Meeting Abstract
19.2 Monday, Jan. 4 Stomach Temperature Recordings Provide Evidence of Feeding During the Internesting Interval for Leatherback Turtles, Dermochelys coriacea CASEY, J.P.*; GARNER, S.A.; SOUTHWOOD, A.L.; Uni. of North Carolina,Wilmington; West Indies Marine Animal Research and Conservation Service, Inc., Frederiksted, St. Croix, USVI; Uni. of North Carolina, Wilmington jpc3073@uncw.edu
Leatherback turtles (Dermochelys coriacea) are long-distance ocean migrants that travel from foraging habitats in temperate latitudes, to tropical nesting beaches to lay eggs every 2-5 years. It is generally assumed that leatherback turtles, like other species of sea turtle, do not feed while offshore from nesting beaches, and rely instead on fat reserves to fuel reproductive activities. We used a combination of physiological sensors, data loggers and telemetry to investigate the foraging behavior and habitat of adult female leatherback turtles from the St. Croix, USVI nesting population. Leatherback gastrointestinal temperatures (TGT) were analyzed for rapid fluctuations that were indicative of ingestion events and laboratory ingestion simulations were used to characterize temperature fluctuations associated with ingestion of prey vs. seawater. Seven leatherbacks were documented to have made a combined total of over one-hundred ingestion events of gelatinous prey items (>300 g) during the turtle’s internesting periods. The number of prey ingestions ranged from 6 to 62 for individual turtles, and the majority (85%) of these events occurred during the daytime (05:00-19:00). The mean (±1S.D.) depth of prey ingestions ranged from 111 ± 70 to 170 ± 90 m for individual turtles, and mean ambient temperature was 23.0 ± 0.9ºC. Mean depth of daytime and nighttime prey ingestions was not significantly different (t = 3.11, df = 3, P = 0.052). Our results indicate the leatherbacks from the St. Croix, USVI nesting population opportunistically feed during the internesting interval to top-off energy stores for reproductive activities.
