Growth Patterns of the Yellow-Margined Box Turtle (Cuora flavomarginata) in Northern Taiwan

Abstract

Growth of the yellow-margined box turtle (Cuora flavomarginata) was studied in northern Taiwan on the basis of recapture data and estimates using the age-carapace length relationship. The growth rate obtained using mark-recapture data from May 1996 to June 2000 was inversely correlated with the body size in both males and females. Growth trends in individuals for whom sex could be determined (i.e., large juveniles and adults) did not significantly differ between sexes. Growth rate in smaller juveniles, although highly variable compared to that of larger individuals, was collectively greater than in the latter. Mean carapace length of females was consistently greater than that of males of the same age. We used nonlinear regression to describe male and female growth trajectories, and the logistic model better fit data on C. flavomarginata than the von Bertalanffy model. Individuals younger than 11 years old occupied no more than 10.3% of the population, 28.8% of which was considered to exceed 18 years of age.