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Description
Elucidating spatio-temporal movements of organisms is an integral component of wildlife management and life-history characterization. In the case of hawksbill turtles (Eretmochelys imbricata), adults have typically been described as coral reef dwellers, with females undertaking long post-nesting migrations. Until recently, hawksbills were thought to have been functionally extirpated in the eastern Pacific Ocean, a perspective changed by the identification of several substantial nesting rookeries. These discoveries provided new opportunities for research and conservation. Here we report on a region-wide satellite telemetry effort that has tracked thirteen adult female hawksbills in the eastern Pacific. In contrast to patterns of habitat use around coral reefs exhibited by their Caribbean conspecifics, the majority of hawksbills in the eastern Pacific occupied home ranges in mangrove estuaries. Post-nesting migrations for all turtles were relatively short (range = 18.1 km - 283.1 km) for the taxon, with several individuals remaining in local habitats after nesting. Also in contrast to previous research, dive computers indicated that adult hawksbills dove to and spent the majority of their time in the top 10 meters of the water column. Our findings suggest that common perceptions of hawksbill habitat use, dive behavior and migrations, largely Caribbean-based, have overlooked some key characteristics of this species displayed by other populations. Moreover, the consistent use of mangrove habitats, use of superficial waters and non-migratory behaviors represent a new life-history paradigm for the species and may explain why hawksbills went virtually undetected in the eastern Pacific for decades. From a conservation standpoint, the spatially restricted, shallow and neritic life cycles of hawksbills in the eastern Pacific present both threats to and conservation opportunities for the species. Although a large proportion (>60%) of turtle location points fell within protected areas, many of these sites lack enforcement and monitoring. Our results underscore the importance of strengthening protected area management, mangrove conservation and hawksbill research and conservation in the eastern Pacific. Furthermore, our findings highlight the variability in life-history strategies that sea turtles and other longlived marine wildlife may exhibit among ocean regions.
