The secret to successfully getting pandas pregnant? It's love, scientists say

Scientists may have cracked the secret of successfully getting pandas pregnant - letting them fall in love.

Giant pandas are notoriously difficult when it comes to reproducing, with phantom pregnancies, reabsorption of foetuses, and a simple refusal to mate all frustrating the process.

Coupled with females only being fertile for three days of the year, their general reluctance to produce offspring has led conservationists to try a number of other ways.

Artificial insemination, genetics-based matchmaking, and even showing videos of other pandas mating in an attempt to get them in the mood have all been used - none of which have proved overly successful.

But now scientists at the San Diego Zoo Institute for Conservation Research say they have found the secret ingredient to making little panda babies: Love.

In a study reported in the Nature Communications journal, researchers found that when the bears are given the chance to choose their own mate, the chances of mating and producing a cub shot up.

The scientists studied more than 40 pandas at a conservation and research centre in China's Sichuan province, with bears put into enclosures where they could choose between two potential mates.

Couples in which both male and female showed an interest in one another had an 80 per cent chance of successfully reproducing, they found.

And even when only one of the pair took a shine to the other, they had a 50 per cent chance of getting pregnant.

That is compared to the zero per cent chance of babies being created when neither panda was interested in the other.

Conservation biologist Meghan Martin-Wintle said:

The pandas showed interest through a number of distinctive behaviours, including 'chirps' and 'bleats', as well as scent-marking by rubbing glands against different objects.

Females displayed their genitalia to the male they were interested in, and backed towards him. Meanwhile, interested males would perform a handstand against a vertical surface and urinate.

"We learned that, just as in humans, breeding signals are complicated," Ms Martin-Wintle added.