03 June 2024

A "rider on the storm"

"Here, I report on a rare case that implies the upper limit of the seabird capacity to tolerate a storm. A GPS-equipped streaked shearwater (Calonectris leucomelas) was apparently caught in a huge typhoon, showing swirling flight high over the mainland of Japan. It finally came through without landfalls when the typhoon returned to the sea...

...the overall direction of the bird's movement overlapped the path of the typhoon, with a sequence of five anticlockwise circles  50–80 km in diameter. While swirling, the movement speed of the bird was between 80 and 170 km h−1, with a GPS-based altitude record of up to 4700 m. These speeds and altitudes were much higher than those recorded during regular flights (flight speed: 10–60 km h−1, altitude: <100 m...

...the horizontal movement directions and high speeds of the shearwater were likely to be passively determined, whereas the altitude might have been partially self-controlled. It remains unknown whether the bird could not or chose not to escape from the typhoon; once caught in the storm and displaced toward land, it might have been safer to stay within the storm rather than to resist it until it returned to the ocean with reduced wind speeds. This speculation was supported by the fact that the bird landed on the water as soon as it returned to the sea..."
Full scientific report at Ecology.

2 comments:

  1. I skimmed through the study because I just wanted to know whether the bird survived. It did!

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  2. Shearwaters - can they just spread their wings and glide out the storm - not much actual wing flapping?

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