Age, state, environment, and season dependence of senescence in body mass
Abstract Senescence is a highly variable process that comprises both age‐dependent and state‐dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age‐dependent and state‐dependent senescence in key life‐history traits acr...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2018-02-01
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| Series: | Ecology and Evolution |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ece3.3787 |
| _version_ | 1819327163659190272 |
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| author | Svenja B. Kroeger Daniel T. Blumstein Kenneth B. Armitage Jane M. Reid Julien G. A. Martin |
| author_facet | Svenja B. Kroeger Daniel T. Blumstein Kenneth B. Armitage Jane M. Reid Julien G. A. Martin |
| author_sort | Svenja B. Kroeger |
| collection | DOAJ |
| description | Abstract Senescence is a highly variable process that comprises both age‐dependent and state‐dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age‐dependent and state‐dependent senescence in key life‐history traits across individuals inhabiting different spatially structured and seasonal environments. We used longitudinal data from wild female yellow‐bellied marmots (Marmota flaviventer), living in two adjacent environments that differ in elevation and associated phenology, to quantify how age and individual state, measured as “time to death,” affect body mass senescence in different environments. Further, we quantified how patterns of senescence differed between two biologically distinct seasons, spring, and late summer. Body mass senescence had an age‐dependent component, expressed as a decrease in mass in old age. Overall, estimated age‐dependent senescence was greater in females living in the more favorable lower elevation environment, than in the harsher higher elevation environment, and greater in late summer than in spring. Body mass senescence also had a state‐dependent component, captured by effects of time to death, but only in the more favorable lower elevation environment. In spring, body mass gradually decreased from 2 years before death, whereas in late summer, state‐dependent effects were expressed as a terminal decrease in body mass in the last year of life. Contrary to expectations, we found that senescence was more likely to be observed under more favorable environmental conditions, rather than under harsher conditions. By further demonstrating that senescence patterns differ among seasons, our results imply that within‐year temporal environmental variation must be considered alongside spatial environmental variation in order to characterize and understand the pattern and magnitude of senescence in wild populations. |
| first_indexed | 2024-12-24T13:06:29Z |
| format | Article |
| id | doaj.art-405e847ea6b046db957bbca61e1879cf |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-12-24T13:06:29Z |
| publishDate | 2018-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-405e847ea6b046db957bbca61e1879cf2022-12-21T16:53:59ZengWileyEcology and Evolution2045-77582018-02-01842050206110.1002/ece3.3787Age, state, environment, and season dependence of senescence in body massSvenja B. Kroeger0Daniel T. Blumstein1Kenneth B. Armitage2Jane M. Reid3Julien G. A. Martin4Institute of Biological and Environmental Sciences School of Biological Sciences Zoology Building University of Aberdeen Aberdeen UKDepartment of Ecology and Evolutionary Biology University of California Los Angeles CA USAEcology and Evolutionary Biology Department The University of Kansas Lawrence KS USAInstitute of Biological and Environmental Sciences School of Biological Sciences Zoology Building University of Aberdeen Aberdeen UKInstitute of Biological and Environmental Sciences School of Biological Sciences Zoology Building University of Aberdeen Aberdeen UKAbstract Senescence is a highly variable process that comprises both age‐dependent and state‐dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age‐dependent and state‐dependent senescence in key life‐history traits across individuals inhabiting different spatially structured and seasonal environments. We used longitudinal data from wild female yellow‐bellied marmots (Marmota flaviventer), living in two adjacent environments that differ in elevation and associated phenology, to quantify how age and individual state, measured as “time to death,” affect body mass senescence in different environments. Further, we quantified how patterns of senescence differed between two biologically distinct seasons, spring, and late summer. Body mass senescence had an age‐dependent component, expressed as a decrease in mass in old age. Overall, estimated age‐dependent senescence was greater in females living in the more favorable lower elevation environment, than in the harsher higher elevation environment, and greater in late summer than in spring. Body mass senescence also had a state‐dependent component, captured by effects of time to death, but only in the more favorable lower elevation environment. In spring, body mass gradually decreased from 2 years before death, whereas in late summer, state‐dependent effects were expressed as a terminal decrease in body mass in the last year of life. Contrary to expectations, we found that senescence was more likely to be observed under more favorable environmental conditions, rather than under harsher conditions. By further demonstrating that senescence patterns differ among seasons, our results imply that within‐year temporal environmental variation must be considered alongside spatial environmental variation in order to characterize and understand the pattern and magnitude of senescence in wild populations.https://doi.org/10.1002/ece3.3787agingaltitudelate lifelifespannatural populationreverse age |
| spellingShingle | Svenja B. Kroeger Daniel T. Blumstein Kenneth B. Armitage Jane M. Reid Julien G. A. Martin Age, state, environment, and season dependence of senescence in body mass Ecology and Evolution aging altitude late life lifespan natural population reverse age |
| title | Age, state, environment, and season dependence of senescence in body mass |
| title_full | Age, state, environment, and season dependence of senescence in body mass |
| title_fullStr | Age, state, environment, and season dependence of senescence in body mass |
| title_full_unstemmed | Age, state, environment, and season dependence of senescence in body mass |
| title_short | Age, state, environment, and season dependence of senescence in body mass |
| title_sort | age state environment and season dependence of senescence in body mass |
| topic | aging altitude late life lifespan natural population reverse age |
| url | https://doi.org/10.1002/ece3.3787 |
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