| Abstract | What do the following foragers have in common: fishermen, grey seals, microzooplankton, wandering albatrosses, bumblebees, deer, reindeer, jackals and human hunter gatherers? Through a series of papers, it has been claimed they exhibit similar movement patterns, namely Levy flights (which are scale-free random walks with step lengths from probability distributions that have heavy power-law tails). However, the power law distributions were concluded by fitting straight lines to log-log histograms of data. I show that such methods are misleading - for simulated data they give the wrong answer. They also implicitly assume that the data are well described by a power law, without allowing for an alternative. Using likelihood methods and Akaike weights (to test simple alternative hypotheses), re-analysis of the data sets finds that Levy flights are far from a universal foraging strategy. Some of this work is published in Nature, 449:1044 and J. Anim. Ecol., 77:1212, yet many new results are also presented. |
|---|
