What keeps them from crashing into the ground up there in northern Canada where the lines of force all intersect at magnetic north?? Other theories posit that they can hear the ocean waves and steer by that sound. Others say they steer by the position of the sun or stars.. In short..Global Warming all over again. Just another cry for government funding.
I dunno about government funding. I have a German
cousin who retired from being a prof at Duke and
who spent his professional life on “How do homing pigeons home, and related questions” He’s in his 70’s now and living in Oberkirche, Germany, but if I see him again, I’ll ask him how much gummint money he got.