wgeoff

After the Beijing Common Swift migration to southern Africa last week, Amur Falcon is another north China/Russia breeding species which migrates to southern Africa for the winter.

Like the Beijing Common Swift, the migration route of Amur Falcon has been recorded by tracking devices and here it is



Here is the Common Swift by comparison



Both incredible journeys (for humans at least) but different. The Amur Falcon goes south of the Himalayas through China and India before flying across the Indian Ocean. The Common Swift goes north of the Himalayas through Iran before flying south into Africa.
The difference in migration routes mean we see Amur Falcon regularly on migration in Hong Kong but Common Swift is a real rarity.

wgeoff

Thanks Dylan, very interesting talk which explains how and perhaps why Amur Falcon takes the migration route that it does.

I've noticed that dragonflies are seasonal on Po Toi, arriving with the spring/summer rains. Perhaps there's another story there.

wgeoff

Thanks Sze.

The amazing journey of the Amur Falcon from its breeding grounds in northeastern China to winter in South Africa is now well-documented - here is an example of part of the journey of one bird from Sze's posting, the part from northeast India to east Africa -

"All three birds flew non-stop first southwest over Bangladesh and then over the Bay of Bengal for a day to arrive at the Andhra Pradesh coast, covering an over-water distance that ranged from 600 to 1,300 km. Incredibly, Naga continued to fly nonstop (across India) and entered air space over the Arabian Sea around 20 km south of Panaji, Goa and flew across to arrive at the northern African shore of Somalia on the morning of November 16. Naga made an incredible nonstop flight from NE India, covering a distance of 5,600 km in 5 days and 10 hrs, flying at a speed of 40 km/hr."

It's good to hear that the Amur Falcon is now protected in at least some of its stop-over sites in northeast India.  

We are lucky to be able to see this fantastic bird in autumn here in Hong Kong. Next time you see one, remember, it still has about 10,000 km to go.

[ Last edited by wgeoff at 28/10/2015 06:58 ]

wgeoff

Thanks Sze, it's very interesting.

I have two questions about this migration.

First is, why does this bird find it beneficial to make such a huge migration twice every year, and how did that develop? I realise what to us seems a spectacular journey may not be so spectacular to a bird like an Amur Falcon which is a superior flyer. But it still must be quite dangerous to fly so far, yet Darwin's Principle 'Survival of the Fittest' has determined this is the best option. The nature of the terrain at either end of the journey - Inner Mongolia and inner Botswana - must be quite similar.
How did it develop? - presumably some time in the distant past when the continents were closer although that was millennia ago. Both questions also apply to Common Swift (see above), which is also a superior flyer and has developed a much different route to the same location.
One reason that Amur Falcons migrate in flocks may be that the experienced birds are showing the newcomers the way.  

Second question is why we see Amur Falcon regularly in autumn but only have one record in spring. I'm surprised to see the return journey from southern Africa to northeast China is approximately the same route as the outward journey China to Africa but if you look carefully it appears to be a few hundred kilometers to the west when crossing China on the return journey. The "common in autumn/rare in spring" combination is common to many of our southeast Asia wintering migrants and I think they all take this more westerly route through China in spring, mostly due to prevailing winds I think.   

Thanks again Sze

[ Last edited by wgeoff at 29/10/2015 07:16 ]