Organisms face the common problems of avoiding death, harvesting and allocating finite resources to maintenance, reproduction, growth and storage. It is the communalty of these problems that provides the unifying basis for life history theories. Many organisms begin life, reach maturity, reproduce once and die in the same year. In contrast, humans and some female turtles postpone sexual maturity for over 15 years, exhibit repeated reproduction over many years, and have maximum life expectancies that approach 100 years. Because of the logistical problems and the duration of study necessary, actuarial and complete life history data are almost completely lacking for most long lived organisms other than man. The primary objective of the proposed research is to complete the documentation of life history traits of turtles on the University of Michigan's, E. S. George Reserve in southeastern Michigan by examining the relationships among age, body size, stored energy, growth rates, clutch size (number of eggs) and clutch frequency of individuals reproducing for the first time in their lives. In conjunction with the previous studies of three species of turtles on the E. S. George Reserve during 26 of the past 36 years, data collected during the tenure of the proposed research will allow tests of current theories of the evolution of delayed sexual maturity, and provide a basis for understanding age specific aspects of the biology of long-lived organisms that is critical for the conservation and management of such species.
