Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon
We examined how glucocorticoid and testosterone concentrations changed from spring to summer by livetrapping free-living populations of arctic ground squirrels (Spermophilus parryii). The primary glucocorticoid was found to be cortisol, with corticosterone below measurable concentrations in most ind...
Main Authors: | , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
NRC Canada
2001
|
Subjects: | |
Online Access: | http://hdl.handle.net/1807/351 |
id |
ftunivtoronto:oai:localhost:1807/351 |
---|---|
record_format |
openpolar |
spelling |
ftunivtoronto:oai:localhost:1807/351 2023-05-15T14:57:52+02:00 Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon Boonstra, Rudy Hubbs, Anne H. Lacey, Eileen A. McColl, Carolyn J. 2001 190830 bytes application/pdf http://hdl.handle.net/1807/351 en eng NRC Canada Can. J. Zool. 79: 49–58 (2001) http://hdl.handle.net/1807/351 Article 2001 ftunivtoronto 2020-06-17T11:06:21Z We examined how glucocorticoid and testosterone concentrations changed from spring to summer by livetrapping free-living populations of arctic ground squirrels (Spermophilus parryii). The primary glucocorticoid was found to be cortisol, with corticosterone below measurable concentrations in most individuals. Livetrapping elicited a strong stress response in both sexes: breeding males and females trapped in spring had free cortisol concentrations 4 and 34 times, respectively, those of base-line animals. The maximum corticosteroid-binding capacity (MCBC) was unaffected by trapping and was about 3 times higher in breeding females than in breeding males. Over the active season, MCBC values were lowest in all male classes (juveniles, nonreproductive adults, and reproductive adults), being less than half those in all female classes; pregnant females had values approximately twice those of juvenile females. However, free cortisol concentrations were similar in all female classes and in juvenile males and about half those in adult males. Livetrapping increased testosterone concentrations in males over those found in samples from base-line males, and testosterone concentrations did not affect MCBC values. Testosterone concentrations in livetrapped animals differed significantly among male classes, with nonreproductive males maintaining concentrations 64% of those in breeding males and 10 times those in juveniles. Article in Journal/Newspaper Arctic Yukon University of Toronto: Research Repository T-Space Arctic Yukon |
institution |
Open Polar |
collection |
University of Toronto: Research Repository T-Space |
op_collection_id |
ftunivtoronto |
language |
English |
description |
We examined how glucocorticoid and testosterone concentrations changed from spring to summer by livetrapping free-living populations of arctic ground squirrels (Spermophilus parryii). The primary glucocorticoid was found to be cortisol, with corticosterone below measurable concentrations in most individuals. Livetrapping elicited a strong stress response in both sexes: breeding males and females trapped in spring had free cortisol concentrations 4 and 34 times, respectively, those of base-line animals. The maximum corticosteroid-binding capacity (MCBC) was unaffected by trapping and was about 3 times higher in breeding females than in breeding males. Over the active season, MCBC values were lowest in all male classes (juveniles, nonreproductive adults, and reproductive adults), being less than half those in all female classes; pregnant females had values approximately twice those of juvenile females. However, free cortisol concentrations were similar in all female classes and in juvenile males and about half those in adult males. Livetrapping increased testosterone concentrations in males over those found in samples from base-line males, and testosterone concentrations did not affect MCBC values. Testosterone concentrations in livetrapped animals differed significantly among male classes, with nonreproductive males maintaining concentrations 64% of those in breeding males and 10 times those in juveniles. |
format |
Article in Journal/Newspaper |
author |
Boonstra, Rudy Hubbs, Anne H. Lacey, Eileen A. McColl, Carolyn J. |
spellingShingle |
Boonstra, Rudy Hubbs, Anne H. Lacey, Eileen A. McColl, Carolyn J. Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon |
author_facet |
Boonstra, Rudy Hubbs, Anne H. Lacey, Eileen A. McColl, Carolyn J. |
author_sort |
Boonstra, Rudy |
title |
Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon |
title_short |
Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon |
title_full |
Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon |
title_fullStr |
Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon |
title_full_unstemmed |
Seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the Yukon |
title_sort |
seasonal changes in glucocorticoid and testosterone concentrations in free-living arctic ground squirrels from the boreal forest of the yukon |
publisher |
NRC Canada |
publishDate |
2001 |
url |
http://hdl.handle.net/1807/351 |
geographic |
Arctic Yukon |
geographic_facet |
Arctic Yukon |
genre |
Arctic Yukon |
genre_facet |
Arctic Yukon |
op_relation |
Can. J. Zool. 79: 49–58 (2001) http://hdl.handle.net/1807/351 |
_version_ |
1766329973030780928 |