Giant panda Mei Xiang gives birth to cub - and avoids return to China Giant panda Mei Xiang takes a nap. The female giant panda which gave birth at Washington's National zoo was under threat of being returned to China and being replaced with a more fertile bear, zoo keepers have said. Mei Xiang gave birth to a cub on Sunday night, thrilling officials and avoiding the prospect of being sent back home. The cub was the second for Mei Xiang - with breeding partner Tian Tian. It was conceived through artificial insemination and arrived at 10.46pm on Sunday, zoo keepers told a press conference. The 2012 breeding season was seen as Mei Xiang's last chance to produce a cub before she grew too old. 'It's true that if she hadn't conceived this time there was some talk about sending her back to China and getting another female," said Pierre Comizzoli, the zoo's reproductive physiologist. The female did produce a cub, Tai Shan, in 2005, through artificial insemination. But about half a dozen subsequent attempts for a sibling, all but one through artificial insemination, failed, the zoo said. Mei Xiang is now 14 years old, relatively advanced in years for a giant panda, and under the terms of the agreement with China could have been returned next year in exchange for a better breeder. Giant pandas are star attractions in the world of charismatic mega fauna - the large animals popular with zoo-goers - and bring prestige and visitors. But keeping pandas is expensive - especially for the National zoo, which does not charge admission. Time was probably running low for Mei Xiang. If you are the zoo director and income is not coming in because there is no cub, you are going to have to find some way of keeping pandas at the zoo and to find some way to pay for them," said Andrea Muller of Pandas International. Only 1,600 giant pandas remain the wild. Zoos pay China $1m a year to rent breeding pairs of pandas. But getting the animals to produce is difficult, Muller said. "When you send breeding pairs to the zoo you have to remember pandas really don't get to pick their mate," she said. Sometimes that might not be the best mate for them. In general, there is only about a 50-50 chance of giant pandas mating. Most zoos resort to artificial insemination. The cub born on Sunday was conceived with frozen sperm collected in 2005, from the same batch that produced Tai Shan. Now that a number of other zoos in the US keep giant pandas, the best way of recouping that cost is generating fresh excitement with a newborn. It was already working for Washington. The zoo's panda cam was overwhelmed by Monday morning, officials said. Tai Shan's arrival brought 500,000 new visitors to the zoo in 2005, the director, Dennis Kelly, said. But he would not offer a figure for what Tai Shan generated in terms of sales of hot dogs, popcorn, stuffed pandas and other souvenirs. The cub was returned to China in 2010. So far, zoo keepers have seen only glimpses of Mei Xiang in the bamboo nest she prepared ahead of birth. But panda cubs are typically born pink and hairless, and weighing in at only 4oz, about the size of a stick of butter - about 1/1000th the size of their mothers. Mother and cub will remain in isolation for the next few weeks. Indeed, zoo keepers only got confirmation that Mei Xiang was pregnant on Sunday night when a member of the team monitoring the 24-hour web camera trained on the bear these last two weeks heard the distinctive noisy squawk of a newborn cub. "This cub was squawking so loudly that really it was the first confirmation," said Suzan Murray, the chief veterinarian at the zoo. It wasn't sight. It was squawking.