Hilton Head birders identify a hybrid bird species. It’s the first of its kind.
Mary Alice Tartler knows her birds, but she didn’t know this one.
She had arrived at her friend’s house on Hilton Head Plantation this past winter to photograph humming birds that frequented a bird feeder. Then, she turned and saw a bird that at first glance, looked like a black-throated blue warbler, a common species that migrates through the area. But quickly, Tartler realized that some things didn’t add up.
Tartler’s keen eye and camera caught what local bird experts would eventually identify a first-of-its-kind hybrid, the result of breeding between a yellow-rumped warbler and a black-throated blue warbler.
This particular bird isn’t the first hybrid warbler ever recorded, but it’s the first combination of these two particular species. Warblers are a family of small, often colorful songbirds found in the Americas. There are over 100 species of warblers, many of which migrate through the region.
Tartler, an Audubon master birder who had moved to Hilton Head over two decades ago, continued to peer at the bird. The closer she looked, the more it didn’t make sense.
It could have been the yellow-throated warbler, but there was no yellow throat patch. As she moved closer, there were marks of a black-throated blue warbler but some patterns on the bird didn’t match that species either.
“I was just stumped,” Tartler said.
She took over 200 photos of the bird before heading home. She sent the pictures to local bird expert Bob Speare, who then sent the photos to Andy Jones, executive director of the Spring Island Trust.
Recreational birders and other experts began parading across the back yard, hoping to get a glimpse of the puzzling bird.
Jones had published scientific papers on hybrid warblers while working for the Cleveland Museum of Natural History. In searching the existing records, he found that there is no record of a hybrid between these two species. The team is currently working on writing a scientific paper on their findings.
While the first hybrid of this kind, warblers have been known to hybridize before. In fact, about 10 percent of the word’s 10,000 bird species have mated with another species. A three species warbler hybrid found in Pennsylvania made headlines in 2018. The mother of that bird was a hybrid, and she mated with a different species of warbler.
Often these hybridizations between warblers are caused by habitat loss in their breeding grounds. When a bird can’t find a member of their own species to mate with, they often settle for another closely related species. Some hybrids live longer than others, but they often can’t produce offspring in adulthood.
This story was originally published August 7, 2025 at 12:54 PM.
