The African penguin colony at the California Academy of Sciences in Golden Gate Park grew by two this month as a pair of the endangered birds were hatched as part of the aquarium’s Species Survival Plan program, officials announced Tuesday.

The chicks, which hatched Nov. 1 and 4 and whose sexes have not yet been released, are nesting behind the scenes with their parents and will soon attend what biologists call “fish school,” where they learn to swim and eat hand-fed fish to prepare them for public feedings once they go on display in January, officials said.

“We’re thrilled to welcome these two new chicks into our African penguin colony,” Bart Shepherd, Director of the Academy’s Steinhart Aquarium, said in a statement. “By engaging the public about why sustaining these and other threatened species is so critical, we hope to inspire people around the world to join us by supporting conservation efforts locally and internationally.”

African penguins are at high risk for extinction and were classified as endangered in 2010. The newest additions to the colony at the Cal Academy are the second and third to mother and father Ty and Robben, both white-banded African penguins, according to academy officials.

It usually takes about a year for chicks to lose their gray plumage and assume the regal tuxedo-like appearance of adult penguins, officials said.

The aquarium will be holding a naming contest for the two chicks once they go on display next year.

Kale Williams is a San Francisco Chronicle staff writer. E-mail: kwilliams@sfchronicle.com Twitter: @sfkale