All Asian Primates is a remarkable source of up-to-date information about all 193 species of primates that occur across Asia. The book is organized in a systematic and user-friendly manner, with content divided into five sections, each dealing with one family of primate species. Each section introduces the family with a colour-coded map showing the distribution of its species, and a reference list is included at the end of each section.

Each species is presented on two pages: one with coloured photographs and the other with detailed information on taxonomy, threats and conservation status, supplemented with range maps. Taxonomic information also includes the phylogenetic relationships with other species, such as how and when a species deviated from its close relatives, probable hybrid populations and morphological variations.

The copious, brilliant photographs are a standout feature of this book. Whenever possible, the authors have included images of adult individuals, infants and juveniles, allowing readers to identify even subtle variations in morphology and colouration. Some pages feature images of several individuals to illustrate variations, such as differences in the facial colouration shown for the moor macaque Macaca maura. This, together with the side-by-side layout of the description and photographs, and that closely related species are placed near each other, facilitates comparison of and differentiation between various species and subspecies. For example, without the photographs, differentiating between the black and brown form of the crested macaque Macaca nigra would be challenging. Species for which photographs are not available, such as the dark crowned long-tailed macaque Macaca fascicularis atriceps or Natuna Islands silver langur Trachypithecus cristatus vigilans, are illustrated with realistic paintings.

The conservation section provides information such as any legal protection status, CITES listing, relevant protected areas and the population trend for each species. For example, the dramatic drop of the Hainan crested gibbon Nomascus hainanus from 2,000 individuals in 1950 to only 13 in 2003, and the absence of protected areas for the Tapanuli orangutan Pongo tapanuliensis, of which only 800 persist in the wild, highlight the urgency of conservation action for these Critically Endangered species. Past, current, long-term and area-specific threats are described in detail, making these sections useful for developing conservation initiatives. For instance, habitat loss is a major threat for the Sumatran orangutan Pongo abelii across its range, whereas uncontrolled hunting and the pet trade are the major concerns for the Yunnan lar gibbon Hylobates lar yunnanensis in China and the Siamang Symphalangus syndactylus in Indonesia, respectively. The IUCN Red List status and the year of the last assessment are listed for each species, and the book indicates which species require immediate protection. The number of species assessed as Data Deficient (8%) or not assessed at all (12%) highlights the need for more research on many species.

There are a few aspects of the book that could be improved. Firstly, some of the range maps would be better if they zoomed in on specific locations. For example, the ranges of the Natuna Islands silvered langur Trachypithecus cristatus vigilans and the western cross-marked langur Presbytis chrysomelas are very small, represented on the maps by smalls dots that are easily missed. Secondly, some of the colour coding would benefit from an explanation; e.g. the range of the rhesus macaque Macaca mulatta is shown with red and blue sections, but the colour coding is not explained. Thirdly, the structure of the descriptive text is not always consistent: for most species, information on threats and conservation are presented in separate paragraphs, but these are missing for some species, creating the impression that these are not threatened or do not require conservation action. Finally, some citations do not have corresponding references.

Overall, All Asian Primates is an excellent reference book that I would recommend to researchers and students working in primate conservation.