Species InteractionHow Many Species Do

You Interact With Everyday?

Species Interaction In nature, species interact all of the time. Sometimes, their interactions can benefit both

species, other times those interactions can cause harm.

Interaction between species forms the structure of communities and ecosystems.

Scientists use the word NICHE to describe the role each organisms plays in an ecosystem.

A niche is impacted by tolerance - ability to survive under changing conditions

A niche is impacted by competition.

Niche vs. Habitat

A species niche is how it acts in its environment. For example, where it lives, how it interacts with other species, and how it moves through each day.

A species’ habitat is just where it lives. Habitats provide organisms with all of the resources they need to survive. It is simply a location. How a species acts inside its habitat is part of its niche.

Ways in Which Species Interact

There are three major types of species interactions that have been identified by scientists:

1. Competition2. Predator-Prey Relationships3. Symbiotic Relationships

1. Parasitism2. Mutualism3. Commensalism

CompetitionCompetition occurs when

individuals or populations attempt to use the same limited resources. It can occur within the same species or with other species.

Indirect competition occurs when species don’t even come in contact with one another. Perhaps feeding on the same plant in the day and the night.

Direct competition occurs when species invade each others niches. The more dominant species will prevail and have better access to the resource.

The two bison pictured are competing for territory, food,

and possibly a mate.

Predator – Prey RelationshipsThe predator hunts and

the prey is hunted. Some predators only eat

certain types of prey, such as the lynx pictured to the right.

Organisms have developed adaptations to make them better predators and/or to enable them to hide better from predators.

Some of those adaptations include camouflage, warning coloration, mimicry, protective covering, etc.

The lynx is preying upon the snowshoe hare, one of the only

things it eats. The snowshoe hare is colored white in the winter so it

is camouflaged in the snow.

Camouflage

Warning ColorationWatch cuttlefish video! Click Here!

Protective Covering

Mimicry

Symbiosis• When two organisms live in close association. • In the relationship at least one of the species benefits.

ParasitismMutualismCommensalism • Most organisms live in symbiosis with another

organism. Some may even evolve together. When that occurs it is called co-evolution. An example of co-evolution is when plants adapt to suit those insects that pollinate them AND the pollinators adapt with the plants.

ParasitismA parasite is an

organism that lives on another organism and feeds on it.

The parasite gets all of its nourishment from its host.

The host is generally harmed by the parasite.

Examples of parasites include ticks, fleas, tapeworms, leeches, and mistletoe.

A tick attached to human skin. The tick is the parasite and the human is

the host.

MutualismMutualism is a close

relationship between two species in which both benefit.

Humans have bacteria in the stomach that help to break down food that we eat. We benefit from them being there, and they survive on the food we eat.

During mutualism, each specie depends upon the other for survival.

Click on the picture to watch a video example of mutualism

between ants and acacia trees.

CommensalismA relationship between

species when one organism benefits and the other one is neither helped or hurt.

A great example of this occurs between sharks and a type of fish called a remora. Remoras attach themselves to sharks and feed on scraps from the shark’s meals. They also use the sharks as transportation.

Another example is when birds nest in trees. The trees are not hurt and they provide a habitat for birds.