{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T13:56:14Z","timestamp":1772718974177,"version":"3.50.1"},"reference-count":54,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2022,9,22]],"date-time":"2022-09-22T00:00:00Z","timestamp":1663804800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100008075","name":"Greenland Institute of Natural Resources","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100008075","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Danish Cooperation for the Environment in the Arctic","award":["2013_01_0289"],"award-info":[{"award-number":["2013_01_0289"]}]},{"name":"Carlsberg Foundation","award":["CF14-0169"],"award-info":[{"award-number":["CF14-0169"]}]},{"DOI":"10.13039\/501100005946","name":"Hokkaido University","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100005946","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Arctic Challenge for Sustainability II","award":["JPMXD142031886"],"award-info":[{"award-number":["JPMXD142031886"]}]}],"content-domain":{"domain":["www.ploscompbiol.org"],"crossmark-restriction":false},"short-container-title":["PLoS Comput Biol"],"abstract":"<jats:p>Detecting structures within the continuous diving behavior of marine animals is challenging, and no universal framework is available. We captured such diverse structures using chaos theory. By applying time-delay embedding to exceptionally long dive records (83 d) from the narwhal, we reconstructed the state-space portrait. Using measures of chaos, we detected a diurnal pattern and its seasonal modulation, classified data, and found how sea-ice appearance shifts time budgets. There is more near-surface rest but deeper dives at solar noon, and more intense diving during twilight and at night but to shallower depths (likely following squid); sea-ice appearance reduces rest. The introduced geometrical approach is simple to implement and potentially helpful for mapping and labeling long-term behavioral data, identifying differences between individual animals and species, and detecting perturbations.<\/jats:p>","DOI":"10.1371\/journal.pcbi.1010432","type":"journal-article","created":{"date-parts":[[2022,9,22]],"date-time":"2022-09-22T13:44:56Z","timestamp":1663854296000},"page":"e1010432","update-policy":"https:\/\/doi.org\/10.1371\/journal.pcbi.corrections_policy","source":"Crossref","is-referenced-by-count":7,"title":["Strange attractor of a narwhal (Monodon monoceros)"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3050-4897","authenticated-orcid":true,"given":"Evgeny A.","family":"Podolskiy","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4846-7622","authenticated-orcid":true,"given":"Mads Peter","family":"Heide-J\u00f8rgensen","sequence":"additional","affiliation":[]}],"member":"340","published-online":{"date-parts":[[2022,9,22]]},"reference":[{"key":"pcbi.1010432.ref001","doi-asserted-by":"crossref","first-page":"7617","DOI":"10.1073\/pnas.1803543115","article-title":"Vulnerability of Arctic marine mammals to vessel traffic in the increasingly ice-free Northwest passage and Northern sea route","volume":"115","author":"DDW Hauser","year":"2018","journal-title":"PNAS"},{"key":"pcbi.1010432.ref002","doi-asserted-by":"crossref","first-page":"2628","DOI":"10.1073\/pnas.1611707114","article-title":"Sustained disruption of narwhal habitat use and behavior in the presence of arctic killer whales","volume":"114","author":"GA Breed","year":"2017","journal-title":"PNAS"},{"key":"pcbi.1010432.ref003","doi-asserted-by":"crossref","first-page":"1328","DOI":"10.1126\/science.aao2740","article-title":"Paradoxical escape responses by narwhals (monodon monoceros)","volume":"358","author":"TM Williams","year":"2017","journal-title":"Science"},{"key":"pcbi.1010432.ref004","doi-asserted-by":"crossref","DOI":"10.3389\/fmars.2021.658173","article-title":"Behavioral response study on seismic airgun and vessel exposures in narwhals","volume":"8","author":"MP Heide-J\u00f8rgensen","year":"2021","journal-title":"Front. 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