Shearwater confirmed as regular HK visitor

PUBLISHED : Sunday, 23 May, 2010, 12:00am
UPDATED : Sunday, 23 May, 2010, 12:00am

You could call it the wrong flight in the right direction for local birdwatchers when the first recorded sighting of a Short-tailed Shearwater was made in Hong Kong in 2004, because it was thought to be a one-off at the time.

However, it's now been proved that rather than it being a rarity, a regular migration of the species occurs in mid-May through Hong Kong. The discovery was confirmed by local birdwatchers Yu Yat-tung and Geoff Welch. Yu initially noted the pattern while doing a seabird survey from a boat for the Hong Kong Environment and Conservation Fund. Welch identified the species while watching for seabirds on Po Toi Island - being out to sea, it serves as a resting point for migrating birds flying along the coast.

Somewhere along its migrational journey from Australia to northern Japan the Short-tailed Shearwater got blown off its traditional route and appeared on the eastern coastline of Hong Kong. The bird spends most of its life at sea.

Twenty million nest each year in the Bass Strait in Australia. Usually after nesting, they migrate en masse up the west Pacific to winter on good feeding grounds at sea around Japan and further north, then return in autumn through the mid-Pacific to Australia. The latest findings though show some obviously prefer the scenic route.

'We now see up to 100 each year which pass through Hong Kong in mid-May,' Welch said. 'This migration has undoubtedly been going on for many years but was previously unrecorded because no observers were in the right place at the right time.

'It is likely the birds go slightly off-course in the early part of their journey somewhere just north of Australia, and then pass through the islands of Indonesia and western Philippines before arriving in the South China Sea.

'They continue north until they hit the coast of south China, where they head east along the coast.'

Last month birdwatchers hailed the arrival of the 500th species of bird to be seen in Hong Kong, expanding the city's bird list to cover about a third of the total number of species found in China.

They also celebrated a steady rise in the species of wild birds seen in the city, at a level of four to five every year.

The 500th species to be seen locally, the red-throated thrush, spotted in November, has a grey upper body. The thrush was among four new species of birds first spotted in the city last year, with three of them found on Po Toi Island.

The other three are a common cuckoo, which comes from as far as Africa, a great stone curlew, from Southeast Asia, and Hodgson's redstart, from the Tibetan plateau or Himalayas.

The Hong Kong Bird Watching Society said it was likely the birds had strayed while migrating.

Birds use their ability to fly to optimise their chances of survival. There are good breeding grounds in the north up to the Arctic. But only in summer as it's too cold to survive in winter, so they migrate - going north for the summer and back south for the winter. Approximately 1,800 of world's 10,000 bird species are long-distance migrants.