Peanuts are like a secret weapon for people who love feeding birds. Your feathered friends will go nuts for the fat- and protein-packed treat that is super easy for backyard bird-watchers to serve.

Going clockwise from top left we have black-oil sunflower, shelled sunflower, white millet with cracked corn, peanuts in the shell, peanuts out of the shell and Nyjer seeds. Credit: PHOTO BY BILL ...