12 October 2021
North American birds that eat flying insects migrate to Central and South America for the winter. Where do Asian insectivores go? Until 2015 the winter home of the common swifts that nest in Beijing was a mystery.
Common swifts (Apus apus) breed across Europe and Asia from Ireland to North China. Those from Europe are known to winter in Africa but where do the far eastern swifts go?
In the spring of 2014 the Beijing Swift Project tagged 31 common swifts with geolocators at the Summer Palace. The birds nested in China, then left in July. When they returned nine months later in April 2015 thirteen were recaptured. Their geolocator data revealed that the swifts had traveled east to the Caspian Sea then south to South Africa, a round trip of 16,000 miles (26,000 km). During those nine months the birds never landed! Their destination is yellow on the map below.
This tweet from October 2020 shows their journey.
Today is #WorldMigratoryBirdDay. A good time to celebrate the incredible migration of the Beijing Swift (????). From late Jul until their return in Apr, these birds – that can fit into the palm of your hand – fly c26,000km and cross 20 borders.https://t.co/2xSe8FHlme pic.twitter.com/oL5EBy90ff
— Birding Beijing ???? (@BirdingBeijing) October 10, 2020
Since Africa is this species’ winter home, those that breed in North China must travel farthest to get there. The journey is so long for Beijing’s swifts that they spend more time in Africa (4 months) than they do in Beijing (3 months).
Read more about the common swifts of China and see their migration maps at the Beijing Swift Project.
(photos, maps and illustrations from Wikimedia Commons)