A long time ago when the world (and I) was simpler I used to hang glide. One of the club memebers had been to Death Valley and his best tale was of gliding in company with a couple of vultures.
Looking for the best lift he followed them as closely as he could - after all they have similar constraints in terms of seeking lift.......
After a couple of minutes a particularly violent air current flung the the lead bird against the rock face they were all following. Scratch one vulture!!!!