Interference Competition

Interference competition is a direct struggle between individuals or species for limited resources, often resulting in aggressive behavior or dominance hierarchies. It influences survival, reproductive success, species communities, and can drive evolutionary changes.

Definition of Interference Competition

At its core, interference competition refers to the direct interactions among individuals within a species or across species to secure limited resources. This is in contrast to exploitation competition, where individuals compete indirectly through the consumption of shared resources.

Resource Scarcity

Interference competition often comes into play when resources (like food, water, shelter, mates, or territories) are limited. The scarcity of resources sparks off a competition, leading to various tactics to monopolize or guard these resources.

Aggressive Behaviors

Interference competition often involves aggressive interactions, which may include physical aggression, intimidation, or sabotage. These behaviors are typically aimed at suppressing the resource acquisition of competitors, thus providing an advantage to the aggressor.

Dominance Hierarchies

A common result of interference competition is the establishment of dominance hierarchies or pecking orders. These hierarchies dictate the order in which individuals can access resources, usually giving priority to the most dominant or aggressive individuals.


Interference competition often leads to territoriality, where an individual or a group claims exclusive rights to a particular area or resource. The act of defending these territories from rivals can involve physical confrontations or displays of dominance.

Costs and Benefits

The decision to engage in interference competition is usually based on an evaluation of potential costs and benefits. Costs can include energy expenditure, increased risk of injury or death, while benefits include increased access to resources and greater reproductive success.

Sexual Selection

Interference competition plays a significant role in sexual selection, where members of one sex compete for access to reproductive opportunities with members of the opposite sex. This can lead to the development of specific traits or behaviors, like bright coloration or elaborate courtship displays, that provide a competitive advantage.

Ecological Impact

Interference competition can shape communities and ecosystems, affecting species distribution, abundance, and diversity. This can result in the exclusion of certain species from habitats or the creation of niche specializations to avoid competition.

Evolutionary Consequences

Over time, interference competition can lead to evolutionary changes within species. This may include the development of new physical traits or behaviors that aid in competition, or changes in life history strategies such as timing of reproduction.

Coexistence Strategies

Interference competition can lead to the evolution of strategies for coexistence, like niche partitioning, where species reduce competition by specializing in different resources or habitats. Alternatively, interference competition can lead to character displacement, where competing species evolve differences that reduce competition.