Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien
Populations characterised by cyclic fluctuations have fascinated and continue to generate a great interest among the scientific community because of the complexity of the regulating factors. Several hypotheses have been proposed to explain these cyclical fluctuations but no consensus has yet been re...
Main Author: | |
---|---|
Other Authors: | , |
Format: | Thesis |
Language: | French |
Published: |
Université Laval
2016
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11794/26955 |
id |
fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/26955 |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/26955 2023-05-15T15:14:22+02:00 Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien Direct and indirect effects of predation on lemmings in the Canadian Arctic Fauteux, Dominique Gauthier, Gilles Berteaux, Dominique Nunavut 2016-01-01 https://hdl.handle.net/20.500.11794/26955 fr fre Université Laval http://hdl.handle.net/20.500.11794/26955 CorpusUL envir geo Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2016 fttriple https://doi.org/20.500.11794/26955 2023-01-22T16:59:58Z Populations characterised by cyclic fluctuations have fascinated and continue to generate a great interest among the scientific community because of the complexity of the regulating factors. Several hypotheses have been proposed to explain these cyclical fluctuations but no consensus has yet been reached despite nearly 100 years of research. The availability of food and social effects (e.g. competitive interactions) has been proposed as factors responsible for cycles in certain species. However, predation is probably the factor most likely to cause cyclical fluctuations in wildlife populations due to its delayed density-dependence. A circular tandem of rarefaction and densification of predators and prey caused by direct effects (i.e. mortalities) can cause cycles of abundance. Moreover, recent studies show that indirect effects of predation such as stress could be as important as direct effects in generating cycles. This thesis aims to identify direct and indirect effects of predation that affect the cyclic brown lemming populations of Bylot Island, Nunavut, which is characterized by 3-4 yr cycles. To do this, we first compared the plausibility of the food limitation hypothesis vs. the predation limitation hypothesis by determining the seasonal timing of lemming cycles. We then we built a 9-ha fence in 2012-2013 covered by an anti-avian predator net in which we trapped lemmings from 2013 to 2015. A second control trapping grid was used for comparisons. These two grids were active since 2008, allowing us to have a pre-experimental control for demographic parameters (direct effects). In 2014 and 2015, we collected lemming feces in the two trapping grids to quantify stress hormone metabolites. A validation of the measurement of fecal glucocorticoid metabolites (i.e. stress hormones) was conducted to measure stress non-invasively. The results are clear: (1) the decline of lemmings occurs in late summer when predators are at their peak abundance and not in late winter, thereby supporting the predator-limitation ... Thesis Arctic Bylot Island Nunavut Unknown Arctic Nunavut Bylot Island |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
French |
topic |
envir geo |
spellingShingle |
envir geo Fauteux, Dominique Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien |
topic_facet |
envir geo |
description |
Populations characterised by cyclic fluctuations have fascinated and continue to generate a great interest among the scientific community because of the complexity of the regulating factors. Several hypotheses have been proposed to explain these cyclical fluctuations but no consensus has yet been reached despite nearly 100 years of research. The availability of food and social effects (e.g. competitive interactions) has been proposed as factors responsible for cycles in certain species. However, predation is probably the factor most likely to cause cyclical fluctuations in wildlife populations due to its delayed density-dependence. A circular tandem of rarefaction and densification of predators and prey caused by direct effects (i.e. mortalities) can cause cycles of abundance. Moreover, recent studies show that indirect effects of predation such as stress could be as important as direct effects in generating cycles. This thesis aims to identify direct and indirect effects of predation that affect the cyclic brown lemming populations of Bylot Island, Nunavut, which is characterized by 3-4 yr cycles. To do this, we first compared the plausibility of the food limitation hypothesis vs. the predation limitation hypothesis by determining the seasonal timing of lemming cycles. We then we built a 9-ha fence in 2012-2013 covered by an anti-avian predator net in which we trapped lemmings from 2013 to 2015. A second control trapping grid was used for comparisons. These two grids were active since 2008, allowing us to have a pre-experimental control for demographic parameters (direct effects). In 2014 and 2015, we collected lemming feces in the two trapping grids to quantify stress hormone metabolites. A validation of the measurement of fecal glucocorticoid metabolites (i.e. stress hormones) was conducted to measure stress non-invasively. The results are clear: (1) the decline of lemmings occurs in late summer when predators are at their peak abundance and not in late winter, thereby supporting the predator-limitation ... |
author2 |
Gauthier, Gilles Berteaux, Dominique |
format |
Thesis |
author |
Fauteux, Dominique |
author_facet |
Fauteux, Dominique |
author_sort |
Fauteux, Dominique |
title |
Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien |
title_short |
Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien |
title_full |
Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien |
title_fullStr |
Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien |
title_full_unstemmed |
Effets directs et indirects de la prédation sur les lemmings dans l'Arctique canadien |
title_sort |
effets directs et indirects de la prédation sur les lemmings dans l'arctique canadien |
publisher |
Université Laval |
publishDate |
2016 |
url |
https://hdl.handle.net/20.500.11794/26955 |
op_coverage |
Nunavut |
geographic |
Arctic Nunavut Bylot Island |
geographic_facet |
Arctic Nunavut Bylot Island |
genre |
Arctic Bylot Island Nunavut |
genre_facet |
Arctic Bylot Island Nunavut |
op_source |
CorpusUL |
op_relation |
http://hdl.handle.net/20.500.11794/26955 |
op_doi |
https://doi.org/20.500.11794/26955 |
_version_ |
1766344831862308864 |