The Oregon Zoo’s California Condors have laid a record-breaking eight eggs since February.

Oregon Zoo

One of the seven California Condors that has laid eggs at the Oregon Zoo's Jonsson Center.

Each pair of mature birds housed in the Zoo’s Jonsson Center for Wildlife Conservation has produced an egg. Since the Center’s start, 15 eggs have been laid and 10 chicks have hatched. The Zoo thinks this could be its best breeding season ever.

The latest addition was laid on April 7 by Wilog. She and her mate, Woy, will sit on the egg for up to two weeks until zoo keepers remove it to test for fertility.

"The eggs are naturally incubated for 10 to 14 days," said Shawn St. Michael, zoo assistant curator. "Then they are pulled, candled, put into an incubator and replaced with dummy eggs."

Around 57 days the eggs begin to hatch, and keepers put them back so they will hatch with their parents.

To get even more eggs, zoo keepers may decide to remove Wilog’s dummy egg to encourage the pair to mate again. This is called “double clutching.

Even though many eggs have been laid this year, it doesn’t necessarily mean there will be a lot of chicks. Last year only three out of seven eggs produced chicks. The low fertility was likely because many of the female birds were young and had never laid eggs before.