There are two subjects in this photograph – one is dark and round (left) and the other is whitish-yellow and brown, and string-like (right). One came out of a barred owl’s mouth; the other came out the opposite end. Do you know which is which? The round, brown object is an owl pellet which owls (and many other birds) cough up roughly 6 – 10 hours after consuming a meal. It is just about odorless, and consists of the indigestible parts of the owl’s prey — bones, teeth and nails wrapped in the fur of, in this case, a vole. (The fur keeps sharp bones from tearing the owl’s esophagus when the pellet is coughed up.) Different owl species have different sized pellets, and typically the larger the owl, the larger the pellet. (The average barred owl pellet is 2 ½” long and 1” wide.) A great gray owl pellet (3”-4” long and 1 ½” wide) I found contained the skulls of three small rodents, in addition to other bones. The whitish substance is the owl’s semi-solid waste. It consists of white uric acid and feces which are excreted through the bird’s cloaca, an opening that is used not only for waste disposal, but also for mating and egg laying.