Raptors overflying Po Toi above 2000 ft
At 7am this morning, I was watching visible migration from the lighthouse on Po Toi. I was following a Yellow Wagtail flying overhead using my binoculars when I noticed another bird much higher above. I followed this bird and found it was one of a pair, both birds drifting slowly south west in a circling movement. From the shape and size, I think they were Amur Falcons. They were invisible to the naked eye (mine at least) and must have been flying above 2000 feet.
After this, I started to search the sky with binoculars for more sightings, a pretty hopeless task, but ten minutes later I saw another group of five birds at around the same height. These were flying more directly in a loose flock, and from the shape and flight I think they were sparrowhawks, possibly Chinese Goshawks.
I didn't see any more in the next 30 minutes.
This observation would indicate that, under favourable weather conditions, certain raptors and perhaps other autumn migrants are overflying Hong Kong at heights which would make them virtually invisible from the ground. The wind early this morning at lighthouse level was E/NE force 5 and the lower clouds were moving west/south west, an ideal direction for migration.