We call them
TICK Birds.
The cow birds are the little black ones that hang around in mid spring. When the Tick Birds show up, you know spring is almost over and summer will be here soon. I love to see the Tick Birds in my pasture.
Cattle egrets are an endangered species. In town they had a problem with the birds nesting in such mass they were creating a health hazard. The city folk wanted them gone, but couldn't kill them. The country folk wanted them nesting in the country. Finally, the city bulldozed the trees while the birds were out in the fields eating. They moved out of town after that. :D :D