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Closed Access item The influence of turning angles on the success of non-oriented animal searches
Viswanathan, G. M.
Raposo, E. P.
da Luz, M. G. E.
|Keywords:||Diffusive properties, Foraging theory, Correlated random walks, Turning angle distributions, Random search, Orientation|
|Citation:||Journal of Theoretical Biology 252 : 43-55 (2008)|
|Abstract:||Animal searches cover a full range of possibilities from highly deterministic to apparently completely random behaviors. However,
even those stochastic components of animal movement can be adaptive, since not all random distributions lead to similar success in
finding targets. Here we address the general problem of optimizing encounter rates in non-deterministic, non-oriented searches, both in
homogeneous and patchy target landscapes. Specifically, we investigate how two different features related to turning angle distributions
influence encounter success: (i) the shape (relative kurtosis) of the angular distribution and (ii) the correlations between successive relative
orientations (directional memory). Such influence is analyzed in correlated random walk models using a proper choice of representative
turning angle distributions of the recently proposed Jones and Pewsey class. We consider the cases of distributions with nearly the same
shape but considerably distinct correlation lengths, and distributions with same correlation but with contrasting relative kurtosis. In
homogeneous landscapes, we find that the correlation length has a large influence in the search efficiency. Moreover, similar search
efficiencies can be reached by means of distinctly shaped turning angle distributions, provided that the resulting correlation length is the
same. In contrast, in patchy landscapes the particular shape of the distribution also becomes relevant for the search efficiency, specially at
high target densities. Excessively sharp distributions generate very inefficient searches in landscapes where local target density
fluctuations are large. These results are of evolutionary interest. On the one hand, it is shown that equally successful directional memory
can arise from contrasting turning behaviors, therefore increasing the likelihood of robust adaptive stochastic behavior. On the other
hand, when target landscape is patchy, adequate tumbling may help to explore better local scale heterogeneities, being some details of the
shape of the distribution also potentially adaptive.|
|Description:||13 páginas,1 tabla, 4 figuras, 3 apéndices.|
|Publisher version (URL):||http://dx.doi.org/10.1016/j.jtbi.2008.01.009|
|E-ISSNmetadata.dc.identifier.doi = DOI:||1095-8541|
|Appears in Collections:||(CEAB) Artículos|
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