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Escalation of a coevolutionary arms race through host rejection of brood parasitic young


Cuckoo nestlings that evict all other young from the nest soon after hatching impose a high reproductive cost on their hosts1. In defence, hosts have coevolved strategies to prevent brood parasitism. Puzzlingly, they do not extend beyond the egg stage2,3,4,5. Thus, hosts adept at recognizing foreign eggs remain vulnerable to exploitation by cuckoo nestlings6,7. Here we show that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle. We found that defences used during the egg-laying period by host superb fairy-wrens (Malurus cyaneus) are easily evaded by the Horsfield's bronze-cuckoo (Chrysococcyx basalis), a specialist fairy-wren brood parasite. However, although hosts never deserted their own broods, they later abandoned 40% of nests containing a lone Horsfield's bronze-cuckoo nestling, and 100% of nests with a lone shining bronze-cuckoo nestling (Chrysococcyx lucidus), an occasional fairy-wren brood parasite. Our experiments demonstrate that host discrimination against evictor-cuckoo nestlings is possible, and suggest that it has selected for the evolution of nestling mimicry in bronze-cuckoos.

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Figure 1: Comparisons of Horsfield's bronze-cuckoo and fairy-wren eggs.
Figure 2: Kaplan–Meier estimate of the survival functions of Horsfield's bronze-cuckoo chicks, shining bronze-cuckoo chicks and lone superb fairy-wren chicks in superb fairy-wren nests.
Figure 3: Sonograms from begging calls recorded six days after hatching from a Horsfield's bronze-cuckoo chick (a), a brood of three superb fairy-wren chicks (b) and a shining bronze-cuckoo chick (c).

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  1. Davies, N. B. Cuckoos, Cowbirds and Other Cheats (Poyser, London, 2000)

    Google Scholar 

  2. Brooke, M. de L. & Davies, N. B. Egg mimicry by cuckoos Cuculus canorus in relation to discrimination by hosts. Nature 335, 630–632 (1988)

    Article  ADS  Google Scholar 

  3. Davies, N. B. & Brooke, M. de L. Cuckoos versus reed warblers: adaptations and counteradaptations. Anim. Behav. 36, 262–284 (1988)

    Article  Google Scholar 

  4. Lotem, A., Nakamura, H. & Zahavi, A. Constraints on egg discrimination and cuckoo host coevolution. Anim. Behav. 49, 1185–1209 (1995)

    Article  Google Scholar 

  5. Marchetti, K. Egg rejection in a passerine bird: size does matter. Anim. Behav. 59, 877–883 (2000)

    Article  CAS  Google Scholar 

  6. Lotem, A. Learning to recognize nestlings is maladaptive for cuckoo Cuculus canorus hosts. Nature 362, 743–745 (1993)

    Article  ADS  Google Scholar 

  7. Kilner, R. M., Noble, D. G. & Davies, N. B. Signals of need in parent–offspring communication and their exploitation by the common cuckoo. Nature 397, 667–672 (1999)

    Article  ADS  Google Scholar 

  8. Brooker, M. G. & Brooker, L. C. The comparative breeding behaviour of two sympatric cuckoos, Horsfield's bronze-cuckoo Chrysococcyx basalis and the shining bronze-cuckoo C. lucidus, in Western Australia: a new model for the evolution of egg morphology and host specificity in avian brood parasites. Ibis 131, 528–547 (1989)

    Article  Google Scholar 

  9. Mason, P. & Rothstein, S. I. Coevolution and avian brood parasitism: Cowbird eggs show evolutionary response to host discrimination. Evolution 40, 1207–1214 (1986)

    Article  Google Scholar 

  10. Krüger, O. & Davies, N. B. The evolution of cuckoo parasitism: a comparative analysis. Proc. R. Soc. Lond. B 269, 375–381 (2002)

    Article  Google Scholar 

  11. Davies, N. B. & Brooke, M. de L. An experimental study of co-evolution between the cuckoo, Cuculus canorus, and its hosts. II. Host egg markings, chick discrimination and general discussion. J. Anim. Ecol. 58, 225–236 (1989)

    Article  Google Scholar 

  12. Davies, N. B., Brooke, M. de L. & Kacelnik, A. Recognition errors and probability of parasitism determine whether reed warblers should accept or reject mimetic cuckoo eggs. Proc. R. Soc. Lond. B 263, 925–931 (1996)

    Article  ADS  Google Scholar 

  13. Lotem, A. & Nakamura, H. in Parasitic Birds and Their Hosts. Studies in Coevolution (eds Rothstein, S. I. & Robinson, S. K.) 223–235 (Oxford Univ. Press, Oxford, 1998)

    Google Scholar 

  14. Mulder, R. A. Evolutionary Ecology of the Mating System of Superb Fairy-wrens. PhD thesis, Australian National Univ. (1992)

    Google Scholar 

  15. Fraga, R. M. in Parasitic Birds and their Hosts. Studies in Coevolution (eds Rothstein, S. I. & Robinson, S. K.) 173–193 (Oxford Univ. Press, Oxford, 1998)

    Google Scholar 

  16. Lichtenstein, G. Low success of shiny cowbird chicks parasitizing rufous-bellied thrushes: chick-chick competition or parental discrimination? Anim. Behav. 61, 401–413 (2001)

    Article  Google Scholar 

  17. Payne, R. B., Woods, J. L. & Payne, L. L. Parental care in estrildid finches: experimental tests of a model of Vidua brood parasitism. Anim. Behav. 62, 473–483 (2001)

    Article  Google Scholar 

  18. Mulder, R. A., Dunn, P. O., Cockburn, A., Lazenby-Cohen, K. A. & Howell, M. J. Helpers liberate female fairy-wrens from constraints on extra-pair mate choice. Proc. R. Soc. Lond. B 255, 223–229 (1994)

    Article  ADS  Google Scholar 

  19. Payne, R. B. & Payne, L. L. in Parasitic Birds and their Hosts. Studies in Coevolution (eds Rothstein, S. I. & Robinson, S. K.) 152–169 (Oxford Univ. Press, Oxford, 1998)

    Google Scholar 

  20. Tidemann, S. C. The Behavioural Ecology of Three Coexisting Fairy-wrens (Maluridae: Malurus). PhD thesis, Australian National Univ. (1983)

    Google Scholar 

  21. Nias, R. C. Co-operative Breeding in the Superb Fairy-wren Malurus cyaneus. PhD thesis, Univ. New England (1987)

    Google Scholar 

  22. Rowley, I. & Russell, E. Fairy-wrens and Grasswrens (Oxford Univ. Press, Oxford, 1997)

    Google Scholar 

  23. Ogilvie, M. A. in Handbook of the Birds of Europe, the Middle East and North Africa, The Birds of the Western Palearctic Vol. VI (eds Cramp, S. & Brooks, D. J.) 193–212 (Oxford Univ. Press, Oxford, 1992)

    Google Scholar 

  24. Bibby, C. J. Some breeding statistics of Reed and Sedge Warblers. Bird Study 25, 207–222 (1978)

    Article  Google Scholar 

  25. Rowley, I. The life history of the superb blue wren Malurus cyaneus. Emu 64, 251–297 (1965)

    Article  Google Scholar 

  26. Brooker, M. G. & Brooker, L. C. Cuckoo hosts in Australia. Aust. Zool. Rev. 2, 1–67 (1989)

    Google Scholar 

  27. Cuthill, I. C., Bennett, A. T. D., Partridge, J. C. & Meier, E. J. Plumage reflectance and the objective assessment of avian sexual dichromatism. Am. Nat. 153, 183–200 (1999)

    Article  CAS  Google Scholar 

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N.E.L. was supported by an Australian Research Council Australian Postdoctoral Fellowship. R.M.K. was supported by a Royal Society Dorothy Hodgkin Research Fellowship and a Royal Society University Research Fellowship. Spectrophotometric equipment was purchased with a BBSRC grant. We thank Environment Australia for allowing us to work at Campbell Park; S. Butchart, A. Cockburn, N. Davies, M. Hall, G. Maurer, J. Madden, N. Macgregor and A. Peters for assistance in the field; A. Cockburn for statistical advice; and M. de la Brooke, A. Cockburn, N. Davies, R. Heinsohn, C. Hinde, A. Lotem, R. Magrath and S. Rothstein for comments on the manuscript.

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Correspondence to Naomi E. Langmore.

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Langmore, N., Hunt, S. & Kilner, R. Escalation of a coevolutionary arms race through host rejection of brood parasitic young. Nature 422, 157–160 (2003).

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