Editing Plains zebra (section)

===Communication===
[[File:Equus quagga (185908025).jpg|thumb|right|Zebras mutually grooming]]
At least six different calls have been documented for the plains zebra. One is its distinctive, high-pitched, contact call (commonly called "[[bark (sound)|barking]]") heard as "a-''ha'', a-''ha'', a-''ha''" or "kwa-ha, kaw-ha, ha, ha"<ref name="Grub 1981"/> also transcribed as "kwahaah",<ref name=Max>{{cite news |last=Max|first=D. T. |title=Can You Revive an Extinct Animal? |url=https://www.nytimes.com/2006/01/01/magazine/01taxidermy.html |access-date=2014-03-03 |newspaper=[[The New York Times]] |date=1 January 2006}}</ref> or "oug-ga".<ref name="1911 quagga">{{EB1911 |noprescript=1 |wstitle=Quagga}}</ref> The species name ''quagga'' is derived from the [[Khoikhoi]] word for "zebra" and is [[Onomatopoeia|onomatopoeic]] for its call.<ref name=skinner>{{cite book |last1=Skinner |first1=J. D. |title=The Mammals of the Southern African Subregion |year=2005 |publisher=[[Cambridge University Press]] |isbn=978-0-521-84418-5 |pages=537–546 |edition = 3rd |last2=Chimimba |first2=C. T. |chapter=Equidae}}</ref> When a predator is sighted, a zebra makes a two-syllable alarm call. A loud snort is made when moving in cover of potential danger. When in contentment, a zebra makes a more drawn-out snort. Males make a short, high-pitched squeal when hurt, and foals  emit a drawn-out wail when in distress.<ref name="Grub 1981"/>

Two main facial expressions are made by zebras; the greeting and threat. In both cases, the lips are pulled back and chewing motions are made. Greeting involves the ears sticking up and directing forward; while the threat involves the ears down.<ref name="Grub 1981"/> Zebras strengthen their social bonds with [[Social grooming|grooming]]. Members of a harem nip and scrape along the neck, withers, and back with their teeth and lips. Mothers and foals groom the most often, followed by siblings. Grooming shows social status and eases aggressive behaviour.<ref name="Estes 1991"/>