FRESNO, Calif. (AP) — The second elephant calf in two weeks has been born at a California zoo.

African elephant Amahle gave birth early Monday morning, according to the Fresno Chaffee Zoo. The event came 10 days after Amahle’s mother, Nolwazi, gave birth to another male calf.

The new additions are the first elephants born at the zoo, about 150 miles (240 kilometers) southeast of San Francisco, which has embarked on a program to breed elephants in the hope that they can be seen by zoogoers in years to come.

“To have two healthy calves is a historic milestone,” Jon Forrest Dohlin, the zoo’s chief executive, said in a statement Tuesday. “We cannot wait for the public to see the new additions to our herd and share in our excitement.”

The elephants and their calves will continue to be monitored behind the scenes for now, Dohlin said. While the zoo expanded its exhibit in anticipation of growing its herd, some animal activists have opposed the breeding program, saying elephants shouldn’t be in zoos because of their complex needs.

In 2022, the zoo brought in male elephant Mabu hoping he’d breed with the two females. The future of elephants — which have relatively few offspring and a 22-month gestation period — in zoos hinges largely on breeding.