Yva Momatiuk & John Eastcott / Barn Owl (Tyto alba) portrait against blue sky in desert, spring, Arizona-Sonora Desert Museum, Arizona

Dr. Axel Gebauer / Costa's Hummingbird (Calypte costae) perched on branch showing iridescence. Arizona-Sonora Desert Museum, Tuscon, Arizona, USA, Small repro only

Dr. Axel Gebauer / Costa's Hummingbird (Calypte costae) with light at angle where iridescence does not show. Arizona-Sonora Desert Museum, Tuscon, Arizona, USA, February.

Yva Momatiuk & John Eastcott / Mountain Lion (Puma concolor) peering from cave, Arizona-Sonora Desert Museum, Arizona

Kevin Schafer / Torch Cactus (Trichocereus sp) flowers, Arizona-Sonora Desert Museum, Tucson, Arizona

Norbert Wu / Hammond's Spadefoot Toad (Spea hammondii), Arizona-Sonora Desert Museum, Tucson, Arizona

Norbert Wu / Bighorn Sheep (Ovis canadensis) ewe, Arizona-Sonora Desert Museum, Tucson, Arizona

Norbert Wu / Sonora Chub (Gila ditaenia) swimming, Arizona-Sonora Desert Museum, Tucson, Arizona

Norbert Wu / Desert Pupfish (Cyprinodon macularius) pair, Arizona-Sonora Desert Museum, Tucson, Arizona

Norbert Wu / Desert Pupfish (Cyprinodon macularius) pair, Arizona-Sonora Desert Museum, Tucson, Arizona

Rob Tilley / Saguaro cactus flower (Carnegiea gigantea) detail with fly, against blue sky. Sonora Desert Museum, Tucson, Arizona. April 2006

Rob Tilley / Ocotillo / Coachwhip / Jacob's Staff in flower (Fouquieria splendens) against the sky, Sonora Desert Museum, Tucson, Arizona, USA

Yva Momatiuk & John Eastcott / Barn Owl (Tyto alba) portrait against blue sky in desert, spring, Arizona-Sonora Desert Museum, Arizona

Konrad Wothe / Broad-billed Hummingbird (Cynanthus latirostris) female building nest, Sonora Desert Museum, Saguaro National Monument, Arizona

Konrad Wothe / Broad-billed Hummingbird (Cynanthus latirostris) female building nest, Sonora Desert Museum, Saguaro National Monument, Arizona

Yva Momatiuk & John Eastcott / Gila Woodpecker (Melanerpes uropygialis) male perching on Saguaro (Carnegiea gigantea) cactus, spring, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Gila Woodpecker (Melanerpes uropygialis) male perching on Saguaro (Carnegiea gigantea) cactus, spring, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Harris' Hawk (Parabuteo unicinctus) portrait in desert, spring, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Copper ore, shines green on rock, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Copper ore, shines green on rock, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Copper ore, shines green on rock, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Coatimundi (Nasua nasua) hanging in tree crown, spring, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Coatimundi (Nasua nasua) hanging in tree crown, spring, Arizona-Sonora Desert Museum, Arizona

Yva Momatiuk & John Eastcott / Desert Bighorn Sheep (Ovis canadensis nelsoni) young female, spring, Arizona-Sonora Desert Museum, Arizona

Konrad Wothe / Broad-billed Hummingbird (Cynanthus latirostris) female building nest, Sonora Desert Museum, Saguaro National Monument, Arizona

Konrad Wothe / Broad-billed Hummingbird (Cynanthus latirostris) close-up portrait of a male, Sonora Desert Museum, Saguaro National Monument, Arizona

Konrad Wothe / Costa's Hummingbird (Calypte costae) male at rest, Sonora Desert Museum, Saguaro National Monument, Arizona

Joel Sartore / Photo Ark / San Diego alligator lizard (Elgaria multicarinata webbii) portrait, Arizona-Sonora Desert Museum, USA. Captive.

Joel Sartore / Photo Ark / San Diego alligator lizard (Elgaria multicarinata webbii) portrait, Arizona-Sonora Desert Museum, USA. Captive.

Joel Sartore / Photo Ark / San Diego alligator lizard (Elgaria multicarinata webbii) portrait, Arizona-Sonora Desert Museum, USA. Captive.

Joel Sartore / Photo Ark / Yucatan banded gecko (Coleonyx elegans) portrait, Arizona-Sonora Desert Museum. Captive, occurs in Mexico, Belize and Guatemala.

Joel Sartore / Photo Ark / Tucson banded gecko (Coleonyx variegatus bogerti) portrait, Arizona-Sonora Desert Museum, Arizona, USA. Captive.

Joel Sartore / Photo Ark / Tucson banded gecko (Coleonyx variegatus bogerti) portrait, Arizona-Sonora Desert Museum, Arizona, USA. Captive.

Joel Sartore / Photo Ark / Yaqui chub (Gila purpurea) female, portrait, Arizona-Sonora Desert Museum, Arizona, USA. Captive.

Steven David Miller / A tiny hummingbird nest, possibly Costa's hummingbird (Calypte costae) held in a hand, inactive nest with non-viable eggs on display, Sonora Desert Museum, Tucson, Arizona, USA. The nest measures 1 x...

Steven David Miller / Costa's hummingbird (Calypte costae) male, Sonora Desert Museum, Tucson, Arizona, USA. Captive.