Natures wonders: bat magnetic field sensing (Introduction)

by David Turell , Monday, May 29, 2023, 20:36 (542 days ago) @ David Turell

Orienting in the dark:

https://www.newscientist.com/article/2375811-migrating-bats-use-earths-magnetic-field-t...

"Migratory bats use a magnetic sense to navigate long distances, calibrating their internal compass based on the position of the setting sun each evening.

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"The researchers trapped 65 soprano pipistrelles on their migration route at Pape Ornithological Station in Latvia. Just before sunset, they manipulated the magnetic field around two groups of bats using a Helmholtz coil, a device that generates magnetic fields. One group had a horizontal shift in polarity 120o clockwise; the other had the same horizontal treatment and a completely reversed vertical shift in inclination, as if they were in the southern hemisphere. A third group had no magnetic manipulation.

"A few hours later, the researchers released the bats into the night and recorded the direction they went. Bats that weren’t subjected to altered magnetic fields unexpectedly flew in two directions, either to the north or to the south – a split possibly due to poor weather nearby.

"Those exposed to the horizontal shift only took off to the north, supporting the idea they can detect the magnetic field. The bats exposed to the horizontal and vertical shifts took off in all directions, indicating for the first time that they are sensitive to the field’s vertical inclination too – and that they were probably very confused.

"This extra information gives a more accurate position, like a GPS system tapping into a number of satellites, says Juan Tomás Alcalde at the Spanish Association for the Study and Conservation of Bats. “These abilities may allow bats not only to migrate confidently in the path they are flying, but also to adapt their magnetic compass to the Earth’s ever-changing magnetic field.'”

comment: this adds to the enormous list of animals using the field.