Could we be hearing the pitter patter of baby Panda feet?

It's a bit late for a Valentine's Day romance, but the UK's giant pandas could be ready to mate within the next month, according to zoo experts.

yang guang

Male panda Yang Guang, exploring the new enclosure

Both the female Tian Tian, Sweetie, and the male Yang Guang, Sunshine, have already started to show important changes in their behaviour, indicating their readiness to mate soon, panda specialists at Edinburgh Zoo said.

Yang Guang recently began doing handstands against trees, walls and rocks, scent-marking as high up as possible - known as a display of virility in the wild.

The male panda has also been noticed as having an increased appetite for bamboo and will shortly start to enhance his body size as male pandas need to be in peak physical shape during breeding season.

Meanwhile Tian Tian has already started calling out to the male - which is common during breeding season.

Experts are able to predict when both giant pandas are ready to breed by a combination of behavioural observation and hormone testing, but to date no hormonal changes have been seen in either panda.

Edinburgh Zoo - where the pandas have lived since their arrival from China in December 2011 - has employed a number of measures to synchronise the breeding cycles of the pandas, including controlled lighting, urine testing for hormone levels and enclosure swapping.

To set the mood for romance, lighting levels inside both panda enclosures were timed to stimulate natural light levels outside – so when the sun comes up lights will go on in the panda enclosures and when the sun goes down it’ll be lights out and early to bed. This is vital as lighting levels dictate panda hormone levels.

The pandas were first introduced to each other last April, however they did not end up fully mating.

Female pandas are in season for less than 48 hours.

Iain Valentine, director of giant pandas and strategic innovations for the Royal Zoological Society of Scotland, said: "We're delighted that both Tian Tian and Yang Guang have started to scent mark and call, both clear behavioural indicators of courtship and mating behaviour.

"Although both giant pandas are showing these changes in their behaviour, it is still early days yet and way too early to give any accurate prediction on timings, however, early indicators do suggest the breeding season will probably fall in March this year.

"In reality we could be as little as four weeks away, although equally the big day could still be as far off as eight weeks.

"This year we will combine both natural and assisted reproduction methods.

"This follows the best practice methodology adopted by other panda-keeping zoos around the world and gives our giant pandas the best possible chance of success."

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  • Tian Tian

  • Yang Guang

  • Yang Guang

  • Tian Tian

  • Tian Tian the Panda in her enclosure at Edinburgh Zoo on her ninth birthday Friday Aug. 24, 2012. Keepers at Edinburgh Zoo made a three-tiered panda cake with carrots instead of candles for Tian Tian, but the birthday girl did not seem too impressed with her gift and refused to eat it this morning. (AP PhotoAndrew Milligan/PA Wire) UNITED KINGDOM OUT NO SALES NO ARCHIVE

  • Tian Tian the Panda in her enclosure at Edinburgh Zoo on her ninth birthday Friday Aug. 24, 2012. Keepers at Edinburgh Zoo made a three-tiered panda cake with carrots instead of candles for Tian Tian, but the birthday girl did not seem too impressed with her gift and refused to eat it this morning. (AP PhotoAndrew Milligan/PA Wire) UNITED KINGDOM OUT NO SALES NO ARCHIVE

  • Yang Guang (Sunshine), a giant male pand

    Yang Guang (Sunshine), a giant male panda, looks on during his ninth birthday, his first on Scottish soil, at Edinburgh Zoo, on August 14, 2012 in Edinburgh. Yang Guang is one of the two giant pandas which arrived at the zoo on December 4, 2011 and which will spend 10 years on loan in the Scottish capital, a deal agreed after years of high-level political and diplomatic negotiations with China. AFP PHOTO / ANDY BUCHANAN (Photo credit should read Andy Buchanan/AFP/GettyImages)

  • Yang Guang (Sunshine), a giant male pand

    Yang Guang (Sunshine), a giant male panda, looks on during his ninth birthday, his first on Scottish soil, at Edinburgh Zoo, on August 14, 2012 in Edinburgh. Yang Guang is one of the two giant pandas which arrived at the zoo on December 4, 2011 and which will spend 10 years on loan in the Scottish capital, a deal agreed after years of high-level political and diplomatic negotiations with China. AFP PHOTO / ANDY BUCHANAN (Photo credit should read Andy Buchanan/AFP/GettyImages)

  • Yang Guang (Sunshine), a giant male pand

    Yang Guang (Sunshine), a giant male panda, chews on bamboo on his ninth birthday, his first on Scottish soil, at Edinburgh Zoo, on August 14, 2012 in Edinburgh. Yang Guang is one of the two giant pandas which arrived at the zoo on December 4, 2011 and which will spend 10 years on loan in the Scottish capital, a deal agreed after years of high-level political and diplomatic negotiations with China. AFP PHOTO / ANDY BUCHANAN (Photo credit should read Andy Buchanan/AFP/GettyImages)

  • Yang Guang (Sunshine), a giant male pand

    Yang Guang (Sunshine), a giant male panda, chews on bamboo on his ninth birthday, his first on Scottish soil, at Edinburgh Zoo, on August 14, 2012 in Edinburgh. Yang Guang is one of the two giant pandas which arrived at the zoo on December 4, 2011 and which will spend 10 years on loan in the Scottish capital, a deal agreed after years of high-level political and diplomatic negotiations with China. AFP PHOTO / ANDY BUCHANAN (Photo credit should read Andy Buchanan/AFP/GettyImages)

  • Yang Guang (Sunshine), a giant male pand

    Yang Guang (Sunshine), a giant male panda, chews on bamboo on his ninth birthday, his first on Scottish soil, at Edinburgh Zoo, on August 14, 2012 in Edinburgh. Yang Guang is one of the two giant pandas which arrived at the zoo on December 4, 2011 and which will spend 10 years on loan in the Scottish capital, a deal agreed after years of high-level political and diplomatic negotiations with China. AFP PHOTO / ANDY BUCHANAN (Photo credit should read Andy Buchanan/AFP/GettyImages)

  • Yang Guang (Sunshine), a giant male pand

    Yang Guang (Sunshine), a giant male panda, chews on bamboo on his ninth birthday, his first on Scottish soil, at Edinburgh Zoo, on August 14, 2012 in Edinburgh. Yang Guang is one of the two giant pandas which arrived at the zoo on December 4, 2011 and which will spend 10 years on loan in the Scottish capital, a deal agreed after years of high-level political and diplomatic negotiations with China. AFP PHOTO / ANDY BUCHANAN (Photo credit should read Andy Buchanan/AFP/GettyImages)

  • Pandas in Edinburgh Zoo

    Female panda Tian Tian at Edinburgh Zoo in Scotland, a keepers at Edinburgh Zoo opened a 'love tunnel' between male Yang Guang and female Tian Tian's enclosures yesterday as they hoped to speed up the mating process.

  • Pandas in Edinburgh Zoo

    Male panda Yang Guang at Edinburgh Zoo in Scotland, a keepers at Edinburgh Zoo opened a 'love tunnel' between male Yang Guang and female Tian Tian's enclosures yesterday as they hoped to speed up the mating process.

  • Pandas in Edinburgh Zoo

    Male panda Yang Guang at Edinburgh Zoo in Scotland, a keepers at Edinburgh Zoo opened a 'love tunnel' between male Yang Guang and female Tian Tian's enclosures yesterday as they hoped to speed up the mating process.

  • Pandas in Edinburgh Zoo

    Male panda Yang Guang at Edinburgh Zoo in Scotland, a keepers at Edinburgh Zoo opened a 'love tunnel' between male Yang Guang and female Tian Tian's enclosures yesterday as they hoped to speed up the mating process.

  • Edinburgh Zoo pandas

    Tian Tian eats her panda cake in her enclosure at Edinburgh Zoo . The UK's only pair of giant pandas were treated to an extra helping of panda cake this morning to celebrate their first Christmas in Scotland.

  • Edinburgh Zoo pandas

    Tian Tian eats her panda cake in her enclosure at Edinburgh Zoo . The UK's only pair of giant pandas were treated to an extra helping of panda cake this morning to celebrate their first Christmas in Scotland.

  • Edinburgh Zoo pandas

    Tian Tian stretches after eating her panda cake in her enclosure at Edinburgh Zoo. The UK's only pair of giant pandas were treated to an extra helping of panda cake this morning to celebrate their first Christmas in Scotland.

  • Edinburgh Zoo pandas

    Tian Tian stretches after eating her panda cake in her enclosure at Edinburgh Zoo. The UK's only pair of giant pandas were treated to an extra helping of panda cake this morning to celebrate their first Christmas in Scotland.

  • Edinburgh Zoo pandas

    Yang Guang the panda at Edinburgh Zoo where it met its keeper Sharon Hatton. PRESS ASSOCIATION Photo. Picture date: Friday December 23, 2011. Photo credit should read: David Cheskin/PA Wire

  • Edinburgh Zoo pandas

    Yang Guang the panda at Edinburgh Zoo where it met its keeper Sharon Hatton.

  • Edinburgh Zoo pandas

    People watch Tian Tian the panda in its enclosure at Edinburgh Zoo as members of the public are let in for the first time to see the animals. PRESS ASSOCIATION Photo. Picture date: Friday December 16, 2011. The first giant pandas to live in the UK for 17 years have gone on show to the public. Tian Tian and Yang Guang have been getting used to their new home at Edinburgh Zoo since arriving from China on Sunday December 4. They spent their first few days indoors acclimatising before emerging to explore their outside enclosure. See PA story ANIMALS Pandas. Photo credit should read: Andrew Milligan/PA Wire

  • Edinburgh Zoo pandas

    Tian Tian the panda in its enclosure at Edinburgh Zoo as members of the public are let in for the first time to see the animals.

  • Edinburgh Zoo pandas

    People watch Tian Tian the panda in its enclosure at Edinburgh Zoo as members of the public are let in for the first time to see the animals.

  • Giant pandas to arrive at new home

    Edinburgh Zoo's Panda Team members (left to right) Christine Colquhoun, Lisette Boxsman and Lisa Baxter at Edinburgh Zoo ahead of the arrival of pandas Tian Tian and Yang Guang this weekend.

  • Pandas in Edinburgh Zoo

    Giant Panda Yang Guang in his new enclosure at Edinburgh Zoo in Scotland ahead of going on public display later this week.