Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System
Common Murre (Uria aalge) are the most abundant avian apex predator nesting in the California Current System (CCS) and nesting is the most energetically demanding phase of their lifecycle. The preyscape within flight distance of their nesting colony determines whether murres produce young, how hard...
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ftsanjosestate:oai:scholarworks.sjsu.edu:etd_theses-8529 2023-07-30T04:02:59+02:00 Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System Schneider, Stephanie Rianne 2018-12-30T08:00:00Z application/pdf https://scholarworks.sjsu.edu/etd_theses/4982 https://doi.org/10.31979/etd.7p63-75jz https://scholarworks.sjsu.edu/context/etd_theses/article/8529/viewcontent/Schneide.PDF unknown SJSU ScholarWorks https://scholarworks.sjsu.edu/etd_theses/4982 doi:10.31979/etd.7p63-75jz https://scholarworks.sjsu.edu/context/etd_theses/article/8529/viewcontent/Schneide.PDF Master's Theses apex predator California Current System common murre diet foraging effort reproduction Ecology Wildlife conservation Wildlife management text 2018 ftsanjosestate https://doi.org/10.31979/etd.7p63-75jz 2023-07-17T19:04:59Z Common Murre (Uria aalge) are the most abundant avian apex predator nesting in the California Current System (CCS) and nesting is the most energetically demanding phase of their lifecycle. The preyscape within flight distance of their nesting colony determines whether murres produce young, how hard they must work to do so, and what prey types are available to them. This study characterized the reproductive performance, foraging effort, and prey composition of murres nesting at a previously unstudied and large nesting colony in the CCS, Castle Rock National Wildlife Refuge, over an 11-year period (2007 - 2017) intended to capture a representative range of prey conditions. Timing of upwelling, coincident with seasonal increase in prey, accounted for 70% of the variability in nest initiation by murres. Reproductive success averaged 61% and, even in the most successful years, murres approached their behavioral limit to increase foraging effort and obtain adequate prey; crossing this threshold resulted in chicks being left unattended and widespread nest failure in 3 study years (2007, 2016, and 2017). Smelt and rockfish dominated the diet in good years and anchovy dominated in bad years. Prey available to murres nesting at this large colony closely matched the amount of prey required for them to produce young and, based on current conditions, even small shifts causing demand to exceed availability could result in large-scale reproductive failure of murres as well as other seabirds nesting here. Text Common Murre Uria aalge Castle Rock uria San José State University: SJSU ScholarWorks Castle Rock ENVELOPE(-130.208,-130.208,57.840,57.840) |
institution |
Open Polar |
collection |
San José State University: SJSU ScholarWorks |
op_collection_id |
ftsanjosestate |
language |
unknown |
topic |
apex predator California Current System common murre diet foraging effort reproduction Ecology Wildlife conservation Wildlife management |
spellingShingle |
apex predator California Current System common murre diet foraging effort reproduction Ecology Wildlife conservation Wildlife management Schneider, Stephanie Rianne Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System |
topic_facet |
apex predator California Current System common murre diet foraging effort reproduction Ecology Wildlife conservation Wildlife management |
description |
Common Murre (Uria aalge) are the most abundant avian apex predator nesting in the California Current System (CCS) and nesting is the most energetically demanding phase of their lifecycle. The preyscape within flight distance of their nesting colony determines whether murres produce young, how hard they must work to do so, and what prey types are available to them. This study characterized the reproductive performance, foraging effort, and prey composition of murres nesting at a previously unstudied and large nesting colony in the CCS, Castle Rock National Wildlife Refuge, over an 11-year period (2007 - 2017) intended to capture a representative range of prey conditions. Timing of upwelling, coincident with seasonal increase in prey, accounted for 70% of the variability in nest initiation by murres. Reproductive success averaged 61% and, even in the most successful years, murres approached their behavioral limit to increase foraging effort and obtain adequate prey; crossing this threshold resulted in chicks being left unattended and widespread nest failure in 3 study years (2007, 2016, and 2017). Smelt and rockfish dominated the diet in good years and anchovy dominated in bad years. Prey available to murres nesting at this large colony closely matched the amount of prey required for them to produce young and, based on current conditions, even small shifts causing demand to exceed availability could result in large-scale reproductive failure of murres as well as other seabirds nesting here. |
format |
Text |
author |
Schneider, Stephanie Rianne |
author_facet |
Schneider, Stephanie Rianne |
author_sort |
Schneider, Stephanie Rianne |
title |
Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System |
title_short |
Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System |
title_full |
Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System |
title_fullStr |
Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System |
title_full_unstemmed |
Reproductive Performance, Foraging Effort, and Diet of an Apex Predator, the Common Murre, at one of the Largest Nesting Colonies in the California Current System |
title_sort |
reproductive performance, foraging effort, and diet of an apex predator, the common murre, at one of the largest nesting colonies in the california current system |
publisher |
SJSU ScholarWorks |
publishDate |
2018 |
url |
https://scholarworks.sjsu.edu/etd_theses/4982 https://doi.org/10.31979/etd.7p63-75jz https://scholarworks.sjsu.edu/context/etd_theses/article/8529/viewcontent/Schneide.PDF |
long_lat |
ENVELOPE(-130.208,-130.208,57.840,57.840) |
geographic |
Castle Rock |
geographic_facet |
Castle Rock |
genre |
Common Murre Uria aalge Castle Rock uria |
genre_facet |
Common Murre Uria aalge Castle Rock uria |
op_source |
Master's Theses |
op_relation |
https://scholarworks.sjsu.edu/etd_theses/4982 doi:10.31979/etd.7p63-75jz https://scholarworks.sjsu.edu/context/etd_theses/article/8529/viewcontent/Schneide.PDF |
op_doi |
https://doi.org/10.31979/etd.7p63-75jz |
_version_ |
1772813897095446528 |