Species of Thailand
Binomial name: Aceros nipalensis, Brian Houghton Hodgson, 1829
The rufous-necked hornbill (Aceros nipalensis) is a species of hornbill in the northeastern Indian Subcontinent and Southeast Asia. Numbers have declined significantly due to habitat loss and hunting, and it has been entirely extirpated from Nepal. It is estimated that there are now less than 10, 000 adults remaining. With a length of about 117 cm, it is among the largest Bucerotine hornbills. The underparts, neck and head are rich rufous in the male, but black in the female.
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.
The female, on the other hand, is black, except for the end-portion of her tailand 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 for both sexes.
Of all hornbills, this species has the northern-most extent, formerly ranging across the mountains from Nepal to Vietnam, but which is now restricted to north-eastern India, Bhutan, Burma, south-eastern Tibet, northern and western Thailand, northern Laos and northern Vietnam.
In India, the hornbill has been recorded from the following protected areas:
- Namdapha National Park, Arunachal Pradesh.
- Manas National Park, Assam.
- Buxa Tiger Reserve, West Bengal.
- Mahananda Wildlife Sanctuary, West Bengal.
- Eaglenest Wildlife Sanctuary, Arunachal Pradesh.
- Kamlang Wildlife Sanctuary, Arunachal Pradesh.
- Sessa Orchid Sanctuary, Arunachal Pradesh.
- Pakke Tiger Reserve & Wildlife Sanctuary, Arunachal Pradesh.
The western limit of the rufous-necked hornbill is the Mahananda National Park in West Bengal.
Kinnaird and O'Brien (2007) have tabulated data for the hornbills of the world and report that rufous-necked hornbills range over 1, 163, 811 km2 of area, of which 825, 837 km2 of area are forested. Within this area, rufous-necked hornbills occur in 90 protected areas comprising 54, 955 km2 of protected forest but only including 7% of optimal hornbill habitat.
While predominantly a bird of ridged and hilly forests, chiefly broadleaved forests at altitudes of 150 – 2200 m, it has also been recorded in dry woodland. The nesting period is from March to June) the trees being preferred are tall and having broad girths. There is evidence to suggest the rufous-necked hornbill communities move seasonally between one forested area to another to avail of the differing abundance of fruiting trees due to local conditions.
Describing the egg, Hume (1889) states:
: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).
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.
In Arunachal Pradesh, rufous-necked hornbills have been hunted by tribals for their feathers and beak.
Already listed in CITES Appendices I & II, the species is vulnerable but occurs in a number of protected areas in India, China, Thailand and Bhutan. 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".
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.
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- Aceros nipalensis
Range map of Aceros nipalensis in Thailand
Important note; our range maps are based on limited data we have collected. The data is not necessarily accurate or complete.
Special thanks to Ton Smits and Parinya Pawangkhanant for their help with many range data.
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