The previous review is misleading. It simply is not possible to write a field guide to the Amazon and Pantana - to catalogue the birds alone would require hundreds of pages as there are well over a thousand species. What this book does, and does very well. Is to provide background bioloogical and ecological information on the two regions, together with plates of the more common species of flora, reptiles, amphibians, mammals and birds. There are no field guides on reptiles and amphibians that I know of, but any half way decent jungle lodge (of which there are sadly few in Brazil) should have a library of more specific birding guides. If not the best is the the Collins Birds of Southern South America and Antarctica (Pantanal) and the Birds of Colombia (Princeton Univ. Press) - a very weighty volume. For mammals Emmons's Neotropical Rainforest Mammals is the best - though it doesn't cover non-forest species.
This is, however and excellent overview biological guide and is well worth getting. It is no more overly academic than a David Attenborough documentary and it doesn't insult its readership, many of whom are already fairly well informed about wildlife. It lacks only information on the better lodges and tour companies. See the Cadogan Amazon Guide (Alex & Gardenia Robinson) for these.