Suzi Eszterhas / Golden Lion Tamarin (Leontopithecus rosalia), Atlantic Forest, Brazil

Suzi Eszterhas / Golden Lion Tamarin (Leontopithecus rosalia), Atlantic Forest, Brazil

Suzi Eszterhas / Golden Lion Tamarin (Leontopithecus rosalia), Atlantic Forest, Brazil

Bernard Castelein / Guianan brown capuchin (Sapajus apella) chewing on branch, Pampas del Yacuma Protected Area, Bolivia

Alex Hyde / Brown / Tufted Capuchin (Cebus apella) family group in cloud forest, Manu Biosphere Reserve, Peru.

Thomas Marent / Cotton-top Tamarin (Saguinus oedipus) with red pollen after feeding on flower nectar, Tayrona National Natural Park, Colombia

Thomas Marent / Saddle-back Tamarin (Saguinus fuscicollis) mother with young, Tambopata-Candamo Nature Reserve, Peru

Thomas Marent / Emperor Tamarin (Saguinus imperator), Manu National Park, Peru

Thomas Marent / Black-faced Lion Tamarin (Leontopithecus caissara), Superagui National Park, Atlantic Forest, Brazil

Mark Bowler / Black capuchin, (Sapajus nigritus) female standing on hind legs, Rio de Janeiro, Brazil.

Cyril Ruoso / Bare-eared Squirrel Monkey (Saimiri ustus) in tree, Peru

Ben Cranke / Black-striped capuchin (Sapajus libidinosus) using rock as a tool to break open palm nut, Parnaiba Headwaters National Park, Piaui, Brazil. August.