Figure 5.

Growth model estimates for hawksbill age-at-maturity. (a) VBGF models fit to known ages of 16 captive-reared Pacific hawksbills places breeding maturity at 12.3 years (range 10–15 years), representing a potential ceiling of the somatic growth parameter, k, at 0.295. VBGF results considering (b) fastest, (c) mean and (d) slowest growth trajectories given the age range from the tissue Δ¹⁴C values, and extreme values of k. All panels use listed values for asymptotic length, L_∞, and gestation time, t₀, obtained from empirical monitoring, but fit k to the age estimates. Together mean results from these models estimate k is 0.13 (range 0.10–0.20) and age at maturity is 29 years (range 18–38). From these results, hawksbills deposit eight scute growth lines annually (range 5–14).