Chivi vireo
Chivi vireo | |
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A chivi vireo at Carlsen Field, Trinidad | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Vireonidae |
Genus: | Vireo |
Species: | V. chivi
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Binomial name | |
Vireo chivi (Vieillot, 1817)
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Range of Chivi Vireo
Non-breeding Breeding Year-round
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Synonyms | |
Vireo olivaceus chivi |
The chivi vireo (Vireo chivi) is a small South American
The chivi vireo mates from May to June or October to January, depending on the region and subspecies. It makes
Taxonomy
The chivi vireo was described by the French
Subspecies
There are 9 subspecies of the chivi vireo:[5]
- V. c. chivi (Amazoniaand south to central Argentina. It weighs 10.9–15.5 g (0.38–0.55 oz), with a bill length of 11–13 mm (0.43–0.51 in) and a wing length of 66–72 mm (2.6–2.8 in).
- V. c. agilis (Lichtenstein, MHK, 1823) – Found in east Brazil south through to Rio de Janeiro. It weighs 14.0–14.5 g (0.49–0.51 oz). It is more brightly colored then the nominate, with a paler gray crown, the sides of the breast, flanks and vent being a brighter yellow.
- V. c. griseobarbatus (von Berlepsch & Taczanowski, 1884) – Found in west Ecuador and northwest Peru. It weighs 13 g (0.46 oz), with a bill length of 16–18 mm (0.63–0.71 in) in males and 17–19 mm (0.67–0.75 in) in females and a wing length of 62.5–71.5 mm (2.46–2.81 in). It tends to have a brighter green back than the nominate, with dark line bordering the crown and more yellow on the underparts, especially the flanks.
- V. c. caucae (Río Cauca. It looks similar to the nominate subspecies, but is darker with more grayish ear coverts.
- V. c. vividior Hellmayr & Seilern, 1913 – Found in Colombia, Venezuela, the Guianas, north Brazil and Trinidad. It weighs 12.8–21 g (0.45–0.74 oz), with a bill length of 12–13 mm (0.47–0.51 in) and a wing length of 71–75 mm (2.8–3.0 in). It has brighter yellow-green upperparts, with a relatively longer bill.
- V. c. solimoensis Todd, 1931 – Found in east Ecuador, northeast Peru and extreme west Brazil. It weighs 12.5–15.0 g (0.44–0.53 oz), with a bill length of 15–18 mm (0.59–0.71 in) in males and 16–17 mm (0.63–0.67 in) in females and a wing length of 60–68 mm (2.4–2.7 in). It is small, with a bright yellow behind, and the gray crown extending over to the hindneck.
- V. c. tobagensis Hellmayr, 1935 – Found in Tobago. It is a large subspecies, with a heavy bill and a darker back.
- V. c. diversus Zimmer, JT, 1941 – Found in east Paraguay, southeast Brazil, Uruguay and northeast Argentina. It weighs 15–17 g (0.53–0.60 oz), with a wing length of 68.0–76.5 mm (2.68–3.01 in). Looks similar to agilis, but has darker and duller upperparts, a brown-tinged back, and a mouse-gray on the top of the head. It is differs from chivi by having greener upperparts, flanks and sides, and a more yellow crissum (area surrounding the cloaca).
- V. c. pectoralis Zimmer, JT, 1941 – Found in north Peru, with a suspected population in Zamora-Chinchipe in southeastern Ecuador. Similar to griseobarbatus, but larger, with gray-tinged breast and throat and darker and duller green on the back.[6]
Description
The species looks similar to the related red-eyed vireo and yellow-green vireo. It is 12–14 cm (4.7–5.5 in) in length, with the mass and length of the bill and wings varying in different subspecies.[6]
Hatchlings are born almost naked with yellow skin and sparse
Adult vireos are very similar, except in the subspecies diversus, where the female is smaller than the male. The
Calls
The calls of the species are typical of most of Vireo, but it has a very simple repertoire with only one song and one vocalization. Its song is a pattern of brief musical sound with pauses in between. The song of the South American subspecies is usually "chew-lee chew-lew wee-chee chew leee", while the song of griseobarbatus is a "tche-wit ... tche-wut" repeated constantly during the breeding season. solimoensis is said to have a shorter and more repetitive song, while the song of the migratory populations in the south of the range is said to more complex than that of resident subspecies. In Bolivia, the song is said to be composed of "chee’wee? chee’wip" repeated. The principal call is a raspy "zheer", or a more nasal "jeeyr", with the warning call being "gweh" or "greh".[6]
Distribution and habitat
This bird is very widespread across most of northern, eastern, and central South America, with the exception of southern Chile and southern Argentina. Resident populations of the chivi vireo occur across northeastern Colombia, into Venezuela and the entirety of the Guianas into eastern Brazil. They also occur alongside many rivers in Amazonia, continuing into parts of Peru, Bolivia and Ecuador, with some resident populations inhabiting western Colombia. More migratory populations are found in south and southeastern Brazil, Paraguay, Bolivia, and Uruguay, along with the northern areas of Argentina. In the non-breeding season these populations travel north as far as Venezuela, eastern Colombia, eastern Ecuador, and eastern Peru.[6]
It inhabits the
Ecology and Behavior
The species is largely resident throughout its range, but in the south of its range, the subspecies chivi and diversus are known to be migratory. There are also some subspecies that are likely to undertake short migrations.[6]
Diet and foraging
The species is primarily an insectivore, but some populations are known to consume fruit, and they may be important seed dispersers for some plants. It mainly consumes
Reproduction
The species nests in the austral spring in the south of its range, and in the middle of the year in the north. The populations in Venezuela, Tobago, and Colombia nest in May–June, while the populations of the nominate subspecies in Peru have been seen nesting in November. Brazilian populations are thought to nest in October–January.[6]
Nests of vividior are generally built in a
Eggs are laid in clutches of 2–4 at a time. Eggs vary in appearance and size between different subspecies. The mean size of eggs in griseobarbatus is reported to be 22.0 mm × 13.1 mm (0.87 in × 0.52 in), while that size of eggs in Brazil is 20.32 mm × 14.65 mm (0.800 in × 0.577 in), and the size of eggs in Argentina being 18.5 mm–19.0 mm × 13.0 mm–14.5 mm (0.73 in–0.75 in × 0.51 in–0.57 in). The average mass of eggs measured in southeastern Brazil was 2.27 g (0.080 oz).[6]
Eggs of vividior are white with some blackish spots on the larger end of the egg. Eggs of griseobarbatus are said to be white with sparse and faint markings. Eggs in eastern Brazil have been described as white. The eggs in northeastern Argentina have been described as being white and having gray or fine chestnut markings and dark lines which were concentrated at the larger end. The incubation period of the eggs is reported as being 10–16 days. Only females incubate the eggs. The nests are probably parasitized by
Status
The chivi vireo is listed as a least concern species by the IUCN. The species is common across its large range, and seems to have a stable population. The population may also be increasing locally. Also, its acceptance of disturbed habitat increases its chances of survival.[7]
References
- ^ Vieillot, Louis Pierre (1817). Nouveau dictionnaire d'histoire naturelle, appliquée aux arts, à l'agriculture, à l'économie rurale et domestique, à la médecine, etc (in French). Vol. 11. Paris: Deterville. p. 174.
- ^ Azara, Félix de (1802). "Del Gaviero". Apuntamientos para la historia natural de los páxaros del Paraguay y de Río de la Plata (in Spanish). Vol. 2. Madrid: Imprenta de la Viuda de Ibarra. pp. 34–40.
- ^ Paynter, Raymond A. Jr, ed. (1968). Check-list of birds of the world. Vol. 14. Cambridge, Massachusetts: Museum of Comparative Zoology. p. 125.
- PMID 28502764.
- ^ a b Gill, Frank; Donsker, David, eds. (2019). "Shrikes, vireos, shrike-babblers". World Bird List Version 9.1. International Ornithologists' Union. Retrieved 16 January 2019.
- ^ , retrieved 21 September 2021
- ^ a b (BirdLife International), BirdLife International (1 August 2019). "IUCN Red List of Threatened Species: Vireo chivi". IUCN Red List of Threatened Species. Archived from the original on 28 October 2018. Retrieved 21 September 2021.