Species Interactions and Their Types

Species interactions

Interactions that occur between two different populations that live in the same area.

Intraspecific interactions

Interactions that occur between individuals of the same species.

Interspecific interactions

Interactions that occur between individuals of different species.

Competition

An interaction between two or more species in which both organisms rely and compete for the same resource(s) and are harmed to some extent.

Intraspecific competition

Competition among individuals of the same species, for example, multiple bidders on eBay driving the cost of an item higher.

Interspecific competition

Competition between individuals of different species, for example, zebras and gazelles grazing on the same grassland.

Exploitation competition

Individuals compete indirectly through the consumption of a common limited resource, with each obtaining as much as it can.

Interference competition

Individuals interact directly with one another by physical force or intimidation.

Predation

An interaction where the action of the predator results in the death of its prey.

Herbivory

An interaction where herbivores feed on plants, having a positive effect for herbivores and a negative effect for plants.

Parasitism

An interaction where one species benefits at the expense of another, often harming the host.

Mutualism

An interaction where both species benefit from the relationship.

Commensalism

An interaction where one species benefits while the other is neither helped nor harmed.

Amensalism

An interaction where one species is harmed while the other is unaffected.

Limiting factors

Factors that can limit population growth such as resources and space.

Survival of the fittest

A concept that describes the process of natural selection where individuals better adapted to their environment tend to survive and reproduce.

Resources

Elements such as territory, prey, or food that are competed for by species.

Positive effect

An interaction that benefits one species.

Negative effect

An interaction that harms one species.

Neutral effect

An interaction that neither benefits nor harms either species.

Predation

Influences the fitness of both predators and prey.

Survival and Reproduction

Individuals must both feed and avoid being eaten to survive and reproduce.

Adaptation

Organisms have adapted to improve ability to survive and reproduce and will be passed on to its offspring.

Predator Traits

Predators exhibit traits such as sharp teeth, claws, and venom, that enhance their ability to catch food.

Prey Avoidance Strategies

Certain organisms have evolved strategies to avoid being the prey, including chemical defense, camouflage, displays of intimidation, mimicry, and armor and weaponry.

Mechanical Defenses

Plant examples include mechanical defenses such as thorns and spines, and various chemicals.

Herbivory

Herbivory is the consumption of plant material by animals (herbivores are animals that eat plants).

Herbivore Adaptations

To maximize nutrient intake, many herbivores have evolved adaptations that allow them to determine which plants contain fewer defensive compounds and more high-quality nutrients.

Chemical Sensors

Some insects, such as butterflies, have chemical sensors on their feet that allow them to taste the plant before they consume any part of it.

Parasitism

Involves an organism (called the parasite) that lives in, on, or with another organism (called the host) that directly or indirectly harms the host.

Parasite-Host Relationship

The parasite feeds off the host and benefits at the host's expense (host is harmed, but not lethal).

Duration of Parasitism

Many parasites inhabit their host for long periods of time, but do not normally kill it outright.

Examples of Parasitism

Example: a flea or tick on a dog.

Mutualism

Both species receive a benefit from the other.

Example of Mutualism

Example: bacteria in our intestines.

Commensalism

One species benefits and the other is unaffected (does not benefit nor harm).

Example of Commensalism

Example: barnacles on a whale.

Amensalism

One species is harmed and the other is unaffected (does not benefit nor harm).

Example of Amensalism

Example: humans causing animals to be harmed due to pollution, fires, etc., and elephants stepping on ants or leveling brush.