predation Flashcards
define predation
the consumption of one organism by another in which the prey is alive and attacked by the predatory
how doesw predation demonstrate exploitation
one organism benefits by feeding on and directly harming another
what are the taxanomic classifications of predators
1) carnivores
2) herbivores
3) omnivores
what are the functional classifications of predators
1) true predators
2) grazers
3) parasitoids
4) parasites
what is a true predator
individuals which kill prey immedielty after an attack and may kill and consume different prey types
what are grazers
individuals which attack large amounts of prey but only remove a part of each prey individual
they are harmful but rarley lethal
what are parasites
individuals which consume parts of their prey which causes harm but is rarley lethal in the short term- only has a few hosts in a life tyime
what is a parasitoid
a group of insects where free living adults lay eggs in or on other insects and the larvae live within the host until they emerge and destory it
outline some characteristics of true predators
- broad diet
- may forage in search of food
- others sit and wait then strike
outline how some true predator diets may differ as a result of the abundance of a prey species
some species when faced with two kinds of prey go for the prey which is most abundant causing them to often switch bewteen prey type
why might a true predator switch from one prey to another
- forms a search imagae of the most common type of prey and orientates towards that prey
- learning enables increased efficiency at capture
what are some traits of herbivores
- mostly small insects
- mostly specialsied to one plant part
- narrow range of plant species
outline how predation is an arms race
within a few million years of the presence of predators, prey evolved defences due to selection pressures, as a result predators must evolve to overcome the defences
how have plant prey species evolved to avoid predation
1) avoidance
2) tolerance
3) defences
what is avoidance
where plants have evloved to avoid predators such as by producing large amounts of seeds or hiding
what is tolerance
where plants have evloved to compensate as a result of predatino such as the removal of tissue stimulating new growth
what are defences
plants have evolved an array of structural defences such as spines and thorns or the production of secondary compunds
what are the two induced defences produced by the tobbacco plant
1) toxic secondary compounds which directly deter herbivores
2) compounds which indireclty deter by attarcting predators
outline some ways predators may over come evolved defences shown by prey
1) subdue with poisions
2) mimcry to avoid presence being known
3) tolerance for chemical defences
what is a saprotroph
an organisms which makes use of dead organic matter and dont control the rate of availability of resources
what are the two types of saprotroph
1) decomposers
2) detrivores
what is a decomposer
individuals which break down dead matter e.g. plants or animal waste and release energy and mineral nutrents
what are detrivores
individuals which consume dead matter