AVIS-IBIS

Birds of Indian Subcontinent

Preferential Allocation of Food by Magpies Pica pica to Great Spotted Cuckoo Clamator glandarius Chicks

Publication Type:Journal Article
Year of Publication:1995
Authors:Soler, M, Martínez, JGabriel, Soler, JJosé, MØLLER, ANDERSPAPE
Journal:Behavioral Ecology and Sociobiology
Volume:37
Issue:1
Date Published:1995
ISBN Number:03405443
Keywords:Clamator, Clamator glandarius, Corvidae, Cuculidae, Cuculus, Cuculus canorus, Pica, Pica pica
Abstract:Adult magpies Pica pica provide parasitic great spotted cuckoo Clamator glandarius nestlings with a diet very similar to that fed to their own chicks. In both naturally and experimentally parasitized nests, great spotted cuckoo chicks were fed at a higher rate than magpie chicks in the same nest. This preferential allocation of food by magpie parents to great spotted cuckoo chicks is consistent with the supernormal stimulus hypothesis, because this result implies that cuckoo chicks provide stronger stimuli for parental care than host chicks. Great spotted cuckoo chicks receive most of the food brought to the nest by the foster parents, because they exploit a series of stimuli which jointly (or sometimes individually) operate as a supernormal stimulus. This hypothesis predicts that if any stimulus is masked, the efficiency of the cuckoo in eliciting parental care will decrease. Here, we analyze experimentally the effects of two of these stimuli, preferential feeding of large nestlings and of nestlings with conspicuous palatal papillae. Firstly, when we experimentally introduced one medium-sized (7-9 days) cuckoo chick into an unparasitized magpie nest where the largest magpie chick was 12-15 days old, the cuckoo did not receive significantly more food than the average or the largest magpie chick. Secondly, when unparasitized nests were experimentally parasitized with a cuckoo chick that had its gape painted to mimic that of magpie chicks, the parasitic cuckoo received less food than the average magpie chick.
URL:http://www.jstor.org/stable/4601099
Short Title:Behavioral Ecology and Sociobiology
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