After months of bored indifference, two giant pandas recently joined for not one, not two but three frenzied bouts of mating.
 | Bai Yun preferred younger males 
| Was it a fluke of cupid's arrow or evidence that researchers now have an improved understanding what it takes to bring the captive black-and-white bears together? Keepers at the San Diego Zoo in California do not believe the mating was a whim. "We have become much better at creating an environment for mating," zoo spokeswoman Yadira Galindo told the BBC. She explained that the matchmaking in this case began when the zoo acquired a younger male, Gao Gao, for their female, Bai Yun. "Age appears to be a big factor, since Bai Yun was not at all interested in our older male," Ms Galindo explained. Howdie Gao Gao Since pandas are solitary animals, the zoo houses their adult male and female in separate enclosures with only a "howdie door" mesh gate allowing interaction. | The keepers noticed Bai Yun was acting strangely
| A few weeks ago, the researchers began to notice that Bai Yun was starting to eat less, become more active and walk through water, which suggested she was in heat, although the reasons for the water trek remain a mystery. The two pandas also started to bark at each other, at first rather testily, but then with more apparent curiosity, through the howdie door. After confirming the female's state through urine hormone analysis, zookeepers switched the panda exhibits so that each animal could scent mark and explore the other's enclosure. When returned to their normal housing, the bears sniffed prodigiously. On the following Monday, the female lifted her tail up. The researchers rushed to open the gate separating the two bears. "They mated," Ms Galindo said. "Afterwards, Bai Yun went one way, Gao Gao went another way, and we closed the gate. This happened two other times in succession." By Tuesday, Gao Gao "was no longer interested" and merely barked a few times at Bai Yun. Mr and Mrs Karen Baragona, managing director of the WWF's Yangtze Programme told the BBC News Website that such "captive breeding is interesting science", but may not add much to giant panda conservation efforts, which have improved multi-fold since the Chinese government enacted a trio of reforestation and wildlife protection measures starting in 1998. "So long as their habitat is protected, wild pandas do not exhibit any of the breeding irregularities we tend to see in captive populations," Baragona said. | Panda births in captivity are a rare event
| She added that the protective measures in China also helped to support hundreds of species of mammals, at least 200 birds, dozens of reptiles and "over half of the plants known to exist in China". Jim Harkness, the former WWF director in China, said that he agreed with Baragona, but he added that the mating success at the San Diego Zoo should prove that "pandas don't need Viagra, panda porn videos, or other previously tried artificial stimulants" when an appropriate environment can allow nature to take its course. "The public may want to see a Mr And Mrs Panda exhibit, but a more accurate grouping would involve several males who compete and fight over one female," Harkness said. But he admitted that such an exhibit "would be hard to arrange". For now, keepers at the San Diego Zoo are on baby-watch, hoping they can detect a "stick of butter-sized infant" in Bai Yun over the weeks to come. If she successfully delivers, she would add to the 1,600 known giant pandas worldwide. | 
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