There is an earlier study which tracked 3 Oriental Honey Buzzards from Japan to their wintering grounds in autumn 2003 and their return journey in spring 2004 - see these tracks
As you can see, the third one of these birds actually passed through Hong Kong (I like to imagine it was Po Toi).
There are three other interesting things about these tracks.
Firstly, it was the first winter bird (Young) that took the coastal route - I think we see mostly first winter birds of all species in autumn, because they are less experienced and more likely to follow the coastline.
Secondly, one of the birds (A2) eventually ended up in Mindanao, Philippines, but took a very long route avoiding long sea crossings whereas the fast route would have been via Taiwan. While it is typical of a raptor to avoid long sea crossings on migration, others e.g. Grey-faced Buzzard and Chinese Sparrowhawk, take the direct route through Taiwan to winter in The Philippines. Oriental Honey Buzzard seems to avoid this route, judging by records from Taiwan. This may be due to differences in physiology of the species, or it may be an evolutionary difference. Anyone like to guess?
Thirdly, the return journey for the one that was still tracking (A1) went far to the north of it's outward route and Hong Kong. I think this northerly route may be used by many species on the spring return migration, perhaps due to favourable prevailing winds. Which is why we rarely see SE Asia wintering birds on spring migration but mostly see them in autumn migration.
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Last edited by wgeoff at 5/10/2012 14:49 ]
