International Encyclopedia of Systems and Cybernetics

An ecological theory that explains important aspects of animal ecology.

Foraging theory's main rule is that "animals make choices that maximize their "Benefit per unit cost" i.e… they'll expend food gathering energy in ways that yield the best energy return "(R. CHALMERS, 2000, p. 39)

Chalmers comments: "The longer a forager exploits one patch, the lower the returns will be, until this patch is overgrazed and worthless"… and… "… the optimal strategy is to move on when the rate of return from a particular patch falls below the average rate over the whole region. This is the marginal value theorem… formulated by Eric CHERNOV in 1976"(Ibid.)

In other words, foragers- which are in some sense parasites of their environment- always try to maximize their rewards.

Of course, the "whole region "value must be monitored, which is more easy for an organized group… but implies also some costs.

It seems that these concepts could be applied in economy. They are surely relevant in cultural anthropology for semi-nomad groups. They could also explain the growing trend toward economic migrations, in our time.

Foraging behavior is in fact systemic in a very general sense.

It is clearly associated with the relation between costs and yield. A good example is the search for an optimal relation between obtaining relevant information and the cost to obtain it, in search time as well as in money.

This can be expressed as "benefit per unit cost".

→ Commons; Density; Density of occupancy; Hexagonal space filling; Parasitism