ESR 1:41-48 (2004)  -  doi:10.3354/esr001041

ABSTRACT: Leatherback turtles Dermochelys coriacea exhibit superlative measures of size, growth, and fecundity among reptiles, yet factors affecting these variables remain poorly studied. We investigated the relationships between the leatherback’s variable remigration interval and measures of growth and fecundity by analyzing 8 years of data from a population of females nesting at Parque Nacional Marino Las Baulas, Costa Rica. We hypothesized that variation in the remigration interval was due to tradeoffs with seasonal fecundity (clutch size and estimated clutch frequency) or growth rate over the interval. Nesting females grew an average of 0.2 cm yr^–1 (range: –1.5 to 2 cm yr^–1) in standard curved carapace length and 0.2 cm yr^–1 (range: –1.6 to 1.7 cm yr^–1) in curved carapace width, with smaller turtles growing significantly faster than larger ones. The small adult growth rates observed indicate that size differences within and between populations are not good indicators of age. Major differences in body size among turtles within a population appear to be set during the juvenile and subadult portions of female leatherbacks’ lives. Remigration interval did not correlate with either growth or measured indices of seasonal fecundity. Because delayed remigration did not result in enhanced growth or measured indices of reproduction, variability of environmental conditions might instead determine the length of the remigration interval and thus the overall reproductive output during a female’s lifetime.

KEY WORDS: Leatherback · Remigration interval · Life history traits · Fecundity · Sea turtle · Clutch size · Costa Rica