Small birds fly at high altitudes towards Africa

August 7, 2018, Lund University

A new study from Lund University in Sweden shows that small birds migrating from Scandinavia to Africa in the autumn occasionally fly as high as 4,000 metres above sea level—probably adjusting their flight to take advantage of favourable winds and different wind layers.

This is the first time that researchers have tracked how high small fly all the way from Sweden to Africa. Previous studies have successfully logged the flight height of larger migratory birds.

"We only followed two individuals and two species. But the fact that both of them flew so high does surprise me. It's fascinating and it raises new questions about the physiology of birds. How do they cope with the , thin air and low temperatures at these heights?" says Sissel Sjöberg, biologist at Lund University and the Zoological Museum in Copenhagen.

The aim of the study was to investigate whether the measuring method itself works on small birds, that is, to measure acceleration, (air ) and temperature throughout the flight using a small data logger attached to the bird.

The was attached to two individuals of different species: the great reed warbler and the red-backed shrike. Among other things, the results show how long it takes for each bird to fly to their destination. The measured barometric pressure showed that the great reed warbler occasionally flies at 3 950 metres, and the red-backed shrike flies at 3,650 metres.

Both individuals flew the highest above ground across the Mediterranean Sea and the Sahara, but the shrike reached higher altitudes closer to its winter grounds in southern Africa.

Sissel Sjöberg thinks it is likely that other small birds fly as high, maybe even higher. But there is no evidence of that yet.

"In this study, we only worked with data collected during the autumn, when the small birds migrate to Africa. There are other studies that indicate that the birds fly even higher when they migrate back in the spring, but we cannot say for sure."

The study was published in the Journal of Avian Biology.

Explore further: Birds migrate away from diseases

More information: Sissel Sjöberg et al, Barometer logging reveals new dimensions of individual songbird migration, Journal of Avian Biology (2018). DOI: 10.1111/jav.01821

Related Stories

Birds migrate away from diseases

April 11, 2018

In a unique study, researchers at Lund University in Sweden have mapped the origins of migratory birds. They used the results to investigate and discover major differences in the immune systems of sedentary and migratory ...

Small birds almost overheat while feeding their young

May 16, 2018

For decades, researchers have thought that access to food determined the brood size of birds. Now, biologists at Lund University in Sweden have discovered a completely new explanation: the body temperature of small birds ...

Small birds have more efficient wing strokes than bats

February 5, 2018

Small birds are more energy-efficient than bats when flying. Researchers previously believed this was due to air resistance created by the bats' ears. However, biologists at Lund University in Sweden have now discovered another ...

Birds fly faster in large flocks

August 16, 2016

New research at Lund University in Sweden shows that the flight speed of birds is determined by a variety of factors. Among the most sensational is that the size of the flock has a significant impact on how fast the birds ...

Recommended for you

Scientists ID another possible threat to orcas: pink salmon

January 19, 2019

Over the years, scientists have identified dams, pollution and vessel noise as causes of the troubling decline of the Pacific Northwest's resident killer whales. Now, they may have found a new and more surprising culprit: ...

Researchers come face to face with huge great white shark

January 18, 2019

Two shark researchers who came face to face with what could be one of the largest great whites ever recorded are using their encounter as an opportunity to push for legislation that would protect sharks in Hawaii.

Why do Hydra end up with just a single head?

January 18, 2019

Often considered immortal, the freshwater Hydra can regenerate any part of its body, a trait discovered by the Geneva naturalist Abraham Trembley nearly 300 years ago. Any fragment of its body containing a few thousands cells ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.