Pär Forslund is at the Dept of Zoology, University of Trondheim, N-7055 Dragvoll, Norway.
Trends Ecol Evol. 1995 Sep;10(9):374-8. doi: 10.1016/s0169-5347(00)89141-7.
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.
众所周知，鸟类的繁殖性能会随着年龄的增长而提高。为了解释这种模式，人们提出了许多假说，涉及到诸如生存差异、延迟繁殖、繁殖经验、觅食能力和繁殖投入等因素。尽管这些假说并非互斥，但它们可以分为三大类，与表现型的逐渐出现或消失、与能力相关的年龄增长、以及繁殖投入的优化有关。然而，对文献的更仔细研究表明，只有少数研究严格检验了这些假说。未来的工作应集中在精心设计的测试上，以批判性地研究这些假说。
