Table 1.
A summary of physical, experimental and behavioral performance data for green turtles used in this study.
Figure 1.
The extraction results of feeding behaviour from head acceleration data.
(A) Depth distribution of feeding events by immature green turtles calculated from head acceleration data. (B) Distribution of the total time period of feeding events at each depth. (C) Depth distribution of feeding dives (dives with feeding events). (D) Distribution of the duration of consecutive feeding dives occurring in shallow water than 3 m.
Figure 2.
A typical profile of dive depth and surging head acceleration (HA) for an immature green turtle (CM2).
The horizontal bars at the bottom represent the timing of feeding events (FE) and feeding bouts (FB), respectively. The recording of head acceleration terminated at 9∶23 on August 23th.
Figure 3.
Video images of typical behaviour by the immature green turtles.
(A) Feeding behaviour of CM8 on seagrass in shallow water and (B) resting behaviour of CM4 under the reef ledge. Video clips from which the images were taken are available in the Movie S1 and S2, which is available online.
Table 2.
A summary of home range area estimates and horizontal movement performance during the entire period and during the three phases (feeding, resting and other) for green turtles.
Figure 4.
Diel pattern in the time spent during feeding bouts by each of the immature green turtles.
Figure 5.
Daily ethogram of an immature green turtle (CM5) over 3 days.
The ethogram consists of three phases, feeding (white), resting (grey) and other (black), which were defined from the depth data (see Materials and Methods).
Figure 6.
Typical profiles of vertical (depth) and horizontal (north-south and east-west distance) movements by an immature green turtle (CM5).
Horizontal bars at the bottom indicate the period of feeding resting and other phases, respectively.
Figure 7.
A map of the study sites at Iriomote Island, and GPS locations for five immature green turtles during three phases.
White, grey and black circles represent feeding, resting and other phases, respectively. Solid and dotted lines represent the low-tide and 10 m interval depth contour lines, respectively.
Figure 8.
GPS locations for an immature green turtle (CM5) during three phases.
(A) feeding (white), resting (grey) and other phases (black). Black and grey dotted lines represent the low-tide and 10 m interval depth contour lines, respectively. GPS locations during (B) feeding and (C) resting phases. Symbols and solid lines represent each phase and its area within a 100% minimum convex polygon.
Table 3.
Comparison of studies on foraging behaviors in green turtles.