AVIS-IBIS

Birds of Indian Subcontinent

The Evolutionary Triad of Microbes, Fruits, and Seed Dispersers: An Experiment in Fruit Choice by Cedar Waxwings, Bombycilla cedrorum

Publication Type:Journal Article
Year of Publication:1990
Authors:Buchholz, R, Levey, DJ
Journal:Oikos
Volume:59
Issue:2
Date Published:1990
ISBN Number:00301299
Keywords:Bombycilla, Bombycilla cedrorum, Bombycilla garrulus, Bombycillidae
Abstract:Microbes that infect fruit are hypothesized to make fruits unattractive to vertebrate seed dispersers as a mechanism to avoid their own consumption. We tested this hypothesis by presenting captive cedar waxwings (Bombycilla cedrorum) with pair-wise choices between infected and uninfected fruits of five species. As predicted, the birds displayed a strong preference for the uninfected fruits. Not only did they initially pick up uninfected before infected fruits, but they dropped significantly more infected fruits. These two levels of discrimination between the infected and uninfected fruits suggest that cedar waxwings use both visual and gustatory cues to detect decayed fruit. Microbial infection of fruits clearly decreases fruit attractiveness to dispersers. However, fruit defenses against infection are thought to have a similar effect. Thus, the interactions between dispersers, fruiting plants and microbes are not independent; selective forces on seed dispersal traits that are generated by one type of frugivore (microbes or seed dispersers) may dampen the evolutionary effects of the other type of frugivore.
URL:http://www.jstor.org/stable/3545535
Short Title:Oikos
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