Avian Perch is a term used to describe the place where birds rest or sleep. The crossword solution for this term is 'ROOST', which is a five letter word. Roosting is a behavior that is common among many species of birds, and it is an important part of their daily routine. Roosts can be found in trees, on ledges, or even on the ground. Roosts provide birds with a safe place to rest and sleep, and they also help protect them from predators.