Edinburgh zoo pandas draw crowds amid mating hope Visitors have been flocking to Edinburgh Zoo to see giant pandas Tian Tian and Yang Guang ahead of the big bears" breeding season. The Corstorphine attraction saw a huge rise in visitor numbers over the weekend, with more than 8000 people paying a visit - a rise of 20 per cent compared with 6575 last year. The boost comes as keepers continue preparations for the 36-hour period when the animals could mate. International attention has also focused on the animals, with the zoo's state-of-the-art panda cam - which broadcasts the pair all over the world - also proving a hit. Bosses at the zoo said the increased number of visitors was fantastic news. Laura Condie, head of visitor services, said: "We're delighted with visitor numbers at Edinburgh Zoo and that our two giant pandas continue to be ever popular. We saw a lot of interest in the pandas over the Scottish and English half-term holidays in February, and last weekend saw visitor numbers increase even beyond comparative figures for 2012. The boost comes amid the possibility that Tian Tian and Yang Guang could be about to mate - producing the first panda cub born in the UK. Breeding giant pandas is difficult, with the females fertile for only 36 hours each year. Last year's mating season ended in disappointment after the pair failed to hit it off, and experts said it was impossible to predict exactly when the mating season would begin, but said it is likely to be this month. Tian Tian's hormones are tested every day, and this year vets will also test Yang Guang to help them better understand male panda behaviour. Already, the pair have expressed an interest in each other, with Yang Guang doing handstands to spread his scent and show his virility, while Tian Tian has also been heard calling to her prospective mate. Even if they do mate, confirming Tian Tian is pregnant will not be straightforward as female pandas often have pseudo-pregnancies, and keepers have been training her to stand on her hind legs so that they can perform ultrasound scans. Experts are not certain how long panda gestation periods are, as females practise delayed implantation - their pregnancies can last from 85 to 100 days. Experts are being brought in from Berlin to perform artificial insemination on Tian Tian as a back-up. Penguins check out their new p-p-p-pad The first penguins have entered their upgraded pool enclosure at Edinburgh Zoo. Footage of the birds" return was shown live on the zoo's Penguin Cam - a recent addition - for a short time yesterday. But the exclusive broadcast was just a sneak peek, and viewers will have to wait until the state-of-the-art enclosure, named Penguin Rock, officially opens to the public on March 14 until the camera operates full-time. The £750,000 pen will provide entertainment for the birds including diving platforms, a mock beach and a bubble machine and will allow visitors to feel closer than ever before to the zoo's colony of penguins.