在2014年5月17日的托福[微博]阅读考试中有这样一道题：栖息地选择。为大家普及一下关于栖息地选择的背景知识，这样有助于考生在面对这类题目时方便作答。

　　托福阅读真题再现：

　　版本一：一个叫Sale的科学家总结总结出了栖息地的寻找和选择是因为多种cue综合形成一个应激发应，他驳斥了固有模式的说法。举了一个鱼类实验的例子，然后还提到这种说法无法解释为何一种鸟会根据日照时间来选择栖息地，最后说这种模式目前还有待研究。

　　版本二： 第三篇讲动物靠什么选择栖息地 某理论说 动物感知器官收集信息然后反馈神经系统 后又说其他理论一个是找更多食物，另一个原因是躲避被捕食，最后说还需要进一步研究什么真正影响，更细节记不得了…

　　版本三：第三篇是选择栖息地。说有的是到了suitable的地方就停下，有的是先有mind然后再找什么的。其他的忘了〒_〒

　　解析：本文围绕动物如何选择栖息地这个主题展开论证。做题时需注意记录笔记，对于结构化阅读及最后一题的解答有很大好处。动物行为主题是托福阅读常见考点，结构不难理解。需注意各例证和主题的支撑关系。由于条理清晰，最后一题尽量考虑从正面选出，排除为辅。

　　托福阅读相关背景：

　　Habitat selection

　　Habitat selection is the process or behavior that an animal uses to select or choose a habitat in which to live; correspondingly, plants and fungi engage in habitat selection, even though their inherent mobility is different from animals. To live in a habitat an animal must first have access to the habitat. Once the animal has access to the habitat it must be able to tolerate the conditions of the habitat and find the resources that it needs to survive in that habitat. Animals must be able to tolerate at least two kinds of factors in the habitat. These factors are abiotic factors and biotic factors. Abiotic factors are non-biological factors such astemperature, humidity, salinity and pH to name a few. Biotic factors are biological factors such ascompetition, predation, and disease. If both abiotic and biotic factors can be tolerated the animal must also be able to find the resources that it needs to survive. These resources include food, shelter from abiotic and biotic factors, and a mate. If an animal can not tolerate abiotic and biotic factors in a habitat or if it does not find food, shelter or a mate in that habitat, it is likely that the habitat will not be selected and the animal will leave the habitat. Habitats that are suitable for animals will often times have many animals of the same species there. This can lead to intraspecific competition. All of these things have an impact on the ecology of the animal (its distribution and abundance)。

　　One way to determine if a habitat is suitable for an animal is to conduct a transplant experiment. In a transplant experiment animals of interest are transplanted or brought to a habitat to test that habitat for suitability. If the animal survives and reproduces in the habitat, it is concluded that the habitat was unoccupied because the animal was unable to get there or because it did not have access to the habitat. If the animal does not stay, survive, or reproduce in the habitat, it is concluded that it could be due to a lack of resources or because certain biotic and or abiotic factors are present and it can not tolerate them. A habitat that is suitable can become unsuitable if the animal's resources and or biotic and abitoic factors change. This is what often happens when we develop areas that are currently undeveloped. This causes us to see animals that we never saw in our environments before. It also can lead to a decline in the number of these animals。