生态学课件J资料.pptVIP

Predation can be defined as the consumption of all or part of another individual (the prey). This wide definition thus encompasses: (I)’true predators’, which kill their prey soon after attacking them; (ii) grazers, which consume only part of a prey individual; (iii)parasites, which live in very close association with a single prey individual (the host), often inside the host’s tissues. Key Notes Defining predation J1 THE NATUES OF PREDATION 肉食者和 草食者 捕食者可以划分为（i）消费植物组织的草食者，（ii）摄食动物组织的肉食者和（iii）既摄食植物组织也摄食动物组织的杂食者。动物、植物食性的差异需要不同的生理和行为适应，从而导致肉食者与草食者世系之间反复的进行分歧。 泛化种和 特化种 捕食者随其摄取猎物的数量多少而变化，某些捕食者是特化种，而另一些是泛化种。一般来说，寄生者比典型捕食者更为特化、而草食者比肉食者更为特化。 健壮的肉食者 新西兰美利诺羊 Predators can be categorized as (i) herbivores which consume plant tissue, (ii) carnivores which food in animal tissue and (iii) omnivores which feed on both. The difference between animals and plants as prey types required different physiological and behavioral adaptations, and has lead to repeated evolutionary divergence between carnivorous and herbivorous lineages. Carnivores and herbivores Predators vary in the number of species of prey they will feed on, with some species being specialists, whilst others are more generalist. Generally, parasites tend to be more specialist than true predators and herbivores tend to be more specialist than carnivores. Generalists and specialists 捕食者对猎物 种群大小的 影响 捕食者和寄生者是否能够调节其猎物种群的大小呢？这一问题并不像看上去的那么简单。有两种主要观点：（i）任一捕食者的作用，只占猎物种总死亡率的很小一部分，因此去除捕食者对猎物种仅有微弱效果；（ii）捕食者只是杀死了对象种中即将死亡的个体，所以最终对猎物种群大小没有影响。然而，在一些例子中确有明显证据表明捕食者对猎物数量有重要影响。 猎物呢？ Do predators and parasites regulate the population size of their prey? This is not as simple q question as it may appear. There are two main issues: (I) the effect of any one predator may only be a small component of the total mortality causes affecting a prey species, so removal of the predator will have only a minor effect; (ii) predation may kill animals which were going to die anyway, so there will be no impact on the final prey population size. However