Department of Systematic Zoology, Institute of Environmental Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland.
Department of Evolution and Ecology and Center of Population Biology, University of California, One Shields Avenue, Davis, CA 95616, USA.
Philos Trans R Soc Lond B Biol Sci. 2021 Dec 6;376(1839):20200375. doi: 10.1098/rstb.2020.0375. Epub 2021 Oct 18.
Many plant species worldwide are dispersed by scatter-hoarding granivores: animals that hide seeds in numerous, small caches for future consumption. Yet, the evolution of scatter-hoarding is difficult to explain because undefended caches are at high risk of pilferage. Previous models have attempted to solve this problem by giving cache owners large advantages in cache recovery, by kin selection, or by introducing reciprocal pilferage of 'shared' seed resources. However, the role of environmental variability has been so far overlooked in this context. One important form of such variability is masting, which is displayed by many plant species dispersed by scatterhoarders. We use a mathematical model to investigate the influence of masting on the evolution of scatter-hoarding. The model accounts for periodically varying annual seed fall, caching and pilfering behaviour, and the demography of scatterhoarders. The parameter values are based mostly on research on European beech () and yellow-necked mice (). Starvation of scatterhoarders between mast years decreases the population density that enters masting events, which leads to reduced seed pilferage. Satiation of scatterhoarders during mast events lowers the reproductive cost of caching (i.e. the cost of caching for the future rather than using seeds for current reproduction). These reductions promote the evolution of scatter-hoarding behaviour especially when interannual variation in seed fall and the period between masting events are large. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'.
这些动物会将种子藏在许多小的贮藏处，以备将来食用。然而，散布贮藏的进化很难解释，因为未受保护的贮藏处很容易被盗。以前的模型试图通过给予藏主在藏食回收方面的巨大优势，通过亲缘选择，或者通过引入对“共享”种子资源的互惠性盗窃来解决这个问题。然而，到目前为止，在这种情况下，环境变异性的作用一直被忽视。这种变异性的一个重要形式是结实性，它是由许多由散布贮藏者传播的植物物种表现出来的。我们使用一个数学模型来研究结实性对散布贮藏进化的影响。该模型考虑了周期性变化的年度种子雨、贮藏和盗窃行为，以及散布贮藏者的种群动态。参数值主要基于对欧洲山毛榉（）和黄颈鼠（）的研究。在结实年份之间，散布贮藏者的饥饿会降低进入结实事件的种群密度，从而减少种子盗窃。在结实事件期间，散布贮藏者的饱食会降低贮藏的生殖成本（即，为未来而不是为当前繁殖而贮藏种子的成本）。这些减少促进了散布贮藏行为的进化，特别是当种子雨和结实事件之间的年际变化较大时。本文是主题为“植物中同步种子生产的生态学和进化”的一部分。
