Style and layout of the book; relationships and taxonomy; breeding behaviour; feeding and ecological separation; mortality and predators; moult; flight; conservation; undescribed species?; watching species; systematic section - cypseloides, streptoprocne, collocalia, schoutedenapus, mearnsia, zoonavena, telacanthura, rhaphidura, neafrapus, hirundapus, chaetura, aeronautes, tachornis, panyptila, cypsiurus, tachymarptis, apus, hemiprocne.