This best-selling dictionary is the most comprehensive and up to date of its kind, containing over 6,000 entries on all aspects of zoology. Complemented by numerous illustrations, it includes terms from the areas of ecology, animal behaviour, evolution, earth history, zoogeography, genetics,and physiology and provides full taxonomic coverage of arthropods, other invertebrates, fish, reptiles, amphibians, birds, and mammals.

Written in a clear, accessible style, this authoritative and wide-ranging dictionary contains entries on all aspects of ecology and related environmental scientific disciplines such as biogeography, genetics, soil science, geomorphology, atmospheric science, and oceanography. Entries cover topics such as plant and animal physiology, animal behaviour, pollution, conservation, habitat management, population, evolution, environmental pollution, climatology, and meteorology.

The Encyclopedia of Life Sciences volumes 1-26 comprises the original 20 volumes of ELS (published in 2002)  plus six supplementary volumes (published in 2007). Volumes 21-26 collates all the information that has been added to the online version on WileyIntersciences since the publication of the first 20-volume set. Together, they provide the reader with the most comprehensive and the up-to-date information in Life Sciences.