came in, flying back and forth just above where the prairie chickens had been dancing. Do prairie chickens have lice or something that the swallows were feeding on?
A. Like all birds, prairie-chickens do, indeed, harbor a few lice and mites, but these parasites stick tight to their hosts, and aren’t normal food for swallows. But during their dancing, prairie-chickens sometimes squabble, and they also take time out for preening. During these times, they often drop small body feathers. Tree Swallows line their nests with feathers, and know how to capitalize on a regular supply! So they fly low and pluck them up as they go.
