Populations In Ecosystems: - Predation

- Predation - 

Predation

A predator is an organism that feeds on another organism known as their prey.

Predation

→ Occurs when one organism is consumed by another. Evidence of predation and prey in the laboratory does not reflect what happens in the wild. At the same time the it's difficult to obtain reliable data on natural populations as it's not possible to count all of the individuals in the population. Size can only be estimated.

Effect of predator-prey relationship on population size:

The relationship between predators & their prey, it's effects on the population is shown in steps as followed:

→ Predator eat their prey, prey population decreases.

→ Fewer prey available predators in greater competition with each other for the other prey.

→ Predator population then decreases as some are unable to obtain enough prey either survival or for them to reproduce.

→ The prey population increases as they are not being hunted for.

→ More prey available for food.

→ Predator population in turn increases.

These periodic population crashes are important in evolution as there is a selection pressure // means that those individuals who are able to escape predators or withstand diseases or adverse climate change are more likely to survive and reproduce.


An example of this would be: the Canadian lynx and the snowshoe hare:

There has been long observation of the population of snowshoe hare, and it is shown that there is fluctuations in cycles. It can be said that various factors caused the fluctuations i.e the predator Canadian lynx also plays a part in this as well as the availability of food and other sources.