Tiny songbirds cross deserts and seas by soaring three times higher than usual
May. 6, 2021 , 2:00 PM
Migration ecologist Sissel Sjöberg had long wondered how tiny birds like the great reed warbler can make it across long expanses of water or desert on their epic migrations. Though just half the weight of a golf ball, they fly 7000 kilometers between Northern Europe and sub-Saharan Africa twice a year. Now, a new study may have the answer: These nighttime flyers soar well into the day and at heights of up to 6000 meters, three times as high as they normally fly.
“That’s totally unexpected,” says Martin Wikelski, an ecologist at the Max Planck Institute of Animal Behavior who was not involved with the work. “It’s like you are building mud houses and suddenly somebody [else] builds a skyscraper. And all you can say is, you didn’t know you could do that.”
University of Amsterdam
A group of international scientists, including UvA professor Judy Shamoun-Baranes, warns that changes to European meteorological data policies threaten biodiversity monitoring as they make vital data unavailable. In a letter published in Science on 16 April, they point out that policies in Europe should be adjusted to take into account the broad role that weather radars play beyond meteorology.
Migrating bramblings. Weather radars are not only used to measure weather, they can also detect animals in the sky, such as these small passerine birds. Picture: Nadja Weisshaupt
Biodiversity is changing at an unprecedented rate and countless initiatives exist to collect suitable information to monitor and understand changes in global biodiversity. Operational weather radars exist in many places around the world and are uniquely suited for monitoring aerial biomass flows, especially of migratory species. Recent changes to data exchange policies in Europe threaten cur