Where Geography meets Biology
Swifts born in Beijing’s old imperial palaces travel 16,000 miles every year to southern Africa and back again without touching ground. I was amazed by this track map. Why don't they just go directly south, by example to one of the Indonesian islands? Why do they take a route north of the Himalaya and not south ?
The Guardian wrote also about it >>This animation shows the incredible migration of the BEIJING SWIFT. Each coloured dot is an individual bird tracked from the Summer Palace. pic.twitter.com/cymTBDKclJ— Birding Beijing 北京观鸟 (@BirdingBeijing) 2 maart 2017