Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey
Can variation in prey density drive changes in the intensity or direction of selective predation in natural systems? Despite ample evidence of density-dependent selection, the influence of prey density on predatory selection patterns has seldom been investigated empirically. We used 20 years of fiel...
Main Authors: | , , |
---|---|
Format: | Other/Unknown Material |
Language: | unknown |
Published: |
Zenodo
2013
|
Subjects: | |
Online Access: | https://doi.org/10.5061/dryad.77f5q |
id |
ftzenodo:oai:zenodo.org:4931635 |
---|---|
record_format |
openpolar |
spelling |
ftzenodo:oai:zenodo.org:4931635 2024-09-15T18:40:12+00:00 Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey Cunningham, Curry James Ruggerone, Gregory T. Quinn, Thomas P. 2013-01-24 https://doi.org/10.5061/dryad.77f5q unknown Zenodo https://doi.org/10.1086/670026 https://zenodo.org/communities/dryad https://doi.org/10.5061/dryad.77f5q oai:zenodo.org:4931635 info:eu-repo/semantics/openAccess Creative Commons Zero v1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/legalcode Oncorhynchus nerka Ursus arctos Foraging: behavior Selection: natural info:eu-repo/semantics/other 2013 ftzenodo https://doi.org/10.5061/dryad.77f5q10.1086/670026 2024-07-25T10:26:43Z Can variation in prey density drive changes in the intensity or direction of selective predation in natural systems? Despite ample evidence of density-dependent selection, the influence of prey density on predatory selection patterns has seldom been investigated empirically. We used 20 years of field data on brown bears (Ursus arctos) foraging on sockeye salmon (Oncorhynchus nerka) in Alaska, to test the hypothesis that salmon density affects the strength of size-selective predation. Measurements from 41,240 individual salmon were used to calculate variance-standardized selection differentials describing the direction and magnitude of selection. Across the time series, the intensity of predatory selection was inversely correlated with salmon density; greater selection for smaller salmon occurred at low salmon densities as bears' tendency to kill larger-than-average salmon was magnified. This novel connection between density dependence and selective predation runs contrary to some aspects of optimal foraging theory and differs from many observations of density-dependent selection because (1) the direction of selection remains constant while its magnitude changes as a function of density and (2) stronger selection is observed at low abundance. These findings indicate that sockeye salmon may be subject to fishery-induced size selection from both direct mechanisms and latent effects of altered predatory selection patterns on the spawning grounds, resulting from reduced salmon abundance. Hansen Creek, Alaska Survey Data for sockeye salmon (Oncorhynchus nerka) These data are a compilation of daily stream surveys in conjunction with a long-term study of the evolutionary ecology of sockeye salmon (Oncorhynchus nerka) in Hansen Creek, a tributary of the Wood River system of Bristol Bay, Alaska. Data pertaining to tagged fish from 1990 to 1993 have been compiled from Dr. Ruggerone. Data from 1997-2012 are daily records of all dead salmon observed at the mouth of Hansen Creek and within the stream proper and have been ... Other/Unknown Material Ursus arctos Alaska Zenodo |
institution |
Open Polar |
collection |
Zenodo |
op_collection_id |
ftzenodo |
language |
unknown |
topic |
Oncorhynchus nerka Ursus arctos Foraging: behavior Selection: natural |
spellingShingle |
Oncorhynchus nerka Ursus arctos Foraging: behavior Selection: natural Cunningham, Curry James Ruggerone, Gregory T. Quinn, Thomas P. Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey |
topic_facet |
Oncorhynchus nerka Ursus arctos Foraging: behavior Selection: natural |
description |
Can variation in prey density drive changes in the intensity or direction of selective predation in natural systems? Despite ample evidence of density-dependent selection, the influence of prey density on predatory selection patterns has seldom been investigated empirically. We used 20 years of field data on brown bears (Ursus arctos) foraging on sockeye salmon (Oncorhynchus nerka) in Alaska, to test the hypothesis that salmon density affects the strength of size-selective predation. Measurements from 41,240 individual salmon were used to calculate variance-standardized selection differentials describing the direction and magnitude of selection. Across the time series, the intensity of predatory selection was inversely correlated with salmon density; greater selection for smaller salmon occurred at low salmon densities as bears' tendency to kill larger-than-average salmon was magnified. This novel connection between density dependence and selective predation runs contrary to some aspects of optimal foraging theory and differs from many observations of density-dependent selection because (1) the direction of selection remains constant while its magnitude changes as a function of density and (2) stronger selection is observed at low abundance. These findings indicate that sockeye salmon may be subject to fishery-induced size selection from both direct mechanisms and latent effects of altered predatory selection patterns on the spawning grounds, resulting from reduced salmon abundance. Hansen Creek, Alaska Survey Data for sockeye salmon (Oncorhynchus nerka) These data are a compilation of daily stream surveys in conjunction with a long-term study of the evolutionary ecology of sockeye salmon (Oncorhynchus nerka) in Hansen Creek, a tributary of the Wood River system of Bristol Bay, Alaska. Data pertaining to tagged fish from 1990 to 1993 have been compiled from Dr. Ruggerone. Data from 1997-2012 are daily records of all dead salmon observed at the mouth of Hansen Creek and within the stream proper and have been ... |
format |
Other/Unknown Material |
author |
Cunningham, Curry James Ruggerone, Gregory T. Quinn, Thomas P. |
author_facet |
Cunningham, Curry James Ruggerone, Gregory T. Quinn, Thomas P. |
author_sort |
Cunningham, Curry James |
title |
Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey |
title_short |
Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey |
title_full |
Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey |
title_fullStr |
Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey |
title_full_unstemmed |
Data from: Size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey |
title_sort |
data from: size-selectivity of predation by brown bears depends on the density of their sockeye salmon prey |
publisher |
Zenodo |
publishDate |
2013 |
url |
https://doi.org/10.5061/dryad.77f5q |
genre |
Ursus arctos Alaska |
genre_facet |
Ursus arctos Alaska |
op_relation |
https://doi.org/10.1086/670026 https://zenodo.org/communities/dryad https://doi.org/10.5061/dryad.77f5q oai:zenodo.org:4931635 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Zero v1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/legalcode |
op_doi |
https://doi.org/10.5061/dryad.77f5q10.1086/670026 |
_version_ |
1810484513972682752 |