Editing Cliff swallow (section)

== Description ==
The cliff swallow's average body length is {{convert|13|cm|in|abbr=on}}, and they have short legs and small [[Bird anatomy|bills]] with relatively long pointed wings.<ref name=":7" /><ref name=":3" /> Adult cliff swallows have an overall dark brownish [[plumage]] covering both their back and wings, and they have a characteristic white forehead, rich red-coloured cheeks with a dark throat, basic white underparts and a buffy-coloured rump.<ref name=":2" /><ref name=":3" /> In good lighting conditions, their crowns and mantle feathers are [[Iridescence|iridescent]].<ref name=":2" /><ref name=":7" /> The Northern population is slightly larger in body size and also differs in facial markings from the Mexican population of cliff swallows, which have a chocolate-brown patch on their foreheads.<ref name=":2" />
{| class="wikitable" style="font-size: 87%;"
! colspan="2" |Average Measurements<ref name=":2" /><ref name=":7" /><ref name=":0">{{Cite journal|last1=Roche|first1=Erin A.|last2=Brown|first2=Mary B.|last3=Brown|first3=Charles R.|date=December 2014|title=The Effect of Weather on Morphometric Traits of Juvenile Cliff Swallows|url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1553&context=natrespapers|journal=Prairie Naturalist – University of Nebraska Lincoln|volume=46 |issue=2|pages=76–87}}</ref>
|-
| style="padding-right: 1em;padding-left:0.35em;" |[[Bird measurement#Total Body Length|length]]
| style="padding-right: 0.5em;padding-left:0.5em;" |{{convert|5|–|6|in|abbr=on|mm}}
|-
| style="padding-right: 1em;padding-left:0.35em;" |[[Bird measurement#Weight|weight]]
| style="padding-right: 0.5em;padding-left:0.5em;" |{{convert|19–31|g|oz|abbr=on}}
|-
| style="padding-right: 1em;padding-left:0.35em;" |[[Bird measurement#Wingspan|wingspan]]
| style="padding-right: 0.5em;padding-left:0.5em;" |{{convert|11–13|in|mm|abbr=on}}
|-
| style="padding-right: 1em;padding-left:0.35em;" |[[Bird measurement#Wing|wing]]
| style="padding-right: 0.5em;padding-left:0.5em;" |{{convert|105.5|–|111.5|mm|abbr=on|in}}
|-
| style="padding-right: 1em;padding-left:0.35em;" |[[Bird measurement#Tail|tail]]
| style="padding-right: 0.5em;padding-left:0.5em;" |{{convert|47|–|51|mm|abbr=on|in}}
|-
| style="padding-right: 1em;padding-left:0.35em;" |[[Bird measurement#Culmen|culmen]]
| style="padding-right: 0.5em;padding-left:0.5em;" |{{convert|6.4|–|7.3|mm|abbr=on|in}}
|-
| style="padding-right: 1em;padding-left:0.35em;" |[[Bird measurement#Tarsus|tarsus]]
| style="padding-right: 0.5em;padding-left:0.5em;" |{{convert|12|–|13|mm|abbr=on|in}}
|}
[[File:Cliff_swallow_7427.jpg|left|thumb|Juvenile cliff swallow]]
[[File:Cliff_swallow_(15372086670).jpg|thumb|right|Juvenile cliff swallow in a gourd-shaped mud nest]]
The male and female have identical plumage, therefore sexing them must be done through [[palpation]] of the [[cloaca]].<ref name=":2" /><ref name=":1" /> During the breeding season, the males will have a harder cloaca that is more pronounced because the [[seminal vesicle]]s are swollen.<ref name=":1" /> In addition, during [[Egg incubation|incubation]] females will lose feathers on their lower breast to create a warm patch for sitting on their eggs.<ref name=":1" /> Cliff swallows are similar in body plumage colouring to the related [[barn swallow]] species but lack the characteristic fork-shaped tail of the barn swallow prominent during flight.<ref name=":3" /> The cliff swallows have a square-shaped tail.<ref name=":2" /><ref name=":7" /><ref name=":3" />

Juvenile cliff swallows have an overall similar body plumage colouring to the adults, with paler tones.<ref name=":2" /><ref name=":1" /><ref name=":3" /> The juveniles lack the iridescent adult plumages, and their foreheads and throats appear speckled white.<ref name=":2" /><ref name=":1" /><ref name=":4">{{Cite journal|last1=Johnson|first1=Allison E.|last2=Freedberg|first2=Steven|date=2014|title=Variable facial plumage in juvenile Cliff Swallows: A potential offspring recognition cue?|journal=The Auk|volume=131|issue=2|pages=121–128|doi=10.1642/AUK-13-127.1|issn=0004-8038|doi-access=free}}</ref> The juvenile cliff swallows' white forehead and throat markings have high variance between unrelated individuals compared with those from the same clutch.<ref name=":4" /> These distinctive white facial markings disappear during maturity following their [[Humphrey–Parkes terminology|complex-basic moult pattern]], because their pre-formative plumage is different from the basic plumage.<ref name=":2" /><ref name=":4" /> The pre-formative facial plumage has been suggested as a possible way for parents nesting in large colonies to recognize their chicks.<ref name=":1" /><ref name=":4" />