单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,J1,捕食的性质,要 点,捕食的定义,捕食可定义为摄取其他个体猎物的全部或局部为食这一广泛的定义包括i典型的捕食者，在袭击猎物后迅速杀死而食之；ii草食者，只消费对象个体的一局部；iii寄生者，与单一对象个体寄生有密切关系，通常生活在寄主的组织中捕食,一个物种的成员以另一物种成员为食,被捕食者常常被杀死.,狭义捕食:动物吃动物,广义捕食那么包括动物以植物为食的现象植食以及茅膏菜、捕蝇草、瓶子草、猪笼草和狸藻等少数植物捕捉昆虫将其消化以吸取含氮物质的情况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,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,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,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,in a number of cases there is clear evidence that predators have a considerable impact on prey numbers.,The impact of predators on prey population size,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局部，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说明捕食者对猎物数量有重要影响猎物呢？,The Lotka_Volterra predator-prey model is a simple mathematical model representing the interaction between predators and their prey.It makes three simplifying assumptions:(i)there is only one predator and one prey species involved in the interaction;(ii)prey numbers increase if the number of predators falls below a threshold and decrease if there are more predators;and(iii)predator numbers increase if the number of prey rises above a threshold and decrease if there are fewer prey.This simple model makes an interesting prediction:predator and prey populations will tend to cycle,as is observed in natural predator-prey dynamics.,Lotka-Volterra predator-prey model,Lotka-Volerra,捕食者,-,猎,物模型,Lotka-Volterra捕食者-猎物模型是描述捕食者与猎物间相互关系的一个简单的数学模型。
这一模型做了三个简单化假设：i相互关系中仅有一种捕食者与一种猎物；ii如果捕食者数量下降到某一阈值以下，猎物数量就上升，而捕食者数量如果增多，猎物种数量就下降和iii如果猎物数量上升到某一阈值，捕食者数量就增多，而猎物种数量如果很少，捕食者数量就下降这一简单的模型做了一个有趣的预测：捕食者和猎物种群动态会发生循环，就像在自然的捕食者-猎物种群动态中所观察到的那样Related topics,Natality,mortality and population Predator behavior and prey,growth (H2)response (J2),Population dynamics fluctuations,The nature of parasitism (K1),cycles and chaos (H4)The dynamics of parasitism K2),相关主题,出生率、死亡率和种群增长H2,种群动态波动、周期和混沌H4,捕食行为和猎物反响J2,寄生的性质K1 寄生的动态K2,Given a choice between two potential prey types,a predator which is optimizing its effort should choose the most profitable prey.Evidence from common shore crabs and pied wagtails demonstrates that prey of a size which return the greatest energy reward per unit time are preferred over smaller and larger individuals.,Key Notes,Profitability of prey,J2,P,RED ATOR BEHAVIOR AND,PREY RESPNSE,J2 捕食行为和猎物反响,要 点,猎物收益率,面对两种类型猎物的选择时，捕食者要获得最佳捕获努力，就应该选择收益最大的猎物。
真蟹和白脊 令 的证据表明捕食者优先选择能使其在单位时间内获得最大能量的一定大小的猎物，而不是比该体积更大或更小的猎物鸟,鸟,Predators may alter or switch their preference for a particular prey species depending on the abundance of that species,When this occurs,common prey are consumed super proportionately whilst less common prey are largely ignored.,Switching between prey types,猎物转换,依据猎物种数量的多少，捕食者有时会转换其选择而捕食某一特定的猎物种这时捕食者主要捕食优势种猎物而大大忽略其他猎物It is generally expected that at high densities of prey,a predators consumption rate will increase and then flatten out as prey saturation occurs,this relationship is termed the functional response and may adopt different patterns,which can be stereotyped into three classes:functional responses I,II and III.,The effect of prey density functional responses,猎物密度影响,功能反响,一般认为在高猎物密度下，捕食者的摄食率会增加，然后随猎物饱和到达最大速度。
这种关系称为功能反响，可能采用多种模式，传统上分为三种类型：功能反响I、II和IIITo obtain food,a predator must first search for its prey and then handle(catch,process and eat)it.Diet width can be regarded as being determined by a balance between a generalist strategy of searching for a wide variey of prey(relatively easy)and a specialist strategy of searching for one type of prey and handling that very efficiently.Optimal foraging theory assumes that evolution will have optimized predator behavior to maximize the rate of energy gain and makes predictions about how we should expect pre。