NB: Publication date of this book is 2012--not 2014 as Amazon listing currently states.
THE GOOD: Packs a lot of information into a compact, lightweight package that a traveler would not think twice about taking overseas. Includes most of the primates and larger mammals about which a traveler would be interested and/or be likely to see, and a representative selection of smaller mammals. Text is well-written and interesting, at least by field guide standards, with brief introductions to each family, and frequent tidbits of fascinating information, e.g. that Lorises are the only venomous primates. Photographs are mostly high-quality. Individual species accounts describe the global range of the species--rather than just the range within the covered area; description of identification features; habits and habitat; a Notes section containing miscellaneous info about the species--such as conservation status or particularly good areas to view the species; and size measurements. At the end of the book there is a useful checklist of all the mammal species occurring in the area, including an indication of the countries in which they occur and their current IUCN conservation status. This allows you to see what species are not included in the book.
ROOM FOR IMPROVEMENT: There is only limited coverage of some groups that are fairly readily seen. Only two treeshrews, twelve squirrels, one Flying Fox, and no rabbits or hares are covered. Species not covered include Gray-bellied Squirrel (readily seen in Malaysia and Thailand), Three-striped Ground Squirrel, and Burmese Hare. There is no information regarding identification of tracks or scat. There is no weight information - only size. A few of the photos are only head shots (e.g. Smooth Otter), which are obviously less than ideal for identification purposes. A few others (e.g. binturong, takin) show a partially obscured animal or an animal at a poor angle, so you will need to Google to see a photo of what the animal really looks like. There is no indication of where a photo was taken, which would be useful so the reader can consider the possibility of regional variation. Text is on the small side but readable. There are no range maps.
COMPARED TO ALTERNATIVES: I have not seen these in hand, but based on website descriptions, Charles Francis' authoritative "A Field Guide to the Mammals of Southeast Asia" (2008) is comprehensive, but more expensive and considerably heavier. It includes accounts for hundreds of species of bats and rodents that only a dedicated mammal-watcher would be likely to encounter. It also has a narrower geographic scope, being limited to mainland Southeast Asia and excluding coverage of Borneo, Indonesia, and the Philippines. (Though it should be noted that the Shepherds' guide does not cover Indonesia east of Bali). Francis also authored a similar compact guide: "A Photographic Guide to the Mammals of Southeast Asia" (2001). It covers more species (192 versus 129 for the Shepherds' guide), but in fewer pages (121 versus 176 for the Shepherds' guide). It is currently listed as temporarily out of stock on Amazon, and prices for used copies are exorbitant.