Editing Flightless bird (section)

{{short description|Birds that cannot fly}}
{{Redirect|Flightless|the record label|Flightless (record label)}}
[[Image:Penguins Edinburgh Zoo 2004 SMC.jpg|thumb|right|[[King penguin]]s (''Aptenodytes patagonicus'').<br>[[Penguin]]s are a well-known example of flightless birds.]]
[[File:TWC Wildlife Centre• Stewart Nimmo • MRD 8502.jpg|thumb|An [[Okarito kiwi]] (''Apteryx rowi''), also known as the rowi]]
[[File:Ostrich in safari.jpg|thumb|[[Common ostrich]] (''Struthio camelus'').<br> [[Ostrich]]es are the largest extant flightless birds as well as the largest extant birds in general.]]
[[File:Extinct flightless bird (21128386393).jpg|thumb|An extinct [[moa]]. Until the arrival of humans, [[New Zealand]]'s only mammals were bats and seals, resulting in many bird species evolving to fill the open niches. While many of New Zealand's flightless birds are now extinct, some, such as the [[Kiwi (bird)|kiwi]], [[kākāpō]], [[weka]], and [[takahē]] have survived to the present day.]]

'''Flightless birds''' are [[birds]] that cannot [[Bird flight|fly]], as they have, through [[evolution]], lost the ability to.<ref>{{cite web |url=http://www.terranature.org/moa.htm |title=New Zealand Ecology&nbsp;– Moa |work=TerraNature |access-date=2007-08-27 }}</ref> There are over 60 extant species,<ref name=Roots_2006/> including the well-known [[ratites]] ([[ostrich]]es, [[emu]]s, [[cassowary|cassowaries]], [[Rhea (bird)|rheas]], and [[Kiwi (bird)|kiwis]]) and [[penguin]]s. The smallest flightless bird is the [[Inaccessible Island rail]] (length 12.5&nbsp;cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird in general, is the [[common ostrich]] (2.7 m, 156&nbsp;kg).

Many domesticated birds, such as the [[domestic chicken]] and [[domestic duck]], have lost the ability to fly for extended periods, although their ancestral species, the [[red junglefowl]] and [[mallard]], respectively, are capable of extended flight. A few particularly bred birds, such as the [[Broad Breasted White turkey]], have become totally flightless as a result of [[selective breeding]]; the birds were bred to grow massive breast meat that weighs too much for the bird's wings to support in flight.

Flightlessness has evolved in many different birds independently, demonstrating repeated [[convergent evolution]].<ref>{{cite journal | doi=10.1126/sciadv.abb6095 | title=Anthropogenic extinctions conceal widespread evolution of flightlessness in birds | year=2020 | last1=Sayol | first1=F. | last2=Steinbauer | first2=M. J. | last3=Blackburn | first3=T. M. | last4=Antonelli | first4=A. | last5=Faurby | first5=S. | journal=Science Advances | volume=6 | issue=49 | pmid=33268368 | bibcode=2020SciA....6.6095S | s2cid=227261010 | doi-access=free | pmc=7710364 }}</ref> There were families of flightless birds, such as the now-extinct [[Phorusrhacidae]], that evolved to be powerful terrestrial predators. Taking this to a greater extreme, the [[terror birds]] (and their relatives the [[bathornithids]]), [[Eogruidae|eogruids]], [[Geranoididae|geranoidids]], [[Gastornithiformes|gastornithiforms]], and [[dromornithidae|dromornithids]] (all extinct) all evolved similar body shapes – long legs, long necks and big heads – but none of them were closely related. Furthermore, they also share traits of being giant, flightless birds with vestigial wings, long legs, and long necks with some of the ratites, although they are not related.<ref name=":0">{{cite journal |title=Phylogenomic evidence for multiple losses of flight in ratite birds |journal= Proceedings of the National Academy of Sciences of the United States of America|date=2 September 2008 |volume=105 |issue=36 |pages=13462–13467 |doi=10.1073/pnas.0803242105 |pmid=18765814 |pmc=2533212 |last1= Harshman|first1= J.|last2= Braun|first2= E. L.|last3= Braun|first3= M. J.|last4= Huddleston|first4= C. J.|last5= Bowie|first5= R. C.|last6= Chojnowski|first6= J. L.|last7= Hackett|first7= S. J.|last8= Han|first8= K. L.|last9= Kimball|first9= R. T.|last10= Marks|first10= B. D.|last11= Miglia|first11= K. J.|last12= Moore|first12= W. S.|last13= Reddy|first13= S.|last14= Sheldon|first14= F. H.|last15= Steadman|first15= D. W.|last16= Steppan|first16= S. J.|last17= Witt|first17= C. C.|last18= Yuri|first18= T.|bibcode= 2008PNAS..10513462H|doi-access= free}}</ref><ref>{{cite web |last=Holmes |first=Bob |date=2008-06-26 |title=Bird evolutionary tree given a shake by DNA study |url=https://www.newscientist.com/article/dn14212-bird-evolutionary-tree-given-a-shake-by-dna-study/ |website=New Scientist}}</ref>