Joel Sartore / Photo Ark / Brazilian free-tailed bat (Tadarida brasiliensis) flying and calling at Night Wings Inc., Texas, USA. Captivity.

Joel Sartore / Photo Ark / European free-tailed bat (Tadarida teniotis) crawling at Wildlife Rescue Centre of Rome, Italy. Captivity.

Joel Sartore / Photo Ark / Florida bonneted bat (Eumops floridanus), listed as federally endangered by USFW, crawling, Florida, USA. Captivity.

Joel Sartore / Photo Ark / Common vampire bat (Desmodus rotundus) crawling at Buffalo Zoo, USA. Captivity.

Joel Sartore / Photo Ark / Striped possum (Dactylopsila trivirgata) head portrait, Henry Doorly Zoo and Aquarium, USA. Captive.

Joel Sartore / Photo Ark / Goodfellow's tree-kangaroo (Dendrolagus goodfellowi) eating fruit, portrait, Melbourne Zoo. Endangered. Captive.

Joel Sartore / Photo Ark / Greater forest wallaby (Dorcopsis hageni) head portrait, Albuquerque BioPark Aquarium, USA. Captive.

Joel Sartore / Photo Ark / Sulawesi bear cuscus (Ailurops ursinus) portrait, Wroclaw Zoo, Poland. Vulnerable. Captive.

Joel Sartore / Photo Ark / Ground cuscus (Phalanger gymnotis) walking, portrait, Plzen Zoo, Czech Republic. Captive.

Joel Sartore / Photo Ark / Yellow-bellied glider (Petaurus australis) with food in mouth, portrait, Taronga Zoo. Captive.

Joel Sartore / Photo Ark / Ground cuscus (Phalanger gymnotis) head close up, portrait, walking, portrait, Plzen Zoo, Czech Republic. Captive.

Joel Sartore / Photo Ark / Female Matschie's tree-kangaroo (Dendrolagus matschiei) with joey in pouch, portrait, Zoo Miami, USA. Endangered. Captive.