![]() ![]() A whole genome sequencing study published in 2014 places the hoatzin as the sister taxon of a clade composed of Gruiformes (cranes) and Charadriiformes (plovers). At various times, it has been allied with such taxa as the tinamous, the Galliformes (gamebirds), the rails, the bustards, seriemas, sandgrouse, doves, turacos and other Cuculiformes, and mousebirds. Because of its distinctness, it has been given its own family, the Opisthocomidae, and its own suborder, the Opisthocomi. Much debate has occurred about the hoatzin's relationships with other birds. The hoatzin was originally described in 1776 by German zoologist Statius Müller. The generic name Opisthocomus comes from Ancient Greek ὄπισθοκομος ópisthokomos derived from ὄπισθε ópisthe ( ὄπισθεν ópisthen before a consonant) "behind" and κόμη kómē "hair" altogether meaning "long hair behind" referring to its large crest. Taxonomy, systematics, and evolution In Brazil A similar trait is seen in turacos, where nestlings are using claws on their wings to climb in the trees. Modern researchers, however, hypothesize that the young hoatzin's claws are of more recent origin, and may be a secondary adaptation from its frequent need to leave the nest and climb about in dense vines and trees well before it can fly. Since Archaeopteryx had three functional claws on each wing, some earlier systematists speculated that the hoatzin was descended from it, because nestling hoatzins have two functional claws on each wing. This has inevitably led to comparisons to the fossil bird Archaeopteryx, but the characteristic is rather an autapomorphy, possibly caused by an atavism toward the dinosaurian finger claws, whose developmental genetics ("blueprint") presumably is still in the avian genome. If discovered, however, they drop into the water and swim under the surface to escape, then later use their clawed wings to climb back to the safety of the nest. When predators such as the great black hawk attack a hoatzin nesting colony, the adults fly noisily about, trying to divert the predator's attention, while the chicks move away from the nest and hide among the thickets. Immediately on hatching, they can use these claws, and their oversized feet, to scramble around the tree branches without falling into the water. Hoatzin chicks have two claws on each wing. These calls are often associated with body movements, such as wing spreading. It is a noisy bird, and makes a variety of hoarse calls, including groans, croaks, hisses, and grunts. The underparts are buff, while the crissum (the undertail coverts surrounding the cloaca), primaries, underwing coverts, and flanks are rich rufous- chestnut, but this is mainly visible when it opens its wings. The upper parts are dark, sooty brown-edged buff on the wing coverts, and streaked buff on the mantle and nape. The long, sooty-brown tail is bronze-green tipped with a broad whitish or buff band at the end. It has an unfeathered blue face with maroon eyes, and its head is topped by a spiky, rufous crest. The hoatzin is pheasant-sized, with a total length of 65 cm (26 in), and a long neck and small head. It is notable for having chicks that have claws on two of their wing digits.ĭescription At Lake Sandoval, Peru The taxonomic position of this family has been greatly debated by specialists, and is still far from clear. It is the only extant species in the genus Opisthocomus which is the only extant genus in the Opisthocomidae family under the order of Opisthocomiformes. The hoatzin ( / h oʊ ˈ æ t s ɪ n/ hoh- AT-sin) or hoactzin ( / h oʊ ˈ æ k t s ɪ n/ hoh- AKT-sin) ( Opisthocomus hoazin) is a species of tropical bird found in swamps, riparian forests, and mangroves of the Amazon and the Orinoco basins in South America.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |