With the onset of the nineties, our world of uncontrolled human populations confronts an intimidating potential for environmental change. It is again timely to update baselines of the status and condition of living things. This coverage of the mammals conducts the sometimes inadequate compilations and discussions of earlier editions into today's more demanding format. In addition to incorporating recent records, it builds upon the broadened purview and documentation adopted in the fourth edition. In this respect I consider Nowak's latest summation of some 50 million years of evolution for the family Equidae to be exemplary.
Horses still rank high in public interest, as do elephants, rhinoceroses, and seals.
Expanded discussions of all these groups merit special notice, but this does not imply disproportionate representation. Walker's original objectives. One of these was to emphasize the small and little known, as well as the large and popular animals. As a note of interest, the late Dr. Hall, director of the Museum of Natural History at the University of Kansas, was Nowak's major professor while the latter was engaged in his doctoral research, finished in 1973. Then and later it was my privilege to be associated with Hall in projects of the National Parks Advisory Board for the Secretary of the Interior.