Joel Sartore / Photo Ark / Eastern saker falcon (Falco cherrug milvipes) head portrait, Dubai Falcon Center, United Arab Emirates. Captive. Endangered.

Joel Sartore / Photo Ark / Shaheen peregrine falcon (Falco peregrinus peregrinator) head portrait, Dubai Falcon Hospital. Captive, occurs in Pakistan and India.

Joel Sartore / Photo Ark / Red-capped peregrine falcon (Falco peregrinus babylonicus) portrait, Dubai Falcon Hospital. Captive, occurs in Asia.

Joel Sartore / Photo Ark / Campbell's rattlesnake (Crotalus campbelli) portrait, Chiricahua Desert Museum. Captive, occurs in Mexico.

Joel Sartore / Photo Ark / Asian leopard cat (Prionailurus bengalensis) sitting, portrait, Angkor Centre for Conservation of Biodiversity. Captive.

Joel Sartore / Photo Ark / Scottish wildcat (Felis silvestris grampia) head portrait, Wildcat Haven Scotland. Captive.

Joel Sartore / Photo Ark / Female Scottish wildcat (Felis silvestris grampia), aged 5 years, with mouth open, head portrait, Wildwood Trust. Captive.

Joel Sartore / Photo Ark / Malayan tiger (Panthera tigris jacksoni) head portrait, Henry Doorly Zoo and Aquarium. Endangered. Captive.

Joel Sartore / Photo Ark / Malayan tiger (Panthera tigris jacksoni) portrait, Henry Doorly Zoo and Aquarium. Endangered. Captive.

Joel Sartore / Photo Ark / Female Bengal tiger (Panthera tigris tigris) lying down, portrait, Alabama Gulf Coast Zoo. Endangered. Captive.

Joel Sartore / Photo Ark / Female Bengal tiger (Panthera tigris tigris) with mouth open, head portrait, Alabama Gulf Coast Zoo. Endangered. Captive.

Joel Sartore / Photo Ark / Snow leopard (Panthera uncia) head portrait, Miller Park Zoo. Federally endangered. Captive.

Joel Sartore / Photo Ark / Snow leopard (Panthera uncia) portrait, Miller Park Zoo. Federally endangered. Captive.

Joel Sartore / Photo Ark / Snow leopard (Panthera uncia) sitting, portrait, Miller Park Zoo. Federally endangered. Captive.

Joel Sartore / Photo Ark / Garden dormouse (Eliomys quercinus) portrait, Plzen Zoo. Captive.