In this video originally posted in 2010, you’ll see a cardinal making its way to a fish pond to feed the goldfish. The goldfish swim to the rocky edge and have their mouths wide open ready to receive food from the cardinal. It appears as though the cardinal is dropping small seeds in their mouths. According to the YouTube user who posted the video, this cardinal would come to the pond on their property sometimes 6 times a day to feed the fish. This strange scenario begs the question: why would a bird continuously feed a species other than its own?

Christina Riehl, a biologist from Princeton, believes “that the appearance of the goldfish’s open mouth at the surface of the water is just similar enough in size and shape to the open mouth of a baby bird that it triggers the instinct in the adult bird to provide food to it.” It seems as though the cardinal’s biological instincts have misguided it to feed the fish instead of its own species. But interspecies care is not as uncommon as you may think. According to the National Geographic, there have been quite a few unlikely pairs found around the world, such as a lioness nursing a leopard cub and a hawklet adopted by bald eagles.