With Petal's passing at 52, Hydari - known affectionately as "Dari" by her keepers - is now the oldest African elephant in a U.S. zoo.
Hogle spokeswoman Holly Braithwaite expressed condolences over Petal's death, and praised the example set by the Philadelphia Zoo's staff in keeping her healthy for so long.
When protected from poachers in the wild, African elephants can live into their 60s. The average age for a captive African elephant is about 40.
"It's great to see that with the proper kinds of care, we can keep these animals alive for such a long time," Braithwaite said.
Hydari's birthday celebration will be held Saturday from 11 a.m. to 2 p.m., with the zoo providing crafts, cupcakes for the first 1,000 guests, an enormous birthday card and African dancers. Hydari and Hogle's other two elephants - both in their 20s -will be presented a cake at 11:30 a.m.
