PATTERNS OF SURVIVAL, GROWTH AND MATURATION IN TURTLES

A review of published data suggests that turtles (Order Testudines) resemble other previously studied Vertebrate and invertebrate groups in terms of the relationships among growth trajectories, adult survival rates, and ages at maturation. For example, most turtles mature at around 70% of maximum size, as do other reptiles. Adult lifespans are proportional to age at maturity, and the relationship between these two variables is similar in turtles to that documented in other reptiles. Although the ratio of the von Bertalanffy growth constant (k) to the adult instantaneous mortality rate (M) appears to be higher than ratios reported for other animals (including squamate reptiles), the general relationship between these two variables corresponds with that seen in other reptiles. These analyses show that turtles exhibit patterns of growth, survivorship and maturation that are of the same form as those that are present in other types of organisms in which growth continues after maturity.