Who Is This Mystery Bird?

Mystery bird, possible hybrid found by Steve Gosser, 6 June 2020

8 June 2020

On Saturday 6 June 2020, photographer Steve Gosser found a bird in the Pittsburgh area that doesn’t match any field guide. He looks like a cross between a rose-breasted grosbeak and a scarlet tanager. He sings like a scarlet tanager.

So I found this bird today that has all the expert birders scratching their heads. It appears to be a cross between a Rose-breasted Grosbeak and a Scarlet Tanager, possibly a hybrid! No one seems to have any records of a hybrid between these birds! I along with two expert ornithologists will try and relocate this bird in the morning and they are interested enough to possibly try and catch this bird and collect a blood sample so it can be DNA tested. It sang exactly like a Tanager, has black wings like a Tanager, a thinner bill like a Tanager, a red throat like a Tanager but the rest looks very much like a RB Grosbeak. I’ll keep everyone posted as to what we find out!

Steve Gosser Facebook post, 6 June 2020

Here’s who the mystery bird resembles: a male scarlet tanager on the left, a male rose-breasted grosbeak on the right.

Scarlet tanager + rose-breasted grosbeak (photos by Chuck Tague and Marcy Cunkelman)

Yesterday ornithologists Bob Mulvihill and Steve Latta netted the bird and took blood samples for DNA testing. Bob says the bird “bit hard but not as nimbly as a rose-breasted grosbeak.” Rose-breasted grosbeaks have very strong bills.

Mystery bird captured for DNA testing, biting Bob Mulvihill (photo by Steve Gosser)

Unlike a rose-breasted grosbeak, this bird has almost no red color in his axillaries (armpits).

Mystery bird still clamping on Bob’s finger (photo by Steve Gosser)

After the blood sample, Steve had the honor of releasing the bird.

Steve Gosser about to release the mystery bird (photo by Courtney Sikora)

We can hardly wait to find out who this bird is. Visit Steve Gosser’s Facebook page for news.

Congratulations, Steve! What a find!

(mystery bird photos by Steve Gosser and Courtney Sikora via Facebook; scarlet tanager by Chuck Tague, rose-breasted grosbeak by Marcy Cunkelman)

UPDATE 21 Feb 2021: The bird is extremely rare! From Steve Gosser on Facebook:

“After all this time we finally know the identity of the mystery bird I found at McConnells Mills back on 6/6/2020!! It is a hybrid!! As far as anyone knows it’s the first hybrid of these two species that has ever been documented.

Here is what Bob Mulvihill wrote moments ago:

The genetic identity of this remarkable bird has just (2/22/21) been confirmed as:
(female parent) grosbeak X (male parent) tanager!! Steve Gosser’s amazing discovery of the “Scarlet Gosserbeak” will be official as soon as we finish writing up all the scientific details–stay tuned!”

UPDATE 4 March 2021: #bioPGH: The Case of the Curious Grosbeak by Dr. Maria Wheeler-Dubas
UPDATE on 7 July 2022: Genetic confirmation: This bird is a true hybrid!

Confirmation of the bird’s hybrid origin is published at Wiley.com, 7 July 2022: Genetic confirmation of a hybrid between two highly divergent cardinalid species: A rose-breasted grosbeak (Pheucticus ludovicianus) and a scarlet tanager (Piranga olivacea)

UPDATE October 2022: Lots of media attention described at: Hybrid Gets More than 15 Minutes of Fame

17 thoughts on “Who Is This Mystery Bird?

  1. That is a pretty neat find! It will be interesting to see what the results are. Do you know how long it would take to do the DNA analysis?

    As an aside, there is someone at the CoL nest this morning, probably Morela.

    1. I have no information on how long it will take for this particular DNA test to provide answers.

  2. It reminds me of a Spotted Oriole a bit. It will be interesting to see results. It is interesting that it was singing the tanager song. Nature is so wild.

  3. How exciting is this…..and how pretty is this sweet bird. I will be waiting, with all the others for the result.

  4. Could you please update us when the DNA results come in? I tried visiting Steve’s Facebook page, but privacy settings prevent me from seeing his posts.

  5. It looks a lot like a Western Tanager, but not fully feathered out? I look forward to seeing the results also.

  6. Kate St. John, I am amazed that the bird was netted. It would seem like an impossible task to net a specific bird in a dense mature wood. I would like to know how they did that.

    1. Gene, they set up mist nets & played the bird’s song and he flew toward the sound and into the net.

    1. I looked at the photo in your ebird checklist and that one looks like a typical immature RBG. It showed a white eyebrow stripe and white wing bars. If you look closely to the bird I found it lacks both of those key characteristics.

  7. How exciting to have seen a “new” bird, netted it and determined its genetic history, and released it to the wild. This is just amazing.

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