Andy Rouse / Dalmatian pelican (Pelecanus crispus) landing on lake, backlit by sunlight, Lake Kerkini, Greece.

Ann & Steve Toon / Lioness (Panthera leo) at night, head portrait, Zimanga private game reserve, KwaZulu-Natal, South Africa.

Ann & Steve Toon / Common genet (Genetta genetta) at night, portrait, Shompole, Kenya.

Andy Rouse / Dalmatian pelican (Pelecanus crispus) landing on lake, backlit by sunlight, Lake Kerkini, Greece.

Andy Rouse / Sparkling violetear hummingbird (Colibri coruscans) perched on branch, reaching up to catch a bee, Cloud forest, Ecuador.

Andy Rouse / Dalmatian pelican (Pelecanus crispus) landing on lake, backlit by sunlight, Lake Kerkini, Greece.

Alex Mustard / Pygmy seahorse (Hippocampus bargibanti) among a Sea fan (Muricella sp.) on a coral reef, Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Joel Sartore / Photo Ark / Usambara three-horned chameleon (Trioceros deremensis) looking around, Tiergarten Schonbrunn, Vienna. Captive.

Joel Sartore / Photo Ark / Black softshell turtle (Nilssonia nigricans) extending neck, showing folded skin, and looking around. This species is endemic to India and Bangladesh. Turtle Island, Graz, Austria. Critically endanger...

Joel Sartore / Photo Ark / East African green mamba (Dendroaspis angusticeps) looking and flicking its tongue, Kentucky Reptile Zoo, Kentucky. Captive.

Joel Sartore / Photo Ark / Eastern diamondback rattlesnake (Crotalus adamanteus) looking and flicking its tongue, Kentucky Reptile Zoo, Kentucky. Captive.

Joel Sartore / Photo Ark / Cotton-top tamarins (Saguinus oedipus) curiously looking around, Safari North, Brainerd. This species is from Colombia. Critically endangered. Captive.