TY - JOUR
T1 - Lévy walk patterns in the foraging movements of spider monkeys (Ateles geoffroyi)
AU - Ramos-Fernández, Gabriel
AU - Mateos, José L.
AU - Miramontes, Octavio
AU - Cocho, Germinal
AU - Larralde, Hernán
AU - Ayala-Orozco, Bárbara
N1 - Funding Information:
Acknowledgements The authors are truly grateful to Eulogio and Macedonio Canul, who provided invaluable assistance in the field by locating the study groups and by collecting data. Laura Vick and David Taub initiated the study of spider monkeys in Punta Laguna. Fieldwork was financed by a graduate scholarship from the National Council for Science and Technology (CONACYT, Mexico) and by grants from the Wildlife Conservation Society, the National Commission for the Knowledge and Use of Biodiversity (CONABIO, Mexico), the Mexican Fund for the Conservation of Nature (FMCN), and the Turner Foundation. Data analysis and manuscript preparation was financed by CONACYT project 32453-E and DGAPA project IN-111000, as well as a visiting scholarship (C tedra Tom s Brody) from the Complex Systems Department at the Physics Institute, National Autonomous University of México. One of the authors (J.L.M.) gratefully acknowledges useful conversations with Michael F. Shlesinger and Joseph Klafter and financial support from UNAM through project DGAPA-IN-111000. Two anonymous reviewers provided useful comments on an earlier version of the manuscript. These observations were performed in compliance with the Mexican Environment Protection Law (LGEEPA).
PY - 2004/1
Y1 - 2004/1
N2 - Scale invariant patterns have been found in different biological systems, in many cases resembling what physicists have found in other, nonbiological systems. Here we describe the foraging patterns of free-ranging spider monkeys (Ateles geoffroyi) in the forest of the Yucatan Peninsula, Mexico and find that these patterns closely resemble what physicists know as Lévy walks. First, the length of a trajectory's constituent steps, or continuous moves in the same direction, is best described by a power-law distribution in which the frequency of ever larger steps decreases as a negative power function of their length. The rate of this decrease is very close to that predicted by a previous analytical Lévy walk model to be an optimal strategy to search for scarce resources distributed at random. Second, the frequency distribution of the duration of stops or waiting times also approximates to a power-law function. Finally, the mean square displacement during the monkeys' first foraging trip increases more rapidly than would be expected from a random walk with constant step length, but within the range predicted for Lévy walks. In view of these results, we analyze the different exponents characterizing the trajectories described by females and males, and by monkeys on their own and when part of a subgroup. We discuss the origin of these patterns and their implications for the foraging ecology of spider monkeys.
AB - Scale invariant patterns have been found in different biological systems, in many cases resembling what physicists have found in other, nonbiological systems. Here we describe the foraging patterns of free-ranging spider monkeys (Ateles geoffroyi) in the forest of the Yucatan Peninsula, Mexico and find that these patterns closely resemble what physicists know as Lévy walks. First, the length of a trajectory's constituent steps, or continuous moves in the same direction, is best described by a power-law distribution in which the frequency of ever larger steps decreases as a negative power function of their length. The rate of this decrease is very close to that predicted by a previous analytical Lévy walk model to be an optimal strategy to search for scarce resources distributed at random. Second, the frequency distribution of the duration of stops or waiting times also approximates to a power-law function. Finally, the mean square displacement during the monkeys' first foraging trip increases more rapidly than would be expected from a random walk with constant step length, but within the range predicted for Lévy walks. In view of these results, we analyze the different exponents characterizing the trajectories described by females and males, and by monkeys on their own and when part of a subgroup. We discuss the origin of these patterns and their implications for the foraging ecology of spider monkeys.
KW - Animal movement
KW - Foraging
KW - Lévy walks
KW - Scale invariance
KW - Spider monkeys
UR - http://www.scopus.com/inward/record.url?scp=4043118128&partnerID=8YFLogxK
U2 - 10.1007/s00265-003-0700-6
DO - 10.1007/s00265-003-0700-6
M3 - Artículo
SN - 0340-5443
VL - 55
SP - 223
EP - 230
JO - Behavioral Ecology and Sociobiology
JF - Behavioral Ecology and Sociobiology
IS - 3
ER -