Greener Grass On The Other Side


Our wild friends, whether they are herbivores or even rodents, have to forage for a living. What happens when their foraging range vanishes? This could be due to weather, invasion by another species, including the most greedy – man.

They have to move to a new range, but what are the processes and what is the best frame of mind for the foragers? Should they be pessimistic or optimistic about their chances? Berger-Tal and Avgar have had a go at modeling the problem and report out in the Public Library of Science (1).

The classic model is based on the idea that the foragers should stick in a new area until the forage quality drops to a certain threshold and then move on. Their new model compares that pessimistic model (i.e. hang on to what you’ve got) to an optimistic model that expects that greener grass is to be found on the other side of the hill.

The simulation shows that a good amount of optimism wins out. They explore more and hence find more forage so that over the experimental lifetime, they consume more forage.

Of course, like everything in life, one might overdo it. Too much wandering might not give enough munching time, but generally a good deal of optimism is a winning strategy. The initial exploration may cost in munching, but the long-term knowledge gain will always pay off in the end.

Maybe we should all learn to stay optimistic as our forage comes under pressure?

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0034578


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