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

Daniel Heuclin / Chuckwalla (Sauromalus ater) male, Death Valley, California, USA.

Daniel Heuclin / Chuckwalla (Sauromalus ater) male, Death Valley, California, USA.

David Welling / Chuckwalla (Sauromalus obesus) basks on a volcanic rock near Eureka dunes, California

Daniel Heuclin / Northern Chuckwalla (Sauromalus ater / obesus) male feeding on seed pods. Controlled conditions. Coachella valley, California, June.

Daniel Heuclin / Northern Chuckwalla (Sauromalus obesus) male eating egg, controlled conditions, Joshua's Tree National Monument, California, USA

Daniel Heuclin / Northern Chuckwalla (Sauromalus obesus) male head portrait, Joshua's Tree National Monument, California, USA

Daniel Heuclin / Northern Chuckwalla (Sauromalus obesus) male, Coachella valley, California, USA

Daniel Heuclin / Northern Chuckwalla (Sauromalus obesus) male 'pumping', Joshua's Tree National Monument, California, USA

Brent Stephenson / Immature Northern chuckwalla (Sauromalus ater) sunning on a rock. Isla Espiritu Santo, Baja California, Mexico, September.

George McCarthy / Chuckwalla Lizard (Sauromalus obesus) in breeding colours, Arizona, USA