The milestone was impressive and so was the guest of honor. So the present had to be just right.

That's why the National Zoo baked 20 birthday cakes to celebrate the fact that Ambika, the zoo's 7,800-pound Asian elephant, was turning 50 years old.

Ambika romped through most of the cakes -- made from a pachyderm-friendly recipe involving herbivore pellets, raw rice, uncooked oats and hay -- as a crowd of well-wishers braved the heat to help her celebrate.

Ambika -- known affectionately as "sneaky beaky" because of the pranks she likes to pull on her keepers -- came to the zoo in 1961 from India, where she had worked for years using her long, roving trunk to haul thousands of felled trees through the forests.

Yesterday's celebration often took a serious tone, drawing attention to the plight of the world's remaining Asian elephants. Marie Galloway, the zoo's elephant manager who has worked with Ambika for the last 11 years, told visitors that as the elephants haul logs across the land, their natural environment is destroyed.

In several Asian countries, where elephants are used to carry tourists or for other entertainment purposes, Galloway said, the level of care given to animals is often dismal. And the training given to animal keepers in that industry, she said, was inadequate.

"But the biggest problem {facing elephants} is still poaching in Africa and the reduction of habitat because of the logging industry," Galloway said.

The U.S. Fish and Wildlife Service listed the species as endangered in 1976 and estimates that between 35,000 and 56,000 Asian elephants remain. The creatures generally have lifespans of 65 to 70 years.

In the elephants' outside compound yesterday, Ambika, her back covered with hay, strutted across the grounds. She lifted her trunk into the air and slapped it down. She drew cheers from the crowd as she rolled a 2,000-pound log.

Ambika's frolic was quickly followed by Nancy, Toni and Shanthi, the zoo's other elephants.

Although she is the oldest of the group, and stands a full seven feet tall, Ambika is not the matriarch of the zoo's elephants. Nancy, the 9,300-pound, 44-year-old elephant, has taken on the role of a mother figure. All the elephants follow her cue, zoo keepers say.

But in the wild, Ambika would be the leader. Generally, younger elephants cling to older elephants, who oftentimes have a keen eye for food and water, said David Glendinning, a training interpreter who announced one of yesterday's demonstrations.

During yesterday's routines, zoo keepers filed the hoofs of the elephants and had them perform exercises that keep them fit.

Although some visitors were shocked to learn that Ambika was 50, 11-year-old Alex Silver, of the District, said she knew it all along.

"I guessed she was 50," said Alex, who watched yesterday's celebration with her sister, Becca. "She looks 50. She's like a big girl, kinda wrinkled." CAPTION: Ryan, 5, Jacob, 5, and Kelsey Goode, 8, above, watch elephant demonstrations at the National Zoo. Marie Galloway, left, the zoo's elephant manager, rides Nancy during the 50th birthday celebration for another elephant, Ambika. Nancy is considered the elephants' mother figure.