Reptiles

Reptiles

The physiological ecology of leatherback turtles

This project was conducted 2003 by Andy Myers as part of his NERC funded studentship and involves close collaboration with a local NGO in Grenada, Ocean Spirits as part of his NERC funded studentship based at the University of Wales Swansea www.swan.ac.uk/bs/turtle/. There are 3 central themes to this project: (1) studies on the nesting ecology of leatherbacks in the Caribbean involving measurements of nest temperature, hatchling success and nest placement (2) studies on the post-nesting movements determined by satellite tracking and (3) studies on internesting diving behaviour. 

Internesting Diving Behaviour

As part of efforts to examine the diving behaviour of turtles, we use a number of different types of data-logger. Data-loggers are attached after a turtle has completed nesting and are then removed when that individual returns to nest subsequently (typically an interval of 10 days or so). In order to record dive profiles we have used time-depth recorders manufactured by Star-Oddi (Iceland). These loggers are capable of operating down to 1000m and so can record the full behavioural repertoire of deep diving in leatherback turtles. 

Image below left shows a Star-Oddi TDR ready for deployment by Ph.D student Andy Myers and image below right a deployment

  

  

Data-loggers are attached to either a flexible harness (used when several types of instrument are simultaneously deployed) or to a metal tag on a rear flipper: see schematic below left and photo below right.

 

 

   
View a video clip from an attachment: Video mpg (4,8 Mb)

Loggers are pre-programmed to record throughout the internesting period. The example data-sets below show two complete internesting records (above) and more detailed examples of deep diving (below left) and surface occupation (below right).

 

During the 2003 field season, over 150 days of internesting diving behaviour was recorded for >10 individuals and a detailed analysis of these data-sets is currently underway.

 
Collaborators

Star-Oddi (Iceland)                 

Ocean Spirits (Grenada)  http://www.oceanspirits.org