==Birds==

===Water and drinking===

Most birds scoop water in their beaks and raise their head to let water run down the throat. Some species, especially of arid zones, belonging to the [[Columbidae|pigeon]], [[Estrildidae|finch]], [[Coliidae|mousebird]], [[Turnicidae|button-quail]] and [[Otididae|bustard]] families are capable of sucking up water without the need to tilt back their heads.<ref>{{Cite journal|first=Sara L.|last=Hallager|title=Drinking methods in two species of bustards|journal=Wilson Bull.|volume=106|issue=4|year=1994|pages=763&ndash;764|url=http://hdl.handle.net/10088/4338}}</ref> Some desert birds depend on water sources and [[sandgrouse]] are particularly well known for their daily congregations at waterholes. Nesting sandgrouse and many plovers carry water to their young by wetting their belly feathers.<ref>{{Cite journal|title=Water Transport by Sandgrouse|first=Gordon L.|last= MacLean|journal=BioScience|volume=33|issue= 6|date=1 June 1983|pages=365&ndash;369|doi=10.2307/1309104|issn=00063568|jstor=1309104}}</ref> Some birds carry water for chicks at the nest in their crop or regurgitate it along with food. The pigeon family, flamingos and penguins have adaptations to produce a nutritive fluid called [[crop milk]] that they provide to their chicks.<ref>{{cite journal|author=Eraud C|coauthors= Dorie A; Jacquet A & Faivre B|year=2008|title= The crop milk: a potential new route for carotenoid-mediated parental effects| journal= Journal of Avian Biology| volume=39| pages= 247–251| doi= 10.1111/j.0908-8857.2008.04053.x|issue=2}}</ref>