Eastern kingbirds are conspicuous and aggressive birds with an attractive black, gray, and white coloration.  They frequently perch on fences, as here, and in behavior if not appearance they are similar to the closely related Western kingbird).   I took these pictures from a car, at the Konza Prairie in eastern Kansas, in Montana, in southeastern Idaho, and at Valentine Wildlife Refuge in Nebraska (many thanks to my friend Dave Rintoul for taking us to Valentine!).