Optimal Foraging Theory

The Optimal Foraging theory, initially formulated in the late 1960s, is an attempt to rationalize and predict the behavior of foragers in ecological studies.

In its most basic idea, the Optimal Foraging theory assumes that a forager will always act to maximize its "fitness", in other words that it will always pick the option with maximal energy return for minimal energy expenditure.

The use of foraging currencies allows scientists to compare the efficiency of different foraging strategies: the optimal option would either maximize the energy return in a given timeframe or minimize the time need to reach energetic requirements.

However, the existence of homeostatic and environmental constraints often prevents the forager to adopt the ideal strategy within the optimality model.

The strength of the Optimal Foraging theory is to provide a framework to understand when foragers switch between different behaviors (e.g. foraging more extensively or switching to different prey), and towards which behavior they are likely to switch to.

After defining an arbitrary and appropriate currency and evaluated the expected switching points between behaviors or strategies, the model is usually compared to field data and observations. If the forager behave along the predictions of the model, then the model is an approximatively accurate depiction of reality. If the forager makes different choices than expected or at different times than predicted, then the model is inaccurate and might have not taken into account an important constraint for example.

A good example resulting from the application of the Optimal Foraging theory is the general assertion that in presence of an increased density of prey, a forager usually switches to a more energetically taxing behavior that provides a greater return rather than restraining to the requirements for survival.

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