The zoo, part of an international campaign to save the critically endangered iguana, normally sees only three or four hatchlings a year, the Los Angeles Times reported Tuesday.
Jeff Lemm, a herpetologist in the Applied Animal Ecology Division at the San Diego Zoo Institute for Conservation, attributes the success to changes for the younger of the center's two breeding females, which had never had a live hatchling.
"I tweaked the nest situation," Lemm said. "She fell for it."
To motivate her to lay eggs after she mated with one of the zoo's male iguanas, Lemm took a hollowed-out tree stump, filled it with soft, warm dirt and bathed it in warm light.
She burrowed in and laid a clutch of eggs, he said.
"I saw the eggs and said, 'Please be fertile,'" Lemm said. "And when we got the hatchlings, it was beautiful. We were all very excited."
Two of the eggs were fertile and produced two hatchlings.
With the seven hatchlings produced by the older, more reliable female, it was a bumper year for iguanas at the zoo.
Lemm is expecting good thing from the younger iguana as she gets older and bigger.
"Next year, I expect her to lay even more good eggs," Lemm said, "but you never know with reptiles."