Two giant pandas in China have broken the record for the longest mating session ever recorded, just hours after the male set the record with a different female.

The noisy marathon session between pandas Xi Mei and Lu Lu at the Sichuan Giant Panda Research Center on Friday lasted 18 minutes and three seconds. It followed an earlier eight-minute record-breaking session the previous day between Lu Lu and a female panda named Zhen Zhen.

The sessions, broadcast on China Network Television's iPanda website, came as welcome news because there are only 1,864 pandas in the world, according to a census last year. The creatures are listed as endangered by the International Union for Conservation of Nature, although numbers are believed to have risen in the past forty years.

According to iPanda, the record-breaking encounter only occurred after Xi Mei rejected an initial suitor.

Typically, copulation time between pandas is about 30 seconds to five minutes.

“Xi Mei was first set up with male giant panda Yi Bao, but two pandas failed to mate,” the site said on YouTube. “Later, Xi Mei was placed together with male giant panda Lu Lu. This matchmaking arrangement is quite successful, and the pair Xi Mei and Lu Lu ended up mating naturally.”

Pandas have a short mating season and are poor at reproducing while in captivity, possibly because they lose interest or do not know how to successfully mate. Female pandas are often only in heat for two or three days a year during the spring.

Britain’s only female giant panda Tian Tian was recently artificially inseminated after failing to mate with her intended partner. She has not mated naturally since arriving at Edinburgh Zoo in 2011 and has twice conceived after being inseminated; both pregnancies failed.

Giant pandas in captivity have long attracted attention for their failure to mate, which has prompted some researchers to use video guides to try to encourage copulation. Chinese researchers have had increasing success in recent years, though they were apparently not expecting such lengthy mating sessions.