Journal ArticleDOI
Recognition Errors and Probability of Parasitism Determine Whether Reed Warblers Should Accept or Reject Mimetic Cuckoo Eggs
TLDR
It is shown that below a threshold of 19-41% parasitism, the warblers should accept mimetic cuckoo eggs because the costs of rejection outweigh the benefits, whereas above this threshold they should reject.Abstract:
Reed warblers sometimes make recognition errors when faced with a mimetic cuckoo egg in their nest and reject one or more of their own eggs rather than the foreign egg. Using the framework of signal detection theory, we analyse responses to model eggs to quantify the costs and benefits of acceptance versus rejection in parasitized and unparasitized nests. We show that below a threshold of 19-41% parasitism, the warblers should accept mimetic cuckoo eggs because the costs of rejection outweigh the benefits, whereas above this threshold they should reject. The warblers behaved as predicted; when they saw a cuckoo at their nest they usually showed rejection, but without the sight of the cuckoo they behaved appropriately for the average parasitism rate in Britain (6%) and tended to accept.read more
Citations
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Journal ArticleDOI
The evolution of egg colour and patterning in birds
TL;DR: A critical review of the literature is presented which, when combined with the results of some comparative analyses, suggests that just a few selective agents can explain much of the variation in egg appearance.
Journal ArticleDOI
Escalation of a coevolutionary arms race through host rejection of brood parasitic young
TL;DR: It is shown that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle and is suggested that it has selected for the evolution of nestling mimicry in bronze-cuckoos.
Journal ArticleDOI
Egg recognition and counting reduce costs of avian conspecific brood parasitism
TL;DR: Clutch size comparisons revealed that females combine egg recognition and counting to make clutch size decisions—by counting their own eggs, while ignoring distinctive parasitic eggs, females avoid a maladaptive clutch size reduction.
Journal ArticleDOI
Spatial patterns in species distributions reveal biodiversity change
Robert J. Wilson,Robert J. Wilson,Chris D. Thomas,Chris D. Thomas,Richard Fox,David B. Roy,William E. Kunin +6 more
TL;DR: It is shown that declines and increases can be deduced from current species distributions alone, using spatial patterns of occupancy combined with distribution size, and this link between current distribution patterns and processes of distribution change could be used to assess relative levels of threat facing different species.
Journal ArticleDOI
Cuckoo adaptations: trickery and tuning
TL;DR: The twin hurdles of effective trickery in the face of evolving host defences and difficulties of tuning into another species' life history may together explain why obligate brood parasitism is relatively rare.
References
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Book
Signal detection theory and psychophysics
David M. Green,John A. Swets +1 more
TL;DR: This book discusses statistical decision theory and sensory processes in signal detection theory and psychophysics and describes how these processes affect decision-making.
Journal ArticleDOI
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Richard Dawkins,John R. Krebs +1 more
TL;DR: The arms race concept is suggested to help to resolve three long-standing questions in evolutionary theory: one lineage may drive the other to extinction, one may reach an optimum, thereby preventing the other from doing so, and both sides may reach a mutual local optimum.
Journal ArticleDOI
A Model System for Coevolution: Avian Brood Parasitism
TL;DR: Systems in which the interacting species are few (optimally only two) provide the clearest examples of coevolution, which includes many mutualistic relationships and some parasite-host associations.
A model system of coevolution: avian brood parasitism.
TL;DR: A rigorous definition of coevolution requires that a trait in one species has evolved in response to a trait of another species, which trait was itself evolved by the first species as discussed by the authors.
Journal ArticleDOI
Cuckoos versus reed warblers: Adaptations and counteradaptations
TL;DR: Reed warblers did not discriminate against unlike chicks (another species) and did not favour either a cuckoo chick or their own chicks when these were placed in two nests side by side and experiments showed that host discrimination selects for egg mimicry by cuckoos.