Observers track migration of birds of prey through Java<\/p>\n
By Paul Jepson<\/p>\n
BOGOR, West Java (JP): A network of observers is tracking the
\nsouthward migration of birds-of-prey into Java and East
\nIndonesia. For many years ornithologists have known about the
\nOctober passages of buzzards and hawks across the straits between
\nEast Java and Bali. But it was only in 1995 that staff of
\nBirdLife International discovered that these birds were funneling
\nover the Puncak Pass on their way through Java. This finding has
\ninspired a desire to know more about migratory routes and the
\nnumbers and species involved.<\/p>\n
BirdLife's Iwan Setiawan, who is coordinating an initiative
\ncalled Raptor Migration in Haze Condition, points out that there
\nis a more serious purpose to these surveys.<\/p>\n
\"We are worried that fires in Sumatra and Kalimantan may
\ndisrupt bird migration. Our surveys aim to assess whether
\nmigratory fly-ways cross fire risk zones and if birds become
\ndisorientated when they meet smoke or haze. An e-mail group of
\nobservers in Japan, Taiwan, Malaysia, Singapore and Indonesia is
\nsharing information to answer these important questions.\"<\/p>\n
Iwan has mobilized local bird clubs to conduct watches
\nthroughout October at 12 sites from Sumatra, east across Java to
\nBali. One of the most active of these clubs is the Cibodas Bird-
\nwatching Association (CIBA).<\/p>\n
\"We started counts at the Puncak Pass on Oct. 6, but the large
\nmovements did not start until around the 16th,\" says the club's
\ndirector, Adam A. Supriatna.<\/p>\n
\"We are now counting about 500 birds a day and expect this
\npeak to continue for about three weeks until early November\".<\/p>\n
Last month, I joined Richard Grimmett, head of BirdLife Asia
\nand a leading expert on bird-of-prey identification at the Puncak
\nobservation point, just above the Rindu Alam restaurant.<\/p>\n
At about 9 a.m. we watched a flock of 80 or more raptors
\nspiral up on a rising thermal from their night-time roost in a
\nforest patch in the tea plantation. After pointing out the five
\nlarge birds as Honey Buzzards, he explained the difficulty of
\nidentifying smaller sparrowhawks that made up the bulk of the
\nflock.<\/p>\n
\"About 80 percent of the birds we identify are Chinese
\nGoshawks but most go over too high to be certain. The other
\nspecies is Japanese Sparrowhawk. This is identified by blunter
\nwings and barred under-wing, but a good view is required to be
\nsure of identification.\"<\/p>\n
He went on to say: \"These are birds moving down from their
\nbreeding grounds in East Russia, Northeast China and the Korean
\nPeninsula. We think they migrate down the Bukit Barisan range of
\nSumatra taking advantage of up-drafts off the mountains but their
\nfinal destination beyond Bali is not clear.\"<\/p>\n
Estimating numbers is difficult. Vincent Nijman, who has made
\na special study of bird-of-prey in central Java notes: \"We
\ncounted 2,800 passing through the Dieng Mountains of central Java
\nlast week, but they are clearly moving over a broad front and we
\nare only seeing a proportion of the birds moving.\"<\/p>\n
The Sumatra-Java-Bali fly-way is not the only migration route
\ninto Indonesia.<\/p>\n
Jim Wardill of the conservation project Action Sampiri, which
\nis based on the remote Sangihe island in North Sulawesi, says:
\n\"We have long suspected that birds of prey island-hop south
\nthrough the Philippines and the Sangihe-Talaud archipelago into
\nNorth Sulawesi. Last year we confirmed this by counting 2000
\nmigratory hawks passing through Sangihe.\"<\/p>\n
According to these experts there is some evidence that the
\nfires and El Nino droughts of the last two years may have
\ndisrupted the migration, but there is no evidence of any decline
\nin numbers. Importantly, these surveys highlight the need for
\ncareful siting of power lines in migratory bottle-neck areas and
\nprotection of forest at critical points along the flyway.<\/p>\n
\"Large numbers of birds-of-prey roost and hunt for food in a
\nsmall patch of forest just below the Puncak Pass in the Telaga
\nWarna tea plantation. It is a critical stop-over site on their
\nmigration. We are working with plantation worker communities to
\nensure protection and restoration of this forest,\" said Adam
\nSupriatna.<\/p>\n
CIBA's work will help ensure that migrating birds-of-prey find
\na safe haven to rest on their long journey east and that bird-
\nwatchers can continue to enjoy the wonderful spectacle of flocks
\nof these magnificent birds spiraling upwards and over the pass.<\/p>\n
The writer is a consultant in several institutions, including
\nthe BirdLife International.<\/p>",
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