We consider a cough a problem while owls find it a solution to their problem. They tend to swallow small animals such as little birds and mice whole. What to do about all those feathers and bones? They cough them up in 1-2 inch pellets which frequently accumulate under their perch.
I was surprised to learn that hawks, shrikes, herons and gulls also regurgitate undigested parts in pellets, called "castings" when they come from hawks. They are thought to scour their digestive tracts clean.
Francis Skalicky's article in the News-Leader describes studies of owl pellets thousands of years old which found remnants of birds long extinct in the Galapagos Islands. These studies have confirmed the presence of some now extinct birds described by Darwin, whose existence was doubted by some experts until now. Details are at Carolina.com
Humans may have been responsible for the birds extinction as we introduced- either deliberately or accidentally- rats, cats, goats, and other species that found defenseless native species which couldn't compete with them. This invasive species story may sound familiar to you now.
Would you believe you can order owl pellets over the internet? Of course you would. To see what you can do when you find an owl pellet, check this MDC site.
See, mom was right- there is a good reason to chew your food well before swallowing.