Some birds follow cows as they graze and eat the insects the cows stir up as they move through the grasses.
They cows do not know or care they are assisting birds to feed.
Probably the most well-know of these is Yucca Plant and Yucca Moth (Tegeticula sp.). One of the most extraordinary partnerships between an insect and the plant that it pollinates is that of the yucca and the yucca moth. They are so interdependent that one cannot live without the other. Actually, there are a number of species of yucca, each with its corresponding partner, a species of Tegeticula or Parategeticula moth. This mutually beneficial relationship probably started as a relationship of exploitation with the moth feeding on the yucca. This is still the case with a number of close relatives of Tegeticula, members of the Prodoxidae family.
I’ve had owls follow me on deer trails, at night. I’m sure they follow deer, and other animals, too. Had a Short-Eared Owl follow my dog, years ago. Flew about 4 feet above him, and a few feet behind. Nemo never knew he was there.