This latest interspecies friendship is one of the more unexpected ones

When Rex, a mixed German shepherd, was abandoned as a puppy, he was vicious and erratic. But after his rescue and years of loving care, he’s turned into a sweet, altruistic dog — who just recently saved the life of a baby hummingbird that had fallen from her nest.

The dog’s owner (and rescuer) Ed Gernon thought the hummingbird was dead, but Rex wouldn’t abandon the bird, who was covered in ants at the time, CBS reports. Once Gernon determined that the bird was still breathing, he took her in and fed her a sugar syrup mixture until the bird grew healthy again.

Over a year later, Hummer refuses to leave Rex and Gernon’s side, just as they didn’t leave hers.

“It’s like living with Tinkerbell,” Gernon told KCBS News. “It was this little creature. This fragile creature that the whole world wanted to kill and he was trying to protect her so I thought I’d go the distance.”

Gernon has been leaving the windows open for Hummer to fly free and mate (it’s about time), but the bird refuses to leave. But no one seems to really mind — not even Rex, whose water bowl has been re-appropriated as a bird bathtub.