ORNITHOLOGICAL LITERATURE 
659 
Caprimulgiformes, and introduction to the species 
accounts. There are 43 pages of useful addenda at 
the end of the book: glossary; further reading: 
acknowledgments; photographic credits (with 
dates and sites); Appendix 1, extinct Caprimulgi¬ 
formes; Appendix 2, alternative English names; 
references; and index to English and scientific 
names (including page references for each species 
text and each photograph). 
Utter nonsense is the statement on the front 
cover flap of the dust jacket that hails this book as 
the ‘ultimate identification guide' to the species 
treated. These nocturnal birds are far more often 
heard than seen. This is because they lend to be 
highly vocal (at least during courtship and 
breeding seasons for migrant species and often 
year-round for resident species) and yet can be 
difficult to observe, unless you’re lucky enough to 
find one by day. Over 95% of the identifications 
of nocturnal birds that I make arc based solely on 
vocalizations. 
The birds themselves are dependent on vocal¬ 
izations for identification because of the lack of 
visual cues at night, resulting in distinct vocali¬ 
zations for each species. Thus, any guide to their 
identification must have a comprehensive section 
on vocalizations, including both detailed descrip¬ 
tions and sonagrams. The descriptions of frog- 
mouth vocalizations are particularly weak. Both 
males and females of each species utter several 
types of calls, some of which are not shared, 
which can not be gleaned from the text. 
An underlying premise of this book seems to be 
that once you have complete photograph coverage 
of all the species, little else is necessary, thus 
justifying the skimpy text. This is true to a certain 
extent since, in any given place, there arc only a 
few' of these species present. However, most of 
these birds are visually much alike and present 
identification difficulties even close up in day¬ 
time. Further, the ‘ultimate identification guide’ 
would also have to deal with the specimen for 
which there are no data. Identification could often 
not be made without measurements. Thus, I hope 
authors using this photograph format in the future 
will either include complete textual identification 
material or refrain from presenting their work as 
an identification guide. 
Relying solely or mostly on photographs for an 
identification guide is not a tenable notion. The 
differing conditions surrounding each photo in the 
field, day/night, time of day. shade/open, cloudy/ 
clear, type of film, film/digital, etc., in addition to 
the variation added by processing, alter the color 
tones of the finished photograph, and render many 
comparisons difficult or impossible. This is 
especially true of species with subtle color or 
pattern differences such as the nocturnal species 
dealt with in this book. Comparison of the 
different field photographs of individual species 
in the book shows some of the variation intrinsic 
to photography rather than that attributable to 
morphology. 
A closer approach could likely be done within 
the present format by using the currently wasted 
space on each species text page, if the author is 
truly committed to producing the ultimate identi¬ 
fication guide. First, the world map could be 
deleted entirely. Second, the distribution maps 
could be reduced in size by 75-85% without losing 
any of the limited detail on them. The ‘main 
confusion species’ sections need to be rewritten to 
include vocal cues as well as a better presentation 
of the visual aspects. Sonograms and complete 
descriptions of each vocalization could then be 
inserted. It would be further useful to have a series 
of diagnostic measurements for each species. 
This volume is not a new edition of Cleere’s 
1998, Nightjars: a guide to the nightjars, night- 
hawks, and their relatives, which covers the same 
species, but has a more extensive text and is 
illustrated by poor to average painted plates. One 
useful feature of the earlier work, in-flight 
paintings of each nightjar, is not present in the 
book under review, but should be. 
A photographic picture book of all the species 
of a single (or several) families in all their 
diversity and glory is to be applauded and 
encouraged; however, the utility of an identifica¬ 
tion guide to all the world’s species of a group of 
birds is to be strongly questioned, with a few 
notable exceptions such as seabirds and shore- 
birds. No one is going to carry all (or even a few) 
of the various world family guides on a trip to a 
single country or continent, although they might 
take along some scanned or xeroxed pages. The 
authors of these books are rarely experienced in 
the field with all the species they cover as is 
amply illustrated by this book. 
This is a fine picture book of all the species 
in the families included, nestled within a modern 
taxonomic framework. The pictures, combined 
with the distributions, will enable identification 
of some birds. However, it fails as an identifi¬ 
cation guide for the Asian species I know 
because of its inadequate text.—BEN F. 
