Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour
Background: Ecologists are collecting extensive data concerning movements of animals in marine ecosystems. Such data need to be analysed with valid statistical methods to yield meaningful conclusions. Principal Findings: We demonstrate methodological issues in two recent studies that reached similar...
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ftnerc:oai:nora.nerc.ac.uk:20555 2023-05-15T15:27:45+02:00 Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour Edwards, Andrew M. Freeman, Mervyn P. Breed, Greg A. Jonsen, Ian D. 2012 text http://nora.nerc.ac.uk/id/eprint/20555/ https://nora.nerc.ac.uk/id/eprint/20555/1/journal.pone.0045174.pdf http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0045174 en eng Public Library Science https://nora.nerc.ac.uk/id/eprint/20555/1/journal.pone.0045174.pdf Edwards, Andrew M.; Freeman, Mervyn P. orcid:0000-0002-8653-8279 Breed, Greg A.; Jonsen, Ian D. 2012 Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour. Plos One, 7 (10). 13, pp. https://doi.org/10.1371/journal.pone.0045174 <https://doi.org/10.1371/journal.pone.0045174> Publication - Article PeerReviewed 2012 ftnerc https://doi.org/10.1371/journal.pone.0045174 2023-02-04T19:32:55Z Background: Ecologists are collecting extensive data concerning movements of animals in marine ecosystems. Such data need to be analysed with valid statistical methods to yield meaningful conclusions. Principal Findings: We demonstrate methodological issues in two recent studies that reached similar conclusions concerning movements of marine animals (Nature 451:1098; Science 332:1551). The first study analysed vertical movement data to conclude that diverse marine predators (Atlantic cod, basking sharks, bigeye tuna, leatherback turtles and Magellanic penguins) exhibited "Levy-walk-like behaviour", close to a hypothesised optimal foraging strategy. By reproducing the original results for the bigeye tuna data, we show that the likelihood of tested models was calculated from residuals of regression fits (an incorrect method), rather than from the likelihood equations of the actual probability distributions being tested. This resulted in erroneous Akaike Information Criteria, and the testing of models that do not correspond to valid probability distributions. We demonstrate how this led to overwhelming support for a model that has no biological justification and that is statistically spurious because its probability density function goes negative. Re-analysis of the bigeye tuna data, using standard likelihood methods, overturns the original result and conclusion for that data set. The second study observed Levy walk movement patterns by mussels. We demonstrate several issues concerning the likelihood calculations (including the aforementioned residuals issue). Re-analysis of the data rejects the original Levy walk conclusion. Conclusions: We consequently question the claimed existence of scaling laws of the search behaviour of marine predators and mussels, since such conclusions were reached using incorrect methods. We discourage the suggested potential use of "Levy-like walks" when modelling consequences of fishing and climate change, and caution that any resulting advice to managers of marine ecosystems would be ... Article in Journal/Newspaper atlantic cod Natural Environment Research Council: NERC Open Research Archive Levy ENVELOPE(-66.567,-66.567,-66.320,-66.320) PLoS ONE 7 10 e45174 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
Background: Ecologists are collecting extensive data concerning movements of animals in marine ecosystems. Such data need to be analysed with valid statistical methods to yield meaningful conclusions. Principal Findings: We demonstrate methodological issues in two recent studies that reached similar conclusions concerning movements of marine animals (Nature 451:1098; Science 332:1551). The first study analysed vertical movement data to conclude that diverse marine predators (Atlantic cod, basking sharks, bigeye tuna, leatherback turtles and Magellanic penguins) exhibited "Levy-walk-like behaviour", close to a hypothesised optimal foraging strategy. By reproducing the original results for the bigeye tuna data, we show that the likelihood of tested models was calculated from residuals of regression fits (an incorrect method), rather than from the likelihood equations of the actual probability distributions being tested. This resulted in erroneous Akaike Information Criteria, and the testing of models that do not correspond to valid probability distributions. We demonstrate how this led to overwhelming support for a model that has no biological justification and that is statistically spurious because its probability density function goes negative. Re-analysis of the bigeye tuna data, using standard likelihood methods, overturns the original result and conclusion for that data set. The second study observed Levy walk movement patterns by mussels. We demonstrate several issues concerning the likelihood calculations (including the aforementioned residuals issue). Re-analysis of the data rejects the original Levy walk conclusion. Conclusions: We consequently question the claimed existence of scaling laws of the search behaviour of marine predators and mussels, since such conclusions were reached using incorrect methods. We discourage the suggested potential use of "Levy-like walks" when modelling consequences of fishing and climate change, and caution that any resulting advice to managers of marine ecosystems would be ... |
format |
Article in Journal/Newspaper |
author |
Edwards, Andrew M. Freeman, Mervyn P. Breed, Greg A. Jonsen, Ian D. |
spellingShingle |
Edwards, Andrew M. Freeman, Mervyn P. Breed, Greg A. Jonsen, Ian D. Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour |
author_facet |
Edwards, Andrew M. Freeman, Mervyn P. Breed, Greg A. Jonsen, Ian D. |
author_sort |
Edwards, Andrew M. |
title |
Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour |
title_short |
Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour |
title_full |
Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour |
title_fullStr |
Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour |
title_full_unstemmed |
Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour |
title_sort |
incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour |
publisher |
Public Library Science |
publishDate |
2012 |
url |
http://nora.nerc.ac.uk/id/eprint/20555/ https://nora.nerc.ac.uk/id/eprint/20555/1/journal.pone.0045174.pdf http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0045174 |
long_lat |
ENVELOPE(-66.567,-66.567,-66.320,-66.320) |
geographic |
Levy |
geographic_facet |
Levy |
genre |
atlantic cod |
genre_facet |
atlantic cod |
op_relation |
https://nora.nerc.ac.uk/id/eprint/20555/1/journal.pone.0045174.pdf Edwards, Andrew M.; Freeman, Mervyn P. orcid:0000-0002-8653-8279 Breed, Greg A.; Jonsen, Ian D. 2012 Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour. Plos One, 7 (10). 13, pp. https://doi.org/10.1371/journal.pone.0045174 <https://doi.org/10.1371/journal.pone.0045174> |
op_doi |
https://doi.org/10.1371/journal.pone.0045174 |
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PLoS ONE |
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7 |
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10 |
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e45174 |
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