Yang Guang munched on a giant edible sculpture in the shape of the number 10, presented to him by bosses at Edinburgh Zoo in recognition of his second birthday on British soil.
The landmark day comes at a time when the nation is waiting to hear if his female counterpart is pregnant.
The zoo last week revealed Tian Tian is showing encouraging signs she may be expecting a cub.
But the main focus was on Yang Guang today, with the first group of visitors through the doors singing him a spontaneous chorus of Happy Birthday.
Alison Maclean, team leader of the giant pandas, said it was a pleasure to see the male bear tucking into his gift.
She said: “His birthday morning’s been pretty busy for us but very quiet for him.
“He decided to have a long lie, so we just cleaned round about him and put his birthday present outside for him.
“Once he came to the door and saw that there was something different in the enclosure he came out and investigated it.
“The birthday present is a bamboo sculpture in the shape of a 10. It was made by our garden department, who did an excellent job. It’s huge and freestanding. They made it specifically with the bamboo species we know he really likes.
“To entice him over to it further, we drizzled it with honey and hid some apple and carrot in amongst it as well. He’s thoroughly enjoying it
“Pandas spend a huge amount of their time sleeping and eating bamboo, so it’s really nice to give them stuff to enrich them and keep them occupied as well.”
Yang Guang’s entry into double figures means he is “pretty much in the prime of his life”, Ms Maclean said.
“It doesn’t feel like a year ago since his ninth birthday, it feels so much shorter than that, but it’s a landmark,” she added.
“It’s great to have the pandas here in this country, it’s amazing, and every year that goes by just seems to get better and better.”
As for the female bear, Ms Maclean said the zoo’s keepers were also playing the waiting game as they hope for the arrival of the nation’s first panda cub.
She said: “We’re obviously monitoring her behaviour closely because we have seen some changes in her behaviour.
“Yesterday, for example, she decided she didn’t want to be on show and she slept most of the time in her cubbing box.
“We’re allowing her to do exactly as she pleases. It’s a wait and see game for us as well.
“There’s a kind of expectant mood for something to happen and there’s a buzz in the air as well.
“Obviously everybody wants to know what’s happening. It’s a very exciting time just now for everyone.
“She’s doing great and she’s feeding well, although her appetite has dropped off slightly, but we were expecting that to happen. If it’s either a pregnancy or pseudo-pregnancy you’ll get that kind of behaviour.
“She is just Tian Tian, but she’s sleepy at the moment.”
Results from further tests of Tian Tian’s hormones are expected in mid-August, which keepers say should give a better indication of whether she is pregnant.
Preliminary results have shown encouraging signs the panda is expecting after an artificial insemination was carried out in April. Her birthday will be marked on August 24.
The pair arrived from China in December 2011 and have been a popular attraction at the zoo, with visits from about 500,000 people in their first year.