Dive and beak movement patterns in leatherback turtles Dermochelys coriacea during internesting intervals in French Guiana
- 22 January 2008
- journal article
- Published by Wiley in Journal of Animal Ecology
- Vol. 77 (2), 236-246
- https://doi.org/10.1111/j.1365-2656.2007.01344.x
Abstract
National audience1. Investigating the foraging patterns of free-ranging species is essential to estimate energy/time budgets for assessing their real reproductive strategy. Leatherback turtles Dermochelys coriacea (Vandelli 1761), commonly considered as capital breeders, have been reported recently to prospect actively during the breeding season in French Guiana, Atlantic Ocean. In this study we investigate the possibility of this active behaviour being associated with foraging, by studying concurrently diving and beak movement patterns in gravid females equipped with IMASEN (Inter-MAndibular Angle SENsor). 2. Four turtles provided data for periods varying from 7.3 to 56.1 h while exhibiting continuous short and shallow benthic dives. Beak movement ('b-m') events occurred in 34% of the dives, on average 1.8 +/- 1.4 times per dive. These b-m events lasted between 1.5 and 20 s and occurred as isolated or grouped (two to five consecutive beak movements) events in 96.0 +/- 4.0% of the recorded cases, and to a lesser extent in series (> five consecutive beak movements). 3. Most b-m events occurred during wiggles at the bottom of U- and W-shaped dives and at the beginning and end of the bottom phase of the dives. W-shaped dives were associated most frequently with beak movements (65% of such dives) and in particular with grouped beak movements. 4. Previous studies proposed wiggles to be indicator of predatory activity, U- and W-shaped dives being putative foraging dives. Beak movements recorded in leatherbacks during the first hours of their internesting interval in French Guiana may be related to feeding attempts. 5. In French Guiana, leatherbacks show different mouth-opening patterns for different dive patterns, suggesting that they forage opportunistically on occasional prey, with up to 17% of the dives appearing to be successful feeding dives. 6. This study highlights the contrasted strategies adopted by gravid leatherbacks nesting on the Pacific coasts of Costa Rica, in the deep-water Caribbean Sea and in the French Guianan shallow continental shelf, and may be related to different local prey accessibility among sites. Our results may help to explain recently reported site-specific individual body size and population dynamicsKeywords
This publication has 51 references indexed in Scilit:
- An alternative technique for the long-term satellite tracking of leatherback turtlesEndangered Species Research, 2008
- Meta-analysis of movements in Atlantic leatherback turtles during the nesting season: conservation implicationsMarine Ecology Progress Series, 2007
- Modeling Approaches to Quantify Leatherback Nesting Trends in French Guiana and SurinameChelonian Conservation and Biology, 2007
- Female–female aggression: structure of interaction and outcome in loggerhead sea turtlesMarine Ecology Progress Series, 2007
- Mouthing off about fish capture: Jaw movement in pinnipeds reveals the real secrets of ingestionDeep Sea Research Part II: Topical Studies in Oceanography, 2007
- Maternal investment in reproduction and its consequences in leatherback turtlesOecologia, 2007
- Marine Turtles Use Geomagnetic Cues during Open-Sea HomingCurrent Biology, 2007
- Do leatherback turtles Dermochelys coriacea forage during the breeding season? A combination of data-logging devices provide new insightsMarine Ecology Progress Series, 2006
- Estimating body mass in leatherback turtles Dermochelys coriaceaMarine Ecology Progress Series, 2006
- Seal-mounted cameras detect invertebrate fauna on underside of Antarctic ice shelfMarine Ecology Progress Series, 2006