Bao Bao, the National Zoo's beloved young panda, celebrates her first birthday with a Zhuazhou ceremony, a Chinese tradition for a 1-year-old child. (Ben Dorger/The Washington Post)

One-year-olds can be known to approach their birthday cake with more enthusiasm than elegance, and giant panda cubs are no exceptions.

In front of the crowds that gathered Saturday at the National Zoo to fete Bao Bao’s first birthday, the charmingly fumbling panda climbed on top of her cake — made of frozen fruits and sweet potatoes — and clung King Kong-style to the giant edible “1.”

“She did pretty good tricks on it, like this,” said Zachary Laffey, 6, of Germantown, Md., spreading his arms out and leaning forward to imitate the way Bao Bao embraced her cake.

Zachary, whose legs were covered with panda stickers, was one of dozens of panda lovers who came despite rainy skies to celebrate Bao Bao’s first rotation around the sun and her transformation from the pink, pint-size baby she was a year ago to the black-and-white furball she is now.

The day started at 8 a.m. with a modified traditional Chinese ceremony, called Zhuazhou, often performed on a child’s first birthday. This one was specially held for embassy and zoo officials and the media.

Bao Bao is just one of the 155 critters born at the zoo in the past year. Here is a look at every animal born since August 23, 2013, at the zoo and the Smithsonian's Conservation Biology Institute in Front Royal.

Three posters were stuck to bamboo poles above a cave in the panda yard. Each poster was painted with a different symbol: peaches signifying longevity, bamboo meaning good health and pomegranates representing fertility — fitting for an endangered species. Keepers placed a honey-coated stick of bamboo under each sign. The symbol Bao Bao chose would signify something about her future. She chose a long life, then moved on to eat the other two treats as well, bestowing herself with all three endowments.

“I think she’s very logical,” said Chinese Ambassador Cui Tiankai, joking about the cub’s ceremonial selections. Cui has called Bao Bao Washington’s other Chinese ambassador, acknowledging a long-standing practice of “panda diplomacy” in which China would give or loan pandas to other countries as a gesture of goodwill.

“This is our shared responsibility to cooperate and preserve their species,” he said. “I think this shows what we can do when we work together.”

Nicole MacCorkle, one of Bao Bao’s keepers, watched with her 3-year-old human daughter, Chloe, who held two stuffed animals and her cutout-panda birthday hat.

MacCorkle recalled the moment 365 days ago when she and the other keepers heard that Bao Bao’s mother, Mei Xiang, was set to give birth. The keepers gathered around the screen in the camera room that was live-streaming high-definition footage of the birth.

“There was lots of nervous energy and then a lot of hugs and high-fives,” she said.

At 9 a.m. Saturday, members of the Friends of the National Zoo rushed in for a private two-hour morning event. At 11 a.m., the event was opened to the public. Fans of all ages beamed as they squeezed in to see the birthday girl.

The celebration for Bao Bao is the latest incarnation of a lasting adoration for the cuddly bears that was also felt for her big brother Tai Shan, who celebrated his first birthday in 2006 and has since moved to China. Some in the crowd said they were new panda fans, brought into the club by Bao Bao’s birth. Others have deep emotional ties to the entire species.

Darrell Lee Martin, donning a furry panda cap, was giddily celebrating his own birthday, No. 43. His best friend drove the panda fanatic all the way from Asheville, N.C., for the double birthday party. Martin said that when he was a boy, his father won him a stuffed panda toy at a carnival.

“It was like Calvin and Hobbes, you know, when he thinks his tiger is real,” Martin said. As he went through school, he did book reports about pandas, but it wasn’t until he grew older that he realized he associated pandas with safety and comfort.

“I lost my son in a day-care accident,” he said. “Pandas make me feel good no matter how bad it gets.”

Martin posts panda photos on Facebook almost every day and has met other panda fans online. From his online community he learned about an opportunity to fly to China to volunteer at a panda reserve in Sichuan province.

“I went over to Chengdu, not speaking the language or anything, a country boy from Asheville,” he said.

For him, the experience was one of two things he wanted most.

“The most impossible thing is to hold my son again,” he said, finding a photo in his phone of himself in China with a panda leaning against him.

“That’s the closest to my son I’m going to feel,” he said. “You see how big I’m smiling?”

“It’s therapeutic,” said Karen Meyers, 51, of Columbia, Md. Meyers met Martin in line waiting to be allowed in to see Bao Bao on Saturday morning.

“Panda lovers are friendly and outgoing. We bond instantly,” she said. After work, she drives home and watches panda cams like the one streamed by the National Zoo.

“Sometimes I just want to reach into the screen and burp them,” she said, recalling the hours she has spent watching baby pandas grow in zoos around the world.

“We each find our own happiness our own way, and ours is pandas,” she said.