The main exodus occurred Monday night, when 55 turtles emerged from the nest. A few more trickled out on their own Tuesday night. The hatchlings dug up by national park staff yesterday were stragglers that failed to leave the nest for some reason.

"When we started to excavate today, there were some only 1 inch or 2 inches below the surface, and those would come out, they would make it. They looked very healthy," Katahira said. "But as we start to get maybe a foot and a half down, we had some that would never have made it because they were very weak."

The endangered hawksbills are extremely rare, with only 65 females estimated remaining in the Hawaiian islands, Katahira said.

About 20 volunteer hikers survey the Ka'u coastline looking for signs of the turtles. Earlier this year searchers found a patch of sand about a quarter-mile from Punalu'u Black Sand Beach that indicated a turtle visit. The nest was located and protected from mongoose raids and other hazards until the hatchlings could emerge.

The nest excavated on the same patch of sand yesterday is the third clutch deposited there by the same female, Katahira said. Eggs usually hatch 50 to 90 days after they are laid, with a nest yielding 100 to 150 hatchlings. Most are able to make it out on their own and head straight for the ocean.

Biologists call the turtle's next stage of life "the lost years," because experts aren't certain exactly where the young go, Katahira said. They likely attach themselves to floating debris and drift, feeding on micro-organisms for about two years before reappearing on reefs in Hawai'i, he said.

The hatchlings that emerged yesterday face long odds, Katahira said. Only about one in 5,000 survive to adulthood, which is about average for sea turtles.