Jack Dykinga / Sunset at Yaki Point on the South Rim with stratified rim rocks and minute storm clouds inside the canyon below, Grand Canyon National Park, Arizona, USA.

Jack Dykinga / Rainbow after a storm over Mount Hayden, Point Imperial, North Rim, Grand Canyon National Park, Arizona, USA.

Mary McDonald / Broad billed hummingbird (Cynanthus latirostris) AZ, USA Madera Canyon, Arizona

HUW CORDEY / Chuckwalla lizard sunning {Sauromalus obesus} Grand Canyon, AZ, USA

Carol Walker / Arabian stallion trotting in paddock, Phoenix, Arizona, USA

Jack Dykinga / Quartermaster Canyon overlooking west into the Colorado River gorge at dawn, Grand Canyon West Hualapai Indian Reserve, Mojave Desert, Arizona, USA

Jack Dykinga / Sunrise on stratified rim rock tower at Grandview Point with meandering Colorado River riffle below, Grand Canyon National Park, Arizona, USA.

John Cancalosi / Regal horned lizard. {Phrynosoma solare} Sonoran desert, AZ, USA

John Cancalosi / Vermillion flycatcher (Pyrocephalus rubinus) perched on branch, AZ, USA

John Cancalosi / Portrait of Northern cardinal (Cardinalis cardinalis) male perched on branch, AZ, USA

John Cancalosi / Portrait of Mourning dove (Zenaida macroura), Sonoran Desert, AZ, USA

Nigel Bean / Gambel's quail (Callipepla gambelii) male, perched on Saguaro cactus, Sonoran Desert, AZ, USA

John Cancalosi / Western diamondback rattlesnake {Crotalus atrox} eating Wood rat, AZ, USA.

David Kjaer / Gambel's quail {Callipepla gambelii} pair on Saguaro cactus, Sonoran desert, AZ, USA

Barry Mansell / Gilded flicker {Colaptes chrysoides} feeding on cholla cactus, AZ, USA.

John Cancalosi / Gila woodpecker {Melanerpes uropygialis} feeding from flower, AZ, USA. Sonoran desert

John Cancalosi / Cactus wren singing {Campylorhynchus brunneicapillus} AZ, USA.

Mary McDonald / Broad billed hummingbird (Cynanthus latirostris) AZ, USA Madera Canyon, Arizona

Tom Vezo / Cactus wren {Campylorhynchus brunneicapillus} Green valley, Arizona, USA

Nigel Bean / Skull of extinct Harrington's mountain goat {Oreamnos harringtoni} AZ, USA. Late pleistocene period. Grand canyon

Nigel Bean / Preserved dung of extinct Shasta ground sloth. AZ, USA {Nothrotheriops shastensis} Rampart cave, Grand Canyon, Arizona. Late Pleistocene

Nigel Bean / Woodrat midden preserved in Grand Canyon from late Pleistocene period. Arizona, USA {Neotoma sp} over 20,000 yrs old. Seeds identified help to reconstruct past vegetation cover of continent.

Nigel Bean / Woodrat faecal pellets + Juniper seeds preserved from late Pleistocene period AZ, USA found in preserved Woodrat midden {Neotoma sp}

Mary McDonald / Bannertail Kangaroo Rat foraging filling cheek pouches (Dipodomys spectabilis) AZ USA

Tom Vezo / Cactus wren pair {Campylorhynchus brunneicapillus} AZ USA Green