The hybrid bird is the product of two species whose habitat ranges began to overlap a few decades ago, potentially due to climate change, researchers said.
For the first time, scientists have documented a wild hybrid between a blue jay and a green jay during fieldwork near San Antonio, Texas.
The discovery, detailed in Ecology and Evolution on September 10, marks the first recorded instance of hybridization between these two species in the wild. Researchers believe the overlap of their ranges—driven in part by climate change—made the pairing possible.
“We think it’s the first observed vertebrate to hybridize because both parent species expanded their ranges due, at least in part, to climate change,” said study co-author Brian Stokes, an ecologist at the University of Texas at Austin.
Blue jays (Cyanocitta cristata) are widespread across the eastern U.S., while green jays (Cyanocorax yncas) are native to Mexico, Central America and southern Texas. The two species diverged around 7 million years ago and are not closely related. But in recent decades, warming temperatures have allowed green jays to push farther north, while blue jays have expanded westward. Their ranges now overlap in central Texas.
Stokes first learned about the hybrid in 2023, after a San Antonio birder posted a photo of an unusual jay in her backyard. She invited him to observe the bird more closely.
“The first day, we tried to catch it, but it was really uncooperative,” Stokes recalled. “But the second day, we got lucky.”
Using a mist net—an almost invisible mesh stretched between poles—Stokes captured the bird, noting its striking mix of traits: blue plumage, green jay-like facial markings, and the ability to mimic calls from both species. He took a blood sample, fitted a leg band, and released the bird.
Genetic analysis confirmed that the bird was the offspring of a female green jay and a male blue jay. While scientists once bred the two species in captivity in the 1970s—producing a taxidermied specimen now housed at the Fort Worth Museum of Science and History—this marks the first known wild hybrid.