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Showing posts from December, 2018

The Limited Scope of Lévy Walk and the LFF Model

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The Lévy flight foraging (LFF) hypothesis describes a toggling between classic Lévy flight/walk (LW) and classic Brownian motion (BM) as a function of the individual’s current resource field properties (its “environment”). Both states of motion are statistical by nature – and explicitly defined as such. The LFF describes movement as random walk in two disparate modes; scale-free LW versus scale-specific BM. However, the LFF premise of animals moving like drunken LW/BM walkers logically does not make sense unless the animal in question does not possess a capacity for spatial memory utilization or because the environment is so volatile that returning to a previous location has no fitness value with respect to optimal foraging. Under these premises of value-less spatial map utlilization the LFF hypothesis should be expected to make sense, otherwise one should expect to find better compliance with other movement-related models and hypotheses.

The theoretical model developments surroundin…

Slow Motion in Books on Animal Movement

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Over the last years we have seen a range of interesting and important books appearing in the field of animal movement and space use. In this post I mention four of them. Unfortunately, only two of these books (disregarding my own contribution) presents any reference to animals’ capacity for spatial reorientation beyond the individual’s current perceptual field. However, all that is offered in these two titles – covering hundreds of pages with deep theory – is a couple of sentences or paragraphs. Why such a slow implementation in mainstream models with respect to this key aspect of behavioural ecology? Why such stubbornness to bridge theory to empirical knowledge by including spatial memory as an important factor that influences how animals use their habitat?

First, I was happy to discover that Turchin’s classic book “Quantitative analysis of animal movement” (Turchin 1998) has now appeared in new print, dated 2015. However, like the original version you will search in vain for any re…