No one knows where they came from or how they ended up in Norfolk. But one thing is certain: now, there are two of them.

Until last week, experts believed there was only one wild beaver living in Pensthorpe nature reserve, about 20 miles outside Norwich. But just in time for Valentine’s Day, two were caught on camera going for a late-night swim together and grooming each other by the riverbank.

The couple are the first wild pair to settle in Norfolk since the early 16th century. The age and sex of the beavers is unknown. “We won’t know for sure whether they’re a breeding pair until the camera shows they have kits, but they’re quite well bonded and they’re living together and behaving as a family unit,” said the reserve’s manager, Richard Spowage. “They are clearly wild animals. They’re not interacting with us at all, they’re avoiding us completely.”