The new updated paperback version of this book arrived recently and I have had a chance to look it over in preparation for a trip to Manu this summer. Yes, there are three new plates with 25 new birds, but other than this, it does not appear that too many other updates (some much needed) have been made. I did notice changes on several of the range maps and one plate adds an additional hummingbird illustration (to these authors a subspecies, though Clements and others consider it a full species). My original hardcover copy is full of notes re: subspecies, reclassifications, etc. and it looks like most of these notes will have to be transferred to the new paperback, something I was hoping to avoid.
That said, if you are going birding in Peru this book is an absolute must. And it is great to have it in a slightly lighter (though not as much lighter as you would think) paperback edition. I give the original effort of the authors five stars. I am giving the revised paperback edition four stars because I had hoped that more updates would have been made. Any field guide to a country like Peru is a monumental undertaking, not in the least because the situation is constantly in flux. I have already read about the discovery of a new barbet species that is not in this updated edition!
UPDATE TO MY REVIEW:
I had a chance to do a little more work with this book over the weekend and I did find a number of taxonomic updates/splits for an additional nine species have been made, making the book fairly essential even to those serious birders who already have the first edition. Page 42: Yellow Billed and Andean Teal; page 252: Black Tailed and Ecuadorian Trogan, also Violacious and Gartered Trogan; page 364: Peruvian Warbling Antbird and Yellow Browed Warbling Antbird; page 370: Spot Winged, Brownish Headed and Humaita Antbirds; page: 604: Yellow Breasted, Vilcabamba and Black Faced Brush Finches, also Slaty and Cuzco Brush Finches.
There may also be additional updates that I haven't found yet, therefore I am changing my rating to give this new updated edition five stars. I have to assume that if the authors did not make certain other updates, that they are not currently recognizing those splits.