Species Interactions and Ecological Relationships

Amensalism

A type of species interaction in which one species is harmed, and the other is unaffected.

Batesian mimicry

The convergence in appearance of an edible species (mimic) with an unpalatable species (model).

Carnivory

An act of predation in which the predator and prey are both animals.

Commensalism

A type of positive species interaction in which one species benefits from the interaction while the other is unaffected.

Competition

A non-trophic interaction in which two or more species overlap in the use of at least some of the same required limiting resources, negatively affecting their growth, reproduction, and/or survival.

Competitive coexistence

The ability of species to coexist with one another despite sharing limiting resources- resource partitioning.

Competitive exclusion

A result of competition between species for a single limiting resource, in which one species completely eliminates the other from a given habitat.

Ectoparasites

A parasite that lives on the surface of its host organism.

Endoparasites

A parasite that lives inside the body of its host organism.

Exploitation competition

Competition in which both species reduce the quantities of their shared but limited resources.

Facultative mutualism

A type of mutualism in which both species benefit from each other but do not need each other to survive.

Fundamental niche

A species' niche as defined by its physiological capabilities.

Herbivory

An act of predation in which the predator is an animal, and the prey is a plant or algae.

Host

An organism that harbors a parasite or symbiont and provides it with nourishment.

Hyperparasites

Parasites of other parasites.

Interference competition

Competition in which one species actively interferes with another species' access to a limiting resource.

Interspecific competition

A form of competition where individuals of different species compete for the same limited resources in an ecosystem, such as food, water, or habitat.

Intraspecific competition

Competition for resources between members of the same species

Limiting resource

The required resource whose supply (or lack thereof) most strongly influences the size of a population.

Macroparasites

Relatively large (compared to microparasites), multicellular parasites. Endo (intestinal worm) or ectoparasites (flea)

Microparasites

Parasite species too small to be seen with the naked eye (Compare with macroparasites.)

Müllerian mimicry

Convergence in appearance of two or more unpalatable species.

Mutualism

A type of positive species interaction in which both species benefit from the interaction, sometimes in a highly dependent and symbiotic manner.

Niche

The set of physical and biological conditions a species requires to grow, reproduce, and survive.

Obligate mutualism

A type of mutualism in which both species are necessary to the survival of each. Complete dependence. Ex: Lichen (fungi+algae) (Compare with facultative.)

Parasite

An organism that kills and/or consumes parts of an organism much larger than itself (known as its host). Parasites sometimes, but not always, kill their host.

Parasitism

An act of predation in which the predator (a parasite) lives symbiotically on or in the prey (its host) and consumes only certain tissues without necessarily killing the host.

Positive interactions (facilitations)

Trophic or nontrophic species interaction between two species in which one or both species benefit, and neither is harmed.

Predation

A trophic or feeding interaction in which an individual of one species (a predator) kills and/or consumes individuals (or parts of individuals) of another species (its prey).

Predator

An organism that kills and/or consumes individuals (or parts of individuals) of another species (its prey).

Prey

An organism killed and/or consumed by a predator as an energy source.

Realized niche

A species' niche as defined by its interactions with other species.

Resource partitioning

A situation in which species share limiting resources by using them in different ways, thereby allowing them to coexist.

Resources

Components of the environment such as food, water, light, and space that are required by all species.

Symbiosis

The living together of two or more species in a prolonged and intimate relationship.

Warning signal

A visual or acoustical defense mechanism used by prey species to advertise to predators that they may be toxic, dangerous or poisonous.