I’m looking out my office window at a flock of 50-100 Canada geese that are wheeling in a large circle, seemingly confused as to which direction to take (but then I’m not a…um…birdyologist).
Does high solar activity such as we are now experiencing, and the resultant effect on magnetic fields, throw a wrench into the on-board navigation systems that migratory birds use? Or are they guided primarily by landmarks?
I remember seeing a program once that said that many migratory birds use the earth’s magnetic field to navigate. I don’t know though whether solar flare activity would disrupt the magnetic field this far down. I would guess no, but i’m afraid i don’t know.
Birds use a lot of multiply redundant systems to navigate, so this is not an either/or question.
Birds are known to use landmarks, celestial cues (position of sun and stars), polarized light, and wind patterns, among other things, to navigate. If one system is unavailable, (say, they can’t see the sky because it’s overcast) they will use another as a fallback.
Some birds have been shown to be able to use the Earth’s magnetic field to navigate. (Homing pigeons were unable to home if their vision was obscured *and]/i] small magnets were attached to their heads.) However, I am not aware of any specific research that shows disruption of migration by solar flares. I would say it’s theoretically possible, though.
This said, it’s unlikely the geese you saw were disoriented by the solar flares, unless it also happened to be a overcast and/or foggy day. Magnetism is probably used mainly when other systems are not working.