Endangered Species Friday: Aceros nipalensis
This Fridays (ESP) – Endangered Species watch Post I have chosen to document on this stunning species known commonly as the Rufous-cheeked Hornbill, because of large population declines throughout most of the birds historical range. More awareness needs to be created with regards to this particular bird specie due to their natural habitat declining and localized extinctions that have already occurred in the past decade. Furthermore extinctions are now likely to occur within Viet Nam and [west] Thiland where hunting is the primary threat to the species.. (Image credit Ian Fulton).
Identified back in 1829 by Mr Brian Houghton Hodgson (1 February 1800 or more likely 1801– 23 May 1894) was a pioneer naturalist and ethnologist working in India and Nepal where he was a British Resident. He described numerous species of birds and mammals from the Himalayas, and several birds were named after him by others such as Edward Blyth.
Listed as vulnerable the A. nipalensis is endemic to Bhutan; China; India; Lao People’s Democratic Republic; Myanmar; Thailand and Viet Nam. Unfortunately A. nipalensis has already been declared extinct locally in Nepal. Like many large birds within this region of Asia the Rufous-cheeked (or necked) Hornbill’s populations are declining quite extensively throughout their range of which deforestation and habitat degradation and, hunting is primarily to blame.
The species has been listed on Cites Appendix (I-II) of which an estimated population census count has determined there are no less than 2,500 birds but no greater than 9,999. A survey count back in 2001 by Bird-Life International concluded that from the [estimate] above the [true] population count is actually by far more lower than previously suggested, however few conservationists are now debating this due to the birds ‘alleged’ extensive range within South East Asia.
From the Bird Life International (2001) census the organisation stated there was no fewer than 1,667 mature individuals but no greater than 6,666, which is rounded to 1,500 to 7,000 mature individuals exactly. Since the last 2001 census its quite possible populations have increased and decreased to date.
A. nipalensis is known to inhabit the following ranges; Bhutan, north-east India, Myanmar, southern Yunnan and south-east Tibet, China, [west] Thailand, Laos and Viet Nam. The species has declined [drastically] and is no longer common throughout most of its known historical range. While we know the species is now regionally extinct within Nepal the next likely localized extinction may very well be within Viet Nam of which its populations have fallen to alarming rates.
Within [most] of Thailand where the species was quite common reports have sadly indicated the bird is no longer commonly seen, and like Viet Nam, Thailand could become the third county to see localized extinctions occurring too, the only known habitat within Thailand that A nipalensis occurs now is within west Thailand. To date reports have confirmed that within Bhutan A. nipalensis remains pretty much common of which Bhutan is known to the birds [largest] stronghold.
Healthy large populations have also been documented back in 2007 within Namdapha National Park, India, Nakai-Nam Theun National Biodiversity Conservation Area, central Laos and perhaps also Huai Kha Khaeng, [west Thailand], and Xishuangbanna Nature Reserve, China. Some conservationists have been led to believe that while populations are considered quite large within these strongholds that the species may very well be “more widespread than previously thought”. Meanwhile the species is known to inhabit north Myanmar, and there are recent records from West Bengal and Eaglenest Wildlife Sanctuary, Arunachal Pradesh, India.
Rufous-cheeked Hornbill commonly resides within broad-leaved forest, some reports have also indicated the species to be present within dry woodland too. Mating and nesting normally occurs from the months of March to June within large wide girth trees, the very trees that the species depends on though are being felled throughout most of the Hornbills historical range.
Image: Rufous-necked-Hornbill (Photographer unknown)
Its dependence on large trees for feeding and nesting makes it especially susceptible to deforestation and habitat degradation through logging, shifting cultivation and clearance for agriculture. Furthermore, viable populations require vast tracts of forest to survive, exacerbating its susceptibility to habitat fragmentation. These problems are compounded by widespread hunting and trapping for food, and trade in pets and casques. Hunting is the primary threat to the species in Arunachal, India. A report from the Wildlife Extra organisation details poaching incidents with regards to Hornbills.
Wildlife Extra stated:
The unique and intriguing breeding habits that caught Pilai Poonswad attention are central to the birds’ plight. Each hornbill pair seeks out a suitable hollow – 15 to 40 metres above the ground in the trunk or branch of a Neobalanocarpus, Dipterocarpus or Syzygium tree – in which to raise a single chick. When a suitable cavity is found, the female walls herself in, using mud supplied by her mate and regurgitated food, to hatch and rear her chick. The male feeds them for the next three months and, if he fails, both mother and chick may perish. The birds consume up to 80 different kinds of fruit, scattering the seeds over many hectares of forest. With other seed-distributing animals such as monkeys now scarce, the hornbill has become pivotal in maintaining the integrity of the forest. But the birds rarely spread the seeds of the trees in which they nest: if these disappear, the hornbills too will vanish – and the trees and plants they help propagate will soon follow.
Click the link above via the [report] to read more on this very fascinating conservationist.
My name is Dr Jose Carlos Depre, MD, B.Env.Sc, BSBio, D.V.M. I myself have been working within bird, tree kangaroo and pachydermata conservation, rescue and reporting for over fifteen years.
Within these unique, wonderful and exhilarating years I have witnessed one of my favorite species of animals [birds] declining to worrying levels that is now so concerning it has led to sleepless nights for many years. Should we continue to see such catastrophic population decreases of birds we’ll eventually witness alarming declines of plants and trees. The same applies with insects and herbivorous mammals too.
Like insects birds are incredibly important for both human and animal survival. The vast majority of all bird species rely on plants for their staple diet. On consuming fruits, leaves, flowers Etc, the very seeds within the birds diet of life needed to continue seed dispersal will be lost should all bird populations go extinct. Should this occur we selfish humans will then become the Planets seed disperses. Think about that next time you fell a tree or rip a plant up.
Dr Jose. C. Depre
Environmental and Botanical Scientist.
Thank you for reading and please share fare and wide to create as much awareness for all Hornbills as possible.