Great Curassow Crax rubra Scientific name definitions

The Great Curassow is a physically large Cracid that ranges from Mexico south to Ecuador. It is a secretive species found in humid tropical forests that feeds mostly on fruits but also eats small invertebrates as well as vertebrates. Males are black with white under parts, a shaggy crest and a bright yellow spherical knob on the bill. Females are polymorphic, usually either barred (rare), rufous, or blackish. The Great Curassow have varying calls that range from low frequency booms to high-pitched yips. The species is declining due to habitat loss and overhunting, but it still can be seen stealing across the forest floor or feeding in the upper levels of the tree canopy.

Male 87–92 cm, 3600–4800 g; female 78–84 cm, 3100–4270 g. Crest very well developed ; this and prominent knob on bill separate male of present species from <em>C. alector</em> , the only other Crax with uniform black tail and yellow cere. In contrast to some congeners, e.g. C. daubentoni, knob size is not positively correlated with age in present species (1 Buchholz, R. (1991). Older males have bigger knobs:correlates of ornamentation in two species of curassow. Auk. 108(1): 153–160. Close ). Unlike any other curassow, female has three morphs; barred morph rare; intermediates between dark and red morphs may occur, as may those of barred and dark morphs; dark and barred morphs unknown in South American part of range, while red morph does not occur in Mexico. Immature male initially similar to dark-morph female , but darker; black adult plumage acquired long before bird fully grown; immature lacks knob on bill. Immature females of all morphs similar to adults. Race griscomi smaller, with some slight colour differences in females.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Heavy rainforest in tropical and lower subtropical zones; usually occurs in lowlands, but also in foothills up to altitudes of c. 1200 m, sometimes higher, e.g. in Volcán Barú, Panama, where species has been recorded up to 1900 m, but only up to 700 m in Ecuador (3 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. Close ). In Yucatán, Cozumel I and parts of Costa Rica also occurs in seasonally drier forest , although, unlike Penelope purpurascens, is absent from drier forests of W Mexico. On Cozumel I, occurrence closely tied to the presence of two trees, Manilkara zapota and Mastichodendron foetidissimum (Sapotaceae) (4 Martínez-Morales, M.A. (1999). Conservation status and habitat preferences of the Cozumel Curassow. Condor. 101(1): 14–20. Close ). Occasionally ventures into ravines, and, if unmolested, into partially cleared areas or even plantations.

Sedentary, although local people report that the species is present in Yaxchilán Natural Monument, Chiapas, Mexico, only during the dry season (5 Puebla-Olivares, F., E. Rodríguez-Ayala, B. E. Hernández-Baños, and A. G. Navarro Sigüenza (2002). Status and conservation of the avifauna of the Yaxchilán Natural Monument, Chiapas, México. Ornitología Neotropical 13(4):381–396. Close ).

Fruits, including figs and those of Spondias (Anacardiaceae), Chione (Rubiaceae) and Casimira (Malpighiaceae); usually fruits fallen from trees taken from ground, but sometimes also those still on trees, mainly in low branches, or shrubs; fruits can be eaten when hard and green. Study in El Salvador reported fruits of 15 plant species in diet, along with leaves (four species), and some invertebrates (3–4 species) (3 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. Close ), while a Guatemalan study identified plants belonging to 44 species and 17 families in this curassow’s diet, of which Lauraceae, Moraceae and Sapotaceae constituted 62% of vegetable matter, and 79·5% of diet by dry weight was fruit or seeds; just 2·5% of diet comprised arthropods (22 species from six orders), mostly a species of scarab beetle (3 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. Close ). Also said to take small vertebrates, located by gleaning foliage and litter. Overall, constituents of diet estimated to be fruits 70%, leaves 20%, invertebrates 5% and vertebrates 5% (6 Muñoz, M.C. and Kattan, G.H. (2007). Diets of cracids: how much do we know? Orn. Neotropical. 18(1): 21–36. Close ). Most feeding occurs between 09:00 hours and 17:00 hours (3 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. Close ). Forages singly , in pairs or in small groups of up to six in non-breeding season (with equal numbers of males and females) (3 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. Close ), but occasionally exceptional aggregations are recorded at fruiting trees, e.g. 40–50 in Belize at fruiting figs (3 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. Close ). Drinks at edges of streams or at waterholes (3 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. Close ).

Vocal behaviour subject to detailed investigation in Costa Rica (7 Baldo, S. and Mennill, D.J. (2011). Vocal behavior of Great Curassows, a vulnerable Neotropical bird. J. Field Orn.. 82(3): 249–258. Close ). Booming song, given only by males, consists of a deep, resonant and ventriloquial “oomp” note  that is not very far-carrying, repeated every c. 10 seconds and used in two types of series, the first rendered “whooó-hoo-hoo”, the second “woo...woooó, hoo, woo... woo” in which the first pause lasts 2–3 seconds and the second five seconds (8 Delacour, J., and D. Amadon (2004). Curassows and Related Birds. Second edition. Lynx Edicions, Barcelona, Spain, and American Museum of Natural History, New York, USA. Close ). In Costa Rica, bouts of booming generally last 35 minutes, occasionally for up to five hours, and is heard between Feb and Jun, peaking in late Apr and early May, and discriminant analysis of boom calls of birds from ten different locations revealed inter-individual variation in call structure (7 Baldo, S. and Mennill, D.J. (2011). Vocal behavior of Great Curassows, a vulnerable Neotropical bird. J. Field Orn.. 82(3): 249–258. Close ). Elsewhere, males mainly start singing c. 2 months before main breeding season and continue well into the female’s incubation period; peak daily vocalization activity is 05:00–07:00 hours, 09:00–13:00 hours and 15:00–17:00 hours; although nocturnal singing is recorded, no data exist to quantify its frequency (3 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. Close ). In alarm gives high-pitched “peep” notes  that trail off or externallink , primarily given by males (7 Baldo, S. and Mennill, D.J. (2011). Vocal behavior of Great Curassows, a vulnerable Neotropical bird. J. Field Orn.. 82(3): 249–258. Close ), while a captive female was reported to utter a soft, repeated “humm” and a louder “hoot, hoot” (8 Delacour, J., and D. Amadon (2004). Curassows and Related Birds. Second edition. Lynx Edicions, Barcelona, Spain, and American Museum of Natural History, New York, USA. Close ). Yip and bark calls are sex-specific alarm calls of very short duration (0·12 and 0·08 seconds, respectively). Also gives short snarl call (0·67 seconds) associated with threat display produced by adults with dependent young (7 Baldo, S. and Mennill, D.J. (2011). Vocal behavior of Great Curassows, a vulnerable Neotropical bird. J. Field Orn.. 82(3): 249–258. Close ).

Season Feb–May in mainland Mexico, just before rains; Feb–Jun on Cozumel I (3 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. Close ); incubating females found late Feb–early Jun in El Salvador, with peak Mar–Apr (3 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. Close ); Mar–May in Costa Rica; Feb–Mar in E Panama, during rains; two laying females in Mar in Chocó and NW Antioquia, Colombia. Considered monogamous, but polygamy possible (3 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. Close ). Pairs start constructing several different nests of which only one is completed (3 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. Close ). Nest sometimes relatively small and flimsy, but usually a more robust basket-shaped (3 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. Close ) structure (mean 37 cm long, 28 cm wide and 9 cm deep) (3 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. Close ) of sticks and lined with green leaves, placed in trees or large bushes (31 different species identified) (3 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. Close ) usually 4–9 m above ground (but overall range 3–23 m) (3 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. Close ) and often in close proximity to liana tangles (3 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. Close ); one nest was constructed entirely of green leaves. Lays two white (8 Delacour, J., and D. Amadon (2004). Curassows and Related Birds. Second edition. Lynx Edicions, Barcelona, Spain, and American Museum of Natural History, New York, USA. Close ) eggs, size 85–93·5 × 60–70·5 mm (3 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. Close ); incubation (in captivity) 28–32 days, in wild 33 days (3 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. Close ), with eggs always laid at sunset at two-day intervals (3 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. Close ); chicks greyish buff with black and chestnut markings above, whitish below, mass 123 g on hatching, 540 g at 30 days, 1250 g at 60 days, 1860 g at 90 days and 2500 g at 180 days (8 Delacour, J., and D. Amadon (2004). Curassows and Related Birds. Second edition. Lynx Edicions, Barcelona, Spain, and American Museum of Natural History, New York, USA. Close ). Small chicks may be carried by female when escaping perceived danger during first days of life (3 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. Close ). Long-lived; one female lived 24 years in captivity, and bred until 23.

VULNERABLE. Overall population considered to number fewer than 40,000 individuals. Rapidly disappears wherever logging roads are built into previously inaccessible forests; thus extirpated from much of Veracruz, Mexico; on other hand, range recently revealed to be more widespread than previously known in Mexican Yucatán (9 Hernández-Pérez, E., Martínez-Morales, M.A., Tobón- Sampedro, A., Pinilla-Buitrago, G., Sanvicente López, M. and Reyna-Hurtado, R. (2014). Registros notables que amplían la distribución conocida de dos especies de crácidos (Aves: Galliformes) en la Península de Yucatán, México. Orn. Neotropical. 25(2): 291–301. Close ) and to encompass additional protected areas in the region (10 Tellkamp, M. P., and T. H. Martin (2015). Noteworthy bird records from southern Yucatán state, México. Cotinga 37:18–21. Close ). In Guatemala, still reported to be fairly common in E Caribbean lowlands, N Quiché and remote areas of Petén, but much reduced and threatened on Pacific slope, occurring in fragmented populations, particularly in Atitlán complex and S slopes of Volcanes Lacandón and Chiquibal. In El Salvador, species survives in El Imposible National Park, where population of at least 120 individuals in 1999 (3 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. Close ). Maintains stable populations throughout vast areas in Nicaragua. In Costa Rica, now mostly scarce and local, but can persist in secondary forest in absence of hunting (11 Whitworth, A., Beirne, C., Flatt, E., Pillco Huarcaya, R., Cruz Diaz, J.C., Forsyth, A., Molnár, P.K. and. Vargas Soto, J.S. (2018). Secondary forest is utilized by Great Curassows (Crax rubra) and Great Tinamous (Tinamus major) in the absence of hunting. Condor 120(4): 852–862. Close ), with good populations persisting mainly in some national parks, including Santa Rosa, Rincón de la Vieja and Corcovado. In Panama, remains only in remote, uninhabited areas, where still apparently fairly common, but disappears quickly, as settlement progresses; more widespread on Caribbean slope, while on Pacific slope perhaps limited to S Veraguas, W Azuero Peninsula, Darién (e.g. Serranía de Majé) (12 Angehr, G.R. and Christian, D.G. (2000). Distributional records from the highlands of the Serranía de Majé, an isolated mountain range in eastern Panama. Bull. Brit. Orn. Club. 120(3): 173–178. Close ), and parts of Canal Zone, where very rare; in 1979 good numbers still occurred in Barro Colorado I Biological Reserve, where well protected, but apparently extirpated from Chiriquí region. In Colombia, persists only in remoter areas and along Pacific coast, but never near roads. In 1986 species was feared completely eradicated from Ecuador, although it was still present in Guayas in 1970s (3 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. Close ), but today the species clings on only in far NW, in Esmeraldas (3 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. Close ) and may number < 100 individuals. Legally hunted in some countries. Race griscomi once feared extinct; in 1965, said to survive, although sometimes hunted; a male was seen around 1990 by a researcher after months of searching, but mid-1990s surveys suggest that population might still number c. 300 birds (4 Martínez-Morales, M.A. (1999). Conservation status and habitat preferences of the Cozumel Curassow. Condor. 101(1): 14–20. Close ), with another estimate of 372 ± 155 individuals, before two hurricanes hit Cozumel in 2005; it has been suggested that a ban on hunting, eradication of feral fauna, particularly dogs, and implementation of a captive-breeding programme to supplement the wild population are needed to ensure this race’s survival (13 Martínez-Morales, M.A., Cruz, P.C. and Cuarón, A.D. (2009). Predicted population trends for Cozumel Curassows (Crax rubra griscomi): empirical evidence and predictive models in the face of climate change. J. Field Orn.. 80(4): 317–327. Close ). Nominate race quite common in captivity, where frequently bred; in Guatemala, small breeding programme initiated with aim of reintroducing species to areas where now extinct. One of cracids most commonly kept in captivity by locals: in Guatemala up to 100 live individuals, mainly young birds, estimated to be sold each year in local trade. CITES III in Guatemala, Costa Rica, Honduras and Colombia.