It was a typical game drive for Patrick Njobvu in Zambia’s South Luangwa National Park—until he witnessed something unique in his 23 years of guiding.

As he and a vehicle of tourists watched on a recent July morning, a hippopotamus emerged from the Luangwa River and approached a sleeping spotted hyena, which soon awakened.

“The hyena didn't run and both started sniffing each other, nose to nose, almost like kissing,” Njobvu, the head guide at Shenton Safaris, told National Geographic by email. For almost 20 minutes, the young animals hung out together, touching noses, with the hyena rolling on its back at one point. “It was very strange indeed,” he says.

Njobvu later described the incident on