Editing Columbidae (section)

=== Anatomy and physiology ===
[[File:Touchdown (pigeon).jpg|thumb|A landing [[Eurasian collared dove|collared dove]] (''Streptopelia decaocto'') displays the contour and [[flight feather]]s of its wings.]]
Overall, the [[Bird anatomy|anatomy]] of Columbidae is characterized by short legs, short bills with a fleshy [[Beak|cere]], and small heads on large, compact bodies.<ref>{{Cite web|url=http://www.faunaparaguay.com/columbidae.html|title=COLUMBIDAE Pigeons and Doves FAUNA PARAGUAY|last=Smith|first=Paul|website=www.faunaparaguay.com}}</ref> Like some other birds, the Columbidae have no [[gall bladder]]s.<ref name="Hagey">{{cite journal|last1=Hagey|first1=LR|last2=Schteingart|first2=CD|last3=Ton-Nu|first3=HT|last4=Hofmann|first4=AF|year=1994|title=Biliary bile acids of fruit pigeons and doves (Columbiformes)|journal=Journal of Lipid Research|volume=35|issue=11|pages=2041–8|doi=10.1016/S0022-2275(20)39950-8|pmid=7868982|doi-access=free}}</ref> Some medieval naturalists concluded they have no [[bile]] (gall), which in the medieval theory of the [[four humours]] explained the allegedly sweet disposition of doves.<ref name="Isidore">{{cite web|url=http://bestiary.ca/beasts/beast253.htm|title=Doves|work=The Medieval Bestiary|access-date=31 January 2010}}</ref> In fact, however, they do have bile (as [[Aristotle]] had earlier realized), which is secreted directly into the [[Gut (anatomy)|gut]].<ref name="Browne">{{cite book|url=http://penelope.uchicago.edu/pseudodoxia/pseudo33.html|title=Pseudodoxia Epidemica|last=Browne|first=Thomas|publisher=available online at [[University of Chicago]]|year=1646|edition=1672|volume=III.iii|author-link=Thomas Browne|access-date=31 January 2010}}</ref>

The wings of most species are large, and have eleven [[Flight feather|primary feathers]];<ref name=":1">{{Cite web|url=http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/columbiformes-pigeons-doves-and-dodos|title=Columbiformes (Pigeons, Doves, and Dodos) – Dictionary definition of Columbiformes (Pigeons, Doves, and Dodos)|website=www.encyclopedia.com}}</ref> pigeons have strong wing muscles (wing muscles comprise 31–44% of their body weight<ref>{{Cite book|url=https://books.google.com/books?id=BTj1ao8leWgC&pg=PA42|title=Twirl: A Fresh Spin at Life|last=Clairmont|first=Patsy|date=2014|publisher=Harper Collins|isbn=978-0-8499-2299-2}}</ref>) and are among the strongest fliers of all birds.<ref name=":1" />

In a series of experiments in 1975 by Dr.{{nbsp}}Mark B. Friedman, using doves, their characteristic head bobbing was shown to be due to their natural desire to keep their vision constant.<ref>{{Cite web|url=https://www.loc.gov/rr/scitech/mysteries/pigeon.html|title=Why do pigeons bob their heads when they walk? Everyday Mysteries: Fun Science Facts from the Library of Congress|website=www.loc.gov}}</ref> It was shown yet again in a 1978 experiment by Dr.{{nbsp}}Barrie J. Frost, in which pigeons were placed on [[treadmill]]s; it was observed that they did not bob their heads, as their surroundings were constant.<ref>{{cite journal|last1=Necker|first1=R|year=2007|title=Head-bobbing of walking birds|url=http://www.reinhold-necker.de/Head%20bobbing%20print.pdf|journal=Journal of Comparative Physiology A|volume=193|issue=12|pages=1177–83|doi=10.1007/s00359-007-0281-3|pmid=17987297|s2cid=10803990}}</ref>