From patch use to environmental conditions: Using theory to reconstruct the past

An intriguing aspect of optimal foraging theory is the link that it makes between local behavior and environmental conditions. This link is obvious from the marginal value theorem, which states that a forager should leave a food patch when its intake rate on the patch falls to the overall rate for the environment. As a result the marginal value theorem can be used to make inferences about the quality of the environment, but I show that it is not straightforward to make inferences about the time required to travel between patches. In particular, if prey are not always captured, then the actual travel time is overestimated by a factor of 1/k, where k is the probability of capture. I also show how different energy-based currencies may mean that the estimate of travel time is distorted.