A blue jay and a green jay mated, researchers say. Their offspring is a scientific marvel

(CNN) — What do you get when you cross a blue jay with a green jay? That’s not the start of a joke, but the subject of a new study that aims to describe a hybrid bird never encountered before in the wild.

The bigger question scientists are puzzling over, though, is why does the mystery bird exist?

“We think it’s the first observed vertebrate that’s hybridized as a result of two species both expanding their ranges due, at least in part, to climate change,” said Brian Stokes, a doctoral student of biology at the University of Texas at Austin and first author of the study published September 10 in the journal Ecology and Evolution .

The vividly colored green jay is found in parts of South and Central America, Mexico and a limited portion of southern Texas. But since 2000, the tropical b