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Idris - photography's avatar

I did not know that! Question - are blue tits and great tits close enough genetically to interbreed? Can they produce viable offspring, I wonder? Especially in the case of fostered great tits?

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Maja Mielke's avatar

Hi Idris, thanks for the question! Yes, there are reports of hybridizations between great tits and blue tits, but they are very rare. Great tits seldom hybridize outside the Parus genus.

People reported finding birds the size of great tits, but with a blue crest, which may be the appearance of Great tit x Blue tit hybrids. I could not find out, however, whether these hybrids are fertile.

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Idris - photography's avatar

thanks!

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Nathaniel Bowler's avatar

Very interesting! Where I live, Black-capped and Carolina Chickadees are known to interbreed to the degree that we are encouraged to enter them as Carolina/Black-capped in eBird. They learn each other’s songs, cause all kinds of confusion. Seems like a different scenario with our tits.

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Maja Mielke's avatar

Hi Nathaniel, interesting! It’s different here, indeed. Great tits and Blue tits normally don’t hybridize. There are reports, but they are rare. Great tits normally don’t hybridize with birds outside their genus.

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Neil Barker's avatar

Interesting research, Maja. I wonder if similar trends would happen here in Canada with Black-capped Chickadees and Boreal Chickadees. There would be some range overlap in those species in some locations and they are also in the Paridae family. Thank you for sharing.

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Maja Mielke's avatar

Hi Neil, indeed an interesting thought. I found a study reporting hybridization between these two species in Canada. But I don’t know whether they also raise each other’s chicks sometimes, and if so, whether this affects their mating preferences. Still so much to explore!

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