Patricio Robles Gil / Gambel's Quail (Callipepla gambelii) adult perched atop a blooming cactus, El Pinacate/Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Claudio Contreras / Mojave desertstar (Monoptilon bellioides) flowers. Sierra El Rosario, El Pinacate Biosphere Reserve, Sonoran Desert.

Claudio Contreras / Evening primrose (Oenothera deltoides), Sand verbena (Abronia villosa) and Snowy sunflower (Helianthus niveus) in sand dune at dawn. Sierra El Rosario mountain range in background. El Pinacate Biosphe...

Claudio Contreras / Ocotillo (Fouquieria splendens) and Saguaro (Carnegiea gigantea) at sunset in Sonoran Desert. El Pinacate Biosphere Reserve, northwest Mexico.

Claudio Contreras / Brittlebush (Encelia farinosa) and Emory's rock daisy (Perytile emoryi). El Pinacate Biosphere Reserve, Sonoran Desert, northwest Mexico.

Claudio Contreras / Sonoran Desert with Teddy-bear cholla (Cylindropuntia bigelovii), Saguaro (Carnegiea gigantea) and Brittlebush (Encelia farinosa). El Colorado volcano in background. El Pinacate Biosphere Reserve, nor...

Claudio Contreras / Sonoran Desert with Saguaro (Carnegiea gigantea) and Teddy-bear Cholla (Cylindropuntia bigelovii) cactic, alongside Ocotillo (Fouquieria splendens). El Pinacate Biosphere Reserve, Sonoran Desert, nort...

Claudio Contreras / Merriam's kangaroo rat (Dipodomys merriami). El Pinacate Biosphere Reserve, Sonoran Desert, northwest Mexico. July.

Claudio Contreras / Teddy-bear cholla (Cylindropuntia bigelovii) in El Elegante volcano crater. El Pinacate Biosphere Reserve, northwest Mexico.

Claudio Contreras / Senita cactus (Lophocereus schottii) in Sonoran Desert, view to El Colorado volcano. El Pinacate Biosphere Reserve, Sonoran Desert, northwest Mexico. January 2009.

Claudio Contreras / Harem cactus (Homalocephala polycephala), cloes up. El Tecolote volcano, El Pinacate Biosphere Reserve, northwest Mexico.

Claudio Contreras / Sonoran Desert on volcanic soil with Teddy-bear cholla (Cylindropuntia bigelovii), Saguaro (Carnegiea gigantea) and ocotillo (Fouquieria splendens). El Tecolote volcano, El Pinacate Biosphere Reserve,...

Jack Dykinga / Desert environ with Cholla cacti (Cylindropuntia) El Pinacate and Gran Desierto de Altar Biosphere Reserve. Pinacate lava flow, near the border wall along the US-Mexican border through the Sonoran Des...

Claudio Contreras / Flat-tailed Horn Lizard (Phrynosoma mcallii). Sonoran desert, El Pinacate Biosphere Reserve, northwest Mexico, July.

Claudio Contreras / Flat-tailed Horn Lizard (Phrynosoma mcallii). Sonoran desert, El Pinacate Biosphere Reserve, northwest Mexico, July.

Patricio Robles Gil / El Colorado Crater, El Pinacate, Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / Sand dunes, El Gran Desierto de Altar, El Pinacate, Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / Ocotillo (Fouquieria splendens) and Brittlebush (Encelia californica), Sonoran Desert, El Pinacate/Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / Sidewinder (Crotalus cerastes) rattlesnake moving across sand dunes at sunset, El Pinacate/Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / Sidewinder (Crotalus cerastes) rattlesnake moving across sand dunes, El Pinacate/Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / Black-tailed Jackrabbit (Lepus californicus) alert adult in El Pinacate/Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / El Elegante Crater is 1400 meters wide and 140 meters deep, El Pinacate, Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / Desert Sand Verbena (Abronia villosa), El Pinacate, Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Patricio Robles Gil / Desert Bighorn Sheep (Ovis canadensis nelsoni) adult running through rocky desert landscape, El Pinacate/Gran Desierto de Altar Biosphere Reserve, Sonora, Mexico

Claudio Contreras / Senita cactus (Lophocereus schottii) in evening sunlight with El Colorado volcano in background, El Pinacate Biosphere Reserve, Sonoran desert, northwest Mexico.

Claudio Contreras / Teddy-bear cholla (Cylindropuntia bigelovii) at sunrise, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / Ocotillo (Fouquieria splendens), Teddy-bear cholla (Cylindropuntia bigelovii) and Saguaro cactus (Carnegiea gigantea) in volcanic ash field, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / Teddy-bear cholla (Cylindropuntia bigelovii) at dawn, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / California barrel cactus (Ferocactus cylindraceus) spine detail, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / Blister beetle (Nemognatha cantharidis) on Snowy sunflower (Helianthus niveus), Sierra El Rosario mountain range, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / Dune evening primrose (Oenothera deltoides) blooming in desert, Sierra El Rosario mountain range, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / Sand dunes and Sierra El Rosario mountain range, El Pinacate Biosphere Reserve, Sonoran desert, Mexico. March.

Claudio Contreras / Purple mat (Nama demissa) in flower with early morning dew on volcanic ash field, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / Emory's rockdaisy (Perityle emoryi) in flower, growing around a log, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Claudio Contreras / Sand dunes and Sierra El Rosario mountain range, El Pinacate Biosphere Reserve, Sonoran desert, Mexico. March.

Claudio Contreras / Saguaro cactus (Carnegiea gigantea), El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Wendy Shattil / Crater from a dormant volcano in El Pinacate Biosphere Reserve, Mexico. March 2020.