Birds Can “Read” the Earth’s Magnetic Signature to Navigate Back on Course

Eurasian Reed Warbler

A Eurasian reed warbler used in the study and then released. Credit: Florian Packmor

Research shows for the first time, how birds displaced beyond their normal migratory route are able to navigate back to their route and gives us an insight into how they accomplish this feat.

Birdwatchers get very excited when a ‘rare’ migratory bird makes landfall having been blown off-course and flown beyond its normal range. But these are rare for a reason; most birds that have made the journey before are able to correct for large displacements and find their final destination.

Now, new research by an international team shows for the first time, how birds displaced in this way are able to navigate back to their migratory route and gives us an insight into how they accomplish this feat.

Writing in Current Biology, the team from Bangor and Keele Universities describe how reed warblers can navigate from a ‘magnetic position’ beyond what they have experienced in their normal migration route, back towards that correct route.

Eurasian Reed Warbler Breeding Range and Variation in Geomagnetic Signature

Map: Eurasian reed warbler breeding range (green) in Europe and variation in the geomagnetic signature (total magnetic intensity, magnetic inclination and magnetic declination). The natural migratory direction from the study site (white dot) towards Africa during autumn is shown as black arrow. The expected compensatory direction from the simulated site (black star) is shown as white arrow. Circular diagrams: Left: orientation of birds experiencing the natural magnetic field at the study site in Austria. Right: orientation of birds experiencing the simulated magnetic field of a site in Russia while still being at the study site in Austria. Arrows depict the respective mean group direction. Black dots show the orientation of the individual birds tested. Credit: Paper authors

Different parts of the Earth have a distinct ‘geomagnetic signature’ according to their location. This is a combination of the strength of the geomagnetic field, the magnetic inclination or the dip angle between magnetic field lines and the horizon and the magnetic declination, or the angle between directions to the geographic and magnetic North poles.

Adult birds already familiar with their migration route, and its general magnetic signatures, were held in captivity for a short period before being released back into the wild, and exposed to a simulation of the earth’s magnetic signature at a location thousands of miles beyond the birds’ natural migratory corridor.

Despite remaining physically located at their capture site and experiencing all other sensory clues about their location, including starlight and the sights, smell and sounds of their actual location, the birds still showed the urge to begin their journey as though they were in the location suggested by the magnetic signal they were experiencing.

Bird Magnetic Set up

The magnetic set-up used in Austria to simulate a displacement of birds off-course by exposing them to the magnetic field of the Russian site. Credit: Florian Packmor

They oriented themselves to fly in a direction that would lead them ‘back’ to their migratory path from the location suggested to them by the magnetic signals they were experiencing.

This shows that the earth’s magnetic field is the key factor in guiding reed warblers when they are blown off course.

“The overriding impulse was to respond to the magnetic information they were receiving,” explained Richard Holland of Bangor University’s School of Natural Sciences.

What our current work shows is that birds are able to sense that they are beyond the bounds of the magnetic fields that are familiar to them from their year-round movements, and are able to extrapolate their position sufficiently from the signals. This fascinating ability enables bird to navigate towards their normal migration route.”

Dr. Dmitry Kishkinev of Keele University’s School of Life Sciences explained:

“What these birds are achieving is “true navigation.” In other words, they are able to return to a known goal after displacement to a completely unknown location without relying on familiar surroundings, cues that emanate from the destination, or information collected during the outward journey.”

Florian Packmor of Bangor University added: “We have already shown that the reed warblers use the same magnetic cues experienced within their natural range, but this study shows that they can extrapolate what they understand about how the magnetic field varies in space far beyond any previous experience they have had.”

But questions remain about whether the birds have an accurate ‘map’ or are just using a ‘rule of thumb’ measurement to judge the general direction of travel needed to get back on course.

The Eurasian reed warbler was selected for the research, but the findings could probably be applied to other migrating songbirds.

Reference: “Navigation by extrapolation of geomagnetic cues in a migratory songbird” by Dmitry Kishkinev, Florian Packmor, Thomas Zechmeister, Hans-Christoph Winkler, Nikita Chernetsov, Henrik Mouritsen and Richard A. Holland, 12 February 2021, Current Biology.
DOI: 10.1016/j.cub.2021.01.051

Funding: The study was funded with grants from the Leverhulme Trust (RPG-2013-288, ECF-2016-378) and the BBSRC research council (BB/R001081/1).

10 Comments on "Birds Can “Read” the Earth’s Magnetic Signature to Navigate Back on Course"

  1. The brainiacs have been discovering alot of interesting things about magnetic fields. High Frequency Gravity Wave production thru high frequency light resonating with a strong magnetic field, appears to make a gravity wave when the magnetic fields collapse. Far out new technology.

  2. Surely the bird navigation theory is very old news? It was hypothesised that they use the iron in their haemoglobin to sense magnetic fields. Lot of work done on pigeons.

    • Sure but the article wasn’t about that they can do it. It was more in depth. It was that it was their primary means of navigation and how they are able to recognize specific magnetic signatures.

  3. Mark Schwendner | February 20, 2021 at 12:39 pm | Reply

    It is hilarious that these college ‘professors’ given grants to study useless meaningless things can come up with such drivel that makes no sense at all. I cannot discern magnetic fields and my brain is light years beyond a bird’s. They make flawed observations, come to flawed conclusions and post as ‘truth’. God Almighty directs their paths, but since they don’t believe in God, they have to draw the most inane conclusions possible. smh

    • JEFFREY SURIANO | February 21, 2021 at 7:51 am | Reply

      Comment left on the page was for you, Mark. I didn’t realize like a directly of a reply until after I commented on your ridiculous comment. Lol. Peace

    • I don’t even know where to begin with this. Their observations make sense just fine. What’s flawed about their observations and conclusions? Your comments really just speak to your lack of comprehension about science in general, not the research. You not being able to sense magnetic fields has absolutely nothing to do with any of this yet you seem to think it invalidates their research some how. Then you bring religion into this for some reason? You’re just mocking their intelligence because you aren’t intelligent enough to understand what they are saying. smh

  4. JEFFREY SURIANO | February 21, 2021 at 7:46 am | Reply

    Geez Mark, to actually think that your brain is light years ahead of a birds? Incorrect! Corvids are problem-solving toolbuilders, who would outsmart an out survive you any day of the week in the wild. Humans tend to exaggerate the importance of their own existence. I read that in your message. Science does not fill the unknown with the god gap. They actually have to roll their sleeves and do the work in order to learn and to know more. God wanted you to be smarter than that. Trust me you make plenty of flawed observations and I just read a bunch of flawed conclusions from your text. Peace.

  5. Madhav Hari Joshi | February 22, 2021 at 10:02 pm | Reply

    I accept that birds fish and almost all others aninals have certain abilities related to sound light navigation etc which we hunans do not have. That does not mean we are lacking something. We do have extraordinary powers which we dont accept. As per my theory (since i am not a scientist i cant publish it) we have ability to decode genetic knowledge. Remember all breakthrough inventions happened without long drawn research and that too simultaneously at multiple places. At right time every one of us get genetic knowledge but only few can decipher it.

  6. If you cannot decipher magnetic fields how does that validate you being light years ahead. You make no sense, Owenstein. Jo momma

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