There are probably only two ways of approaching this book. Firstly on your knees, bowing low and, secondly, after several weeks of serious weight-training. I have recently come back from a short bird-watching holiday to Ecuador and the Galapagos Islands. I knew these books were coming out, but they weren't out in time for me. So, like thousands of birdwatchers in the past, I had to make do with Hilty & Brown's "Birds of Colombia" (Princeton University Press) as the next best thing. Hilty & Brown is an EXCELLENT book, but Ecuador has some 500 more bird species than Colombia and is arguably the richest birding country on the planet. A comparison is instructive. Hilty & Brown's paperback covers its remit in 820 pages and weighs 1.3kg. Ridgely & Greenfield consists of two paperback volumes totalling nearly 1600 pages which,in their thick cardboard slipcase, weigh 3.1 kg ! Hence the need for weight-training - even so, these may be more than you can comfortably carry and even the authors suggest you leave one volume at home ! Both Paperbacks are called "The Birds of Ecuador" but one is sub-titled "Vol. I. Status, Abundance & Taxonomy", whilst the other is "Vol. II. Field Guide". They are VERY different. Volume II is the more immediately traditional. It is 740 pages long, has nearly 100 colour plates illustrating the birds of Ecuador and is supported by a text giving details of each bird, habits, voice etc. and a distribution map. Volume I is 850 pages long and only has one illustration. It has an 80-page section on various topics such as ecosystems, migration, conservation, a history of Ecuadorian birdwatching, a gazeteer. The rest is a detailed account for each species of abundance and distribution in different districts and important birding sites in Ecuador. Are there any limitations ? Yes, chiefly geographical ones. The authors have deliberately left out the Galapagos (which belong to Ecuador) and have restricted seabirds to those that can be seen for a few kilometres out to sea. They also omit the large "Disputed Territory" which either belongs to Ecuador or Peru depending on whose map you look at - on balance this is probably a wise precaution. Some of the illustrations look as if they have come from Ridgely's masterwork on the Birds of South America but since this is only appearing at the rate of about one volume every decade this is hardly a criticism. Do you need both volumes - given that you can buy them separately if you want ? The answer is probably YES. I think if you had only bought volume I you would definitely NEED volume II - the Field Guide. If you had only bought Volume II you would WANT Volume I as well. Ecuador should be on the wish list of every travelling birdwatcher and these books should therefore be on the shopping list. Without serious competition, they are the immediate "Bible" for the birds of Ecuador and should be treated with reverence as a labour of love, a work of high scholarship and a delight to birdwatchers everywhere.