The Nature Item referred to in
http://www.smh.com.au/text/articles/2003/03/13/1047431151091.htm is
accessible at:
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v422/
n6928/abs/nature01460_fs.html
Those interested in accessing the article can email the lead author
13 March 2003
Nature 422, 157 - 160 (2003); doi:10.1038/nature01460
Escalation of a coevolutionary arms race through host rejection of
brood parasitic young
NAOMI E. LANGMORE*, SARAH HUNT† & REBECCA M. KILNER‡
* School of Botany and Zoology, Australian National University,
Canberra, Australian Capital Territory 0200, Australia
† School of Biological Sciences, University of Bristol, Woodland Road,
Clifton, Bristol, BS8 1UG, UK
‡ Department of Zoology, University of Cambridge, Downing Street,
Cambridge, CB2 3EJ, UK
Correspondence and requests for materials should be addressed to N.E.L.
(e-mail:
Cuckoo nestlings that evict all other young from the nest soon after
hatching impose a high reproductive cost on their hosts. In defence,
hosts have coevolved strategies to prevent brood parasitism.
Puzzlingly, they do not extend beyond the egg stage. Thus, hosts adept
at recognizing foreign eggs remain vulnerable to exploitation by cuckoo
nestlings. 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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