• Chelonia mydas;
  • Costa Rica;
  • East Pacific green turtle;
  • Guanacaste;
  • reproductive output;
  • ultrasound


Reproductive output is one of the most relevant aspects of life history. We analyzed the reproductive output of the endangered East Pacific green turtle (Chelonia mydas) nesting in Nombre de Jesús, Costa Rica. We supplemented beach patrols with ultrasonography to estimate clutch frequency. With ultrasound scans, we classified the stage of turtle ovaries as: early stage (2 or more clutches), late stage (1 clutch), and depleted ovaries (no clutches). We calculated mean (±SD) estimated clutch frequency (ECF) to be 3.7 ± 1.8 (n = 24) and an adjusted frequency considering individual stage (ECFU; ECF + number of clutches remaining as observed in the last ultrasound) as 5.1 ± 1.3. This is greater than previously described for East Pacific green turtles. Greater individual output could be representative of a healthier population; but could also indicate a decrease in the estimate population numbers previously reported. © 2011 The Wildlife Society.