The sheer diversity of Amazonian monkeys is staggering. These enchanting, fascinating creatures range in size from Pygmy Marmosets just 115 grams in weight and around 10 cm high, when fully grown, to the largest Amazonian species, Humboldt's Woolly monkeys, who weigh in at up to 10 kg and 70 cm high. For all their numbers - so far 209 species have been identified - these monkeys live well camouflaged, hidden high up in the thick, tangled vegetation of the rainforest canopy. This book reveals the secret lives of these busy, social creatures.