HONG KONG — Ying Ying and Le Le, two giant pandas who could never quite get in the mood over 13 years of living together in a Hong Kong zoo, successfully mated on Monday, a rare feat for the famously low-libido species and a cause of celebration in the world of animal conservation.

The coupling of the pandas, animals that have a mating “season” of just a few days per year, lifted hope that the population of the vulnerable species might be about to increase. Whether in captivity or in the wild, giant pandas rarely show the desire or skill to mate, imperiling their survival and making their infrequent romps worthy of acclaim.

Perhaps Ying Ying and Le Le just needed some privacy. Ocean Park shut down on Jan. 26 as part of Hong Kong’s measures to fight the coronavirus, leaving the amusement park and zoo free of its usual throngs of visitors.

“Since Ying Ying and Le Le’s arrival in Hong Kong in 2007 and attempts at natural mating since 2010, they unfortunately have yet to succeed until this year upon years of trial and learning,” said Michael Boos, executive director in zoological operations and conservation at Ocean Park. “The successful natural mating process today is extremely exciting for all of us, as the chance of pregnancy via natural mating is higher than by artificial insemination.”