动物行为研究的新进展(十):栖息地选择

New advance on study of animal behavior(X):habitat selection

概要介绍了栖息地对动物生存的重要性、动物对栖息地的选择行为、散布和迁移的原因,以及迁移行为的起源和进化史。动物最喜欢的栖息地应当是那些能使其生殖成功率达到最大的栖息地。Steve Fretwell利用博弈论提出了理想自由分布理论,该理论可使行为学家能够预测,当动物必须在两个质量不同的栖息地之间进行选择的时候应该怎么做。理想自由分布可以导致在质量不同的栖息地内定居的个体其适合度是大体相同的。很多动物年轻个体的散布可以减少近亲交配的机会,而近亲交配通常会对适合度产生负面影响。当两个近缘个体交配时,它们所产生的后代更有可能携带有害的等位隐形基因,这常常会导致近缘交配者后代的适合度明显下降。短距离迁移是先于长距离迁移的。也就是说,长距离迁移鸟类,很可能是起源于那些每年迁移距离比较短的鸟类。迁移物种起源于热带地区的非迁移祖先。

I briefly introduce the importance of habitat to animals and animals＇ habitat selection behavior, the reason of animal dispersal and migration, the origin and evolution history of animals＇ migration. An animal＇ s preferred habitat to be the one where its breeding success is the greatest. Steve Fretwell used game theory to develop ideal free distribution theory. This theory enables behaviorist to predict what animals should do when they choose between alternative habitats of different quality. The ideal free distribution lead to the fitness of animals in choose superior habitat or in lower-ranked habitat is consistent. Dispersal by juvenile animals reduces the chance of inbreeding, which often affects fitness negatively. When two closely related individuals mate, the offspring they produce are more likely to carry damaging recessive alleles in a double dose than the offspring produced by unrelated individuals. Migration typically involves movement away from and subsequent return to the same location on an annual basis migration apparently also occurred in some extinct dinosaurs and is seen today in many mammals, fishes, sea turtles, and even some insects. Short-range migration preceded long-distance migration. Thus, long-distance migrants are probably descended from species that moves far less on an annual basis. Migratory species evolved from tropical non-migratory ancestors.