Question

The marginal value theorem in optimal foraging theory examines which one of the following foraging decisions?

• A. How long to stay in a patch of food
• B. How to allocate time to foraging versus reproduction
• C. How to minimise risk while foraging
• D. How to select between different food types within a patch

Hint:

Marginal Value Theorem: Foragers should stay longer in patches with higher food availability but leave when returns start to decrease.

Answer 1

The Correct Option is A

The Marginal Value Theorem (MVT) is a central concept in optimal foraging theory, which was formulated by Eric Charnov in 1976. This theorem helps explain the foraging decisions of animals, particularly the time spent in each foraging patch, which ultimately impacts their overall energy intake. The goal is to maximize energy gain while minimizing the costs associated with foraging.
The key idea behind MVT is that animals, while foraging, must decide how long to stay in a specific food patch. The optimal time to leave a patch depends on the diminishing returns from foraging in that patch. As time passes, the rate of energy gain from the patch decreases. The optimal strategy, according to MVT, is to stay in a patch as long as the marginal benefit (additional food collected) from the patch exceeds the marginal cost (energy spent). Once the returns from the patch decrease to the average rate of return in the environment, the animal should leave the patch and search for a new one.
This decision directly addresses the question of how long to stay in a patch of food, which is the primary focus of the marginal value theorem. Therefore, the correct answer is (A).