The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach
We examined how manipulating operational sex ratio (OSR: the ratio of reproductively active males to fertilizable females), could affect the intensity of competition in reindeer (Rangifer tarandus) using an experimental approach to test mating systems theory on the very first field study on large ma...
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ftconcordiauniv:oai:https://spectrum.library.concordia.ca:981445 2023-05-15T18:04:04+02:00 The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach Alo, Franco M. 2016-08 text https://spectrum.library.concordia.ca/id/eprint/981445/ https://spectrum.library.concordia.ca/id/eprint/981445/1/Alo_MSc_F2016.pdf en eng https://spectrum.library.concordia.ca/id/eprint/981445/1/Alo_MSc_F2016.pdf Alo, Franco M. (2016) The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach. Masters thesis, Concordia University. term_access Thesis NonPeerReviewed 2016 ftconcordiauniv 2022-05-28T19:02:07Z We examined how manipulating operational sex ratio (OSR: the ratio of reproductively active males to fertilizable females), could affect the intensity of competition in reindeer (Rangifer tarandus) using an experimental approach to test mating systems theory on the very first field study on large mammals of its kind. Study was conducted at the Kutuharju Reindeer Research Station where we had access to a herd of semi-domesticated reindeer. We manipulated OSR on two levels in two enclosures, a female biased treatment (3♂:6♀ = OSR 0.5) and a sex balanced treatment (3♂:3♀ = OSR 1). Female reindeer were injected with 1 ml of estrumate prior to a trial to promote early and synchronized oestrous to assure competition among our 1.5-year-old males. We predicted that with increasing OSR, male-male aggression would increase and courtship behaviours would decrease, unless males adopted alternative mating tactics. Conversely, female-female aggression was predicted to decrease with increasing OSR. The propensity for males to act agonistically was predicted to increase with increasing OSR. Male-male rate of aggression did not differ between treatments. Female-female rate of aggression was found to decrease significantly with increasing OSR. Propensity to act agonistically was not significantly different between treatments. 1.5-year-old males may be too young and inexperienced to behave predictably. We conclude that the intensity of competition cannot be predicted at the group level based on OSR alone, though some trends emerged. Thesis Rangifer Rangifer tarandus Spectrum: Concordia University Research Repository (Montreal) |
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Spectrum: Concordia University Research Repository (Montreal) |
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English |
description |
We examined how manipulating operational sex ratio (OSR: the ratio of reproductively active males to fertilizable females), could affect the intensity of competition in reindeer (Rangifer tarandus) using an experimental approach to test mating systems theory on the very first field study on large mammals of its kind. Study was conducted at the Kutuharju Reindeer Research Station where we had access to a herd of semi-domesticated reindeer. We manipulated OSR on two levels in two enclosures, a female biased treatment (3♂:6♀ = OSR 0.5) and a sex balanced treatment (3♂:3♀ = OSR 1). Female reindeer were injected with 1 ml of estrumate prior to a trial to promote early and synchronized oestrous to assure competition among our 1.5-year-old males. We predicted that with increasing OSR, male-male aggression would increase and courtship behaviours would decrease, unless males adopted alternative mating tactics. Conversely, female-female aggression was predicted to decrease with increasing OSR. The propensity for males to act agonistically was predicted to increase with increasing OSR. Male-male rate of aggression did not differ between treatments. Female-female rate of aggression was found to decrease significantly with increasing OSR. Propensity to act agonistically was not significantly different between treatments. 1.5-year-old males may be too young and inexperienced to behave predictably. We conclude that the intensity of competition cannot be predicted at the group level based on OSR alone, though some trends emerged. |
format |
Thesis |
author |
Alo, Franco M. |
spellingShingle |
Alo, Franco M. The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach |
author_facet |
Alo, Franco M. |
author_sort |
Alo, Franco M. |
title |
The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach |
title_short |
The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach |
title_full |
The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach |
title_fullStr |
The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach |
title_full_unstemmed |
The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach |
title_sort |
influence of operational sex ratio on the intensity of competition in reindeer (rangifer tarandus) during rut: an experimental approach |
publishDate |
2016 |
url |
https://spectrum.library.concordia.ca/id/eprint/981445/ https://spectrum.library.concordia.ca/id/eprint/981445/1/Alo_MSc_F2016.pdf |
genre |
Rangifer Rangifer tarandus |
genre_facet |
Rangifer Rangifer tarandus |
op_relation |
https://spectrum.library.concordia.ca/id/eprint/981445/1/Alo_MSc_F2016.pdf Alo, Franco M. (2016) The Influence of Operational Sex Ratio on the Intensity of Competition in Reindeer (Rangifer tarandus) during Rut: An Experimental Approach. Masters thesis, Concordia University. |
op_rights |
term_access |
_version_ |
1766175329155547136 |