A baby goldeneye duckling getting a lift on a Common Loon in Paul Lake Provincial Park, British Columbia. Photo: Doug Giles

Something was amiss. This June, when Canadian photographer Doug Giles snapped some shots of a pair of Common Loons tending to their fuzzy fledglings in Paul Lake Provincial Park, British Columbia, he realized that one of the chicks hitching a ride was not like the others. More brown than black, with pale cheeks and a shorter, rounder bill, it was clearly not a loon. But what was it?

Baffled, Giles sent his shots over to Walter Piper, lead scientist and founder of The Loon Project in northern Wisconsin. After digging through records of other breeding waterbirds, Piper was able to identify the chick in question. The loons, he concluded, had accepted a Common Goldeneye into their family and were raising it as their own (because goldeneyes are difficult to distinguish so young, there's a slight chance the duckling could also be a Barrow's Goldeneye). Since the discovery, Giles' photos and images from others capturing the potentially unprecedented relationship have been bouncing around the internet.

In nature, inter-species adoption is a rare occurrence, but here’s what makes this scenario even more incredible: Loons and other waterfowl don’t exactly get along. In fact, they can be downright nasty to each other, Piper says. Sharing the same territory, the birds can get competitive, and because of the loon’s size advantage over the goldeneyes, they’re often the aggressors (and champs). Loons have even been known to stalk Mallard ducklings and pin them underwater to drown them. It’s an act of survival, not malice, Piper says: Mallards nest along the shoreline, drawing in predators and endangering baby loons in the process.

Luckily for this little goldeneye, that wasn’t the case here.

Piper is familiar with the nurturing side of loons. In the past, he and his collaborators from Chapman University have introduced orphaned loons to wild adults and have found that they’re extremely receptive to fostering unrelated birds. But this is the first time he’s seen them take in a member of another species. While it’s highly unusual, he’s not totally surprised. “After mating, loons are hormonally primed,” Piper says. “They’ll cast a broader net and will care for babies that look like their own.”

As for how this unlikely pairing happened, it’s possible this was just a mistake on both sides. Unlike loons, which only lay one or two eggs per year, Common Goldeneyes raise anywhere from 12 to 15 chicks in a summer. That’s a lot of fluff balls to keep track of, so this one could have simply gotten separated from its mother for a brief time. Couple that with the fact that loons can’t identify individual chicks, and the Paul Lake scenario isn’t completely outlandish.

No matter how it happened, it’s a good thing it did for the goldeneye. Given this baby’s brownish down, it was probably only a few weeks old when it was picked up by the loons, and according to Piper, it likely would have died if it were left too long on its own. Though little goldeneyes can dive and feed themselves from birth, they need guidance and protection to make it past predators like raptors, raccoons, and even humans. Despite its self-reliance during mealtime, this duckling was more than happy to take up the diet of its adopted parents; Giles photographed it being served a spread of freshwater fish, a major shift from its typical insect- and crustacean-filled diet.

It's unknown if the duckling stuck with its new parents through the summer, but if it did and stays all the way until it gets to breeding age (about two years), it might be in for a serious culture shock. The bird could experience what’s called sexual imprinting, forgetting its real identity and its species-specific mating instincts—not great for the goldeneye’s future dating prospects. If the bird did try to mate with other loons, it would likely face a terrible beat down, Piper says. So for its own sake, here’s hoping the alternative happened: It survived long enough with its adoptive family and eventually made it back to its own kind, where choosing a mate isn’t nearly as dicey.