Unofficially dubbed the "grue jay," this new bird may be an early example of how the impact of climate change on animals' habitats could lead to other hybrids in the future.
The University of Texas at AustinA blue jay on the left, a green jay on the right, and the hybrid “grue jay” in the middle.
Biologists at the University of Texas at Austin recently discovered a new bird outside of San Antonio, which has been dubbed the “grue jay.”
Part blue jay, part green jay, this bird is a potential early example of how climate change — and range expansion — could lead to more new hybrids. It is, in other words, a “bellwether” that environments are changing at a rapid pace.
The Backyard Bird That Became The Subject Of A Study
Although they sound similar on paper, blue jays and green jays are actually separated by about seven million years of evolution. Up until a few decades ago, their ranges didn’t overlap. Climate change, however, has caused the green jay to move farther and farther north, just as blue jays are heading farther west.
“One of the things that we were wondering is, when they encounter blue jays, would that stop this expansion? That they would be antagonistic to each other,” Professor Timothy Keitt of the University of Texas’ Department of Integrative Biology, an author of the study, told KXAN.
The University of Texas at AustinThe hybrid “grue jay” is the first recorded bird of its kind, but more could exist.
As it turned out, these birds were the opposite of antagonistic toward each other.
In 2023, a homeowner in a San Antonio suburb reported a strange bird they had never seen before. When Ph.D. candidate Brian Stokes heard about it, he made the drive out to take photographs of the bird.
“The first day, we tried to catch it, but it was really uncooperative,” Stokes said in a statement from the university. “But the second day, we got lucky.”
After the bird was caught in a net, Stokes took a blood sample, banded its leg, and set it free.
The University of Texas at AustinThe researchers opted not to name the bird, but “grue jay” follows similar hybrid names like the “grolar bear” or the “coywolf.”
It’s remarkable that the homeowner noticed the creature in the first place. The “grue jay” is only slightly paler than a blue jay, but its face markings resemble that of a green jay. Most people probably wouldn’t have thought anything of it.
“I don’t know what it was, but it was kind of like random happenstance,” Stokes said. “If it had gone two houses down, probably it would have never been reported anywhere.”
Climate Change Drove Green Jays Into Blue Jay Territory
Blue jays and green jays don’t typically mate. Once, in the 1970s, researchers crossed the two species in captivity and created a hybrid that looked very much like Stokes and Keitt’s wild bird, but this is the first time a “grue jay” has been found outside of a lab setting.
“It’s not unusual to have hybrids in birds,” Keitt noted, “but these are intelligent, social animals that live in family groups.”
Even as green jays have moved northward, they are still relatively scarce and remain on the fringes of blue jay territory. However, blue jays are also expanding westward, so the two species are encountering each other more often.
A map charting typical green jay and blue Jjay territory, and where they now overlap.
While Stokes stated that this is thought to be the first observed hybrid vertebrate that came about from two species both expanding their ranges due to climate change, more “grue jays” and animals like them exist than we’re aware of.
“Hybridization is probably way more common in the natural world than researchers know about because there’s just so much inability to report these things happening,” Stokes said.
“And it’s probably possible in a lot of species that we just don’t see because they’re physically separated from one another and so they don’t get the chance to try to mate.”
After learning about the “grue jay,” meet nine of Earth’s creepiest bird species. Then, see 11 of the weirdest animals on our planet.
