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Effects of Temporal Resolution on an Inferential Model of Animal Movement

Recently, there has been much interest in describing the behaviour of animals by fitting various movement models to tracking data. Despite this interest, little is known about how the temporal ‘grain’ of movement trajectories affects the outputs of such models, and how behaviours classified at one t...

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Autores principales: Postlethwaite, Claire M., Dennis, Todd E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646004/
https://www.ncbi.nlm.nih.gov/pubmed/23671558
http://dx.doi.org/10.1371/journal.pone.0057640
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author Postlethwaite, Claire M.
Dennis, Todd E.
author_facet Postlethwaite, Claire M.
Dennis, Todd E.
author_sort Postlethwaite, Claire M.
collection PubMed
description Recently, there has been much interest in describing the behaviour of animals by fitting various movement models to tracking data. Despite this interest, little is known about how the temporal ‘grain’ of movement trajectories affects the outputs of such models, and how behaviours classified at one timescale may differ from those classified at other scales. Here, we present a study in which random-walk state-space models were fit both to nightly geospatial lifelines of common brushtail possums (Trichosurus vulpecula) and synthetic trajectories parameterised from empirical observations. Observed trajectories recorded by GPS collars at 5-min intervals were sub-sampled at periods varying between 10 and 60 min, to approximate the effect of collecting data at lower sampling frequencies. Markov-Chain Monte-Carlo fitting techniques, using information about movement rates and turning angles between sequential fixes, were employed using a Bayesian framework to assign distinct behavioural states to individual location estimates. We found that in trajectories with higher temporal granularities behaviours could be clearly differentiated into ‘slow-area-restricted’ and ‘fast-transiting’ states, but for trajectories with longer inter-fix intervals this distinction was markedly less obvious. Specifically, turning-angle distributions varied from being highly peaked around either [Image: see text] or [Image: see text] at fine temporal scales, to being uniform across all angles at low sampling intervals. Our results highlight the difficulty of comparing model results amongst tracking-data sets that vary substantially in temporal grain, and demonstrate the importance of matching the observed temporal resolution of tracking devices to the timescales of behaviours of interest, otherwise inter-individual comparisons of inferred behaviours may be invalid, or important biological information may be obscured.
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spelling pubmed-36460042013-05-13 Effects of Temporal Resolution on an Inferential Model of Animal Movement Postlethwaite, Claire M. Dennis, Todd E. PLoS One Research Article Recently, there has been much interest in describing the behaviour of animals by fitting various movement models to tracking data. Despite this interest, little is known about how the temporal ‘grain’ of movement trajectories affects the outputs of such models, and how behaviours classified at one timescale may differ from those classified at other scales. Here, we present a study in which random-walk state-space models were fit both to nightly geospatial lifelines of common brushtail possums (Trichosurus vulpecula) and synthetic trajectories parameterised from empirical observations. Observed trajectories recorded by GPS collars at 5-min intervals were sub-sampled at periods varying between 10 and 60 min, to approximate the effect of collecting data at lower sampling frequencies. Markov-Chain Monte-Carlo fitting techniques, using information about movement rates and turning angles between sequential fixes, were employed using a Bayesian framework to assign distinct behavioural states to individual location estimates. We found that in trajectories with higher temporal granularities behaviours could be clearly differentiated into ‘slow-area-restricted’ and ‘fast-transiting’ states, but for trajectories with longer inter-fix intervals this distinction was markedly less obvious. Specifically, turning-angle distributions varied from being highly peaked around either [Image: see text] or [Image: see text] at fine temporal scales, to being uniform across all angles at low sampling intervals. Our results highlight the difficulty of comparing model results amongst tracking-data sets that vary substantially in temporal grain, and demonstrate the importance of matching the observed temporal resolution of tracking devices to the timescales of behaviours of interest, otherwise inter-individual comparisons of inferred behaviours may be invalid, or important biological information may be obscured. Public Library of Science 2013-05-06 /pmc/articles/PMC3646004/ /pubmed/23671558 http://dx.doi.org/10.1371/journal.pone.0057640 Text en © 2013 Postlethwaite, Dennis http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Postlethwaite, Claire M.
Dennis, Todd E.
Effects of Temporal Resolution on an Inferential Model of Animal Movement
title Effects of Temporal Resolution on an Inferential Model of Animal Movement
title_full Effects of Temporal Resolution on an Inferential Model of Animal Movement
title_fullStr Effects of Temporal Resolution on an Inferential Model of Animal Movement
title_full_unstemmed Effects of Temporal Resolution on an Inferential Model of Animal Movement
title_short Effects of Temporal Resolution on an Inferential Model of Animal Movement
title_sort effects of temporal resolution on an inferential model of animal movement
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646004/
https://www.ncbi.nlm.nih.gov/pubmed/23671558
http://dx.doi.org/10.1371/journal.pone.0057640
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