Palmer thrasher leaving nest in cholla cactus.

Palmer thrasher just leaving nest in cholla cactus. Image note: shadow on body.

Herbert Brown standing beside a cholla cactus looking at a Palmer thrasher nest.

Cactus wren nest showing four eggs. Nest is partially torn away from cactus.

Palmer thrasher nest in a cholla cactus.

Palmer thrasher on edge of nest. Image note: large size, shadow across body, taken from blind.

Female plumbeous gnatcatcher standing in nest with wings spread to protect young bird from the sun.

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.