Yearsley Jonathan M, Villalba Juan J, Gordon Iain J, Kyriazakis Ilias, Speakman John R, Tolkamp Bert J, Illius Andrew W, Duncan Alan J
Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, United Kingdom.
Am Nat. 2006 May;167(5):705-16. doi: 10.1086/502805. Epub 2006 Mar 20.
Animals often face complex and changing food environments. While such environments are challenging, an animal should make an association between a food type and its properties (such as the presence of a nutrient or toxin). We use information theory concepts, such as mutual information, to establish a theory for the development of these associations. In this theory, associations are assumed to maximize the mutual information between foods and their consequences. We show that associations are invariably imperfect. An association's accuracy increases with the length of a feeding session and the relative frequency of a food type but decreases as time delay between consumption and postingestive consequence increases. Surprisingly, the accuracy of an association is independent of the number of additional food types in the environment. The rate of information transfer between novel foods and a forager depends on the forager's diet. In light of this theory, an animal's diet may have two competing goals: first, the provision of an appropriate balance of nutrients, and second, the ability to quickly and accurately learn the properties of novel foods. We discuss the ecological and behavioral implications of making associational errors and contrast the timescale and mechanisms of our theory with those of existing theory.
动物常常面临复杂多变的食物环境。尽管这样的环境具有挑战性，但动物应该能够将食物类型与其特性（如某种营养物质或毒素的存在）联系起来。我们运用信息论概念，如互信息，来建立关于这些联系形成的理论。在这个理论中，假设这些联系能使食物与其后果之间的互信息最大化。我们发现这些联系总是不完美的。一种联系的准确性会随着进食时段的时长以及某种食物类型的相对频率而增加，但会随着进食与摄入后后果之间的时间延迟增加而降低。令人惊讶的是，一种联系的准确性与环境中其他食物类型的数量无关。新食物与觅食者之间的信息传递速率取决于觅食者的饮食。根据这一理论，动物的饮食可能有两个相互竞争的目标：其一，提供营养物质的适当平衡；其二，能够快速准确地了解新食物的特性。我们讨论了产生关联错误的生态和行为影响，并将我们理论的时间尺度和机制与现有理论的进行了对比。
