Researchers have for the first time confirmed that a blue jay and a green jay have mated in the wild to produce a rare hybrid with mixed features. Spotted by a birder named Donna in her backyard in San Antonio in the U.S. state of Texas, this hybrid may have resulted from the two jay species expanding to new areas, partly due to climate change, researchers say in a recent study.
Lead author Brian Stokes, from the University of Texas at Austin, first encountered the bird in a grainy image posted online by the local birder. Suspecting it wasn’t a “normal” blue jay, Stokes and his colleague Timothy Keitt went over to Donna’s house at her invitation and managed to capture the bird. They drew a blood sample, attached a band to its leg for future identification, then released it.
Seeing the bird in person, they felt confident it was a hybrid between a blue (Cyanocitta cristata) and green jay (Cyanocorax yncas), Stokes told Mongabay by email. The bird had a bluish body like a blue jay, but the black facial markings around its eyes were typical of green jays, he added.
Genetic analysis of the bird’s blood sample confirmed their suspicion: it was indeed the first recorded blue-green-jay hybrid in the wild. The only other such hybrid known was produced in a Texan zoo in 1965.
Historically, green jays have been a tropical species, ranging from the northern Andes through Central America into southern Texas. Blue jays, by contrast, are a temperate bird, spread across southern Canada down to Florida and northeastern Texas.
Warming climate, however, has helped green jays expand northward over the past half-century, Stokes said. Meanwhile, blue jays have also moved to newer areas, although their expansion is strongly linked to the expansion of human settlements where food is more easily available, and there may be some influence of climate change, he added.

Green and blue jays, belonging to different genera, went their separate evolutionary ways 7.5 million years ago. Hybrids between evolutionarily distant bird species aren’t rare, but what makes this case significant is “the role of range expansion in bringing two historically isolated species together,” Stokes said. “It could be viewed as a bellwether for many of the unexpected outcomes of climate change globally.”
The hybrid isn’t a new species so it hasn’t been formally named. However, Stokes said that “grue jay,” “teal jay” and “bleen jay” have come up as contenders. “As authors we don’t have a strong opinion on it — but the original observer, Donna, took to calling the individual ‘Henry’ which I think is quite cute!”
Banner images: From left: A blue jay, a hybrid individual, a green jay. Images courtesy of Travis Maher/Cornell Lab of Ornithology/Macaulay Library; Brian Stokes; Dan O’Brien/Cornell Lab of Ornithology/Macaulay Library.