Though the Burrowing Owl probably obtains most of its food in the early twilight, it is frequently in motion on the brightest days, capturing its prey or evading its pursuer with the greatest ease. Like the sparrowhawk, it frequently hovers in the air and drops upon its prey. Its food consists of the smaller rodents, including the young of the prairie dog, frogs, fish, lizards, snakes and insects of various kinds. In fact, its food is so varied and consists of noxious animals to so great an extent that it is of great service to the agriculturist. Dr. Fisher says: In summer and fall, when grasshoppers and crickets are exceedingly abundant on the western plains, the Burrowing Owl feeds almost exclusively on such food. Like the sparrowhawk, this little Owl will chase and devour grasshoppers until its stomach is distended to the utmost. It is rare and only when pressed for food that it attacks and kills other birds.
Dr. C. S. Canfield gives the following account of its nesting habits: I once took pains to dig out a nest of the Burrowing Owl. I found the burrow was about four feet long and the nest was only about two feet from the surface of the ground. The nest was made in a cavity of the ground, of about a foot in diameter, well filled with dry, soft horse-dung, bits of an old blanket and the fur of a coyote that I had killed a few days before. One of the parent birds was on the nest, and I captured it. It had no intention of leaving the nest, even when entirely uncovered with shovel and exposed to the open air. It fought bravely with beak and claws. I found seven young ones, perhaps eight or ten days old, well covered with down, but without any feathers. The whole nest, as well as the birds, swarmed with fleas. It was the filthiest nest I ever saw. There are few birds that carry more rubbish into the nest than the Burrowing Owls, and even the vultures are not more filthy. In this nest Dr. Canfield found scraps of dead animals, both of mammals, snakes and insects.
Major Bendire believes that when these Owls are once mated they are paired for life. He also likens their love-note, which is heard about sundown, to the call of the English cuckoo. He says that it is a mellow, sonorous and far-reaching coo-c-oo, the last syllables somewhat drawn out, and this concert is kept up for an hour or more. These notes are only uttered when the bird is at rest, sitting on the little hillock surrounding the burrow. While flying about a chattering sort of note is used and when alarmed a short shrill tzip-tzip. When wounded and enraged it utters a shrill scream and snaps its mandibles rapidly together, making a sort of rattling noise, throws itself on its back, ruffles its feathers and strikes out vigorously with its talons, and with which it can inflict quite a severe wound.