Wood Storks (Mycteria americana) Prey on Eggs and Hatchlings of Olive Ridley Sea Turtles (Lepidochelys olivacea) at Ostional, Costa Rica

Abstract

Abstract. The foraging behavior of Wood Storks (Mycteria americana) has been studied extensively because of their dramatic population decline and endangered status. The foraging by Wood Storks at an arribada beach with olive ridley sea turtles (Lepidochelys olivacea; turtle) at Ostional, Costa Rica, was examined to determine their depredation behavior on turtle eggs and hatchlings. Wood Storks, in association with Black Vultures (Coragyps atratus), foraged on turtle nests exposed by stream, tidal, and wind erosion, and on nests dug up by dogs (Canis familiaris). Wood Storks also foraged on emerging turtle hatchlings and those crawling to the sea. Wood Storks concentrated near stream beds where nearly half of the predation events (eggs/hatchlings being eaten) occurred. Usually, one to three Wood Storks fed at a turtle nest; an average of 87% of the Wood Storks that were within 5 m of a turtle nest obtained eggs or hatchlings. The number of Wood Storks present and feeding, and the percent feeding, depended ...