In a rare case, scientists discovered that the bird observed in Pennsylvania is actually a hybrid of three birds.

What does this imply about the warbler species involved?

Bird Sighting

It was in May 2018 that dedicated bird-watcher Lowell Burket noticed the one-of-a-kind bird in his family’s property in Pennsylvania. He took photos and videos of the birds he saw, but then he noticed something rather odd about a male bird he took a video of: the bird was singing like a Chestnut-sided warbler but had the physical characteristics of both the Golden-winged warbler and the Blue-winged warbler.

He saw the bird several times and got in touch with Cornell Lab’s Fuller Evolutionary Biology Lab. Someone came down within a week, and they collected blood samples and measurements of the bird for testing. In just a few days, Burket’s hypothesis was confirmed.

Three-Species Hybrid

In a study published in the journal Biology Letters, researchers describe the unique bird that Burket saw in his property. DNA testing revealed that the bird really is a hybrid of not just two but three bird species: the Golden-winged warbler, the Blue-winged warbler, and the Chestnut-sided warbler.

Genetic analyses revealed that the bird’s mother was a Golden-winged/Blue-winged warbler hybrid also called a Brewster’s warbler, while its father was a Chestnut-sided warbler. While hybridization is said to be common between the Golden-winged and the Blue-winged warblers, the combination of these species resulted in a three-species hybrid that has never been recorded before.

Hybrid Bird Problems

As mentioned, hybridization is quite common for Golden-winged and Blue-winged warblers, but this doesn’t mean that it no longer poses problems for the species’ involved. In fact, this has caused a dramatic decline in some Golden-winged warbler populations. Furthermore, it’s possible that the hybridization that resulted in the triple hybrid may have been a result of declining warbler populations.

“That this hybridization occurred within a population of Golden-winged Warblers in significant decline suggests that females may be making the best of a bad situation,” said study lead author David Toews, also noting how it shows that warblers may still be genetically compatible despite evolutionary differences.

The question now is whether the new triple-hybrid will thrive or if it will be a pariah among warblers.