Reproductive migrations and local movements of black turtles (Chelonia mydas): telemetry and flipper tagging offer novel insights for conservation planning

CATHERINE E. HART; GABRIELA S. BLANCO; MICHAEL S. COYNE; CARLOS DELGADO; BRENDAN J. GODLEY; T. TODD JONES; ANTONIO RESENDIZ; JEFFREY A. SEMINOFF; MATHEW WITT; WALLACE J. NICHOLS

San Diego, California, USA

Simposio; 31st Annual Symposium on Sea Turtle Biology and Conservation; 2011

International Sea Turte Siciety

The status of many marine vertebrates mandates an increased understanding of the factors determining population distribution and coincident threats. Here we combine published data from traditional flipper tagging and early satellite tracking studies with additional satellite tracking data (n=12) to begin to describe patterns of movement of black turtles (Chelonia mydas) to and from the Michoacán rookery and within foraging grounds in northwestern Mexico. We tracked three turtles on their homing migrations (1337-2928km) from foraging grounds near the Baja California peninsula, Mexico, to the breeding grounds of Michoacán, Mexico, and three post-nesting females from Colola beach, Michoacán to foraging grounds in Southern Mexico and Central America (941.3-3020km). A further six were tracked within their Baja California foraging grounds giving preliminary insights into the scale of ranging behaviour. Turtles undertaking long-distance migrations showed a tendency to follow the coastline. Deployment duration within the foraging grounds were of limited duration (9-53 days) but were sufficient to show that foraging individuals typically ranged upto 691.6km (maxima) from release site location. We then combine all data to create best available distributional patterns and contextualise with a range of data layers that may offer insights into potential threats faced. We suggest that this integrated approach offers considerable utility to allow focussing of conservation efforts, especially as further spatially explicit threat layers become available.