Editing Boidae

{{Short description|Family of snakes}}
{{Redirect|Boid|the artificial intelligence program|Boids}}
{{Automatic taxobox
| fossil_range      = {{Fossil range|70.6|0}} [[Late Cretaceous]] to Present
| image             = Red-tailed boa (Boa constrictor constrictor) Rio Napo.jpg
| image_caption     = Boa constrictor (''[[Boa constrictor|B. c.  constrictor]]'')
| taxon             = Boidae
| authority         = [[John Edward Gray|Gray]], 1825<ref name=Gray1825 /><ref name="McD99">McDiarmid, R.W.; Campbell, J.A.; Touré. T. 1999. ''Snake Species of the World: A Taxonomic and Geographic Reference Vol. 1''. Herpetologists' League. 511 pp. {{ISBN|1-893777-00-6}} (series). {{ISBN|1-893777-01-4}} (volume).</ref>
| subdivision_ranks = Subfamilies
| subdivision       = [[Boinae]] <br />
[[Calabar python|Calabariinae]]{{efn|name=Calabaria|Traditionally placed in Erycinae}} <br />
[[Candoia|Candoiinae]]{{efn|name=Candoia|Traditionally placed in Boinae}} <br />
[[Erycinae]] <br />
[[Sanziniinae]]<br />
[[Ungaliophiinae]]
}}

The '''Boidae''', commonly known as '''boas''' or '''boids''',<ref name="ITIS">{{ITIS |id=174321 |taxon=Boidae |access-date=14 July 2008}}</ref> are a [[Family (biology)|family]] of nonvenomous [[snake]]s primarily found in the Americas, as well as Africa, Europe, Asia, and some Pacific islands. Boas include some of the world's largest snakes, with the [[green anaconda]] of South America being the [[List of largest snakes|heaviest and second-longest snake]] known; in general, adults are medium to large in size, with females usually larger than the males. Six [[Subfamily|subfamilies]] comprising 14-15 [[Genus|genera]] and 54-67 [[species]] are currently recognized.<ref name="ITIS"/>

==Description==
Like the [[Pythonidae|python]]s, boas have elongated [[supratemporal]] bones. The [[quadrate bone]]s are also elongated, but not as much, while both are capable of moving freely so when they swing sideways to their maximum extent, the distance between the hinges of the lower jaw is greatly increased.<ref name="P&G77">Parker, H.W.; Grandison, A.G.C. 1977. ''Snakes – A Natural History''. Second Edition. British Museum (Natural History) and Cornell University Press. 108 pp. 16 plates. LCCCN 76-54625. {{ISBN|0-8014-1095-9}} (cloth), {{ISBN|0-8014-9164-9}} (paper).</ref>

[[File:Rudimentary hindlegs spurs in Boa constrictor snake.jpg|thumb|left|Cloaca region of a ''Boa constrictor'' with spurs (rudimentary hindlegs)]] Both families share a number of primitive characteristics. Nearly all have a relatively rigid lower jaw with a coronoid element, as well as a vestigial [[pelvic girdle]] with hind limbs that are partially visible as a pair of [[spur (zoology)|spurs]], one on either side of the [[Cloaca|vent]]. In males, these [[anal spurs]] are larger and more conspicuous than in females. A long row of palatal teeth is present, and most species have a functional left lung that can be up to 75% as large as the right lung.<ref name="P&G77"/><ref>[http://www.curator.org/legacyvmnh/weboflife/kingdom/P_Chordata/ClassReptilia/O_Squamata/InfraSnakes/FBoidae/boidae.htm Boidae] {{webarchive|url=https://web.archive.org/web/20080518091427/http://www.curator.org/legacyvmnh/weboflife/kingdom/P_Chordata/ClassReptilia/O_Squamata/InfraSnakes/FBoidae/boidae.htm |date=2008-05-18 }} at [http://www.curator.org/ VMNH]. Accessed 15 July 2008.</ref>

Boids are, however, distinguished from the pythons in that none has postfrontal bones or premaxillary teeth, and that they give birth to live young. When [[Infrared sensing in snakes|labial pit]]s are present, these are located between the scales as opposed to on them. Also, their geographical distributions are almost entirely mutually exclusive. In the few areas where they do coexist, the tendency is for them to occupy different habitats.<ref name="P&G77"/>
[[Image:Boavus idelmani.JPG|thumb|left|A fossil of ''[[Boavus]] idelmani'', an extinct species of boa]]

Formerly, boas were said to be found in the [[New World]] and pythons in the [[Old World]]. While this is true of [[Boinae|boine boas]], other boid species are present in Africa, much of southern Eurasia, [[Madagascar]], [[New Guinea]], and the [[Solomon Islands]], so this is not accurate. However, they seem more abundant in evolutionarily isolated areas. South America was isolated until a few million years ago, with a [[fauna]] that included [[marsupial]]s and other distinctive [[mammal]]s. With the formation of the [[Isthmus of Panama|Panamanian land bridge]] to North America about three million years ago, boines have migrated north as [[Colubridae|colubrids]] (and various [[Nearctic]] mammals) have migrated south, as part of the [[Great American Interchange]].

==Distribution and habitat==
Most species are found in North, Central, and South America, as well as the [[Caribbean]], while a few are found in southeastern Europe and [[Asia Minor]], North, Central and East Africa, [[Madagascar]], the [[Arabian Peninsula]], Central and Southwestern Asia, [[India]] and [[Sri Lanka]], [[Indonesia|Indonesian islands]] ([[Moluccas]], [[Western New Guinea|West Papua]], [[Talaud Islands|Talaud]], [[Sulawesi]]) and [[Papua New Guinea]] through [[Melanesia]] and [[Samoa]].<ref name="McD99"/>

==Feeding==
Prey is killed by [[constriction]]; after an animal has been grasped to restrain it, a number of coils are hastily wrapped around it. Then, by applying and maintaining sufficient pressure, the snake prevents its prey from inhaling, so that it eventually succumbs to [[asphyxia]]tion. Recently, the pressures produced during constriction have been suggested as the cause of cardiac arrest by interfering with blood flow, but this hypothesis has not yet been confirmed.

Larger specimens usually eat animals about the size of a [[Cat|domestic cat]], but larger food items are not unknown: the diet of the green anaconda (''[[Eunectes murinus]]'') is known to include subadult [[tapir]]s. Prey is swallowed whole, and may take several days or even weeks to fully digest. Despite their intimidating size and muscular power, they are generally not dangerous to humans.

Contrary to popular belief, even the larger species do not crush their prey to death; in fact, prey is not even noticeably deformed before it is swallowed. The speed with which the coils are applied is impressive and the force they exert may be significant, but death is caused by suffocation, with the victim not being able to move its ribs to breathe while it is being constricted.<ref name="Meh87">{{cite book |author=Mehrtens JM |year=1987 |title=Living Snakes of the World in Color |location=New York |publisher=Sterling Publishers |isbn=0-8069-6460-X |url-access=registration |url=https://archive.org/details/livingsnakesofwo00mehr }}{{page needed|date=January 2011}}</ref><ref name="Sti74">{{cite book |author=Stidworthy J |year=1974 |title=Snakes of the World |publisher=Grosset & Dunlap |isbn=0-448-11856-4}}</ref><ref name="Car63">{{cite book |last=Carr |first=Archie Fairly |year=1963 |title=The Reptiles |url=https://archive.org/details/reptiles00carr |url-access=registration |series=Life Nature Library |publisher=Time |location=New York |lccn=63012781}}{{page needed|date=January 2011}}</ref>

==Reproduction==
Most species of boa are [[Ovoviviparity|ovoviviparous]], with females giving birth to live young. This is in contrast to the [[Pythonidae|python]]s, which lay eggs ([[Oviparity|oviparous]]).

==Subfamilies==
{|cellspacing=0 cellpadding=2 border=1 style="border-collapse: collapse;"
!bgcolor="#f0f0f0"|Subfamily<ref name="ITIS"/>
!bgcolor="#f0f0f0"|Taxon author<ref name="ITIS"/>
!bgcolor="#f0f0f0"|Genera<ref name="ITIS"/>
!bgcolor="#f0f0f0"|Species<ref name="ITIS"/>
!bgcolor="#f0f0f0"|Common name
!bgcolor="#f0f0f0"|Geographic range<ref name="McD99"/>
|-
|[[Boinae]]
|[[John Edward Gray|Gray]], 1825<ref name=Gray1825 />
|align="center"|5
|align="center"|34
|true boas
|style="width:40%"|[[Central America|Central]] and South America and the [[West Indies]]
|-
|Calabariinae{{efn|name=Calabaria}}
|[[John Edward Gray|Gray]], 1858
|align="center"|1
|align="center"|1
|[[Calabar python]]
|tropical [[West Africa|West]] and [[Central Africa]]
|-
|[[Candoia|Candoiinae]]{{efn|name=Candoia}}
|Pyron, Burbink & Wiens, 2013
|align="center"|1
|align="center"|5
|bevel-nosed boas or keel-scaled boas
|from [[Sulawesi]] through the [[Maluku Islands]], [[New Guinea]] and [[Melanesia]] to [[Samoa]] and [[Tokelau]]
|-
|[[Erycinae]]
|[[Charles Lucien Bonaparte|Bonaparte]], 1831
|align="center"|3
|align="center"|18
|Old World sand boas
|Southern and Southeastern Europe, [[Asia Minor]], North, Central, West and East Africa, [[Arabia]], Central and Southwest Asia, India, [[Sri Lanka]], western Canada, the western United States, and northwestern Mexico
|-
|[[Sanziniinae]]
|Romer, 1956
|align="center"|2
|align="center"|4
|Madagascan boas or Malagasy boas
|[[Madagascar]]
|-
|[[Ungaliophiinae]]
|McDowell, 1987
|align="center|2
|align="center"|3
|neotropical dwarf boas
|Central and South America from southern Mexico to Colombia
|-
|}
[[Type genus]] = ''[[Boa (genus)|Boa]]'' – Gray, 1825<ref name="McD99"/>

==Taxonomy==
[[Pythonidae|Python]]s were historically classified as a subfamily of Boidae (called Pythoninae), but it was later determined that they are not closely related to boas despite having superficial similarities.<ref name="Reynolds14">{{cite journal|last1=Reynolds|first1=RG|last2=Niemiller|first2=ML|last3=Revell|first3=LJ|title=Toward a Tree-of-Life for the boas and pythons: multilocus species-level phylogeny with unprecedented taxon sampling|journal=Molecular Phylogenetics and Evolution|date=2014|volume=71|pages=201–213|url=http://www.rgrahamreynolds.info/wp-content/uploads/2014/01/Reynolds_etal_2014_MPE.pdf|doi=10.1016/j.ympev.2013.11.011|access-date=2018-05-14|archive-url=https://web.archive.org/web/20151202212953/http://www.rgrahamreynolds.info/wp-content/uploads/2014/01/Reynolds_etal_2014_MPE.pdf|archive-date=2015-12-02|url-status=dead|pmid=24315866}}</ref>

Almost all of the [[Boinae|non-boine]] boids are frequently elevated to their own full families: Calabariidae/inae, Candoiidae/inae, Charinidae/inae, Erycidae/inae, Sanziniidae/inae, and Ungaliophiidae/inae.<ref name="Reynolds14"/> The taxonomy of boid snakes has been long debated, and ultimately the decision whether to assign a particular clade to a particular [[Linnaean taxonomy|Linnaean rank]] (such as a [[Superfamily (zoology)|superfamily]], [[Family (biology)|family]], or [[subfamily]]) is arbitrary.

The subfamily Ungaliophiinae was formerly made up of four genera. Two of them (''[[Tropidophis]]'' and ''[[Trachyboa]]'') are actually more closely related to the American pipe snake (''[[Anilius|Anilius scytale]]'') than to the boas, and are now placed in the family [[Tropidophiidae]] within the superfamily [[Amerophidia]]. The other two genera (''[[Ungaliophis]]'' and ''[[Exiliboa]]'') are the sister group of the ''[[Charina]]''/''[[Lichanura]]'' clade within Boidae.<ref name="Reynolds14"/><ref name="Pyronetal2014">{{cite journal|last1=Pyron|first1=R. A.|last2=Reynolds|first2=R. G.|last3=Burbrink|first3=F. T.|title=A Taxonomic Revision of Boas (Serpentes: Boidae)|journal=Zootaxa|date=2014|volume=3846|issue=2|pages=249–260|url=https://home.gwu.edu/~rpyron/publications/Pyron_et_al_2014a.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://home.gwu.edu/~rpyron/publications/Pyron_et_al_2014a.pdf |archive-date=2022-10-09 |url-status=live|doi=10.11646/zootaxa.3846.2.5|pmid=25112250}}</ref>

== Gallery ==
<gallery class="center">
File:Boa constrictor, Vaňkovka, Brno (2).jpg|''[[Boa (genus)|Boa]]'' [[type species]]; the [[boa constrictor]] (''B''. ''constrictor'')
File:Puerto rican boa.jpg|''[[Chilabothrus]]'' type species; the [[Puerto Rican boa]] (''C''. ''inornatus'')
File:Corallus hortulanus head, Peru.jpg|''[[Corallus]]'' type species; the Amazon tree boa ([[Corallus hortulana|''C''. ''hortulana'']])
File:EpicratesCenchriaCenchria1.jpg|''[[Epicrates (snake)|Epicrates]]'' type species; the [[rainbow boa]] (''E''. ''cenchria'')
File:Sucuri verde.jpg|''[[Eunectes]]'' type species; the [[green anaconda]] (''E''. ''murinus'')
File:Pazifikboa.jpg|''[[Candoia]]'' type species; the Pacific ground boa ([[Candoia carinata|''C''. ''carinata'']])
File:Calabar Serpent2.jpg|''Calabaria'' type species; the [[Calabar python]] (''C''. ''reinhardtii'')
File:Charina bottae 190641815.jpg|''[[Charina]]'' type species; the [[Rubber boa|northern rubber boa]] (''C''. ''bottae'')
File:Eryx jaculus.jpg|''[[Eryx (snake)|Eryx]]'' type species; the javelin sand boa ([[Eryx jaculus|''E. jaculus'']])
File:Lichanura-trivirgata.jpg|''[[Lichanura]]'' type species; the [[desert rosy boa]] (''L. trivirgata'')
File:Dumeril's Madagascar ground boa (Acrantophis dumerili) male head Isalo.jpg|''[[Acrantophis]]'' type species; Dumeril's boa (''[[Acrantophis dumerili|A. dumerili]]'')
File:Ferme des Reptiles - Sanzinia madagascariensis 02.jpg|''[[Sanzinia]]'' type species; the Madagascar tree boa (''[[Sanzinia madagascariensis|S. madagascariensis]]'')
</gallery>

==See also==
* [[List of boine species and subspecies]]
* [[List of erycine species and subspecies]]

==Notes==
{{notelist|30em}}

==References==
{{Reflist|30em|refs=
<ref name=Gray1825>{{cite journal|last1=Gray|first1=John Edward|title=A Synopsis of the Genera of Reptiles and Amphibia, with a Description of some new Species|journal=Annals of Philosophy|date=1825|volume=10|issue=3|pages=209–210|url=https://www.biodiversitylibrary.org/page/2531437}}</ref>
}}

==Further reading==
{{refbegin}}
* Kluge, A.G. 1991. ''Boine Snake Phylogeny and Research Cycles''. Misc. Pub. Museum of Zoology, Univ. of Michigan No. 178. [http://deepblue.lib.umich.edu/bitstream/2027.42/56422/1/MP178.pdf PDF] at [http://deepblue.lib.umich.edu/ University of Michigan Library]. Accessed 8 July 2008.
{{refend}}

==External links==
{{EB9 Poster|Boa}}
*{{commons category-inline}}
{{Snake families}}
{{Boidae}}
{{Taxonbar|from=Q45556}}
{{Authority control}}

[[Category:Boidae| ]]
[[Category:Extant Maastrichtian first appearances]]
[[Category:Snake families]]
[[Category:Taxa named by John Edward Gray]]