Some researchers believe that the highest rates of mortality result from hatchlings being eaten by fish when they enter the shallow surf. Hatchlings emerge at night, which is thought to be an adaptation to avoid terrestrial predators and birds. However, predators still take their toll. Ghost crabs and night herons patrol the beach at night, eagerly eating hatchlings that are too slow making it to the water. If the hatchlings should err in their judgment and emerge during the day, birds eat most of them, including the magnificent frigate bird that flies down and scoops the hatchlings from the water's surface.
Hatchlings usually spend only a few minutes on the beach before crawling down to the waves.
It is in the surf that the real danger lies. As part of the study, Nellis had to identify aquatic predators. During the first part of the study, he cast into the water a turtle-like lure to see what would attack it. For the second part, he followed the hatchlings by snorkeling along behind them up to 100 yards from shore at dusk. Nellis was surprised by his results.