Rufous-necked hornbill

The rufous-necked hornbill (Aceros nipalensis) is a species of hornbill in Bhutan, northeastern India, especially in Arunachal Pradesh, Indian Subcontinent and Southeast Asia. It is locally extinct in Nepal due to hunting and significant loss of habitat.^[1] There are less than 10,000 adults left in the wild.^[3] With a length of about 117 cm (46 in),^[3] it is among the largest Bucerotine hornbills. The underparts, neck and head are pigmented as a rich rufous in the male, but black in the female.

Rufous-necked hornbill
An adult male in Mahananda Wildlife Sanctuary
An adult female in Mahananda Wildlife Sanctuary
Conservation status
Vulnerable  (IUCN 3.1)[1]
CITES Appendix I (CITES)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Bucerotiformes
Family:	Bucerotidae
Genus:	Aceros Hodgson, 1844
Species:	A. nipalensis
Binomial name
Aceros nipalensis (Hodgson, 1829)[2]

Taxonomy

The scientific name Buceros nipalensis was coined for the rufous-necked hornbill by the English naturalist Brian Houghton Hodgson in 1829 who described several rufous-necked hornbills caught by hunters in sal forests in Nepal.^[2] The species was placed in the genus Aceros by Hodgson in 1844.^[4] The authorship of the genus name has sometimes been credited to John Edward Gray but Gray was the editor not the author of the list.^[5] The genus name is from Ancient Greek akerōs meaning "hornless".^[6]

Description

An immature in Namdapha National Park

An adult in flight Mahananda Wildlife Sanctuary

An adult in Mahananda Wildlife Sanctuary

The head, neck, and lower body of the male are coloured rufous, with deeper colouration on the flanks and abdomen. The middle primaries and the lower half of the tail are tipped white. The rest of the hornbill's plumage is a glossy dark-green and black. The lower tail-covert feathers are coloured chestnut mixed with black.^[7] The female is black, except for the end-portion of her tail and the tips of the middle primaries, which are white. Juvenile hornbills resemble adults of the same sex, but lack the ridges at the base of the upper beak. The beak lacks a true caique but is thickened at its base. It has a number of dark ridges on the upper beak which are absent in the young and increase in number with age up to about seven. The commissure of the beaks is broken in both sexes.^[7]

Distribution and habitat

The rufous-necked hornbill has the northernmost distribution ranging from Northeast India, central Bhutan to western Thailand and northwestern Vietnam. It ranges over an area of 1,163,811 km² (449,350 sq mi), of which 825,837 km² (318,857 sq mi) is forested. Within this area, it lives in 90 protected areas comprising 54,955 km² (21,218 sq mi) of protected forest but only including 7% of optimal hornbill habitat.^[8]: 238 Mahananda Wildlife Sanctuary in West Bengal represents its westernmost limit; it has also been recorded in Buxa Tiger Reserve, Manas National Park, Eaglenest Wildlife Sanctuary, Sessa Orchid Sanctuary, Kamlang Wildlife Sanctuary, Namdapha National Park^[9] and Pakke Tiger Reserve.^[10]

It predominantly inhabits ridged and hilly forests, primarily temperate broadleaf and mixed forests at elevations of 150–2,200 m (490–7,220 ft),^[1] It has also been recorded in dry woodland.^[3]

Behaviour and ecology

The nesting period is from March to June, the trees preferred are tall and have broad girths. These hornbill communities move between one forest to another depending on seasonally to forage from fruiting trees that change with local conditions.^[3] Describing the egg, Hume (1889) states:^[11]

The egg is a broad oval, compressed somewhat towards one end, so as to be slightly pyriform. The shell is strong and thick, but coarse and entirely glossless, everywhere pitted with minute pores. In colour it is a very dirty white, with a pale dirty yellowish tinge, and everywhere obscurely stippled, when closely examined, with minute purer white specks, owing to the dirt not having got down into the bottoms of the pores. It measures 2-25 by 1'75 (inches).

Conservation

Already listed in CITES Appendices I, the species is vulnerable but occurs in a number of protected areas in India, China, Thailand and Bhutan.^[3] Due to increased information coming in about range and extent, it has been suggested that the rufous-necked hornbill be downgraded from IUCN status "Vulnerable" to "Near Threatened".^[8]: 234

Recent initiatives by the Wildlife Trust of India, Arunachal Pradesh Forest Department and other citizens to conserve hornbills, which also target the rufous-necked hornbill, are the Hornbill Nest Adoption Programme, and a programme for replacing the use of real beaks with fibre-made replicas.^[10][12]

In culture

"Bulup" or Cane hat of the Minyong tribe of East Siang district of Arunachal Pradesh with hornbill beak, most likely that of rufous-coloured hornbill

The rufous-necked hornbill occurs in Sanskrit literature under the epithet vārdhrīnasa, a term which at times also has been used to refer to other Bucerotidae.^[13]

In Arunachal Pradesh, rufous-necked hornbills have been hunted by tribals for their feathers and beaks.^{[citation needed]}

References

1. BirdLife International (2020). "Aceros nipalensis". IUCN Red List of Threatened Species. 2020: e.T22682510A176267243. Retrieved 26 January 2022.
2. Hodgson, B. H. (1833). "On a new species of Buceros". Asiatic Researches. 18 (2): 178–186.
3. BirdLife Species Factsheet
4. Hodgson, Brian Houghton (1844). "Catalogue of Nipalese Birds, collected between 1824 and 1844 by B.H. Hodgson, Esq.". In Gray, John Edward (ed.). The Zoological Miscellany. London: Treuttel, Wurtz and Co. pp. 81–86 [85].
5. Dickinson, E.C.; Walters, M. (2006). "Systematic notes on Asian birds. 53. The authorship and date of publication of the "Catalogue of the Specimens and Drawings of Mammalia and Birds of Nepal and Thibet presented by B.H. Hodgson, Esq. to the British Museum"". Zoologische Mededelingen. 80: 137–153.
6. Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 30. ISBN 978-1-4081-2501-4.
7. Blanford, W. T.; Oates, E. W. (1889–98). The fauna of British India, including Ceylon and Burma. Birds. Vol. 3. London: Taylor and Francis. pp. 149–150. doi:10.5962/bhl.title.8366. Retrieved 4 April 2012.
8. Kinnaird, M. & O'Brien, T. G. (2007). The Ecology and Conservation of Asian Hornbills: Farmers of the Forest. University of Chicago Press. ISBN 978-0-226-43712-5.
9. Ghose, D.; Lobo, P. & Ghose, N. (2006). "A record of the Rufous-necked Hornbill Aceros nipalensis from West Bengal, India" (PDF). Indian Birds. 2 (2): 37–38.
10. PTI (2012). "Artificial beaks save hornbills from extinction in Arunachal". Firstpost. Retrieved 2012-04-04.
11. Hume, Allan Octavian (1889–1890). Oates, Eugene William (ed.). The nests and eggs of Indian birds, volume III. Vol. 3 (Second ed.). London: R. H. Porter. pp. 77–79. doi:10.5962/bhl.title.17497. Retrieved 4 April 2012.
12. WTI staff (7 May 2004). "This beak does not bite". Wildlife Trust of India - News. Wildlife Trust of India. Retrieved 14 April 2012.
13. Dave, K. N. (2005). Birds in Sanskrit literature. Motilal Banarsidass. p. 510. ISBN 978-81-208-1842-2.

External links

• ARKive - images and movies of the rufous-necked hornbill (Aceros nipalensis)