DOI 10.1186/s40462-019-0184-2 Background
A strong behavioural plasticity is commonly evidenced in the movements of marine megafauna species, and it might be related to an adaptation to local conditions of the habitat. One way to investigate such behavioural plasticity is to satellite track a large number of individuals from contrasting foraging grounds, but despite recent advances in satellite telemetry techniques, such studies are still very limited in sea turtles.
Methods
From 2010 to 2018, 49 juvenile green turtles were satellite tracked from five contrasting feeding grounds located in the South-West Indian Ocean in order to (1) assess the diel patterns in their movements, (2) investigate the inter-individual and inter-site variability, and (3) explore the drivers of their daily movements using both static (habitat type and bathymetry) and dynamic variables (daily and tidal cycles).
Results
Despite similarities observed in four feeding grounds (a diel pattern with a decreased distance to shore and smaller home ranges at night), contrasted habitats (e.g. mangrove, reef flat, fore-reef, terrace) associated with different resources (coral, seagrass, algae) were used in each island.
Conclusions
Juvenile green turtles in the South-West Indian Ocean show different responses to contrasting environmental conditions - both natural (habitat type and tidal cycle) and anthropogenic (urbanised vs. uninhabited island) demonstrating the ability to adapt to modification of habitat.
Chelonia mydas, Home range, Satellite tracking, Diel pattern, Tidal cycle
| File | Pages | Size | Access | |
|---|---|---|---|---|
Publisher's official version | 15 | 2 Mo | ||
Additional file 1: Figure S1. GPS locations on (a) Europa, (b) Glorieuses, (c) Juan de Nova, (d) Mayotte and (e) La Reunion. Red dots refer to release locations. (f) Migratory movements of two individ | 1 | 442 Ko | ||
Additional file 2: Figure S2. Correlation matrices of the kernel areas tested for different tracking durations during day (left) and night (right) in (a, b) Europa, (c, d) Glorieuses, (e, f) Juan de N | 1 | 23 Ko | ||
Additional file 3: Figure S3. Correlation matrices of the kernel areas tested for different number of locations during day (left) and night (right) in (a, b) Europa, (c, d) Glorieuses, (e, f) Juan de | 1 | 25 Ko | ||
Additional file 4: Figure S4. Box plots of the distance to shore extracted at each turtle location showing the inter-individual variability. | 1 | 9 Ko | ||
Additional file 5: Figure S5. Box plots of the bathymetry extracted at each turtle location showing the inter-individual variability. | 1 | 9 Ko | ||
Additional file 6: Figure S6. Maps of the seafloor habitats in (a) Europa, (b) Glorieuses, (c) Mayotte and (d) La Reunion. Habitat available are illustrated by the MCP (dotted black lines) and the ind | 1 | 1 Mo | ||
Additional file 7: Table S1. Summary of the data collected from the 49 juvenile green turtles satellite tracked. N refers to the total number of GPS locations retained for the analysis. | 2 | 194 Ko |
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