A great horned owl perched in its nest on a saguaro cactus.

An unidentified man photographing a great horned owl perched in its nest on a saguaro cactus.

An unidentified man with a camera on a tripod photographing a red-tailed hawk perched in a nest on a saguaro cactus.

An unidentified man with a camera on a tripod photographing a red-tailed hawk perched in a nest on a saguaro cactus.

A red-tailed hawk perched in a nest on a saguaro cactus.

Three red-tailed hawks perched in a nest on a saguaro cactus.

Three red-tailed hawks perched in a nest on a saguaro cactus.

Male plumbeous gnatcatcher on the edge of nest after feeding young.

Male plumbeous gnatcatcher on the edge of nest after feeding young. Image note: side view.

Male plumbeous gnatcatcher on the edge of nest in cholla cactus. Location note: beyond university.