Nightjars, Potoos, Frogmouths, Oilbird, and Owlet-nightjars of the World, the book's full title, is a photographic guide to all 135 species belonging to these families. First, the photos are great. They are very large, most being half, or even a full, page. 3-4 photos, on average, depict each bird. For about a dozen species, the only photos are of museum specimens. But for some of these, these specimens are the only time the bird has ever been seen! So that's not really an issue. My main complaint is that very few, apart from the nighthawks, are shown in flight.
The text covers identification, status, and some natural history information. It is disappointingly sp..... For some birds, this is nothing more than an indication of how little we know about them. But for others, more info was available to be included, and there was plenty of room here for it.
There are two range maps – a detailed map and a smaller map of the entire world with a box outlining the area shown in the detailed map. I think the world map is a waste of space, especially since the detailed maps aren't actually "zoomed in" as far as they could be. But subspecies ranges are indicated, which I very much appreciate.
The introduction gives a good, if shallow, overview of these birds, and is liberally illustrated with photos, figures, and tables.
Overall, nightjar fans should be pleased with this guide. The photos alone are worth it. And if you're not already a fan of these sublime, mysterious birds, this book will convert you.
Here's my full review of Nightjars of the World