Behavioral Timing without Clockwork
Occurrence of 24-h rhythms in species apparently lacking functional molecular clockwork indicates that strong circadian mechanisms are not essential prerequisites of robust timing, and that rhythmical patterns may arise instead as passive responses to periodically changing environmental stimuli. Thu...
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Online Access: | http://dx.doi.org/10.1177/0748730416662778 http://journals.sagepub.com/doi/pdf/10.1177/0748730416662778 http://journals.sagepub.com/doi/full-xml/10.1177/0748730416662778 |
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crsagepubl:10.1177/0748730416662778 2023-05-15T15:00:59+02:00 Behavioral Timing without Clockwork Photoperiod-Dependent Trade-Off between Predation Hazard and Energy Balance in an Arctic Ungulate Tyler, Nicholas J. C. Gregorini, Pablo Forchhammer, Mads C. Stokkan, Karl-Arne van Oort, Bob E. H. Hazlerigg, David G. 2016 http://dx.doi.org/10.1177/0748730416662778 http://journals.sagepub.com/doi/pdf/10.1177/0748730416662778 http://journals.sagepub.com/doi/full-xml/10.1177/0748730416662778 en eng SAGE Publications http://journals.sagepub.com/page/policies/text-and-data-mining-license Journal of Biological Rhythms volume 31, issue 5, page 522-533 ISSN 0748-7304 1552-4531 Physiology (medical) Physiology journal-article 2016 crsagepubl https://doi.org/10.1177/0748730416662778 2022-09-28T18:55:32Z Occurrence of 24-h rhythms in species apparently lacking functional molecular clockwork indicates that strong circadian mechanisms are not essential prerequisites of robust timing, and that rhythmical patterns may arise instead as passive responses to periodically changing environmental stimuli. Thus, in a new synthesis of grazing in a ruminant (MINDY), crepuscular peaks of activity emerge from interactions between internal and external stimuli that influence motivation to feed, and the influence of the light/dark cycle is mediated through the effect of low nocturnal levels of food intake on gastric function. Drawing on risk allocation theory, we hypothesized that the timing of behavior in ruminants is influenced by the independent effects of light on motivation to feed and perceived risk of predation. We predicted that the antithetical relationship between these 2 drivers would vary with photoperiod, resulting in a systematic shift in the phase of activity relative to the solar cycle across the year. This prediction was formalized in a model in which phase of activity emerges from a photoperiod-dependent trade-off between food and safety. We tested this model using data on the temporal pattern of activity in reindeer/caribou Rangifer tarandus free-living at natural mountain pasture in sub-Arctic Norway. The resulting nonlinear relationship between the phasing of crepuscular activity and photoperiod, consistent with the model, suggests a mechanism for behavioral timing that is independent of the core circadian system. We anticipate that such timing depends on integration of metabolic feedback from the digestive system and the activity of the glucocorticoid axis which modulates the behavioral responses of the animal to environmental hazard. The hypothalamus is the obvious neural substrate to achieve this integration. Article in Journal/Newspaper Arctic caribou Rangifer tarandus SAGE Publications (via Crossref) Arctic Norway Journal of Biological Rhythms 31 5 522 533 |
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Open Polar |
collection |
SAGE Publications (via Crossref) |
op_collection_id |
crsagepubl |
language |
English |
topic |
Physiology (medical) Physiology |
spellingShingle |
Physiology (medical) Physiology Tyler, Nicholas J. C. Gregorini, Pablo Forchhammer, Mads C. Stokkan, Karl-Arne van Oort, Bob E. H. Hazlerigg, David G. Behavioral Timing without Clockwork |
topic_facet |
Physiology (medical) Physiology |
description |
Occurrence of 24-h rhythms in species apparently lacking functional molecular clockwork indicates that strong circadian mechanisms are not essential prerequisites of robust timing, and that rhythmical patterns may arise instead as passive responses to periodically changing environmental stimuli. Thus, in a new synthesis of grazing in a ruminant (MINDY), crepuscular peaks of activity emerge from interactions between internal and external stimuli that influence motivation to feed, and the influence of the light/dark cycle is mediated through the effect of low nocturnal levels of food intake on gastric function. Drawing on risk allocation theory, we hypothesized that the timing of behavior in ruminants is influenced by the independent effects of light on motivation to feed and perceived risk of predation. We predicted that the antithetical relationship between these 2 drivers would vary with photoperiod, resulting in a systematic shift in the phase of activity relative to the solar cycle across the year. This prediction was formalized in a model in which phase of activity emerges from a photoperiod-dependent trade-off between food and safety. We tested this model using data on the temporal pattern of activity in reindeer/caribou Rangifer tarandus free-living at natural mountain pasture in sub-Arctic Norway. The resulting nonlinear relationship between the phasing of crepuscular activity and photoperiod, consistent with the model, suggests a mechanism for behavioral timing that is independent of the core circadian system. We anticipate that such timing depends on integration of metabolic feedback from the digestive system and the activity of the glucocorticoid axis which modulates the behavioral responses of the animal to environmental hazard. The hypothalamus is the obvious neural substrate to achieve this integration. |
format |
Article in Journal/Newspaper |
author |
Tyler, Nicholas J. C. Gregorini, Pablo Forchhammer, Mads C. Stokkan, Karl-Arne van Oort, Bob E. H. Hazlerigg, David G. |
author_facet |
Tyler, Nicholas J. C. Gregorini, Pablo Forchhammer, Mads C. Stokkan, Karl-Arne van Oort, Bob E. H. Hazlerigg, David G. |
author_sort |
Tyler, Nicholas J. C. |
title |
Behavioral Timing without Clockwork |
title_short |
Behavioral Timing without Clockwork |
title_full |
Behavioral Timing without Clockwork |
title_fullStr |
Behavioral Timing without Clockwork |
title_full_unstemmed |
Behavioral Timing without Clockwork |
title_sort |
behavioral timing without clockwork |
publisher |
SAGE Publications |
publishDate |
2016 |
url |
http://dx.doi.org/10.1177/0748730416662778 http://journals.sagepub.com/doi/pdf/10.1177/0748730416662778 http://journals.sagepub.com/doi/full-xml/10.1177/0748730416662778 |
geographic |
Arctic Norway |
geographic_facet |
Arctic Norway |
genre |
Arctic caribou Rangifer tarandus |
genre_facet |
Arctic caribou Rangifer tarandus |
op_source |
Journal of Biological Rhythms volume 31, issue 5, page 522-533 ISSN 0748-7304 1552-4531 |
op_rights |
http://journals.sagepub.com/page/policies/text-and-data-mining-license |
op_doi |
https://doi.org/10.1177/0748730416662778 |
container_title |
Journal of Biological Rhythms |
container_volume |
31 |
container_issue |
5 |
container_start_page |
522 |
op_container_end_page |
533 |
_version_ |
1766333042147721216 |