Page 293 - French Polynesia

Predation and Disease

T urtles are highly vulnerable to predation the exposure time to predators. Predation by
and the kind of predator depends on their fish during the early morning hours is greater

developmental stage. Eggs are most suscepti- than at night (Mann, 1977; Limpus, 1978). Crabs,

ble to predation even if they are safely buried, particularly ghost crabs (Ocypode sp.), are per-

because of their long incubation period. Sand haps the most efficient nocturnal predators of

or ghost crabs often burrow into the nest and hatchling sea turtles (Raymond, 1984).

eat the eggs, and the resultant tunnel provides
Naccess to additional predators such as dipterous
esting turtles become easy prey on land
maggots and ants. They may also be eaten by because of their sluggishness. Feral mam-

varanid lizards and terrestrial mammals. Fungal mals may hurt them and take on their eggs

and bacterial infections are also common. but such predation is minimal. Man is the most

Upon emerging from the sand, hatchlings explicit example of a predator. Green turtles in
are usually preyed on by ghost crabs, Hawaii, Florida and Bahamas have been found
develop fibropapillomas that appear as lobe-

which by instinct know that the part of the like tumors, that grow primarily in the skin but

body to be damaged first are the eyes (Mros- can also appear between scales and scutes, in

ovsky, 1968). Sea birds and varanid lizards also the mouth, eyes and on the internal organs.

prey on the little hatchlings. While in the water, These tumors are debilitating. The cause and

predation continues, by birds at the surface and mode of transmission is yet unknown. Different

fishes in the water column. Sharks are formida- species of barnacles have been found to infest

ble enemies throughout the life cycle of marine turtles

turtles. Any hatchling disorientation increase