Friday, 14 April 2017

Leucistic American Robin (Merle d'Amérique) in Waterloo

     American Robin Turdus migratorius seems to be more prone than other birds to the condition known as leucism, a condition where there is a partial loss of pigmentation, resulting in white, pale or patchy colouration of the feathers, but not the eyes. I have seen leucistic robins fairly frequently and have blogged about this phenomenon before
     Recently, Mary Voisin located a leucistic bird in her neighbourhood and let us all know about it. Franc Gorenc captured these two photographs of the bird.





     As you can see this bird has very substantial loss of regular colour.
     Based purely on observation and without applying scientific rigour it seems to me that these birds do not seem disadvantaged in any way, as might be the case with an albino bird, for example. It begs the question, however, whether they are more visible to predators, and are thereby in greater danger of capture.
     I was curious about the following bird which I saw the other day, which has two small white patches on its back.



     I am assuming that is leucism to a very minor degree but it verges on serendipitous that the spots would be geometrically arranged in this way.
     Leucism certainly compels us to examine American Robins closely for interesting variations in plumage.

21 comments:

  1. Wow,what a fantastic find,lovely to sse.
    john.

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  2. Beautiful Robin, I found a white headed Robin where I was living. Fabulous photos David.

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  3. Hi David, what an interesting post, something I have never heard of previously. Do the birds still mate and if so does the condition pass on. All the best to you both. John

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    1. I forgot to use the reply button so my reply is down below, John.

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  4. Hello David,
    Fantastic specimen, very good meeting. Thank you for this sharing and your beautifull pictures.

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  5. Hi John: My understanding is that the condition results from a recessive allele and is heritable. The reproductive system is not affected and the birds are completely fertile. However, since colour plays such an important role in mating leucistic birds may have trouble securing a mate.

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    1. Hi David and thank you for the reply, that was my thought as to finding a mate would not be easy, all the best to you both John

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  6. That looks weird. We saw a leucistic crow a couple of months ago, for a few seconds I had no idea what we were looking at!

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  7. Wow. Although the color is missing, the bird is great looking. We in Finland has shown only domesticated doves as a rule, variations of color.

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  8. Sin duda en la última foto ese ave tiene leucismo en un pequeño grado. En España el ave más propensa al leucismo es el Mirlo común (Turdus merula) curiosamente es un primo del American Robin Turdus migratorius. Me ha gustado mucho este artículo David, enhorabuena amigo mío. Un fuerte abrazo desde España.

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    1. That is really interesting. Perhaps the Turdus thrushes are especially prone to leucism for some reason.

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  9. Hi David.

    Wonderful that American Robin.
    The other bird is beautiful.

    Groettie from Patricia.

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  10. Hi David. Germán has raised an interesting point as it seems to be Blackbird that I notice leucism in most in these parts. I did once come across a family of Carrion Crow in Yorkshire where one adult and all three juveniles exhibited significant degrees of leucism, particularly in the wings, again indicating the hereditory aspects of this - although it wouldn't rule out dietry factors.

    Your leucistic American Robin has a strange beauty about it - a delightful bird.

    Love to you both - - - Richard

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  11. Hi David, very interesting photos. I have heard of this condition but have never seen it yet. It looks a pretty little bird but not good camouflage I expect.

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  12. Very interesting pattern of leucism in the bird. I had never seen leucism in the genus Turdus, although I saw a few birds with that kind of chromatic aberration, I have uploaded them in a section on my blog Aves Bonaerenses, including a so-called carotenism.

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  13. I have to say I think this bird look quite pretty despite not being its true colour. Strange how these things come about. I would never have been able to identify it I must say!! Have a great weekend Diane

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  14. Great photos of an unusual but beautiful bird!

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  15. Very special to see this American red breast with its few pigments. These are places of interest. Here in the Netherlands we had a white-headed blackbird. Unfortunately, I did not photograph them.
    I have loved these special pictures David :-)

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  16. What fantastic colouring, lovely photographs.

    All the best Jan

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  17. What a lovely and unusual bird, you must have been thrilled with these pics :)

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