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Horned guan
Horned guan, Sendero Vega Del Volcan, San Marcos Department, Guatemala
Female Oreophasis derbianus call
Conservation status
Endangered  (IUCN 3.1)
CITES Appendix I (CITES)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Galliformes
Family:	Cracidae
Subfamily:	Oreophasinae Sclater & Salvin, 1870
Genus:	Oreophasis G.R. Gray, 1844
Species:	O. derbianus
Binomial name
Oreophasis derbianus Gray, 1844

The horned guan (Oreophasis derbianus) is an endangered species in an ancient group of birds of the family Cracidae, which are related to the Australasian megapodes or mound builders (Megapodiidae). It is found in Mexico, Guatemala, and possibly Honduras.

Taxonomy and systematics

The horned guan is not closely related to other guans, but merely resembles these birds in overall shape and color, whereas the horn is more reminiscent of the helmeted curassows. The species is the only survivor of a very ancient lineage of cracids that has been evolving independently from all other living members of this family for at least 20 million years, and possibly as much as 40 million years. Given that the basal relationships of the living cracids are not well resolved, the horned guan is often placed in its own subfamily Oreophasinae. Other taxonomists have placed it in either subfamily Cracinae or Penelopinae.

The holotype specimen of the horned guan is held in the collections of National Museums Liverpool at World Museum, with accession number NML-VZ D210. The specimen was collected from Volcán de Fuego, Guatemala by Don Joaquin Quinones circa 1843 and came to the Liverpool national collection via the 13th Earl of Derby’s collection which was bequeathed to the people of Liverpool.

The horned guan is monotypic.

Description

The horned guan is 75 to 85 cm (30 to 33 in) long. Its most distinctive feature is the tall, red, fleshy "horn" on its forehead. It has a small head, long strong legs, and a long broad tail. The sexes are alike in plumage but males have a taller horn and longer wings, tail, and legs than females. Adults have a glossy black head, neck, and upperparts with a bluish sheen. Their tail is black with a wide white band near its base. Their throat, breast, and upper belly are whitish with black flecks and their lower belly and flanks are brown. They have a small red dewlap, a white iris, a yellow bill, and red legs and feet. Juveniles resemble adults but are duller and have a smaller horn.

Distribution and habitat

The horned guan is found in the southern Mexican state of Chiapas, possibly in Oaxaca, and in southern Guatemala. Reports from Honduras have not been confirmed. Its distribution is not continuous but highly local. It inhabits humid subtropical montane evergreen forest, cloudforest, and pine-oak forest. Its habitat is characterized by much undergrowth of tree ferns, epiphytes, mosses, and vines. In elevation it mostly ranges between 2,300 and 3,100 m (7,500 and 10,200 ft) but locally occurs as low as 1,200 m (3,900 ft) and as high as 3,350 m (11,000 ft).

Behavior

Movement

The horned guan is a year-round resident throughout its range.

Feeding

The horned guan feeds mostly on a very wide variety of fruits; green leaves are a significant part of its diet with flowers and possibly insects eaten in small amounts. It forages singly or in small groups at all levels of the forest including the ground. Many seeds pass intact through its system, which suggests that it might be a significant dispersal agent.

Breeding

Most of the information about the horned guan's breeding biology comes from Mexico in a study published in 1995. Its breeding season appears to span at least from January to March. It is believed to be polygynous, with males spending a few days with each of three to five females. Its nest is an oval structure of dry leaves and roots place high in a tree and usually near running water. The clutch size is two eggs. The female incubates the clutch for 34 to 36 days and chicks leave the nest about three to six days after hatch.

Vocalization

Male and female horned guans have very different vocalizations. Males have a repertoire of at least five calls and females have seven or eight. Female's calls are "guttural and louder compared to those of males". The male's main call is "a very deep, slow and soft 'mooing'...comprising seven notes, a single brief hum followed by six paired hums, i.e. 'hum; hum, hummm; hum, hummm; hum, hummmmm' " that can be repeated for an hour. Females usually call in response to males, with a "guurk, guurk, guurk,... or guauuu, guauuu, guauuu".

Status

The IUCN originally in 1988 assessed the horned guan as Threatened, then in 1994 as Vulnerable, and since 2000 as Endangered. It has a very limited range and its estimated population of 600 to 1700 mature individuals is believed to be decreasing. Its range has contracted due to logging, firewood gathering, conversion of forest to agriculture, and subsistence hunting pressure. "The isolation of disjunct subpopulations makes this species especially vulnerable to further local extirpation. Climate change is further expected to exacerbate horned guan population declines by inducing shifts in the species' already restricted range". It does occur in at least one protected area in each of Mexico and Guatemala. However, one of its largest populations is on the unprotected Volcán Tacaná on the border between the two countries.

References

1. ^ BirdLife International (2020). "Horned Guan Oreophasis derbianus". IUCN Red List of Threatened Species. 2020: e.T22678453A177970135. doi:10.2305/IUCN.UK.2020-3.RLTS.T22678453A177970135.en. Retrieved 7 April 2024.
2. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
3. ^ Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (January 2024). "Megapodes, guans, guineafowl, New World quail". IOC World Bird List. v 14.1. Retrieved April 6, 2024.
4. Pereira, Sérgio Luiz; Baker, Allan J., & Wajntal, Anita (2002): Combined nuclear and mitochondrial DNA sequences resolve generic relationships within the Cracidae (Galliformes, Aves). Systematic Biology 51(6): 946–958. doi:10.1080/10635150290102519 PMID 12554460 PDF fulltext
5. Eo Soo Hyung, Bininda-Emonds, O.R.P., and Carroll, J.P. (2009). A phylogenetic supertree of the fowls (Galloanserae, Aves). Zool. Scripta. 38(5): 465–481.
6. ^ del Hoyo, J. and G. M. Kirwan (2020). Horned Guan (Oreophasis derbianus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.horgua1.01 retrieved April 7, 2024
7. ^ Fagan, Jesse; Komar, Oliver (2016). Field Guide to Birds of Northern Central America. Peterson Field Guides. Boston: Houghton Mifflin Harcourt. pp. 38–39. ISBN 978-0-544-37326-6.
8. Check-list of North American Birds (7th ed.). Washington, D.C.: American Ornithologists' Union. 1998. p. 114.
9. ^ del Hoyo, J., and A. Motis (2004). Update chapter. In Curassows and Related Birds (J. Delacour, and D. Amadon), Second edition. Lynx Edicions, Barcelona, Spain, and American Museum of Natural History, New York, USA. pp. 322–476.
10. ^ González-García, F., Santana-C., E., Jordano Barbudo, P.D., Rico-Gray, V. and Urios Moliner, V. (2017). Diet and feeding behavior of the Horned Guan (Oreophasis derbianus) in Mexico. Wilson J. Orn.. 129(4): 771–782.

External links

• BirdLife species factsheet
• Article Aventuras Naturales
• Horned Guan image; Article (Oil paintings)
• Horned Guan photo gallery VIREO

v t e Genera of landfowl and their extinct allies
Kingdom: Animalia Phylum: Chordata Class: Aves Superorder: Galloanserae Clade: Pangalliformes
Pangalliformes incertae sedis †Anisolornis? †Archaeophasianus? †Argillipes? †Austinornis? †Chambiortyx †Coturnipes? †"Gigantibis"? †Litoripes? †Percolinus? †Tegulavis? †Gallinuloididae Gallinuloides Paraortygoides †Paraortygidae Paraortyx Pirortyx Scopelortyx Xorazmortyx †Quercymegapodiidae Ameripodius Quercymegapodius Taubacrex †Sylviornithidae Megavitiornis Sylviornis Galliformes See below ↓
Galliformes Galliformes †Amitabha †Bumbanipodius †Bumbanortyx †Linquornis †Namaortyx †Palaeoalectoris †Procrax †Sobniogallus †Taoperdix Megapodiidae †Garrdimalga? †Mwalau †Ngawupodius Alecturini Aepypodius Alectura †Latagallina Leipoa †Progura Talegalla Megapodiini Eulipoa Macrocephalon Megapodius Cracidae †Archaealectrornis †Boreortalis †Palaeonossax †Procrax Penelopinae Aburria Chamaepetes Penelope Penelopina Pipile Cracinae Oreophasis Ortalis Cracini Crax Mitu Nothocrax Pauxi Phasianoidea See below ↓
Phasianoidea Numididae Acryllium Agelastes Guttera Numida †Telecrex Odontophoridae †Miortyx †Nanortyx †Neortyx Ptilopachinae Ptilopachus Odontophorinae Callipepla Colinus Cyrtonyx Dactylortyx Dendrortyx Odontophorus Oreortyx Philortyx Rhynchortyx Phasianidae See below ↓
Phasianidae Phasianidae †Bantamyx †Centuriavis †Diangallus †Eurobambusicola †Lophogallus †Megalocoturnix †Miogallus †Mioryaba †Palaeocryptonyx †Palaeortyx †Panraogallus †Pliogallus †Plioperdix †Rustaviornis †Schaubortyx †Shandongornis †Shanxiornis †Titanoperdix †Tologuica Rollulinae Arborophila Caloperdix Melanoperdix Rhizothera Rollulus Xenoperdix Pavoninae Tropicoperdix Coturnicini Alectoris Ammoperdix Coturnix Margaroperdix †?Ophrysia Perdicula Pternistis Synoicus Tetraogallus Gallini Bambusicola Campocolinus Francolinus Gallus Ortygornis Peliperdix Scleroptila Pavonini Afropavo Argusianus Pavo Rheinardia Polyplectronini Galloperdix Haematortyx Polyplectron Phasianinae †Chauvireria Ithaginis Lerwa Lophophorini Lophophorus Tetraophasis Tragopan Phasianini Catreus Chrysolophus Crossoptilon Lophura Perdix Phasianus Syrmaticus Tetraonini Bonasa Canachites Centrocercus Dendragapus Falcipennis Lagopus Lyrurus Meleagris †Palaealectoris †Proagriocharis Pucrasia †Rhegminornis Tetrao Tetrastes Tympanuchus

• IUCN Red List endangered species
• Guans (bird)
• Birds of Guatemala
• Birds of Mexico
• Birds described in 1844
• Taxa named by George Robert Gray
• Central American montane forests