The yellow-knobbed curassow (''Crax daubentoni'') is a species of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

in the family

Cracidae The chachalacas, guans, and curassows are birds in the Family (biology), family Cracidae. These are species of tropical and subtropical Central America, Central and South America. The range of one species, the plain chachalaca, just reaches south ...

, the

chachalaca Chachalacas are galliform birds from the genus ''Ortalis''. These birds are found in wooded habitats in the far southern United States (Texas), Mexico, and Central and South America. They are social, can be very noisy and often remain fairly ...

s, guans, and curassows. It is found in

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

and

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

Taxonomy and systematics

The yellow-knobbed curassow was formerly classified as a subspecies of blue-billed curassow (''Crax alberti''). It is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

. A few subspecies previously proposed for it were determined to be hybrids or aberrant individuals and so were not adopted.del Hoyo, J. and G. M. Kirwan (2020). Yellow-knobbed Curassow (''Crax daubentoni''), 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.yekcur1.01 retrieved October 1, 2021

Description

The yellow-knobbed curassow is long. Males usually weigh between but one weighed only . A female weighed . The male is the only curassow with a knobbed yellow

cere The beak, bill, or Rostrum (anatomy), rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for pecking, wikt:grasp#Verb, grasping, and holding (in wikt:probe ...

and wattle. Males and females are mostly black with a white lower belly, vent area, and tips of the tail feathers. Females have a black cere and pale barring on the breast and lower belly.

Distribution and habitat

The yellow-knobbed curassow is found in northern Venezuela as far east as

Sucre Sucre (; ) is the ''de jure'' capital city of Bolivia, the capital of the Chuquisaca Department and the sixth most populous city in Bolivia. Located in the south-central part of the country, Sucre lies at an elevation of . This relatively high ...

and

Monagas Monagas State (, ) is one of the 23 states of Venezuela. Monagas State covers a total surface area of and, as of the 2011 census, had a population of 905,443. Monagas State is surrounded by Sucre State in the north, Anzoátegui State in the ...

states and in immediately adjacent northeastern Colombia. It primarily inhabits

gallery forest A gallery forest is one formed as a corridor along rivers or wetlands, projecting into landscapes that are otherwise only sparsely treed such as savannas, grasslands, or deserts. The gallery forest maintains a more temperate microclimate above th ...

and tall scrub in the ''

llanos The Llanos ( Spanish ''Los Llanos'', "The Plains"; ) is a vast tropical grassland plain situated to the east of the Andes in Colombia and Venezuela, in northwestern South America. It is an ecoregion of the tropical and subtropical grasslands, ...

''. It also occurs in valleys and ravines in the nearby foothills. In elevation it ranges between in Colombia and in Venezuela.

Behavior

Feeding

The yellow-knobbed curassow forages in small family groups, or in combined ones of up to 15 birds in the dry season. Its primary foods are fruits and seeds with very small amounts of leaves, other plant parts, and insects. It feeds at all levels from the ground to the treetops.

Breeding

The yellow-knobbed curassow lays eggs during May and June, the early part of the rainy season. It appears to be

polygynous Polygyny () is a form of polygamy entailing the marriage of a man to several women. The term polygyny is from Neoclassical Greek πολυγυνία (); . Incidence Polygyny is more widespread in Africa than in any other continent. Some scholar ...

. It builds an oval nest of branches and lianas lined with leaves and grass and usually sites it in a tree and concealed by vines. The clutch size is two eggs.

Vocalization

Male yellow-knobbed curassows sing a "bomb-dropping" descending whistle, sometimes combined with a wing-clapping display or booming. The former is "4–10 rapid cracks of wings above the bird’s back, 'wapp!, wapp!, wapp!-wapp!-wapp!'". The booming is described as "uuumh...uhh".

Status

The

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

has assessed the yellow-knobbed curassow as Near Threatened. It has a small population that is declining due to habitat loss and hunting.

Gallery

File:Crax daubentoni -Hamerton Zoo, Cambridgeshire, England -male-8a (1).jpg, Male at Hamerton Zoo Park, England File:Crax daubentoni -Philadelphia Zoo -female-8a-4c.jpg, Female at

Philadelphia Zoo The Philadelphia Zoo is a zoo located in the Centennial District of Philadelphia on the west bank of the Schuylkill River. It was the first true zoo in the United States; it was chartered by the Commonwealth of Pennsylvania on March 21, 1859 ...

, USA File:Yellow-knobbed Curassow SMTC.jpg, Female File:Yellow-knobbed Curassow RWD2.jpg, Female File:Yellow-knobbed Curassow RWD3.jpg, Female

References

{{Taxonbar, from=Q1267444 Crax Curassows Birds of Venezuela Birds described in 1867 Taxa named by George Robert Gray Taxonomy articles created by Polbot