Another gorilla baby has been born at Zoo Atlanta, the 20th infant gorilla born there since the opening of the Ford African Rain Forest exhibit in 1988.

Sukari, a 15-year-old western lowland gorilla, gave birth Friday to a female infant. The baby was the second gorilla born at the zoo this year.

Sukari’s half-sister, Lulu, gave birth to her own infant, Andi, in March.

Both Sukari and Lulu are offspring of the late Willie B., a Zoo Atlanta legend and the zoo’s most famous resident for 39 years. Sukari and Lulu’s offspring are Willie B.’s fifth and sixth surviving grandchildren.

“We’re thrilled about Sukari’s new addition, not only because this is a critically endangered species, but also because western lowland gorillas are a very special part of our history and our collection,” said Raymond B. King, Zoo Atlanta president and CEO, in a statement. “Willie B. was the face of the zoo for two generations of Atlantans, and his legacy is very much in evidence today — particularly with the arrival of his newest grandchild.”

Sukari’s baby was fathered by the 24-year-old silverback Taz. The pair are also the parents of Gunther, now 6 years old.

Zoo Atlanta has the continent’s largest collection of western lowland gorillas.