Editing Hornbill (section)

==Taxonomy==
{{See also|List of hornbills}}

The family Bucerotidae was introduced (as Buceronia) by the French [[polymath]] [[Constantine Samuel Rafinesque]] in 1815;<ref>{{cite book |last=Rafinesque |first=Constantine Samuel |author-link=Constantine Samuel Rafinesque |year=1815 |title=Analyse de la nature ou, Tableau de l'univers et des corps organisés |publisher=Self-published |place=Palermo |language=fr |page=66 |url=https://www.biodiversitylibrary.org/page/48310144}}</ref><ref name="AFGN">{{cite book |last=Bock |first=Walter J. |year=1994 |title=History and Nomenclature of Avian Family-Group Names |series=Bulletin of the American Museum of Natural History |volume= 222 |publisher=American Museum of Natural History |place=New York |pages=146, 252 |hdl=2246/830 |url=http://digitallibrary.amnh.org/handle/2246/830}}<!--Linked page allows download of the 48MB pdf--></ref> it comes from the genus name [[Buceros]] given by [[Carl Linnaeus]] in 1758 from the [[Greek language|Greek]] word {{lang|el|βούκερως}} ''bōukeros'' which means "cow horn".<ref name="AFGN"/><ref>{{cite book | last=Jobling | first=James A. | year=2010 | title=The Helm Dictionary of Scientific Bird Names | location=London, England, UK | publisher=Christopher Helm  | isbn=978-1-4081-2501-4 | page=79 }}</ref>

There are two [[subfamilies]]: the [[Bucorvinae]] contain the two ground hornbills in a single [[genus]], and the Bucerotinae contain all other [[taxa]]. Traditionally they are included in the order [[Coraciiformes]] (which includes also [[kingfisher]]s, [[Coraciidae|roller]]s, [[hoopoe]]s and [[bee-eater]]s). In the [[Sibley-Ahlquist taxonomy]], however, hornbills are separated from the [[Coraciiformes]] into an [[order (biology)|order]] of their own, [[Bucerotiformes]], with the subfamilies elevated to family level. Given that they are almost as distant from the rollers, kingfishers and allies as are the [[trogon]]s,<ref>{{cite journal |title=Molecular support for a sister group relationship between Pici and Galbulae (Piciformes ''sensu'' Wetmore 1960) |journal=[[Journal of Avian Biology|J. Avian Biol.]] |year=2003 |first1=Ulf S. |last1=Johansson |first2=Per G.P. |last2=Ericson |volume=34 |issue=2 |pages=185–197 |doi=10.1034/j.1600-048X.2003.03103.x |url=http://www.nrm.se/download/18.4e32c81078a8d9249800021325/Johansson%2520%26%2520Ericson%2520-%2520Piciformes%5B1%5D.pdf |access-date=2008-10-30 |archive-date=2018-10-04 |archive-url=https://web.archive.org/web/20181004210235/http://www.nrm.se/download/18.4e32c81078a8d9249800021325/Johansson%2520%26%2520Ericson%2520-%2520Piciformes%5B1%5D.pdf |url-status=dead }}</ref> the arrangement chosen is more a matter of personal taste than any well-established taxonomic practice. All that can be said with reasonable certainty is that placing the hornbills outside the Coraciiformes and the trogons inside would be incorrect.

Genetic data suggests that [[Bucorvidae|ground hornbills]] and ''[[Bycanistes]]'' form a clade outside the rest of the hornbill lineage.<ref>Woodruff, D. S. & Srikwan, S. 2011. "Molecular genetics and the conservation of hornbills in fragmented landscapes." In Poonswad, P. (ed) ''The Asian Hornbills: Ecology and Conservation''. National Center for Genetic Engineering and Biotechnology, Bangkok, pp. 257–264.</ref> They are thought to represent an early African lineage, while the rest of Bucerotiformes evolved in Asia. However, another study claims that the ground hornbills diverged first, followed by  ''[[Tockus]]''. Within ''Tockus'', two clades have been identified based on genetics and vocal types—'whistlers' and 'cluckers'. The 'cluckers' have been placed in a separate genus, ''[[Lophoceros]]''.<ref name=gonzalez>{{Cite journal |last1=Gonzalez |first1=J.-C.T. |last2=Sheldon |first2=B.C. |last3=Collar |first3=N.J. |last4=Tobias |first4=J.A. |date=2013 |title=A comprehensive molecular phylogeny for the hornbills (Aves: Bucerotidae) |journal=Molecular Phylogenetics and Evolution |volume=67 |issue=2 |pages=468–483 |doi=10.1016/j.ympev.2013.02.012|pmid=23438388|bibcode=2013MolPE..67..468G }} See also the correction: {{Cite journal |last1=Gonzalez |first1=J.-C.T. |last2=Sheldon |first2=B.C. |last3=Collar |first3=N.J. |last4=Tobias |first4=J.A. |date=2013 |title=Corrigendum to "A comprehensive molecular phylogeny for the hornbills (Aves: Bucerotidae)" [Mol. Phylogenet. Evol. 67 (2013) 468–483] |journal=Molecular Phylogenetics and Evolution |volume=68 |issue=3 |page=715 |doi=10.1016/j.ympev.2013.05.008|doi-access=free|bibcode=2013MolPE..68..715G }}</ref><ref name=ioc/>

''Bycanistes'' belongs to a clade of mostly African species that also includes ''[[Ceratogymna]]'' and ''[[Tropicranus]]''. Another member of this clade is the [[Black dwarf hornbill]]. The Black dwarf hornbill is typically classified in the genus ''Tockus'' but in this study, is a sister species to the White-crested hornbill. If these two species are classified in congeneric, ''Tropicranus'' becomes a junior synonym of ''[[Horizocerus]]'', as that was one of the old names used for the Black dwarf hornbill. This clade also includes one Southeast Asian species, the [[white-crowned hornbill]].

As for the other Asian hornbill species, ''[[Buceros]]'' and ''[[Rhinoplax]]'' are each other's closest relatives, ''[[Anorrhinus]]'' is part of a clade that has ''[[Ocyceros]]'' and ''[[Anthracoceros]]'' as sister taxa, and ''[[Aceros]]'', ''[[Rhyticeros]]'', and ''[[Penelopides]]'' form another clade. However, according to this study, ''[[Aceros]]'' is polyphyletic; the [[rufous-headed hornbill]], [[writhed hornbill]], and [[wrinkled hornbill]] form a clade with the [[Sulawesi hornbill]], and are in turn more closely related to ''[[Penelopides]]''. These four species have been classified in a separate genus, ''[[Rhabdotorrhinus]]''. Similarly, the [[knobbed hornbill]] is more closely related to ''[[Rhyticeros]]'', leaving the [[rufous-necked hornbill]] the only member of the genus ''[[Aceros]]''.<ref name=gonzalez /><ref name=ioc/>

The following cladogram showing the relationships between the genera is based on a [[molecular phylogenetic]] study by Juan-Carlos Gonzalez and collaborators that was published in 2013.<ref name=gonzalez/> The number of species in each genus is taken from the list of world birds maintained by [[Frank Gill (ornithologist)|Frank Gill]], [[Pamela C. Rasmussen]] and David Donsker on behalf of the [[International Ornithologists' Union]].<ref name=ioc>{{cite web| editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela C. Rasmussen | date=December 2023 | title=Mousebirds, Cuckoo Roller, trogons, hoopoes, hornbills | work=IOC World Bird List Version 14.1 | url=https://www.worldbirdnames.org/bow/mousebirds/ | publisher=International Ornithologists' Union | access-date=9 January 2024 }}</ref>
{{Clade | style=font-size:90%;line-height:90%
|label1='''Bucerotidae'''
|1={{clade
   |1={{clade
      |1=''[[Lophoceros]]'' – 8 species
      |2=''[[Tockus]]'' – 10 species
      }}
   |2={{clade
      |1={{clade
         |1={{clade
            |1=''[[Berenicornis]]'' – white-crowned hornbill
            |2=''[[Horizocerus]]'' – 4 species
            }}
         |2={{clade
            |1=''[[Ceratogymna]]'' – 2 species
            |2=''[[Bycanistes]]'' – 6 species
            }}
         }}
      |2={{clade
         |1={{clade
            |1=''[[Rhinoplax]]'' – helmeted hornbill
            |2=''[[Buceros]]'' – 3 species
            }}
         |2={{clade
            |1={{clade
               |1=''[[Anorrhinus]]'' – 3 species
               |2={{clade
                  |1=''[[Ocyceros]]'' – 3 species
                  |2=''[[Anthracoceros]]'' – 5 species
                  }}
               }}
            |2={{clade
               |1=''[[Aceros]]'' – rufous-necked hornbill

               |2={{clade
                  |1=''[[Rhyticeros]]'' – 6 species
                  |2={{clade
                     |1=''[[Rhabdotorrhinus]]'' – 4 species
                     |2=''[[Penelopides]]'' – 5 species
                     }}
                  }}
               }}
            }}
         }}
      }}
   }}
}}

<gallery widths="200px" heights="200px">
File:Redbilledhornbill129.jpg|The [[red-billed hornbill]] now usually includes several species-level [[taxa]]
File:Indian Grey Hornbill I2 IMG 9029.jpg|The [[Indian grey hornbill]] is an overall grey bird and native to the [[Indian subcontinent]]. So are other members of genus ''Ocyceros''.
File:Anthracoceros marchei -Palawan-8.jpg|All members of ''Anthracoceros'', like these [[Palawan hornbill]]s, have a pied plumage
File:Helmeted Hornbill.jpg|upright|The uniquely long-tailed [[helmeted hornbill]] is commonly placed in its own genus, though some place it in ''Buceros''
File:Blackwhitecasquedhornbill1.jpg|Like all ''Bycanistes'', the [[black-and-white-casqued hornbill]] has pied plumage and a dull beak. It is found in wooded habitats in Africa.
File:Naturalis Biodiversity Center - MMNAT01 AF NNM001000152 - Natuurkundige Commissie voor Nederlandsch-Indië - Bird species - Art.jpg|Knobbed hornbill, ''Aceros cassidix'', early 19th century, Indonesia
File:Bucorvus leadbeateri toss.jpg|[[Southern ground hornbill]] (bluish throat indicates female) about to swallow a [[grasshopper]]
</gallery>

=== Fossil record ===
* ''[[Bucorvus]] brailloni'' – Late Miocene (Morocco)<ref name="Brunet, J 1971" />
* ''[[Euroceros]] bulgaricus'' – Late Miocene (Bulgaria)<ref name="Boev, Z. 2007" />
* ''[[Tockus]]'' sp. – Early Miocene (Uganda)<ref>{{Cite journal|url=https://onlinelibrary.wiley.com/doi/10.1111/ibi.12907|doi=10.1111/ibi.12907|title=Bucerotidae from the early Miocene of Napak, Uganda (East Africa): The earliest hornbill with a modern-type beak|year=2021|last1=Riamon|first1=Ségolène|last2=Pickford|first2=Martin |last3=Senut|first3=Brigitte|last4=Louchart|first4=Antoine|journal=Ibis|volume=163|issue=2|pages=715–721|s2cid=230632701}}</ref>

Some scientist believe the hornbill [[phylogenetic tree|evolutionary tree]] spread from the Indian microcontinent after [[Gondwana]], before [[Indian subcontinent#Geology|India merged with Asia]].<ref>{{cite journal |last1=Viseshakul |first1=N. |last2=Charoennitikul |first2=W. |last3=Kitamura |first3=S. |last4=Kemp |first4=A. |last5=Thong-Aree |first5=S. |last6=Surapunpitak |first6=Y. |last7=Poonswad |first7=P. |last8=Ponglikitmongkol |first8=M. |title=A phylogeny of frugivorous hornbills linked to the evolution of Indian plants within Asian rainforests: Frugivorous hornbills link to evolution of Asian rainforests |journal=Journal of Evolutionary Biology |date=July 2011 |volume=24 |issue=7 |pages=1533–1545 |doi=10.1111/j.1420-9101.2011.02285.x|pmid=21545425 |doi-access=free}}</ref><ref>{{cite web |title=Forest guardians in the Western Ghats |url=https://www.researchgate.net/publication/318339218 |date=January 2017}}</ref>