10-Million-Years in the Making – Researchers Discover First-Ever Documented Hybrid of Its Kind

Rare Hybrid Bird

This healthy, 1-year-old male offspring of a rose-breasted grosbeak and scarlet tanager is the first-ever documented hybrid of its kind. The two species have such divergent nesting preferences that they have been on independent evolutionary trajectories for at least 10 million years — until now. Credit: Stephen Gosser

Birdsong reveals a rare hybrid coupling.

Stephen Gosser, a self-described “diehard birder,” was out in the Western Pennsylvania woods in June of 2020 when he believed he heard the singing of the elusive and breathtakingly beautiful scarlet tanager. The blood-red bird, which has black wings and a tail, is a favorite among birders because of both its beauty and rarity since the species prefers to remain hidden high in the forest canopy.

When Gosser finally located the songbird, he found what looked like a rose-breasted grosbeak but sounded just like a scarlet tanager. He snapped a few photos and called for backup; shortly after, a team from National Aviary in Pittsburgh arrived to catch the bird and collect a blood sample.

In order to follow up on Gosser’s tip, a group of scientists headed by Penn State was able to identify the specimen as a unique hybrid bird, whose relatives haven’t congregated in the same breeding location or lineage for 10 million years. Their findings were recently published in the journal Ecology and Evolution.

“I love this story because it starts with a little mystery and ends with a surprising discovery,” said David Toews, lead author of the study and assistant professor of biology at Penn State.

The story begins with an unlikely encounter between a female rose-breasted grosbeak and a male scarlet tanager. Since the two species favor different habitats, experts are still unsure of how and where they met. Tanagers normally favor the canopy cover of mature forests, whereas rose-breasted grosbeaks prefer the open spaces along woodland edges. According to Toews, the two species have been on different evolutionary trajectories for at least 10 million years—until now—because of their vastly different nesting preferences.

Genetics DNA Mutation Concept

The bird’s DNA confirmed that it had a grosbeak mother and tanager father.

The researchers determined that the bird Gosser spotted was the healthy, 1-year-old male offspring of a rose-breasted grosbeak and scarlet tanager, the first-ever documented hybrid of its kind. Yet, his origin story was largely a mystery.

Luckily, Toews had a host of techniques available for solving just this type of mystery. From the blood sample, they could obtain a small sample of DNA. The combination of audio and genetic material would get them as close as they could to solving the mystery of the bird’s genesis.

Their methodology relied on analyzing both nature and nurture. For the most part, songbirds learn to sing from their fathers. Their vocalizations can reveal how and by whom they were raised.

“We knew Mom was there, she was the one who laid the egg and sat on the nest,” Toews said. “It’s still not obvious to us where that would have been, because the two species prefer such different habitats. Wherever it was, her pair either stayed around long enough for the young offspring to learn his father’s song or learned a neighborhood scarlet tanager song.”

The researchers used a method called bioacoustic analysis to confirm the vocalizations they captured did, in fact, match the song of a scarlet tanager — revealing that the hybrid likely learned to sing from his father.

“Something people may not understand is that when we analyze birdsongs, we’re not actually listening to them. We’re looking at them,” said Toews. “We’re looking at wavelengths of the sound — or the ‘spectrogram’ is a more accurate term — and we’re actually measuring visual components of a soundwave to analyze the song.”

With the vocalizations confirmed, the team turned to genomic sequencing to track the genetic ancestry of the hybrid. Nature confirmed what nurture had already revealed, a grosbeak mother and tanager father.

“We used the same tools that we’ve used to identify other hybrids, but we typically have more ambiguous answers that are a bit more esoteric,” said Toews. “In this case, we identified the species. We know who the parents were and we have a somewhat satisfying conclusion at the end. I find this story resonates with more than just your average ornithological nerd like myself.”

Reference: “Genetic confirmation of a hybrid between two highly divergent cardinalid species: A rose-breasted grosbeak (Pheucticus ludovicianus) and a scarlet tanager (Piranga olivacea)” by David P. L. Toews, Tessa A. Rhinehart, Robert Mulvihill, Spencer Galen, Stephen M. Gosser, Tom Johnson, Jessie L. Williamson, Andrew W. Wood and Steven C. Latta, Ecology and Evolution.
DOI: 10.1002/ece3.9152

The study was funded by startup funds from Penn State’s Eberly College of Science and the Huck Institutes of the Life Sciences.

Bird handling was approved by the Institutional Animal Care and Use Committee of the National Aviary and Pittsburgh Zoo and PPG Aquarium. 

18 Comments on "10-Million-Years in the Making – Researchers Discover First-Ever Documented Hybrid of Its Kind"

  1. Is the hybrid bird in captivity?

  2. Josue O Herrera | November 7, 2022 at 8:20 am | Reply

    Is not a hybrid if it’s of it same kind of species. A bird is a bird. A bird and a snake’s offspring will be consider a hybrid.

  3. Deforestation and other habitat disruptions may have produced the conditions that brought the parent birds together.

  4. Digital Bookworm | November 7, 2022 at 9:46 am | Reply

    I saw no mention of whether they tested for fertility. Parents coming from 2 different families should create an infertile offspring.
    Josue – A snake-bird would not be a hybrid. It would be about as likely as an ostrich-wren. I suggest you read a different book before trying to keep up with the adults here.

  5. Of its kind? Does that mean this particular combination of species?

  6. A snake bird would be chimera, unless it’s just a bird that likes to eat snakes.

  7. Dumb. By definition, different species cannot interbreed. What they have proved is that they were wrong by assuming these birds were 2 different species. They, obviously are not. They are variations within the same species.

  8. Wrong. A specie is a variation within a genus. Different species within the SAME genus can interbreed.

  9. So… interesting choice of words. How are we defining a ‘kind’?

  10. Did they factor in, that a bird in the hand, is worth two in the bush?

  11. Shamus Arileus Prime Esquire | November 10, 2022 at 2:05 am | Reply

    Worry Not about the singing of birds but the Sudden Evolution of all the apes moving right to and advancing thru the Stone age per-say. Orangutans learning to hunt fish and other smaller monkeys with Self-made Weapons ie; Spears,Knives,Clubs etc. and even operating Machinery without being taught but from observation and repetition. Not long and we may have a suitable adversary ,A.I.,Zombies,Apes,Oh Forgot Aliens!
    P.S.- Que- The Song Birds!

  12. The classic concept of species is itself evolving. It is a more or less convenient way for us, as humans,to classify our world. Cross species infertility is not necessarily the outcome.

  13. Where is this poor bird now? Please tell me theu released it?

  14. Well,did anyone ask what the bird ” identifies as??
    It’s CRULE to assume anything nowadays. Tomato tomato. Lol

  15. Very Interesting. On the word choice –of its “kind”: this is referring to this particular previously unknown hybrid offspring between those two species… as I read it. Don’t let some self serving muck book merchants steal a perfectly ģood word with their silliness. And – agreed that a bird-snake would be a chimera… by convention this bird is a proposed hybrid of two species of the same genus. If this particular interbreading combo became reproductively successful, found a niche and persisted it would become known as a new specie needing a name… may I suggest: “serpens avis” if it’s not already taken.

  16. Fools believe in evolution. The wise know that the LORD God created all that is created. Every kind after its kind.

  17. Bob, are Lions and Tigers the same species? Are they simply cats?

    Were humans and Neanderthals the same species? Were they simply apes?

    Evolution is a little more nuanced my friend.

  18. It is easiest to see the changes in evolution within bird species and can be easily identified with in 10 to 20 years. Food sources and weather patterns also Play a huge part.

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