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...
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Data Archiving and Networked Services (DANS)
2013
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Online Access: | https://doi.org/10.5061/dryad.77f5q |
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fttriple:oai:gotriple.eu:50|dedup_wf_001::e17290e3e88914a312601c69c53d37d5 2023-05-15T18:42:02+02:00 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. 2013-01-01 https://doi.org/10.5061/dryad.77f5q undefined unknown Data Archiving and Networked Services (DANS) http://dx.doi.org/10.5061/dryad.77f5q https://dx.doi.org/10.5061/dryad.77f5q lic_creative-commons oai:easy.dans.knaw.nl:easy-dataset:82875 oai:services.nod.dans.knaw.nl:Products/dans:oai:easy.dans.knaw.nl:easy-dataset:82875 10.5061/dryad.77f5q 10|re3data_____::84e123776089ce3c7a33db98d9cd15a8 10|eurocrisdris::fe4903425d9040f680d8610d9079ea14 10|openaire____::9e3be59865b2c1c335d32dae2fe7b254 10|re3data_____::94816e6421eeb072e7742ce6a9decc5f re3data_____::r3d100000044 10|openaire____::081b82f96300b6a6e3d282bad31cb6e2 10|opendoar____::8b6dd7db9af49e67306feb59a8bdc52c Life sciences medicine and health care Oncorhynchus nerka Ursus arctos Fish Density Dependence Foraging: behavior Selection: natural Hansen Creek Wood River System Bristol Bay Alaska Lake Aleknagik envir geo Dataset https://vocabularies.coar-repositories.org/resource_types/c_ddb1/ 2013 fttriple https://doi.org/10.5061/dryad.77f5q 2023-01-22T17:42:10Z 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 ... Dataset Ursus arctos Alaska Unknown Sockeye ENVELOPE(-130.143,-130.143,54.160,54.160) Wood River ENVELOPE(-63.157,-63.157,82.502,82.502) Hansen Creek ENVELOPE(-96.803,-96.803,55.591,55.591) |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
unknown |
topic |
Life sciences medicine and health care Oncorhynchus nerka Ursus arctos Fish Density Dependence Foraging: behavior Selection: natural Hansen Creek Wood River System Bristol Bay Alaska Lake Aleknagik envir geo |
spellingShingle |
Life sciences medicine and health care Oncorhynchus nerka Ursus arctos Fish Density Dependence Foraging: behavior Selection: natural Hansen Creek Wood River System Bristol Bay Alaska Lake Aleknagik envir geo 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 |
Life sciences medicine and health care Oncorhynchus nerka Ursus arctos Fish Density Dependence Foraging: behavior Selection: natural Hansen Creek Wood River System Bristol Bay Alaska Lake Aleknagik envir geo |
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 |
Dataset |
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 |
Data Archiving and Networked Services (DANS) |
publishDate |
2013 |
url |
https://doi.org/10.5061/dryad.77f5q |
long_lat |
ENVELOPE(-130.143,-130.143,54.160,54.160) ENVELOPE(-63.157,-63.157,82.502,82.502) ENVELOPE(-96.803,-96.803,55.591,55.591) |
geographic |
Sockeye Wood River Hansen Creek |
geographic_facet |
Sockeye Wood River Hansen Creek |
genre |
Ursus arctos Alaska |
genre_facet |
Ursus arctos Alaska |
op_source |
oai:easy.dans.knaw.nl:easy-dataset:82875 oai:services.nod.dans.knaw.nl:Products/dans:oai:easy.dans.knaw.nl:easy-dataset:82875 10.5061/dryad.77f5q 10|re3data_____::84e123776089ce3c7a33db98d9cd15a8 10|eurocrisdris::fe4903425d9040f680d8610d9079ea14 10|openaire____::9e3be59865b2c1c335d32dae2fe7b254 10|re3data_____::94816e6421eeb072e7742ce6a9decc5f re3data_____::r3d100000044 10|openaire____::081b82f96300b6a6e3d282bad31cb6e2 10|opendoar____::8b6dd7db9af49e67306feb59a8bdc52c |
op_relation |
http://dx.doi.org/10.5061/dryad.77f5q https://dx.doi.org/10.5061/dryad.77f5q |
op_rights |
lic_creative-commons |
op_doi |
https://doi.org/10.5061/dryad.77f5q |
_version_ |
1766231624442183680 |