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White-backed night heron

White-backed night heron
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Pelecaniformes
Family: Ardeidae
Genus: Calherodius
Bonaparte, 1855
Species:
C. leuconotus
Binomial name
Calherodius leuconotus
(Wagler, 1827)
Synonyms
  • Ardea leuconotus
  • Nycticorax leuconotus
  • Gorsachius leuconotus

The white-backed night heron (Calherodius leuconotus) is a species of medium-sized heron in the family Ardeidae, found in sub-Saharan Africa.

Taxonomy

The white-backed night heron was formally described in 1827 by the German naturalist Johann Wagler under the binomial name Ardea leuconotus. He specified the type locality as Senegambia.[2][3] This species was formerly placed with the Japanese night heron and the Malayan night heron in the genus Gorsachius. Based on the results of a molecular genetic study published in 2023,[4] it is now the only species placed in the resurrected genus Calherodius that had originally been introduced in 1855 by the French naturalist Charles Bonaparte. Bonaparte specified the type species as Ardea cucullata Lichtenstein which is now considered to be a junior synonym of Ardea leuconotus Wagler.[5][6][7] The species is treated as monotypic: no subspecies are recognised.[7]

Description

The white-backed night heron is 50–55 cm (20–22 in) in length with a black head and a short crest, or prominent feather display on the top of its head.[8] The heron has large red eyes with white-ringed markings around them, and the lores, or the region behind the eye, are a pale yellow hue.[8][9] The throat feathers are white, whereas the neck and breast are rufous, or a reddish-brown hue.[8] There is a notable white triangular patch along the back formed by the white scapulars, or small feathers, on the shoulder of the bird.[8] The belly feathers are a whitish-brown and the legs are yellow.[10][11] An immature heron can be identified by its streaked breast and the white spots on the upper-wing coverts.[12] Chicks are covered with olive-brown down.[10]

Distribution and habitat

The white-backed night heron is located throughout central and southern Africa, with a range estimated at 20,900,000 km2 (8,100,000 sq mi).[1] Its primary habitat is dense forests with neighboring waterways, particularly streams, lakes, mangroves and marshes.[13]

Behavior and ecology

The white-backed night heron can be found living individually or in pairs.[9] Nocturnal by nature, they roost in the dense vegetation of marshes and forests during the daylight hours, often nesting high within the trees.[13] Their nests are well-hidden, usually built in vegetation near water and sometimes in reedbeds, mangroves, rocks and caves.[13] The nest is built resembling a platform of sticks or reeds, 25–30 cm (9.8–11.8 in) wide.[10] They usually breed during the rainy season or early in the dry season.[13] There are two to three greenish-white eggs in a clutch, and incubation lasts roughly 24 to 26 days. The chicks leave the nest after six to seven weeks.[10] The white-backed night heron seems to be sedentary, but it has been observed in some circumstances to have migrated to locations with heavy rain.[14] White-backed night herons are known foragers, meaning they search for food primarily along waterways. They have been observed to eat fish, amphibians, mollusks and insects.[10] Though usually quiet, they let out a loud kroak call when alarmed and a taash call when disturbed.[10]

Status

The population of the white-backed night heron is believed to be stable because it does not appear to undergo significant population declines or experience any notable threats.[13] Due to these factors and its large range, the IUCN Red List has assessed the species to be of least concern.[1] The species is currently experiencing a small number of threats, including habitat loss in southern Africa and hunting in Nigeria, where they are used for traditional medicine.[13]

References

  1. ^ a b c BirdLife International (2016). "Calherodius leuconotus". IUCN Red List of Threatened Species. 2016: e.T22697226A93603192. doi:10.2305/IUCN.UK.2016-3.RLTS.T22697226A93603192.en.
  2. ^ Wagler, Johann Georg (1827). Systema avium (in Latin). Vol. pars 1. Stuttgartiae: J.G. Cottae. p. 189, Species 33.
  3. ^ Mayr, Ernst; Cottrell, G. William, eds. (1979). Check-List of Birds of the World. Vol. 1 (2nd ed.). Cambridge, Massachusetts: Museum of Comparative Zoology. p. 231.
  4. ^ Hruska, J.P.; Holmes, J.; Oliveros, C.; Shakya, S.; Lavretsky, P.; McCracken, K.G.; Sheldon, F.H.; Moyle, R.G. (2023). "Ultraconserved elements resolve the phylogeny and corroborate patterns of molecular rate variation in herons (Aves: Ardeidae)". Ornithology. 140 (2): ukad005. doi:10.1093/ornithology/ukad005.
  5. ^ Bonaparte, Charles Lucien (1855). Conspectus Generum Avium (in Latin). Vol. 2. Lugduni Batavorum: Apud E.J. Brill. p. 139. For a discussion of the publication date see: Zimmer, John T. (1926). Catalogue of the Edward E. Ayer Ornithological Library. Field Museum of Natural History, Zoology Series. Volume 16, Part 1. Chicago: Field Museum of Natural History. pp. 68–69. and Dickinson, E.C.; Overstreet, L.K.; Dowsett, R.J.; Bruce, M.D. (2011). Priority! The Dating of Scientific Names in Ornithology: a Directory to the literature and its reviewers. Northampton, UK: Aves Press. pp. 75–79. ISBN 978-0-9568611-1-5.
  6. ^ Mayr, Ernst; Cottrell, G. William, eds. (1979). Check-List of Birds of the World. Vol. 1 (2nd ed.). Cambridge, Massachusetts: Museum of Comparative Zoology. p. 228.
  7. ^ a b Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (December 2023). "Ibis, spoonbills, herons, Hamerkop, Shoebill, pelicans". IOC World Bird List Version 14.1. International Ornithologists' Union. Retrieved 4 August 2024.
  8. ^ a b c d Borrow, Nik; Demey, Ron (2013). Birds of Senegal and The Gambia. Bloomsbury. p. 42. ISBN 9781408171011.
  9. ^ a b Redman, Nigel; Stevenson, Terry; Fanshawe, John (2010). Birds of the Horn of Africa. Bloomsbury. p. 50. ISBN 9781408135761.
  10. ^ a b c d e f "White-backed Night Heron Nycticorax leuconotus (Wagler)". HeronConservation. IUCN-SSC Heron Specialist Group. 2011. Retrieved 25 October 2016.
  11. ^ Newman, Kenneth (2002). Newman's Birds of Southern Africa. Struik. p. 90. ISBN 9781868727353.
  12. ^ Hancock, Peter; Weiersbye, Ingrid (2015). Birds of Botswana. Princeton University Press. p. 62. ISBN 9781400874170.
  13. ^ a b c d e f "Species factsheet: Calherodius leuconotus". birdlife.org. BirdLife International. 2016. Retrieved 22 October 2016.
  14. ^ A. P. Martin. "Whitebacked Night Heron" (PDF). The Atlas of Southern African Birds. p. 67.
Quelle: https://en.wikipedia.org/wiki/Calherodius