The story of how these owls lived in the Smithsonian Castle in the 1970s (it's a hoot):
Our Secretary at the time, S. Dillon Ripley, was an ornithologist and thought barn owls could hunt the rats attracted to the new garbage cans on the National Mall. He named them Increase and Diffusion—a nod to the Smithsonian’s mission of “the increase and diffusion of knowledge”—and they lived in the building's west tower.
The pair hatched three owlets in the spring of 1977. One of those new owlets fell out of the tower but was brought safely inside by a staff member, and is seen here refusing to take a message.
After raising their family, the owls departed and never returned. These photos are from @smithsonianarchives. #InternationalOwlAwarenessDay