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Subject: [Indoor] The Discovery of the Chinese Grassbird 發現Chinese Grassbird [Print This Page]

Author: HKBWS WY    Time: 28/09/2010 15:58     Subject: The Discovery of the Chinese Grassbird 發現Chinese Grassbird

WHAT IS THIS? 這是甚麼鳥?


Rufous-rumped Grassbird has long confused ornithologists is Hong Kong, and recent research has shown that the population occurring in Hong Kong and south China should be treated as a separate species, Chinese Grassbird.   

A population of large skulking warblers was first noted on Tai Mo Shan in the 1950’s and although originally thought to be a species of prinia, it later proved to be Large Grass Warbler, a species occurring from Hong Kong to Nepal.  It was subsequently reclassified as a babbler, being quite unrelated to the warblers, and recently it has been found that the populations in the Indian subcontinent and in south-east Asia are better treated as different species.
Resolving the mystery of Hong Kong’s most enigmatic breeding bird required mist nets on Hong Kong's highest mountain, sound recordings in the terai grasslands of Nepal, examination of 100-year-old skins in museums in Germany and England, and DNA analysis of samples by Swedish biochemists.

Paul Leader, who led the international team of experts that finally put all the pieces together, will tell the whole story for the first time, and explain what must be done to protect Chinese Grassbird for future generations, and give you a reason to climb Hong Kong's highest mountain to look for one of its shyest and globally important birds!  

Date:7 Oct 2010 (Thursday)
Time:7pm
Venue:Room 902, Scout Association of HK, Austin Road, Kowloon 
Speaker:Mr Paul Leader
Language:English
Fee:Member HK$10  Non-memberHK$30


大草鶯的辨認一向都令本地的鳥類學家感到迷惑,而最新的研究正好顯示在香港及華南地區出沒的大草鶯其實是一個獨立品種,現已命名為Chinese Grassbird

早於1950年代,已有資料顯示一群行踪隱蔽的鶯在大帽山出沒,當時以為是其中一種鷦鶯,但其後被確認為廣泛分佈於香港至尼泊爾的大草鶯,但稍後又被認為是其中一種鶥,與鶯分別頗大。最後,這群位於印度次大陸及東南亞的鳥種被確認為是另一個獨立鳥種。

為了解決香港一個最令人迷惑的繁殖雀鳥謎團,鳥類學家需要在香港的高山放置霧網,在尼泊爾的terai草原收錄鳥聲,在德國及英國的博物館查核超過一百年的雀鳥樣本,最後加上瑞典的生物化學專家測試其基因序列。

利雅德先生(Mr Paul Leader)正是領導是次研究及把各研究成果串連的鳥類學家,他將會首次向公眾披露故事的來龍去脈,並提醒大家如何保護這個獨特鳥種,甚至吸引大家攀登香港最高的山峰,找尋山上最害羞的全球重要鳥種。


日期:2010年10月7日(星期四)
時間:下午七時
地點:香港童軍中心902室 (九龍柯士甸道)
講者:Mr Paul Leader 利雅德先生
語言:英語
費用:會員港幣$10  非會員港幣$30


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Author: HKBWS WY    Time: 7/10/2010 20:57

Hong Kong ornithologist resolves 30-year riddle of China’s most enigmatic bird
Hong Kong grasslands crucial to survival of newly classified Chinese Grassbird


HKBWS Press Release
7 Oct 2010



Hong Kong-based ornithologist Paul Leader and an international team of experts have resolved a 30-year mystery to reveal the true identity of Chinese Grassbird, a globally threatened species which depends on protection of grasslands in Hong Kong for its continuing survival.

Requiring trapping with mist nets on Hong Kong's highest mountain, sound recordings in the terai grasslands of Nepal, examination of 100-year-old skins in museums in Germany and England, securing export permits for blood and feather specimens from Government officials during the avian influenza outbreak, and DNA analysis of samples by Swedish biochemists, the story reads like a cross between an Indiana Jones adventure and an episode of CSI.

“Assembling the evidence that has led to the identification of Chinese Grassbird as a full species has been an interesting challenge,” Paul Leader, Director of Asia Ecological Consultants, the ornithologist who led the work. “ But now we know how rare this bird is, the real work is ensure its survival. To do that we must protect and manage the grassland habitats it depends upon from the threats of development and reforestation.”

Resolving the mystery
The mystery began when a large skulking warbler, first noted on Tai Mo Shan in the 1950s, was thought to be Brown Prinia. However a bird mist-netted by David Melville former Executive Director of WWF (Hong Kong) in 1982 proved to be Large Grass Warbler, a species which occurs from Hong Kong to Nepal.  

But in 2006 DNA analysis of Large Grass Warbler showed that it was not a warbler at all, but belonged to a completely different family – the babblers, and it was renamed Rufous-rumped Grassbird, as it was thought to be the same species as a very similar bird found in Nepal, India and Bangladesh.

It was only last month when the final part of the mystery was resolved.  Mr Leader and his collaborators showed that birds from the Indian subcontinent, and southern China were in fact different by analysing the vocalisations, structure and plumage, and the DNA of birds from both locations. They have proposed that the two species should now be called Chinese

Grassbird and Indian Grassbird. Full details can be found in the newly released Forktail paper, which was co-authored by Mr Leader.

The history of Chinese Grassbird
First recorded in Hainan in 1892 by tea merchant and ornithologist Frederick Styan, and with a range that once extended to grasslands in Myanmar, Vietnam and Thailand, as well as Guangxi and Guangdong Provinces in China, Chinese Grassbird, has only twice been seen away from Hong Kong in the last 80 years.

The first of these records was from Shiwandashan in Guangxi in May 1997, and the second, in May 2001 was from Wutong Shan - the mountain that lies directly across the border from Robin’s Nest at the western end of the Frontier Closed Area. Curiously, both records were made by another Hong Kong ornithologist, Lee Kwok-shing, while conducting surveys for Kadoorie Farm & Botanic Garden.

The need for active conservation
Because it is found in low densities and difficult to detect – it rarely sings or calls – and is found mostly in remote mountainous areas, including Tai Mo Shan, Lantau Peak, and Robin’s Nest, the population of Chinese Grassbird is poorly known.  Initial estimates suggest that there are no more that 50-100 pairs in Hong Kong – giving a maximum known global population of just 200 birds.
  
In Hong Kong Chinese Grassbird is found in low densities in grassland and dwarf bamboo habitats between 200 and 800 metres – and much of this habitat is protected within Hong Kong’s Country Parks. However, as Hong Kong continues to become greener and grassland becomes forest through a natural process called succession, the area of habitat available to this bird is shrinking steadily. In lowland areas outside the Country Parks, its habitat is also threatened by housing and infrastructure development.

As a result, in order to effectively protect the Chinese Grassbird, it is very important that sufficient grassland habitat is identified and actively managed to prevent further development and to prevent grasslands becoming forest (in which the birds cannot survive).

Mike Kilburn, Vice Chairman of Hong Kong Bird Watching Society called on the Hong Kong Government to take immediate steps to protect Chinese Grassbird and the habitat it depends on. This will require an accurate assessment of the current population, ecology and habitat requirements of the bird, as well as an assessment of the total area, quality and threats to its habitat. These would serve as essential steps in the development and the development and implementation of a species conservation plan that would ensure a secure future for Chinese Grassbird in Hong Kong.

Author: HKBWS WY    Time: 7/10/2010 21:01

困擾香港鳥類學者三十年的雀鳥謎團終於破解
「大草鶯」-香港的草地是這個新鳥種的重要棲息地


香港觀鳥會新聞稿
2010年10月7日



以香港為基地的鳥類學家利雅德先生(Mr. Paul Leader)與一群國際專家合力破解了一個三十年未解的鳥類謎團,「大草鶯」(Chinese Grassbird)的真正身份終於被確定,而本港的草地正是這種瀕危雀鳥賴以生存的重要生境。

為了解決香港一個最令人迷惑的鳥類謎團,鳥類學家需要在香港最高的山嶺放置霧網捕捉雀鳥,在尼泊爾的terai草原收錄牠的鳴叫聲,在德國及英國的博物館查核超過一百年的雀鳥毛皮,在禽流感爆發期間獲得有關當局批准把雀鳥的血液及羽毛樣本寄往外地,最後加上瑞典的生物化學專家測試其基因序列,過程曲折有如奪寶奇兵及滅罪鑑證科的情節。

利雅德先生是亞洲生態環境顧問有限公司的執行董事及領導是次研究的鳥類學家,他指出:「能夠綜合各項研究結果以確立大草鶯成為一個新品種是一項非常有趣的挑戰,正由於這項研究成果,我們更可以了解這種雀鳥的稀有程度,以及如何確保牠們的延續,包括保護及管理其賴以生存的草地生境,避免受到任何發展及植林的破壞。」

謎團的破解
謎團始於上世紀五十年代,一群行踪隱蔽的鶯出沒於大帽山,當時被認為是「褐山鷦鶯」;到了1982年,前世界自然基金會(香港)總監梅偉義先生捕捉了一個樣本,經研究後更名為廣泛分佈於香港至尼泊爾的「大草鶯」。

2006年,經過一輪基因測試,這種原本是「鶯」的雀鳥被劃分入「鶥」科,並認為與在尼泊爾、印度及孟加拉出現的均屬同一種,因此更名為「Rufous-rumped Grassbird」(中文名稱仍然為大草鶯)。

直至上月,謎底終於全部解開,利雅德先生與其團隊根據雀鳥的鳴聲、身體結構及羽毛的分析,與及基因序列的比較,終於確認在南中國及印度次大陸出現的雀鳥實屬兩個不同品種,並把兩種鳥分別命名為Chinese Grassbird(中文名稱仍暫譯為“大草鶯”)及Indian Grassbird(未有正式中文名稱),詳細的研究結果可以參考最新出版的Forktail期刊所刊登由利雅德先生及其團隊撰寫的報告。
 
大草鶯的故事
大草鶯的首個紀錄由茶葉商人及鳥類學家Frederick Styan於1892年在海南島發現,其後在緬甸、越南、泰國、廣西省及廣東省的草地生境均有發現,但過去八十年在香港以外地區只有兩個紀錄。第一個紀錄在1997年5月於廣西的十萬大山發現,第二個紀綠在2001年於深圳的梧桐山發現,梧桐山與位於新界東北部禁區內的紅花嶺相鄰。有趣的是兩個紀錄均由嘉道理農場暨植物園的鳥類學者李國誠先生在進行鳥類普查時發現。

保育的重要性
由於大草鶯的數量稀少,加上極少鳴叫及歌唱,而且只在偏遠的高山出沒,包括大帽山、大嶼山及紅花嶺,因此很難觀察,也不容易知道牠們的真實數量,初步估計在香港只有五十至一百對,即全球估計最多約二百隻。

在香港,大草鶯主要棲息於海拔二百至八百公尺的草地及低矮的竹林生境,雖然這些生境大部份位於郊野公園而得到一定的保護,但隨着自然演替,香港的草地生境逐漸轉變成樹林,令這類生境不斷縮小,而位於較低海拔及在郊野公園以外的草地生境,卻往往受到房屋及基建的發展所威脅。

為了有效保護大草鶯,我們需要確認及管理足夠的草地生境,並防止這些生境演化成樹林,因為樹林生境並非大草鶯所需。

香港觀鳥會副主席吳敏先生呼籲有關部門應該立即行動,保育那些大草鶯賴以生存的生境,並且調查大草鶯的準確數目及分佈、生態特徵、生境的要求及這些生境的面積、質素及潛在威脅,這都是成功制訂及實施一套物種保育計劃及確保大草鶯有一個安全未來的重要步驟。





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