Bird gives away little secret ... it's HK's own

PUBLISHED : Friday, 08 October, 2010, 12:00am
UPDATED : Friday, 08 October, 2010, 12:00am

It's an unobtrusive little bird, hard to distinguish from the grass on the high, remote Hong Kong slopes it makes its home. It's also hard to distinguish from a brownish, white-bellied bird that lives in Nepal, India and Bangladesh, so much so that for more than a century they were regarded as the same species.

But eight years of research by a Hong Kong bird expert and colleagues in Nepal and Sweden has uncovered its secret: the local variety is a separate species now known to exist only in Hong Kong.

The rare Chinese grassbird made its public debut yesterday as ornithologist Paul Leader announced the team's findings. The first clue was the great distance between the two populations of what was then known as the Indian grassbird. 'The Indian grassbirds ... they are quite far away from Hong Kong, and usually that is an indication that they are two species,' he said. 'We checked the differences in their sizes, carried out DNA sequencing and analysed their songs.'

The big giveaway was the song: the Chinese variety has a higher pitch and a different rhythm. But even that was difficult as the birds sing only when mating. To solve the puzzle, Leader teamed up with a bird expert from Nepal and two Swedish genealogists.

As well as studying live birds they went to museums in Germany and England for specimens - some collected a century ago. Other subtle differences discovered in the 10cm birds include white tips on the tail of the Chinese species and a darker head and neck on the Indian one.

Leader, director of Asia Ecological Consultants, said there were only about 200 of the birds in Hong Kong, living on remote hillsides such as Tai Mo Shan and Lantau Peak, and he has applied to BirdLife International for the species to be listed as endangered. Conservationists are also calling for preservation of dwindling grasslands and a protection effort like those for the black-faced spoonbill and Chinese white dolphin.

'In 2003 to 2004, the size of grassland in country parks dropped from 25,000 hectares to 21,000 hectares,' Leader said. 'If we lose the grassland habitat, the birds will get rarer.'

The Agriculture, Fisheries and Conservation Department said most of the uphill grasslands had been designated as country parks.

Small differences

There are only subtle differences in appearance between the two species

The length of the birds, in centimetres: 10

Now you're ours

Features of the Chinese grassbird

- 10cm long
- White front
- Brown back

Differences between the Chinese grassbird and the Indian grassbird

- The Chinese one has white tips on its tail, the Indian one has none
- The Indian one has a blackish head, neck and back. These are browner in the Chinese species
- Their songs are different

Source: Ornithologist Paul Leader