Meeting Abstract
The inaccessibility of sea turtles to census during pelagic foraging and substantial cyclic variation in yearly nesting numbers (cohorting) complicate efforts to understand turtle population sizes and dynamics and efforts to conserve turtles. We formulated a relatively simple, physiologically based, stochastic model of sea turtle remigration intervals (intervals between nesting bouts) as influenced by conditions on the foraging grounds – particularly temperatures. Simulations suggest that cohorts (cyclic variation in numbers of turtles) were likely to develop under a variety of conditions, but could be enhanced by cyclic variation in foraging conditions (temperature). Cohorts once developed, however, were not stable and tended to diffuse over 3-10 years, unless reinforced by continued cyclic variation in foraging conditions. Temperatures on the foraging ground affected the diffusion of cohorts in our simulations, with relatively low temperatures resulting in faster dissolution of cohorts. Single year temperature pulses could synchronize nesting, inducing cyclic variation in nesting. This suggests that sea turtle nesting dynamics are a complex mix of induced cohorts that tend to diffuse away but can be reinforced by cyclic variation in conditions on the foraging ground. These cyclic variations will tend to be superimposed on longer term dynamics of the sea turtle population itself.
