Abstract:
My research focuses on the impact of conservation practices for green sea turtle (Chelonia mydas ) on its native egg-predator snakes (Oligodon formosanus ) in Lanyu Island, Taiwan. The Oligodon snakes are specialized for eggs of squamate reptiles by using blade-like teeth to open leathery eggshell, and consume yolk. Between June and August 1997, a total of 97 snakes were recorded to prey on eggs in 13 nests laid by 8 female sea turtles. The snakes were satiated before early August while the egg-laying of sea turtles peaked in late August, resulting in later broods more successful. Conservation practices for sea turtles, such as fence protection and nest translocation, were effective in preventing nest-depredation of snakes and increased hatchling productivity of sea turtles. In addition, it also led to frequent fights among snakes. A total of 16 females and 7 males were recorded with broken tails, an indication of severe physical confrontation. The occurrence of snakes with broken tails peaked first in early June due to competition for scarce turtle nests, and peaked again in early August due to overwhelming competitors. The strong competition implied that this nonlethal anti-predator project might have unforeseen ecological consequence on the snakes and other squamate species.

Oligodon Boie (1826), Kukuri snake, 56 spp.

Range: Turkmenistan in USSR, Iran to Eastern China, Indonesian Archipelago

Habitat: drier environment from semi-desert to rainforest margins

Length: 25-100 cm (10-39 in)

Character: large upturned rostral shield, smooth dorsal scale

Habit: nocturnal, terrestrial, hind under stones at day time, oviparous, <16 eggs