexisted with the moa and rheas that both exhibit gigantism. This could be the result of different ancestral flighted birds arrival or because of competitive exclusion.[11] The first flightless bird to arrive in each environment utilized the large flightless herbivore or omnivore niche, forcing the later arrivals to remain smaller. In environments where flightless birds are not present, it is possible that after the K/T Boundary there were no niches for them to fill. They were pushed out by other herbivorous mammals.[10]
Independent evolution of flightlessness in Palaeognathes
Morphological changes and energy conservation
Two key differences between flying and flightless birds are the smaller wing bones of flightless birds[17] and the absent (or greatly reduced) keel on their breastbone. (The keel anchors muscles needed for wing movement.)[18]
Adapting to a cursorial lifestyle causes two inverse morphological changes to occur in the skeleto-muscular system: the pectoral apparatus used to power flight is paedorphically reduced while
Some flightless varieties of island birds are closely related to flying varieties, implying flight is a significant biological cost.[19] Flight is the most costly type of locomotion exemplified in the natural world. The energy expenditure required for flight increases proportionally with body size, which is often why flightlessness coincides with body mass.[8] By reducing large pectoral muscles that require a significant amount of overall metabolic energy, ratites decrease their basal metabolic rate and conserve energy.[19][20] A study looking at the basal rates of birds found a significant correlation between low basal rate and pectoral muscle mass in kiwis. On the contrary, flightless penguins exhibit an intermediate basal rate. This is likely because penguins have well-developed pectoral muscles for hunting and diving in the water.[19] For ground-feeding birds, a cursorial lifestyle is more economical and allows for easier access to dietary requirements.[7] Flying birds have different wing and feather structures that make flying easier, while flightless birds' wing structures are well adapted to their environment and activities, such as diving in the ocean.[21]
Species with certain characteristics are more likely to evolve flightlessness. For example, species that already have shorter wings are more likely to lose flight ability.[22] Some species will evolve flatter wings so that they move more efficiently underwater at the cost of their flight.[23] Additionally, birds that undergo simultaneous wing molt, in which they replace all of the feathers in their wings at once during the year, are more likely to evolve flight loss.[24]
A number of bird species appear to be in the process of losing their powers of flight to various extents. These include the Zapata rail of Cuba, the Okinawa rail of Japan, and the Laysan duck of Hawaii. All of these birds show adaptations common to flightlessness, and evolved recently from fully flighted ancestors, but have not yet completely given up the ability to fly. They are, however, weak fliers and are incapable of traveling long distances by air.[25]
Continued presence of wings in flightless birds
Although
In penguins, wings structure is maintained for use in locomotion underwater.[27] Penguins evolved their wing structure to become more efficient underwater at the cost of their efficiency in the air.[28]
The only known species of flightless bird in which wings completely disappeared was the gigantic, herbivorous moa of New Zealand, hunted to extinction by humans by the 15th century. In moa, the entire pectoral girdle is reduced to a paired scapulocoracoid, which is the size of a finger.[29]
List of flightless birds
Many flightless birds are extinct; this list shows species that are either still extant or became extinct in the Holocene (no more than 11,000 years ago). Extinct species are indicated with a cross (†). A number of species suspected, but not confirmed to be flightless, are also included here.
Longer-extinct groups of flightless birds include the Cretaceous
Palaeognathae (ratites)
Struthioniformes (ostriches)
- Common ostrich, Struthio camelus
- North African ostrich, Struthio camelus camelus
- South African ostrich, Struthio camelus australis
- Masai ostrich, Struthio camelus massaicus
- Arabian ostrich, Struthio camelus syriacus †
- Somali ostrich, Struthio molybdophanes
- Asian ostrich, Struthio asiaticus †
- East Asian ostrich, Struthio anderssoni †
Casuariiformes (cassowaries and emus)
- Common emu, Dromaius novaehollandiae
- Mainland emu, Dromaius novaehollandiae novaehollandiae
- King Island emu, Dromaius novaehollandiae minor †
- Kangaroo Island emu, Dromaius novaehollandiae baudinianus †
- Tasmanian emu, Dromaius novaehollandiae diemenensis †
- Dwarf cassowary, Casuarius bennetti
- Bennett's cassowary, Casuarius bennetti bennetti
- Papuan dwarf cassowary, Casuarius bennetti westermanni
- Southern cassowary, Casuarius casuarius
- Northern cassowary, Casuarius unappendiculatus
Dinornithiformes (moa) †
- North Island giant moa, Dinornis novaezealandiae †
- South Island giant moa, Dinornis robustus †
- Bush moa, Anomalopteryx didiformis †
- Eastern moa, Emeus crassus †
- Broad-billed moa, Euryapteryx curtus †
- Heavy-footed moa, Pachyornis elephantopus †
- Mantell's moa, Pachyornis geranoides †
- Crested moa, Pachyornis australis †
- Upland moa, Megalapteryx didinus †
Aepyornithiformes (elephant birds) †
- Hildebrandt's elephant bird, Aepyornis hildebrandti †
- Giant elephant bird, Aepyornis maximus †
- Lesser elephant bird, Mullerornis modestus †
Apterygiformes (kiwi)
- Southern brown kiwi, Apteryx australis
- Stewart Island tokoeka, Apteryx australis lawryi
- Fiordland tokoeka, Apteryx australis australis
- Great spotted kiwi, Apteryx haastii
- North Island brown kiwi, Apteryx mantelli
- Little spotted kiwi, Apteryx owenii
- North Island little spotted kiwi, Apteryx owenii iredalei †
- South Island little spotted kiwi, Apteryx owenii owenii
- Okarito kiwi, Apteryx rowi
Rheiformes (rheas)
- Greater rhea, Rhea americana
- American rhea, Rhea americana americana
- Intermediate rhea, Rhea americana intermedia
- Argentine rhea, Rhea americana albescens
- Paraguayan rhea, Rhea americana nobilis
- Brodkorb's rhea, Rhea americana araneipes
- Lesser rhea, Rhea pennata
- Darwin's lesser rhea, Rhea pennata pennata
- Garlepp's rhea, Rhea pennata garleppi
- Puna Rhea, Rhea pennata tarapacensis
Neognathae
Galliformes (landfowl)
- New Caledonian giant scrubfowl, Sylviornis neocaledoniae †
- Noble megapode, Megavitornis altirostris †
- Viti Levu scrubfowl, Megapodius amissus †
Anseriformes (waterfowl)
- Mihirung, Genyornis newtoni †
- Amsterdam wigeon, Anas marecula †
- Bermuda flightless duck, Anas pachyscelus †
- Auckland Island teal, Anas aucklandica
- Campbell teal, Anas nesiotis
- Eaton's pintail, Anas eatoni
- Finsch's duck, Chenonetta finschi †
- Steamer ducks
- Fuegian steamer duck, Tachyeres pteneres
- Falkland steamer duck, Tachyeres brachypterus
- Chubut steamer duck, Tachyeres leucocephalus
- Moa-nalo †
- Turtle-jawed moa-nalo, Chelychelynechen quassus †
- Small-billed moa-nalo, Ptaiochen pau †
- O'ahu moa-nalo, Thambetochen xanion †
- Maui Nui large-billed moa-nalo, Thambetochen chauliodous †
- Nēnē-nui, Branta hylobadistes † (possibly flightless or very weak flier)
- Giant Hawaiʻi goose, Branta rhuax †
- California flightless sea-duck or Law's diving goose, Chendytes lawi†
- Kaua'i mole duck, Talpanas lippa †
- New Zealand goose, Cnemiornis gracilis and C. calcitrans †
Aegotheliformes (owlet-nightjars)
- New Zealand owlet-nightjar, Aegotheles novaezealandiae †
Mesitornithiformes (mesites)
- Brown mesite Mesitornis unicolor (possibly flightless, has not been seen flying)[30]
Columbiformes (pigeons, doves)
- Dodo, Raphus cucullatus †
- Rodrigues solitaire, Pezophaps solitaria †
- Viti Levu giant pigeon, Natunaornis gigoura †
- Saint Helena dove, Dysmoropelia dekarchiskos †
- Henderson ground dove, Gallicolumba leonpascoi †
Gruiformes (cranes, rails, and coots)
- Cuban flightless crane, Grus cubensis †
- Red rail, Aphanapteryx bonasia †
- Rodrigues rail, Erythromachus leguati †
- Woodford's rail, Nesoclopeus woodfordi (most likely flightless)
- Bar-winged rail, Nesoclopeus poecilopterus † (probably flightless)
- Weka, Gallirallus australis
- New Caledonian rail, Gallirallus lafresnayanus (likely †)
- Lord Howe woodhen, Gallirallus sylvestris
- Calayan rail, Gallirallus calayanensis
- Pink-legged rail, Gallirallus insignis
- Guam rail, Gallirallus owstoni
- Roviana rail, Gallirallus rovianae (flightless, or almost so)[31]
- Tahiti rail, Gallirallus pacificus †
- Dieffenbach's rail, Gallirallus dieffenbachii †
- Wake Island rail, Gallirallus wakensis †
- numerous other unnamed Gallirallus rails from various Pacific islands
- Chatham rail, Cabalus modestus †
- Snoring rail, Aramidopsis plateni
- Invisible rail, Habroptila wallacii
- New Guinea flightless rail, Megacrex inepta
- Aldabra (white-throated) rail, Dryolimnas (cuvieri) aldabranus
- Réunion rail, Dryolimnas augusti †
- Sauzier's wood railor Cheke's wood rail, Dryolimnas chekei †
- Inaccessible Island rail, Atlantisia rogersi
- Saint Helena rail, Aphanocrex podarces †
- Ascension crake, Mundia elpenor †
- Saint Helena crake, Porzana astrictocarpus †
- Laysan rail, Porzana palmeri †
- Hawaiian rail, Porzana sandwichensis †
- Small Maui crake, Porzana keplerorum †
- Liliput crake, Porzana menehune †
- Great Oʻahu crake, Porzana ralphorum †
- Great Maui crake, Porzana severnsi †
- Small Oʻahu crake, Porzana ziegleri †
- Kosrae crake, Porzana monasa †
- Henderson crake, Porzana atra
- Mangaia crake, Porzana rua †
- Tahiti crake, Porzana nigra †
- numerous other unnamed Porzana crakes from various Pacific islands
- Lord Howe swamphen, Porphyrio albus †
- North Island takahē, Porphyrio mantelli †
- Takahē, Porphyrio hochstetteri
- Samoan woodhen, Gallinula pacifica
- Makira woodhen, Gallinula silvestris
- Tristan moorhen, Gallinula nesiotis †
- Gough Island moorhen, Gallinula comeri
- Tasmanian native hen, Tribonyx mortierii
- Giant coot, Fulica gigantea (adults only; immature birds can fly)
- Hawkins' rail, Diaphorapteryx hawkinsi †
- Snipe-rail, Capellirallus karamu †
- Antillean cave rail, Nesotrochis debooyi †
- Hispaniolan cave rail, Nesotrochis steganinos †
- Cuban cave rail, Nesotrochis picapicensis †
- Adzebills, Aptornis otidiformis and A. defossor †
Podicipediformes (grebes)
- Junín grebe, Podiceps taczanowskii
- Titicaca grebe, Rollandia microptera
- Atitlán grebe, Podilymbus gigas † (reportedly flightless)[32]
Charadriiformes (shorebirds and allies)
- Great auk, Pinguinus impennis †
Sphenisciformes (penguins)
- Emperor penguin, Aptenodytes forsteri
- King penguin, Aptenodytes patagonicus
- Adélie penguin, Pygoscelis adeliae
- Chinstrap penguin, Pygoscelis antarctica
- Gentoo penguin, Pygoscelis papua
- Little blue penguin, Eudyptula minor
- Magellanic penguin, Spheniscus magellanicus
- Humboldt penguin, Spheniscus humboldti
- Galapagos penguin, Spheniscus mendiculus
- African penguin, Spheniscus demersus
- Yellow-eyed penguin, Megadyptes antipodes
- Waitaha penguin, Megadyptes waitaha †
- Fiordland penguin, Eudyptes pachyrhynchus
- Snares penguin, Eudyptes robustus
- Erect-crested penguin, Eudyptes sclateri
- Northern rockhopper penguin, Eudyptes moseleyi
- Southern rockhopper penguin, Eudyptes chrysocome
- Royal penguin, Eudyptes schlegeli
- Macaroni penguin, Eudyptes chrysolophus
- Chatham penguin, Eudyptes warhami †
Suliformes (boobies, cormorants and allies)
- Flightless cormorant, Nannopterum harrisi
Pelecaniformes (pelicans, herons, ibises and allies)
- Ascension night heron, Nycticorax olsoni †
- Jamaican ibis, Xenicibis xymphithecus †
- Hawaiian flightless ibises, Apteribis glenos and A. brevis †
Strigiformes (owls)
- Cuban giant owl, Ornimegalonyx spp. † (possibly flightless)
- Cretan owl, Athene cretensis † (possibly flightless)
- Andros Island barn owl, Tyto pollens † (possibly flightless)
Bucerotiformes (hornbills and hoopoes)
- Saint Helena hoopoe, Upupa antaios †
Falconiformes (falcons and caracaras)
- Jamaican caracara, Caracara tellustris †
Psittaciformes (parrots)
- Kākāpō, Strigops habroptilus
Passeriformes (perching birds)
- Lyall's wren, Xenicus lyalli †
- Long-billed wren, Dendroscansor decurvirostris †
- North Island stout-legged wren, Pachyplichas jagmi†
- South Island stout-legged wren, Pachyplichas yaldwyni†
- some Scytalopus tapaculos (possibly flightless, never seen flying)
- Long-legged bunting, Emberiza alcoveri †
References
- ^ "New Zealand Ecology – Moa". TerraNature. Retrieved 2007-08-27.
- ISBN 978-0-313-33545-7.
- S2CID 227261010.
- ^ PMID 18765814.
- ^ Holmes, Bob (2008-06-26). "Bird evolutionary tree given a shake by DNA study". New Scientist.
- ^ PMID 22831877.
- ^ PMID 20525622.
- ^ a b c d Noble, J. C. (1991). "On ratites and their interactions with plants" (PDF). Revista Chilena de Historia Natural. 64: 85–118.
- ^ "Flightlessness - an overview | ScienceDirect Topics".
- ^ S2CID 206555952.
- ^ PMID 24825849.
- ^ .
- ^ "New Zealand's Icon:Flightless". Archived from the original on 2007-08-18. Retrieved 2007-08-27.
- PMID 22977150.
- PMID 18765814.
- ^ PMID 22831877.
- .
- ^ "The Bird Site: Flightless Birds". Archived from the original on 2007-07-13. Retrieved 2007-08-27.
- ^ S2CID 86511951.
- ^ S2CID 951896.
- PMID 23690614.
- S2CID 37855732.
- ISSN 0362-2525.
- S2CID 225249314.
- ISBN 9780313335457.
- .
- .
- PMID 23690614.
- ^ "Moa forelimb structure and forelimb initiation gene network. A. The moa..." ResearchGate. Retrieved 2020-08-25.
- ^ Roots, Clive. Flightless Birds. Westport, CT: Greenwood, 2006. 136-37. Print.
- JSTOR 4088088.
- JSTOR 1368847.
External links
- TerraNature pages on New Zealand flightless birds
- Kiwi in Te Ara – the Encyclopedia of New Zealand