Whilst I am very pleased to have this book, I do not wish to give unqualified praise. I think the coverage is unfortunately scanty in some areas, and often says nothing about familiar species.
This is a beautiful book with a lot of lovely pictures and information, and not over-populist in its content. However given the number of mammalian species, there is a limit to what you can cover in 1000 pages, and I think the balance is sometimes unfortunate. It is sometimes said that this encyclopaedia covers all mammalian species, however a great many are found only in a list of names. Entire families are given this treatment. Many other species are covered only with an uninformative three-line one-column entry. The coverage of bats is particularly weak, which is disappointing given that such a large proportion of mammalian species are bats. I have a slimmer encyclopaedia covering all vertebrate animals, which has at least a drawing of and a paragraph describing at least one representative of every mammalian family.
Just because an animal is familiar doesn't mean you will find any information on it. I give two examples. 1. A recent BBC programme on African wild-life spent some time showing Simien Foxes hunting African Mole Rats, a common and unusually large rodent much used as a human food source. It is related to the Bamboo Rat eaten in SE Asia. If you look up the African Mole Rat in the index, you will be referred to the section on Mole-Rats, which is an entirely different group of rodents. When you eventually find it many pages away, there is only a misleading and brief mention. 2. If, like many tourists, you travel to the high Andes of Peru or Bolivia, you will probably see Mountain Viscachas, and very little else. They are much photographed, featured in TV programmes, etc. But you will find no information on this animal beyond its name. However a drawing of the rarely-seen Plains Viscacha is provided.
The taxonomic list of all mammals would be much improved if it had page cross-references to the main section of the book.