Last updated at 13:42 09 May 2008

The world's oldest gorilla celebrated her 55th birthday today with a four-layer frozen fruit cake and banana leaf-wrapped treats.

Jenny's caretakers at the Dallas Zoo say she's having a few joint issues and her eyesight isn't what it used to be but she still looks good for an old ape.

"It's a special milestone for us," said Todd Bowsher, curator of the zoo's Wilds of Africa exhibit. "It signifies that we've made great strides in veterinary care, nutrition and animal husbandry."

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Tea-time: Jenny has a reputation for being bossy with her keepers at Dallas zoo

The International Species Information System, which maintains records on animals at 700 institutions around the world, said Jenny is the oldest gorilla in its database.

"I think it's amazing," said Kristen Lukas, curator of conservation and science at Cleveland Metroparks Zoo in Ohio and the gorilla species survival plan coordinator for the Association of Zoos and Aquariums. "I think it's a testament to the good care that she's received at the Dallas Zoo and also the resilience of gorillas in general."

Lukas said gorillas in the wild normally would live to age 30 or 35. Health care and protection from predators has extended the lifespan in zoos.

Jenny gave birth in 1965 to a female named Vicki, who was sent to Alberta, Canada, at age 5. Zoo officials aren't sure why Jenny hasn't conceived again.

Jenny's keepers describe her as very sweet though a little bossy.

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Tasty treat: Jenny the gorilla carts off her birthday cake this morning as she turned 55

"If she doesn't want to go out on a certain day, she doesn't," Bowsher said. "But she really likes people."

There were plenty of them at the Jake L. Hamon Gorilla Conservation Research Center Thursday, chowing down on giant sheets of chocolate and vanilla birthday cake as they peered at Jenny through the glass.

Born in the wild of western central Africa in 1953, the exact date of her birth is unknown but the zoo marks it on May 8. Jenny lived with a family on the Cape Verde islands before the Dallas Zoo acquired her in 1957.

"I remember the day she arrived," said Nancy Hamon, 89, of Dallas, whose family bought the gorilla for the zoo and continues to be among its strongest supporters.

Jenny, a 213-pound (97-kilogram) Western lowland gorilla, is one of four gorillas at the zoo.

"It's a good time for the zoo," said Sean Greene, director of Community Relations for the Dallas Zoological Society.

He said the upbeat birthday party was a welcome contrast to the tragedy that occurred in 2004 when another gorilla, 13-year-old Jabari, broke out of his enclosure. He went on a 40-minute rampage in which he snatched up a toddler with his teeth and attacked three other people before officers shot him.

So to what does Jenny attribute her longevity? She's not saying. But her vegetarian diet couldn't hurt: seeds, cereal and one of her favorites, banana peels.