Interactions within a Community

The five main types are:

Predation

Competition

Parasitism

Mutualism

Commensalism

PREDATION

In predation, one individual, the predator, captures, kills, and consumes another individual, the prey.

Predators, Prey, and Natural Selection

Natural Selection favors adaptations that improve a predator‘s efficiency at finding, capturing, and consuming prey.

These adaptations include a shark’s jaws, a scorpion’s claws and stinger, and a spider’s web and fangs

Prey-predation interaction

A

The cycles of increase and decrease reflects a predator –prey intercation

e.g lions feeding on impalas, lynx feeding on rabbits

Prey population reaches higher density than predator population

Portion A = geometric phase- rapid increas of prey, predator pop too low to hinder increase

More prey means more food for predators and the population increases

More predators = increase in mortality of prey

Less prey could cause predators to emigrate / die , hence prey population can increase again

Graph interpretation

Competition

Competition occurs when organisms in the same community seek the same limiting resource. This resource may be prey, water, light, nutrients, nest sites, etc.

Competition among members of the same species is intraspecific.

Competition among individuals of different species is interspecific.

Intraspecific Competition

Competition between organisms of the

same species

Interspecific Competition

Panthera leo

Crocuta crocuta

Competition between

organisms of the different

species