Guy Edwardes / Neolithic earthworks and Knowlton Church, Dorset, England, UK. May 2014.

Pete Oxford / Huaorani Indian, Ontagamo Kaimo, hunting in Amazon rainforest, dead Colombian red howler monkeys (Alouatta seniculus) and South American coati (Nasua nasua) slung over shoulders. Animals shot using bl...

Enrique Lopez-Tapia / Blue-winged kookaburra (Dacelo leachii) perched on branch, portrait. Occurs in Northern Australia Captive.

Enrique Lopez-Tapia / Blue-winged kookaburra (Dacelo leachii) perched on branch. Occurs in Northern Australia . Captive.

Jeff Foott / Mantled howler monkey (Alouatta palliata) in tree, portrait. Ecuador.

Neil Aldridge / Guianan red howler monkeys (Alouatta macconnelli) feeding in a tree, Iwokrama Forest, Guyana.

Suzi Eszterhas / Bornean orangutan (Pongo pygmaeus) sub-adult vocalising in rainforest. Tanjung Puting National Park, Indonesia.

Ernie Janes / Black howler (Alouatta caraya) male and female, portrait, captive.

David Pattyn / Mantled howler monkey (Alouatta palliata) foraging for fruit in tree, La Selva Biological research station, Heredia, Costa Rica

David Pattyn / Mantled howler monkey (Alouatta palliata) in tree, La Selva Biological research station, Heredia, Costa Rica

David Pattyn / Mantled howler monkey (Alouatta palliata) female and young in tree, La Selva Biological research station, Heredia, Costa Rica

David Pattyn / Mantled howler monkey (Alouatta palliata) silhouet jumping from tree to tree La Selva biological research station, Heredia, Costa Rica La Selva Biological research station, Heredia, Costa Rica.. July

Wendy Shattil / Coyote (Canis latran) howling within no-man's land, Southmost Preserve, The Nature Conservancy Reserve. The border wall separates 85% of the reserve from the United State's side of the barrier...

Robert Pickett / Coyote (Canis latrans) female adult howling in woodland, summer, Minnesota, USA, captive.

Robert Pickett / Coyote (Canis latrans) nine week pup howling in woodland, Minnesota, USA, captive.