Ideal free distribution

An ideal free distribution is an ecological term that describes the way in which animals distribute themselves between several patches of resources. The theory states that individual animals will aggregate in various patches proportionately to the amount of resources available in each. So for example, if patch A contains twice as much food as patch B, there will be twice as many individuals foraging in patch A as in patch B.The ideal free distribution (IFD) theory predicts the distribution of animals that compete for resources that are distributed in patches (Fretwell, 1972 ; Fretwell and Lucas, 1970 ).

The term "ideal" means that animals are "ideal" in their assessment of patch quality; they know how profitable each available patch is. The term "free" means that animals are capable of moving unhindered from one patch to another. Both these assumptions are often violated, for example if the animals stop in the first patch they get to without looking for others, or if there are dominant individuals preventing others from foraging optimally. As is the case for many ecological theories, this does not mean that the theory is flawed. Indeed, ecologists often use the theory to test for violations. If a population of animals does not follow an ideal free distribution, it is interesting to find out why.

ee also

*Behavioural ecology
*Optimal foraging theory
*Marginal value theorem

External links

* [http://beheco.oxfordjournals.org/cgi/content/full/14/1/109#BDY The ideal free distribution when the resource is variable - Introduction]