Classic book on bird speciation (that could also be applied on other groups of animals) in tropical South America, with enphasis in the amazon. Haffer presents here a review of an exhaustive research on several groups of birds, principally toucans, jacamars and manakins, presenting evidence of the pleistocene refuges theory, according to which during the glaciations (and consecutively drought times in South America) much of the forest fauna was restricted to certain humid locations in the amazonian basin, where they suffered an allopatric process of speciation; and in the interglatiation periods (more humid times for South America) isolated populations could recontact with each other, so nowadays very close species live in sympatry in the Amazon. The book is divided in two parts, the first describing the refuge theory and the second one the systematics of toucans and jacamars. Specially nice are the characters for differentiating the different spcies based on morphology and voice. Haffer's work helps to understand important features on bird distribution in the amazon, both for forest and non-forest avifauna, and is a must-read for the neotropical ecologist.