Two elf owls in cactus. Image note: good.

Elf owl looking out of nest hole in giant cactus. Image note: large size.

Elf owl looking out of nest hole in giant cactus. Image note: large size, best plate.

Two elf owls in cactus. Image note: side view.

Two elf owls perched in cholla cactus. Image note: side view.

Herbert Brown standing at the top of a ladder examining an elf owl nest in the top of a giant cactus. Horse and buggy in the background.

Herbert Brown standing at the top of a ladder examining an elf owl nest in the top of a giant cactus. Horse and buggy in the background.

William L. Finley using a ladder to climb to the top of a saguaro cactus to investigate a bird’s nest. A touring car is parked in the foreground.

William L. Finley using a ladder to climb to the top of a saguaro cactus to investigate a bird’s nest. A touring car is parked behind a bush in the distance.

William L. Finley using a ladder to climb to the top of a saguaro cactus to investigate a bird’s nest.