After years of waiting, rare turtles have bred 41 hatchlings at the San Diego ZooIn a first for North America, an endangered species of turtles has bred at the San Diego Zoo."This is a thrilling moment for us at the San Diego Zoo, and an incredible step forward in the conservation of this species," said Kim Gray, curator of herpetology and ichthyology at the San Diego Zoo, in a statement.Turtle experts at the zoo say nests are often tough to find in the enclosure, as the turtles like to lay their eggs overnight and cover them with dirt.Environmental pollution, sandbar habitat destruction, the international pet trade and human food harvesting have all contributed to the species' decline over the years, the San Diego Zoo Wildlife Alliance says."We have been focused on caring for these turtles for a very long time, and part of that care is to gain a greater understanding of the species' natural history," the zoo's Kim Gray added."