In late May 2023, an unfamiliar bird appeared in a suburban residence near San Antonio, Texas. A homeowner, later identified as Donna Currey, posted images to a local birding group. Graduate student Brian R. Stokes from the University of Texas at Austin quickly recognized the significance of this peculiar sighting.
From Facebook Post to Scientific Breakthrough
First Wild Hybrid of Blue Jay and Green Jay Called the Grue Jay was Discovered in Texas and Reveals the Role of Climate Change
A Tale of Two Jays
Stokes captured the bird in early June 2023 using mist nets. He then collected blood samples, morphometric data, and detailed photographs for further evaluation before releasing it with a U.S. Geological Survey aluminum band. The mysterious bird was sighted again on 9 June 2025. This confirmed survival of at least two years in the wild.
Morphological inspection revealed a mosaic of traits. Its back and tail resembled the Blue Jay or Cyanocitta cristata, while the black mask and nasal tufts recalled the Green Jay or Cyanocorax yncas. Yellow underparts, typical of Green Jays, were absent. Vocalizations included Blue Jay calls, but also rattling and bill-clicks characteristic of Green Jays.
The research team sequenced nearly 94 million single-end reads and mapped them to the Steller Jay reference genome. Nuclear genome analysis showed approximately 49.8 percent Cyanocitta ancestry and 48.1 percent Cyanocorax. The maternal parent was confirmed after mitochondrial DNA matched Green Jay sequences with 97.9 percent identity.
Surprises Hidden in the Feathers
The research team uncovered several important findings that together illustrate the significance of the Grue Jay and its context in a changing environment. The species was not a simple curiosity. Each discovery provides insight into how changing environments and human activity are reshaping natural interactions. The following are the key findings:
• A One-of-a-Kind Discovery: This was the first time a Blue Jay and Green Jay hybrid was confirmed in the wild. Until now, only a single zoo-bred hybrid from 1965 was on record, making this San Antonio bird scientifically historic.
• Half-Blue and Half-Green: Genetic sequencing showed an even split. The mother was a Green Jay, confirmed by mitochondrial DNA, while nuclear DNA showed almost equal shares from both species. The bird is a first-generation hybrid.
• Patchwork of Traits: It has blue wings and tail from its Blue Jay father, and a black face mask from its Green Jay mother. The hybrid also mixed the languages of both species, producing familiar jay calls alongside rattles and bill-clicks.
• Ranges Now Colliding: Checklists from birdwatchers showed the two species are meeting more often in central Texas over the past two decades. Human-altered landscapes and a warming climate are drawing them together.
• Future Overlap Zones: Climate models showed their overlap today covers about 5198 sq km near San Antonio. This could shrink to 483 sq km and slide more than 100 km north within a few decades as global warming reshapes distribution.
• Proving It Could Survive: In June 2023, the hybrid was banded and released. To the delight of scientists, it was seen again in June 2025, alive and thriving in the same area. The Grue Jay had proven its resilience in the wild.
The Bigger Picture
The two parent species diverged approximately 7 million years ago during the late Miocene. This means that intergeneric hybridization is highly unusual. Previously, only one hybrid between these species was recorded, produced in captivity at the Fort Worth Zoological Park in 1965. This new wild case is the first genetically validated example.
Nevertheless, considering the findings above, the wild Grue Jay demonstrates how climate change, human land use, and ecological reshuffling can produce unexpected biological outcomes. The hybrid avian species serves as tangible evidence of rapid changes transforming ecological landscapes and evolutionary possibilities in the Anthropocene.
FURTHER READING AND REFERENCE
- Stokes, B. R., and Keitt, T. H. 2025. “An Intergeneric Hybrid Between Historically Isolated Temperate and Tropical Jays Following Recent Range Expansion.” Ecology and Evolution. 15(9). DOI: 1002/ece3.72148
Photo Credit: Brian R. Stokes