Ernie Janes / Black howler (Alouatta caraya) captive, occurs in South America.

Willi Rolfes/ BIA / European Wolf (Canis lupus), Lower Saxony, Germany

Karine Aigner / Bengal tiger (Panthera tigris tigris) head, close up. Ranthambore National Park, Rajasthan, India.

Thomas Marent / Buckley's Slender-legged Treefrog (Osteocephalus buckleyi), Putumayo, Colombia

Paul Williams / Sumatran tiger (Panthera tigris sumatrae) close up portrait, captive.

Staffan Widstrand / Wild Wonders of China / Portrait of a Golden snub-nosed monkey (Rhinopithecus roxellana) full frame of the face, Foping Nature Reserve, Shaanxi, China. Endangered species

Ralph Pace / Silky Shark (Carcharhinus falciformis), Galapagos Shark (Carcharhinus galapagensis), Dusky Shark (Carcharhinus obscurus), and Black-tip Shark (Carcharhinus limbatus) group working with Yellowfin Tuna...

Ralph Pace / Silky Shark (Carcharhinus falciformis), Galapagos Shark (Carcharhinus galapagensis), Dusky Shark (Carcharhinus obscurus), and Black-tip Shark (Carcharhinus limbatus) group working with Yellowfin Tuna...

Phil Savoie / Pink lady mayfly (Epeorus albertae) close up of eye of male, Madison River, Montana, USA, August.

Theo Bosboom / Small red damselfly (Ceriagrion tenellum) close up portrait, warming up in the early morning. De Hatertse Vennen Nature Reserve, near Nijmegen, the Netherlands, July.

Theo Bosboom / Emerald damselfly (Lestes sponsa) hiding behind a stem, Meinerswijk, Arnhem, the Netherlands, July.

Theo Bosboom / Close-up of Emerald damselfly (Lestes sponsa) compound eye, covered in dewdrops, Hatertse vennen, the Netherlands, July.