Research Contents

After hatchlings escape from their nests confirmed during the breeding surveys (about two months later), we dig out all the shells after they have hatched and examine the hatching conditions.

What did the staff find out

There are differences in hatching conditions between beaches. The main causes are the shape of the beach, the temperature of the sand, the quality of the sand, and damage from predators.


The shape of the beach makes it prone to flooding

On beaches with narrow depths and streams, typhoons and heavy rains can submerge breeding nests and cause them to flow out. If the eggs are immersed in water for a long time, they cannot breathe and will die. (Examples are Genie beach, Kohama, etc.)

Temperature of the sand & sand quality

Sandy breeding nests that are overexposed to the sun and are colored tend to be hot, and the hatching period is shortened, however, some eggs may die due to high temperatures. Clay beaches don’t drain water well and eggs may be submerged in water. (Examples are Uguisu Beach, Buta Beach, etc.)

Predatory Damage

Snow crabs and rats dig up nests and eat them. Other damage also occurs from termites. Termites and ant damage used to be limited to the Yaiba Coast, but now they can be found on all beaches.