Scale-free foraging by primates emerges from their interaction with a complex environment

Boyer, Denis; Ramos‐Fernández, Gabriel; Miramontes, Octavio; Mateos, José L.; Cocho, G.; Larralde, Hernán; Ramos, Humberto Fernández; Rojas, Fernando Huerta

doi:10.1098/rspb.2005.3462

Cited by 222 publications

(234 citation statements)

References 52 publications

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“…Finally, the possibility that the complexity of the environment in itself influences animal behavior needs to be carefully considered. 24 The fluctuating-threshold dynamics discussed here is biologically plausible and reproduces well the observed rat motor activity. It is possible that appropriate modifications of this model can provide insights on the long-term rhythm alterations observed on individuals with mood disturbances, depression, and other neurological disorders such as chronic pain.…”

Section: Final Observationssupporting

confidence: 68%

Unraveling the fluctuations of animal motor activity

Anteneodo¹,

Chialvo²

2009

Chaos: An Interdisciplinary Journal of Nonlinear Science

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Human and animal behavior exhibits power law correlations whose origin is controversial. In this work, the spontaneous motion of laboratory rodents was recorded during several days. It is found that animal motion is scale-free and that the scaling is introduced by the inactivity pauses both by its length as well as by its specific ordering. Furthermore, the scaling is also demonstrable in the rates of event's occurrence. A comparison with related results in humans is made and candidate models are discussed to provide clues for the origin of such dynamics. © 2009 American Institute of Physics. ͓DOI: 10.1063/1.3211189͔ Recent findings of heavy tailed distributions in the patterns of human activity reemphasized our poor understanding on the mechanisms responsible for such type of dynamics. To shed light on the most significant features of these fluctuations, the problem is here oversimplified by studying a much elementary system: the spontaneous motion of rodents recorded during several days. The analysis of the animal motion reveals a robust scaling not only in univariate distributions, comparable with the results previously reported in humans, but also in its correlation structure. It is shown that the most relevant features of the experimental results can be replicated by the statistics of the activation-threshold model proposed in another context by Davidsen and Schuster. It constitutes an alternative mechanism to queuing, cascading, and nonhomogeneous processes, currently contemplated as candidates to account for the statistics of diverse human activities, but that seem not suitable for motion patterns.

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Section: Final Observationssupporting

confidence: 68%

Unraveling the fluctuations of animal motor activity

Anteneodo¹,

Chialvo²

2009

Chaos: An Interdisciplinary Journal of Nonlinear Science

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“…We recognize, however, that our analysis could not detect how the movement patterns arose, that is, whether the patterns identified were an adaptive behaviour or whether observed patterns were an emergent property of the spatial distributions of prey 13,17,27 . Controlled experiments 28 , rather than natural experiments as here, will be needed to progress from asking whether Lévy flights (walks) occur in animals 8,9 to exploring why they occur and whether animals evolved such that they exploit Lévy flights as an optimal search strategy for life in complex, highly changeable landscapes.…”

mentioning

confidence: 88%

Environmental context explains Lévy and Brownian movement patterns of marine predators

Humphries

Queiroz

Dyer

et al. 2010

Nature

810

816

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An optimal search theory, the so-called Lévy-flight foraging hypothesis 1 , predicts that predators should adopt search strategies known as Lévy flights where prey is sparse and distributed unpredictably, but that Brownian movement is sufficiently efficient for locating abundant prey [2][3][4] . Empirical studies have generated controversy because the accuracy of statistical methods that have been used to identify Lévy behaviour has recently been questioned 5,6 . Consequently, whether foragers exhibit Lévy flights in the wild remains unclear. Crucially, moreover, it has not been tested whether observed movement patterns across natural landscapes having different expected resource distributions conform to the theory's central predictions. Here we use maximum-likelihood methods to test for Lévy patterns in relation to environmental gradients in the largest animal movement data set assembled for this purpose. Strong support was found for Lévy search patterns across 14 species of open-ocean predatory fish (sharks, tuna, billfish and ocean sunfish), with some individuals switching between Lévy and Brownian movement as they traversed different habitat types. We tested the spatial occurrence of these two principal patterns and found Lévy behaviour to be associated with less productive waters (sparser prey) and Brownian movements to be associated with productive shelf or convergence-front habitats (abundant prey). These results are consistent with the Lévy-flight foraging hypothesis 1,7 , supporting the contention 8,9 that organism search strategies naturally evolved in such a way that they exploit optimal Lévy patterns.Lévy flights are a special class of random walk with movement displacements (steps) drawn from a probability distribution with a power-law tail (the so-called Pareto-Lévy distribution) 1,10 , and give rise to stochastic processes closely linked to fractal geometry and anomalous diffusion phenomena 7,11 . Lévy flights describe a movement pattern characterized by many small steps connected by longer relocations, with this pattern having scale invariance under projection, such that the probability density function, P(l j ), has a power-law tail in the long-distance regime: P(l j ) < l j 2m , where l j is the flight length (step length of move j), and m, 1 , m # 3, is the power-law exponent. Lévy flights comprise instantaneous steps and hence involve infinite velocities, whereas a Lévy walk 10 refers to a finitevelocity walk such that displacement is determined after a time t, reflecting a dynamical process such as movement 1,10,11 . Lévy flights and walks are theorized to be the most efficient movement pattern for locating patchy prey in low concentrations on spatial scales beyond a searcher's sensory range, with an optimal search having a power-law exponent of m < 2 (refs 4, 13). It is proposed that organisms have therefore naturally evolved search patterns that can be modelled as optimal Lévy flights 1,7,13 .However, burgeoning empirical support for this hypothesis recently foundered following studies sug...

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“…Throughout the history of primate socioecological research, these kinds of models have been used by various researchers (Boyer, Miramontes, Ramos-Fernández, Mateos, Cocho, and Larralde 2004;Boyer, Ramos-Fernández, Miramontes, Mateos, Cocho, Larralde, Ramos, and Rojas 2006;Ramos-Fernández, Boyer, and Gómez 2006;Rodman and Di Fiore 1993;te Boekhorst and Hogeweg 1994;reviewed by Dunbar 2002), but they have yet to gain widespread acceptance (Bryson, Ando, and Lehmann 2007).…”

Section: A Way Forward? Deriving An Inclusive Spatial Null Modelmentioning

confidence: 99%