Adult cactus wren about to enter nest with food. Image note: side view, very good.

Female plumbeous gnatcatcher sitting on the edge of a nest in a cholla cactus.

Verdin nest on the limb of a cholla cactus.

Old road-runner sitting on edge of nest in cactus. Image note: side view, negative cracked and repaired.

Female plumbeous gnatcatcher on edge of nest feeing her young. Image note: upright plate.

Female plumbeous gnatcatcher sitting on edge of nest after feeding young. Image note: side view.

Female plumbeous gnatcatcher sitting on edge of nest with food for her young. Image note: upright plate.

An unidentified man standing at the base of a saguaro cactus looking up at a red-tailed hawk’s nest in the top of the cactus.

An unidentified man standing at the base of a saguaro cactus looking up at a red-tailed hawk’s nest in the top of the cactus.

An unidentified man photographing a great horned owl perched in its nest on a saguaro cactus. A ladder is leaning against the side of the cactus.