Strange Nest Behaviour of European Stone Curlews

This is the not the best selection of European Stone-Curlew images but I thought the birds’ behaviour sufficiently unusual to post them and see if anyone can shed light on it.

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We were driving alongside a peach grove on the Judaean Plain in central Israel when two stone-curlews suddenly appeared walking away from the vehicle. One of the birds then trotted back through the trees to a spot just by a peach stump and genuflected its thick knees and I immediately assumed it was a nest, where she may well resume brooding.

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Instead of that, however, she stabbed down (as I now know to puncture the egg; see above) and resumed an upright posture with the egg fixed in her bill tip, holding it only by its lower end. It was an oddly plain and pale egg for this species with patterning concentrated at the top end, but of a size and colour to match stone-curlew.

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Then the bird trotted off back the way it had come with yolk and clear white apparently spilling out of the hole. It then dropped it and stabbed it until there was a large hole all along one side (see top pic, where it is just visible at the front of the egg)

Pandemonium broke out in our car as we tried to get images. We left the birds one behind the other with what was assumed to be the female standing over a punctured stone-curlew egg. But what was happening here? Had we disturbed them close to a recently laid egg and she had therefore destroyed her own egg? Apparently stone-curlews are highly site faithful and return year in, year out to the same spot. It seems unlikely that another stone-curlew pair had laid in their territory and she was destroying the nest of usurpers. But some nests do contain eggs from multiple females.

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Was it therefore an old egg in the old nest that she was simply getting rid of in preparation for a re-nest? They apparently lay in April. A single egg is the common clutch size but we didn’t want to go and see if there were other eggs in the nest. There was little sense that this was an old addled egg. The white ran clear when it dribbled out the crack. Apologies that the images are not brilliant and the information is sketchy but if anyone can shed any light I would be fascinated to hear.

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6 Comments

  1. murray marr

     /  April 6, 2016

    I think this is called filial cannibalism:
    https://en.wikipedia.org/wiki/Filial_cannibalism
    Not a very useful comment however.

    Reply
  2. murray marr

     /  April 6, 2016

    http://www.ncbi.nlm.nih.gov/pubmed/18171171
    And then there’s this, but I don’t have enough bricks to the load to read much of it.
    Good luck.

    Reply
  3. mark cocker

     /  April 6, 2016

    thanks Murray, yes Amir Balaban a friend in Israel suggest that the parents are clearing out their nest of debris in preparation for a relay. Made sense to me. Presumably that is what filial cannibalism is about! Eating the calcium and protein in preparation for generating more living proteins.

    Reply
  4. David Garbutt

     /  November 29, 2016

    Is it a Kaiser Sose predator distraction strategy? At least the bird keeps the proteins and calcium?

    Reply
  5. Hello.This post was really fascinating, particularly because I was looking for thoughts on this
    subject last Monday.

    Reply

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