This book won the "Birdwatch" book of the year award in 2004, and it certainly deserved it. Gulls can - if you get into them - pose a fascinating identification challenge, because of the wide range of plumages exhibited by each individual species. This book covers in detail - and I do mean detail - the identification of all 43 "Holarctic" gulls. The species accounts are presented as a series of monographs, and while this means that to compare different species you have to flick between pages I can't think of a better was of presenting this depth of information. For each species there is an excellent text, a distribution map and numerous high quality colour illustrations and photographs covering all they key plumages, including hybrids. There are over 800 photographs in all (an incredible 46 of the humble Herring Gull alone), all with individual notes highlighting the specific features they show. Illustrations and photographs both have their pros and cons as identification aids - with this book you get the best of both worlds.
The standard of presentation is excellent, as usual with a Helm guide, and for the keen birder this book is a joy. A word of caution though - it's really not for beginners, who will be overwhelmed by the amount of detail and will miss the "side by side" comparisons of similar species that are a feature of good general field guides.