To discover what an owl eats. To learn about an owl's digestive system. To learn about the value of dissecting the contents of an owl pellet. To make some inferences about the nature of the community in which the owl lives. The Great Horned Owl feeds on an extremely wide variety of prey, including waterfowl, rabbits, squirrels, marsh birds, and rodents.
Owls eat their prey whole and then regurgitate the indigestible parts of their feast each day.
They rarely tear the prey into pieces before eating. Yet owls have weak stomach muscles and weak digestive juices. Because of this, they don't digest their prey completely. This is a very neat system for scientists, because it is easy to collect and analyze these regurgitated owl pellets or castings to see what the owls have been eating recently. With owls doing the collecting, the scientist must simply locate the owl roost to obtain the skulls and bones of the small prey species living in the area.