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Monday, April 26, 2010

SOARING HIGH: An Oriental Honey Buzzard flies high above.

By Cheong Ah Kwan
THE first of the birds caught the thermals to soar as a tiny speck on the horizon. In the late morning heat they flew in formation like bombers on a mission. By midday, thousands of raptors had crossed the narrow straits from the island of Sumatra into Melaka at Tanjung Tuan.
“And there was evening, and there was morning — the fifth day” (Genesis 1:23). For the last 11 years, the Malaysian Nature Society has been counting raptors at Tanjung Tuan — a stopover for thousands of eagles, hawks and buzzards on a gruelling journey homeward bound to Siberia, China, Mongolia, Korea and Japan as winter draws to an end in the northern hemisphere.
This year, members of the society started the counts on Feb 20 and as of March 19, the number of raptors that had flown across from Sumatra stood at 51,000. On March 19 itself, 7,000 raptors made the perilous crossing into Tanjung Tuan en route to their northern breeding grounds. The different species of raptors that flew in were recorded.
MAGNIFICENT: Raptors hover above. — Photo by Hans Hazebroek

Among the most frequently sighted species were the Oriental Honey Buzzard (Pernis ptilorhynchus), Black Baza (Aviceda leuphotes), Japanese Sparrowhawk (Accipiter gularis), Chinese Goshawk (Accipiter soloensis) and Grey-faced Buzzard (Butastur indicus).
It is no mean feat to identify, in a few seconds, the raptors that soar by overhead. Hence, a great deal of experience through observation is required to acquire the skills at our fingertips.
In Sarawak, raptors are grossly under-recorded and a possible reason for it could be the lack of expertise in identifying these majestic birds while they are in flight. The Raptor Workshop held by the Asian Raptor Research and Conservation Network (ARRCN) last December kindled interest in raptors among the bird-watchers in Sarawak.
As a follow-up to that inaugural workshop, the ARRCN conducted a Raptor ID Workshop last month to equip keen raptor watchers with raptor identification skills so that more people can come forward with raptor information on the island ofBorneo. At the recently completed Raptor ID Workshop in Kuching, an introduction to raptor morphology set the course to their identification. Physical features such as size, tail length, and body and wing shapes are good indicators to the type of raptor seen.
It is commonly believed that raptors refer to huge birds of prey with an average size of 60 centimetres — it comes as a surprise that the Black-thighed Falconet (Microhierax fringillarius) is no more than 14 to 17 centimetres. A comparison with the Eurasian Tree Sparrow (Passer montanus), the ubiquitous Kuching ‘coffee shop’ bird, which stands at 14 centimetres would categorise the falconet as small.
The standard reference to raptor size is small, medium and large and is relative to a familiar bird.
Falcons have long tails with respect to body length. Besides tail lengths, the various tail shapes also facilitate raptor identification.
The White-bellied Sea-eagle (Haliaeetus leucogaster) has a tail that is typically wedged. Other tail shapes include rounded, squared, triangular, forked and deeply forked. At close range, markings on the tail such as the number of bands and the thickness and position of each band provide accurate identification to the speciesObservation of the flight style is another useful method that allows identification of the birds from a distance. Some raptors flutter and glide. Others flap their wings slowly and glide. The Oriental Honey Buzzard (Pernis ptilorhynchus) displays six to seven controlled flaps of the wings which are followed by a glide. When raptors are soaring, the angles by which the wings are stretched out give further clues to their species. Some wings are stretched out horizontally, while others are held in a shallow V-shape.
When opportunities of close encounters present themselves, special attention should be given to observing body markings and underwing patterns such as the presence of bars, streaks, and bands.
Wing tips are often distinctive features in themselves. The presentation slides clicked away and it soon dawned upon us that a combination of ID features is necessary for successful raptor identification.
RAPTOR WATCHERS: A section of the participants at the Raptor ID Workshop.

Raptors are flagshipspecies of the avian world. Being at the top of the food chain, they are excellent indicators of a healthy environment in which case it makes sense to monitor their presence so that we can assess the state of our own environment. This year, the Malaysian Nature Society has recorded the highest number of migratory birds in Tanjung Tuan since annual official records of the raptors began 11 years ago. Over 71,000 birds were recorded as of the end of last month. According to the society, over 300,000 birds were seen in the 1970s, but the numbers dwindled to between 20,000 and 30,000 about a decade ago.
A spokesman for the society suggested that the record sighting this year could be due to changes in the timing of the birds, or their migration paths, or even to effects of climate change. Should we not be more vigilant and determine why significant changes have occurred? Strangely, I am reminded of the time when Noah sent out the raven from the ark to check whether flood waters had subsided.

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