Scramble competition

In ecology, scramble competition (or complete symmetric competition) refers to a situation in which a resource is accessible to all competitors (that is, it is not monopolizable by an individual or group). However, since the particular resource is usually finite, scramble competition may lead to decreased survival rates for all competitors if the resource is used to its carrying capacity. Scramble competition is also defined as “[a] finite resource [that] is shared equally amongst the competitors so that the quantity of food per individual declines with increasing population density”. A further description of scramble competition is “competition for a resource that is inadequate for the needs of all, but which is partitioned equally among contestants, so that no competitor obtains the amount it needs and all would die in extreme cases.”

Researchers recognize two main forms of intraspecific competition, where members of a species are all using a shared resource in short supply. These are contest competition and scramble competition.

Contest competition is a form of competition where there is a winner and a loser and where resources can be attained completely or not at all. Contest competition sets up a situation where “each successful competitor obtains all resources it requires for survival or reproduction”. Here "contest" refers to the fact that physical action plays an active role in securing the resource. Contest competition involves resources that are stable, i.e. food or mates. Contests can be for a ritual objective such as territory or status, and losers may return to the competition another day to try again.

In scramble competition resources are limited, which may lead to group member starvation. Contest competition is often the result of aggressive social domains, including hierarchies or social chains. Conversely, scramble competition is what occurs by accident when competitors naturally want the same resources. These two forms of competition can be interwoven into one another. Some researchers have noted parallels between intraspecific behaviors of competition and cooperation. These two processes can be evolutionarily adopted and they can also be accidental, which makes sense given the aggressive competition and collaborative cooperation aspects of social behavior in humans and animals. To date, few studies have looked at the interplay between contest and scramble competition, despite the fact that they do not occur in isolation. There appears to be little understanding of the interface between contest competition and scramble competition in insects. Much research still needs to be conducted concerning the overlap of contest and scramble competition systems. Contests can arise within a scramble competition system and conversely, scramble competition “may play a role in a system characterized by interference”.

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Wikipedia