Caldecott, J., Miles, L., eds [2005] World Atlas of Great Apes and their Conservation. Prepared at the UNEP World Conservation Monitoring Center. University of California Press, Berkeley, USA
It gives a thorough background on ape behavior and ecology for each species, including detailed habitat requirements, the apes' ecological role, and the possible consequences of their decline. Despite the dedicated efforts of many individuals and organizations, the great apes all fall into the Endangered or Critically Endangered category of The IUCN Red List of Threatened Species. This atlas offers a full description of the threats, current conservation efforts, and additional protection needed for each species across its entire range.