Nils van Duivendijk & Marc Guyt, 2024. ID Handbook of European Birds (2 volumes). KNNV Uitgeverij/Princeton University Press. ISBN 978069125357. Hardcover, 1.048 pages. Price: € 99,99.

This might be the easiest book review I have ever had to write… The ID Handbook of European Birds (Volume I and II) by Nils van Duivendijk and Marc Guyt is fantastic and every birder should have it. Full stop. There can be no doubt about it.

Allow me to elaborate. There have been many, specialised books on bird identification in recent years, but this set of two volumes takes things to a new level. It is like all of the identification sections from the nine-volume The Birds of the Western Palearctic (Cramp & Simmons 1977 – 1994) were taken out, dusted off, polished up and revamped. It is like the Collins Bird Guide (Svensson et al 2022) but bigger, more digital, and with twice as many pages. I have been very interested in bird identification for 35 years now, avidly reading any books, papers and online articles that have been published, but here is a new handbook in which I am learning something new on nearly every page! That is not just due to new information in it, but, especially, by the way knowledge from well over a hundred different sources has now been collected, condensed and visualised.

The two books, one treating the non-passerines and one the passerines, cover 720 European species (including some very rare vagrants, such as Sulphur-bellied Warbler, Short-tailed Shearwater and Great Blue Heron, the latter even getting two pages) in more than 1.000 pages and 5.500 photographs. The species accounts are very systematic, showing almost every plumage and age for each species, geographical variation, and birds perched as well as in flight – even in the case of many passerines. Key identification and ageing features are described and shown on the photographs by using callouts, something that is also done in the Collins Guide and that works really well to help you remember clues. The quality of the photographs is outstanding. Some people have reported an odd bluish hue to the white parts of, among others, 1st-winter Caspian Tern, but I do not see it in the copies that I have received. The only strong digital artefacts that I came across were an oddly yellowish looking tail of a Black-headed Bunting on page 984 and a heavily overexposed tail in a juvenile Cinereous Bunting on page 994 (bottom left). Also, on page 788, the adult Lesser whitethroat bottom left looks completely different (i.e. blue) from the 1st winter-type bottom right, which looks brown. Such unintended differences are the result of different light conditions at the moment the photo was taken, and are probably unavoidable when using digital images. They are not problematic though, since they actually reflect various tricks of the light that birders often encounter in field conditions.

Someone at Princeton (Sam Gobin?) had the daunting task to digitally erase the surroundings in each photograph, and did an excellent job at it, so that all the birds are presented against a uniformly grey background and the pages look well organised and neat. Here are some scoter heads as an example (pages 54-55):

Note that the text and annotations are solely focused on plumage and structural features. There are no maps in the books, nor descriptions of songs, calls or behaviour. This has freed up some space, not only for more identification pointers but also for ageing criteria. The latter add an extra dimension to the books, especially to the non-passerines volume. I think it is the first time that I have seen the ageing (and sexing) features in species like European Lapwing, White and Black Storks, European Golden Plover, Common Snipe, Eurasian Woodcock, Long-eared Owl, Eurasian Hoopoe etc. so clearly and visually presented. The extensive information on ageing, the visual presentation of critical identification features such as the scoter heads above, and the level of detail, showing even in-hand characters like tail patterns, primary patterns, and wing formulae, are some of the main differences from the Collin’s Guide.

The English version has only just been published, but the handbook has been available to a Dutch audience for two years now. It has been reprinted several times already, and so will the English version, undoubtedly. Interestingly, content keeps getting added with each new edition. For instance, in the first pressing of the Dutch version, page 445 (on Long-tailed Skua) showed a blank space near the bottom. Someone must have told Nils about an exciting field character that was missing, namely the shape of the white ‘flash’ on the underside of the hand, and he reacted promptly: the feature has now been added into the blank space, with callouts, annotations, and accompanying text.

From this example, it is clear that the information in the handbook is very much up to date. It is therefore slightly surprising that some important, recent references are missing from the bibliography, e.g. all books by Steve Howell (Molt in N. American Birds 2010; Petrels, Albatrosses and Storm-Petrels of N. America 2012; Oceanic Birds of the World 2019; …), the new Seabirds guide (Harrison et al 2021), the Shorebird guide (O’Brien et al 2006) and the new Shrikes of the World (Lefranc 2022). Perhaps these works were erroneously omitted from the bibliography or they were not consulted, but either way the text in the handbook is comprehensive and full of recent information. As far as I could tell, the only important feature that has been missed, is the difference in tertial pattern between female Eurasian Teal and Green-winged Teal. Although on page 85 the handbook points out a “broad grey centre” on the lowermost tertial as different from female Eurasian, there is actually a bigger difference in the length and shape of the black submarginal stripe and whitish fringe on this feather. This was discovered by Japanese birders and originally published in the ‘Identification Guide to the Ducks of Japan’ (Ujihara & Ujihara 2015). It was brought to the attention of European birders through a short paper in British Birds in 2019 (vol. 112: 35-43).

So, how thorough and accurate is the information in the handbook? To test this, I delved into a family that I know well, namely the gulls. I could find only very few shortcomings, and only have these (mostly nitpicking) remarks:

• Page 456, bottom right: the black pattern on the outer edge of P10 is given as an ageing feature for 3cy Kittiwake, “extending along outer edge (contra adult)”, yet, P10 shows a long, black outer edge also in adults. The pattern of P9 is more useful for ageing (not indicated).
• Page 459: a few useful differences between 1st-winter Bonaparte’s Gull and Black-headed Gull have been omitted, namely the pattern of the tertials (with more extensive grey area in Bonaparte’s) as well as that of the median coverts (unmarked grey in Bonaparte’s).
• Page 464: I would have liked a photograph of a fully moulted, 1st-summer Franklin’s Gull here, in addition to the actively moulting one (bottom left). Since they have the most extensive black wingtip at this age, such birds could present an identification pitfall versus Laughing Gull.
• Page 467: the Audouin’s Gull at the bottom left has been wrongly aged. It is actually one year older than stated (i.e. 4cy/3rd summer, not 3cy/2s), and hence is the same age as the bird to its right. Important differences from 2nd summer are the larger number of adult-like, grey primaries (6 in this case, as opposed to maximum 4 in 2s), the adult-like inner and outer secondaries (all black in 2s), and the grey, adult-like inner primary coverts (blackish in 2s).
• Page 478, top right: “spring moult gives pale head” – The pale head of 2nd calendar year European Herring Gull in spring is actually a result of wear and fading, not moult.
• Page 480-481: Reference is made to two different moults during the first year of age in the large gulls: a post-juvenile one and a “moult to 1st-summer plumage”. In fact, there is only one moult (the post-juvenile), as studies by Howell et al have shown (in 1999 – 2000). There is no separate 1st-summer plumage in large gulls (or even Common Gull), as opposed to the small gulls.
• Page 496, middle left, on ID of 1st-winter American Herring Gull in Europe: “In Greenland especially, but also on the Faroe Islands, herring gulls occur which can be very dark and look very similar”. – Herring Gull is a (very) rare breeding bird in Greenland, and has only been breeding there since 1986. Presumably, the author was referring to Iceland.
• Page 505, bottom right: this 3rd-winter Thayer’s Gull is labelled as “relatively straightforward” (to identify), but it is actually very similar (if not identical) to a 3w Kumlien’s Gull. I noticed that the photograph was taken by Liam Singh, who is based near Vancouver, British Columbia, so the bird is most likely a Thayer’s indeed, but perhaps a more distinctive example could have been selected?
• Page 516, top left, adult Kelp Gull: it might have been useful to mention that leg colour can be yellowish in some adult Great Black-backed Gulls, not just pinkish, presenting an identification pitfall.

In conclusion, the ID Handbook of European Birds offers a stunning collection of beautiful, educational and cleverly annotated images as well as comprehensive, detailed and accurate text, making it the new standard for any birder who wants to study bird identification or who wants to confidently identify, age and sex the birds he/she has photographed. The Collins Guide will probably always remain the number one field guide, but, when it comes to analysis at home, the ID Handbook may very well be at the same level.