EQ: How do organisms interact?

  

Classroom Unsquared

Rabbits reproduce often and in large numbers. How come they don’t quickly overpopulate an ecosystem?

http://en.wikipedia.org/wiki/Rabbit

http://veterinarylegacy.blogspot.com

One reason is that foxes or other predators will eat some of them. The fox is the predator and the rabbit the prey.

http://howtomakearabbithutch.com

Scarce resources in the environment that limit the size of a population are called limiting factors. Food, water, and living space are good examples. The largest size of a population is called the carrying capacity.

Another reason is that rabbits eat grasses, wildflowers, and shrubs. If there are too many rabbits, they will reduce the available food, and their population will shrink.

What are some ways, or adaptations, that prey use to avoid being eaten?

What are some adaptations made by predators to catch their prey?

Speed to escape predatorStay in groups

Can you think of a real example?

Example?

Ability to hide (camouflage)

Example?

Poisonous skin or biteWarning colors

Example?

Speed Example?

Good eyesight Example?

Ambush or hide

Example?

So what controls the fox population?

Coyotes often prey on the same organisms as the fox. Since these food resources are limited, the fox and the coyote will have less.

http://veterinarylegacy.blogspot.com

http://a-z-animals.com/animals/coyote/

This interaction is called competition. Can you think of other examples?

These busy honey bees are drinking nectar from a cactus flower. When they do, they get pollen on their bodies and then fly off to another cactus. How do the bee and the cactus benefit?

http://commons.wikimedia.org/wiki/File%3ACreation-Via-Pollination.jpgBy Jessie Eastland (Own work) The bees get food and the cactus reproduces

The bee and the cactus interact closely in this way for a long period of time. This interaction is an example of Symbiosis.

There are 3 different types of symbiotic relationships between species:

1. Mutualism – when both species benefit (like the bee and cactus)

2. Commensalism – when one species benefits while the other is not harmed. Which picture is commensalism?3. Parasitism – when one species benefits and the other is harmed. Which is parasitism?

http://commons.wikimedia.org/wiki/User:Nhobgood

http://blog.affinityhealth.org/wp-content/uploads/2011/06/tick1.jpg

Poisonous Sea Anemone and Clownfish

A Tick on Human Skin