Seasonal nesting of green turtles at Huyong Island, Thailand

Abstract

In this paper, we report the current results of the studies on the reproductive biology of green turtles nested at Huyong Island, Thailand. The Huyong Island is a year-round nesting rookery of green turtles. Although information on year-round nesting population of sea turtles is very important to understand the ecology of sea turtles, there were few comprehensive data sets on year-round nesting populations. Therefore, three methods were used to investigate reproductive features of year-round nesting population of green turtles. Firstly, tagging studies were conducted to examine nesting seasonality of female green turtles. Next, satellite tracking studies were conducted to examine horizontal distributions of the female green turtles during post-nesting periods. In addition, bio-logging studies using data loggers were used to examine diving behavior of the female green turtles during inter-nesting periods. Our results showed that: 1) nesting in the Huyong green turtles occurred more or less at the same time on an individual basis, 2) nesting throughout the season might be attributed to proximity to feeding grounds, 3) there is seasonal difference in reproductive output among individuals, and 4) diving behavior of females during inter-nesting periods may be a key determinant of the seasonal difference in reproductive output.