Friday, December 24, 2010

Yellow Holly Berries





 
These berries, belonging to the yellow cultivar of holly Ilex europaeus 'bacciflava', are the only berries left in my garden after weeks of freezing weather. All the scarlet holly berries disappeared within a week of the first snowfall, along with all the other red berries, but the birds have completely ignored these yellow fruits. As far as I can tell, they haven't eaten a single berry.

Birds' vision is much more sensitive to the red end of the spectrum (bird-pollinated flowers are almost always red) and it's tempting to speculate that these yellow fruits simply aren't visible to the blackbirds and thrushes that stripped all the other berries. But I'm sceptical about so simple an explanation. They quickly find and eat the blueberries that I try to grow in autumn, which reflect light at the short-wave blue end of the spectrum, and yellow berries are much closer to the red end of the spectrum. So maybe there's something else that makes yellow holly berries unappealing to birds, even when they are on the verge of starvation in a winter such as this.......... 

8 comments:

  1. Merry Christmas Phil to you and your family; and thanks for a most informative blog in 2010.
    All the best for 2011.

    The yellow berries? I think they all have a preference for red; then orange, and finally yellow. They'll be gone soon enough ;)

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  2. Now I know why my pomegranate fruits are beseiged by birds!But the parakeets left hardy anything for me of the corn I had planted. They knew exactly when the corn was fit for eating, although it was completely covered by its green covering. The corn itself was yellow.
    Happy Christmas!

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  3. Yes Phil, it's strange that these berries are being left. It would be interesting to know the reason for this.

    Just a short walk from our house, there's a lane bordered by hawthorn bushes - it's been lovely to see a flock of bullfinches come for the berries.

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  4. Merry Christmas and a Happy New Year.
    John.

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  5. Hope you had a great Christmas Keith. I've really enjoyed your posts in 2010 ... and your terrific photos

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  6. Season's Greetings lotusleaf!

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  7. Hi Lesley, there are still quite a lot of hawthorn berries along the lanes near us, although the fieldfares are polishing them off pretty quickly..

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  8. ... and a Merry Christmas to you too, John, and all the best for 2011

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