The Library
Adaptive Lévy processes and area-restricted search in human foraging
Tools
Hills, Thomas Trenholm, Kalff, Christopher and Wiener, Jan M. (2013) Adaptive Lévy processes and area-restricted search in human foraging. PLoS One, Volume 8 (Number 4). e60488. doi:10.1371/journal.pone.0060488 ISSN 1932-6203.
|
Text
WRAP_Hills_Adaptive_journal.pone.0060488.pdf - Published Version Available under License Creative Commons Attribution Non-commercial. Download (866Kb) | Preview |
Official URL: http://dx.doi.org/10.1371/journal.pone.0060488
Abstract
A considerable amount of research has claimed that animals’ foraging behaviors display movement lengths with power-law distributed tails, characteristic of Lévy flights and Lévy walks. Though these claims have recently come into question, the proposal that many animals forage using Lévy processes nonetheless remains. A Lévy process does not consider when or where resources are encountered, and samples movement lengths independently of past experience. However, Lévy processes too have come into question based on the observation that in patchy resource environments resource-sensitive foraging strategies, like area-restricted search, perform better than Lévy flights yet can still generate heavy-tailed distributions of movement lengths. To investigate these questions further, we tracked humans as they searched for hidden resources in an open-field virtual environment, with either patchy or dispersed resource distributions. Supporting previous research, for both conditions logarithmic binning methods were consistent with Lévy flights and rank-frequency methods–comparing alternative distributions using maximum likelihood methods–showed the strongest support for bounded power-law distributions (truncated Lévy flights). However, goodness-of-fit tests found that even bounded power-law distributions only accurately characterized movement behavior for 4 (out of 32) participants. Moreover, paths in the patchy environment (but not the dispersed environment) showed a transition to intensive search following resource encounters, characteristic of area-restricted search. Transferring paths between environments revealed that paths generated in the patchy environment were adapted to that environment. Our results suggest that though power-law distributions do not accurately reflect human search, Lévy processes may still describe movement in dispersed environments, but not in patchy environments–where search was area-restricted. Furthermore, our results indicate that search strategies cannot be inferred without knowing how organisms respond to resources–as both patched and dispersed conditions led to similar Lévy-like movement distributions.
Item Type: | Journal Article | ||||
---|---|---|---|---|---|
Subjects: | B Philosophy. Psychology. Religion > BF Psychology Q Science > QA Mathematics |
||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Psychology | ||||
Library of Congress Subject Headings (LCSH): | Lévy processes, Animals -- Food, Human behavior -- Psychological aspects, Brownian motion processes, Poisson processes, Stochastic processes | ||||
Journal or Publication Title: | PLoS One | ||||
Publisher: | Public Library of Science | ||||
ISSN: | 1932-6203 | ||||
Official Date: | 5 April 2013 | ||||
Dates: |
|
||||
Volume: | Volume 8 | ||||
Number: | Number 4 | ||||
Page Range: | e60488 | ||||
DOI: | 10.1371/journal.pone.0060488 | ||||
Status: | Peer Reviewed | ||||
Publication Status: | Published | ||||
Access rights to Published version: | Open Access (Creative Commons) | ||||
Date of first compliant deposit: | 24 December 2015 | ||||
Date of first compliant Open Access: | 24 December 2015 | ||||
Funder: | Volkswagenstiftung (VWS), Deutsche Forschungsgemeinschaft (DFG), Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung [Swiss National Science Foundation] (SNSF) | ||||
Grant number: | 100014 130397/1 (SNSF) |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year