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Updated: Jun 5, 2026

Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients
Published on: August 22, 2018
Age and reproduction in birds - hypotheses and tests
1Pär Forslund is at the Dept of Zoology, University of Trondheim, N-7055 Dragvoll, Norway.
Abstract:
It is well known that reproductive performance improves with age in birds. Many hypotheses, involving factors such as differential survival, delayed breeding, breeding experience, foraging ability and reproductive effort, have been proposed to explain this pattern. Although these hypotheses are not mutually exclusive, they can be classified in three major groups relating to progressive appearance or disappearance of phenotypes, age-related improvements of competence, and optimization of reproductive effort. However, a closer examination of the literature reveals that only few studies have rigorously tested the hypotheses. Future work should focus on carefully designed tests that critically investigate the hypotheses.
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