American Birding Podcast



Another Colossal Gull Guide

A review by Peter Adriaens and Amar Ayyash

Gulls of the World: A Photographic Guide, by Klaus Malling Olsen

Princeton University Press, 2018

488 pages—hardcover

ABA Sales / Buteo Books 14824

It’s been 15 years since Klaus Malling Olsen and Hans Larsson presented us with their Gulls of North America, Europe, and Asia. Unlike that predecessor, the new Gulls of the World is strictly a photographic guide, the first of its kind, covering all of the world’s species. 

The simple, user-friendly design makes this an easy book to read and use. The twenty-five page introduction begins by emphasizing that the author’s objective here is “not to present an authorized taxonomic update nor a bewildering mass of putative hybrids, aberrant individuals or atypical moulting gulls.” For detailed plumage descriptions and measurement data, the reader is directed to the 2004 guide. With this in mind, the new photographic guide is very much suitable for the beginning to intermediate birder, as well as for more advanced gull aficionados.

Taxonomic disclaimers aside, the introduction includes a clarification of the author’s decision to give some “recognizable forms” separate accounts, among them the Steppe, Mongolian, Azores, Baltic, and Kamchatka Gulls. For what it’s worth, the Thayer’s is also given its own chapter, but the Taimyr Gull, for instance, is not. Oddly, the book is described as having 488 pages, but my copy comes to precisely 368.

The calendar-year system for aging is used throughout the text, with terms such as “1st year,” “2nd year,” “1st winter,” “1st summer,” and the author makes no apologies for it. That system is easy to follow, and its use here does not obscure any important identification questions. In our opinion, though, the decision not to use the modified Humphrey-Parkes system, based on plumage cycles, represents a step backwards in the effort to advance the sophistication and accuracy of gull identification in general.

The introduction concludes with several general tips for approaching gull identification. The notes on the nuances of wear, color abnormalities, the effects of lighting, and judging size and structure in the field are invaluable. There is also a reminder of the real possibility of encountering hybrid gulls in the field. The glossary defines six technical terms used by gull observers, and topography is covered in two pages of plates.

The rest of the guide—some 325 pages—is taken up by the 61 “species” accounts, in a sequence based mostly on that in the HBW Illustrated Checklist of Birds of the World. Some of the species accounts are as brief as 2 or 3 pages, others as long as 7 pages, with an average of about 4 pages devoted to each gull.

Each account begins with notes on identification, aging, and voice. The discussions of molt go into some detail when it is deemed “very useful” for identification. The sections describing Geographic Variation include some excellent paragraphs. The accounts covering the Mew Gull complex, Kelp Gulls, and Lesser Black-backed Gulls are especially impressive, loaded with much of the latest available data.

These “species” chapters also mention the most common hybrids one could expect. Depending on how pervasive hybridization is, the discussion may be a couple of paragraphs, down to a short sentence for rare occurrences. Most useful for many birders will be the quite detailed “Similar Species” paragraphs, clarifying some pitfalls and distinguishing confusion species.

The range maps are easy to read, with three colors denoting breeding, migration/winter, and year-round ranges. Arrows are used to indicate migration, but it is not clear whether they represent known migration routes or presumed routes. Question marks are used in some instances, presumably to signify that the taxon is suspected here but that more study may be needed. We did find several instances where the range maps come up short; we have included those cases in the list of errata. The sections on “Status, Habitat and Distribution” generally clarify what’s depicted in the range maps.

The species accounts conclude with a section titled “References,” but, disappointingly, there are no superscripts to show which part of the text a given reference is meant to support, nor is there a detailed bibliography with complete citations.

A very important component of any photographic guide is, obviously, the photographs. The publisher advertises over 600 photos, a fact that by itself makes this a desirable reference. The images range from absolutely stunning, some of the finest we’ve seen in a gull guide, to average at best.

The photos achieve their goal of displaying key features, with reinforcement from the captions. While previous gull guides have been criticized for offering photos too small to show important details, the images here range in size from large half-page photos to medium and small images. There are never more than five photos to a page, and the lack of clutter is very much appreciated. Most of the images are close-ups of individuals in profile or in flight; there are very few composites permitting the comparison of two or more species. 

All age groups are shown, including some birds that are in molt. The captions are succinct, indicating the month and location of the photo along with other pertinent details. Where appropriate, subspecies identifications are included in the captions.

Klaus Malling Olsen is to be commended for another colossal gull guide. Gulls of the World is an unprecedented achievement that fills a great demand. The text will be of good use to anyone wishing to advance their knowledge of gulls and sharpen their gull identification skills. The earlier, co-authored guide, Gulls of Europe, Asia and North America, is still relevant, though, for those wishing to delve deeper. 

Personally, we would have hoped for a modern gull guide that describes plumages with reference to the molt that produced them. But in the end, the necessary ideas are conveyed in ways easily understood by a broad audience. The accompanying photographs are welcome. However, if you’re looking for side-by-side photos of American Mew Gull and European Common Gull, for example, this guide doesn’t provide that (nor does it make any claim to). 

The book is not free of errors (you can find a list of those here), but thanks to the updated range maps, recent identification information, and some recent taxonomic notes, we would certainly recommend making the relatively small investment to own this guide.

Amar Ayyash is both an expert on gull identification and an evangelist for “gull recreation.” He hosts several websites devoted to gulling, including the popular Ayyash has published various technical articles on gull ID and range shifts, and is a frequent speaker at birding events. He and his family live in Orland Park, Illinois


Peter Adriaens is a birdwatcher from Belgium, where he has had the good fortune to work in gull and tern colonies for several years. He has also worked on wildlife surveys in other countries,including Armenia, Guinea, Egypt, Israel, and Portugal.  In his spare time, Adriaens travels to photograph as many gulls as possible.

Recommended citation:

Adriaens, P., and A. Ayyash. 2018. Another Colossal Gull Guide [a review of Gulls of the World: A Photographic Guide, by Klaus Malling Olsen]. Birding 50 (3): 68-69.