The Philadelphia Zoo will soon have another baby gorilla: Kira, the zoo's 17-year-old western lowland gorilla, is pregnant for the first time.
The zoo said Thursday that Kira is due to give birth in early summer.
The birth will come less than a year after another baby gorilla, Amani, was born in August.
"Kira loves babies," Kristen Farley-Rambo, the primary gorilla keeper, said in a statement. "She’s shown a lot of interest in baby Amani. And she was a great older sister to her younger siblings. We think she’s well-prepared to be a first time mother."
The new gorilla will be Amani's half-sibling: Motuba, 32, fathered both. The baby will be Motuba's third offspring.
Kira is in good health, the zoo said. Her baby will live with its parents for years after its birth; baby gorillas typically aren't separated from their parents until age 7 to 10.
The zoo has a total of six western lowland gorillas, which are a critically endangered species: Kira, Motuba, Amani, Honi (who is Amani's mother), Louis and Kuchimba.
Kira was born in August 1999 at the Franklin Park Zoo in Boston. She arrived in Philadelphia in 2013. Motuba was born at the Columbus Zoo and came to Philadelphia from Omaha's Henry Doorly Zoo in 2014.
Keepers had taken note of their budding romance years before Kira became pregnant.
"One other distinguishing characteristic about Kira is that she is absolutely smitten with our silverback, Motuba. She sits close to him whenever possible and stares at him intently. If you see one of our girls gazing lovingly at Motuba, it's most likely Kira," a primate keeper wrote in 2015 blog post about the gorilla. "Though we decided to let the gorillas take things slow and really get to know each other before reproducing, we can happily report that they are now a very stable and cohesive troop, so we hope to see babies sometime in the near future."