How birds cooperate to defeat cuckoos

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Why help another when you can help yourself? Cooperation is very common in nearly all life, from genes and cells to humans and other animals. However understanding why can be difficult: being selfish seems more rewarding. In a new study published in Science, we investigated whether the evolution of cooperative breeding in birds could be linked to defending their nests.

Cooperative breeding is when three or more individuals contribute to the care of young. While this happens in many animals, it is the social system of approximately 9% of birds, and is particularly prevalent in sub-Saharan Africa and Australasia.

However, understanding why evolution drove such behaviour remains controversial. Some studies have linked its occurrence with variable and unpredictable environmental conditions, while others have linked it to stable and predictable conditions.

We thought it might have something to do with defending their nests against brood parasitism, a behaviour where other birds to raise your babies. Brood parasitism is most easily recognisable among cuckoo birds, who never build their own nest or raise their own offspring. Instead they lay their eggs in the nests of birds from other species, and leave the substantial task of raising their chick to the unsuspecting host.

 

Written By: William Feeney and Naomi Langmore
continue to source article at theconversation.com

9 COMMENTS

  1. God, that Wren is so beautiful!

    I’d be interested to know how the Cuckoo first adopted its strategy; does anyone here know? Is it known?

    If it is I should have learnt about it by now, or perhaps I did and have forgotten.

    It doubtless comes under the heading of extended phenotype.

    • In reply to #2 by Stafford Gordon:

      God, that Wren is so beautiful!

      I’d be interested to know how the Cuckoo first adopted its strategy; does anyone here know? Is it known?

      I don’t know, but ducks quite often lay eggs in other duck’s nests. Sometimes the host duck broods them. Other times it throws them out. There is an element of reciprocal support in this, in that where there is egg swapping and predation of nests occurs, there are survival benefits from not putting all your eggs in one basket (or nest).

      It would be possible for some progressive imbalance to produce a strain leading to speciation, where some individuals raised none of their own eggs, thus avoiding the work-load involved – and possibly going on to produce more eggs.

    • In reply to #2 by Stafford Gordon:

      >

      I’d be interested to know how the Cuckoo first adopted its strategy; does anyone here know? Is it known?

      Google “mafia hypothesis”

      It can’t answer your question but I think you’ll find it interesting.

      Chris

      • In reply to #6 by chris 116:

        In reply to #2 by Stafford Gordon:I’d be interested to know how the Cuckoo first adopted its strategy; does anyone here know? Is it known?Google “mafia hypothesis”It can’t answer your question but I think you’ll find it interesting.Chris

        Kleptoparasitism; I’d argue that that’s a human trait found in some national leaders; no names no pack drill, but lots of the poorer nations are run by kleptocrats. Saddam Hussein was one such.

        But of course he was making “intellectual” choices, not ones stemming from instincts; although he was most probably insane.

        I remember R D saying that it was a shame they didn’t preserve his brain for analysis.

        Anyway, it would seem that it’s not yet fully understood precisely what environmental pressures caused the cuckoo to behave as it does.

        Thanks for the heads up on the Google search.

        S G

  2. @OP – However understanding why can be difficult: being selfish seems more rewarding. In a new study published in Science, we investigated whether the evolution of cooperative breeding in birds could be linked to defending their nests.

    I saw a fascinating David Attenborough programme on the Arctic, where a colony Arctic Terns attacked and drove off a Polar Bear by pecking its nose (drawing blood) until it gave up and went away from their nests.

    Interestingly an Eider Duck had made its nest in the middle of the Tern colony where the Terns ignored it, but it gained protection from the bear, because of the Terns defensive attacks to protect their own nests.

  3. In reply to #3 by Alan4discussion:

    One duck has already gone down that path. The black-headed duck, a.k.a. the cuckoo duck, has lost the ability to build nests and all of its broody bits. It paratatasizes other species, leaving bright white eggs amongst speckled brown ones in well lit nests.

    Unlike cuckoos, there doesn’t appear to be much, if any, cost to the host. If they hatch in the morning, they leave the same evening , without having scrounged a single meal.

    Chris

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