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Twardek WM, Knight K, Reid C, Lennox RJ, Cooke S, Lapointe N. Insights into Chinook salmon movement ecology in the terminal reaches of the upper Yukon River during the spawning migration. CAN J ZOOL 2022. [DOI: 10.1139/cjz-2022-0012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chinook salmon (Oncorhynchus tshawytscha, Walbaum 1792) from the upper Yukon River are highly unique, with some populations migrating nearly 3,000 km to spawning habitat near the northern range limit for the species. We conducted a 4-year study to understand the behaviour of Chinook salmon in the terminal reaches of their migration by tagging salmon with acoustic and radio transmitters in Whitehorse, Yukon, ~2800 rkm from the ocean. Various migration characteristics were quantified for Chinook salmon including en route mortality, diel behaviour, migration rates, and homing patterns, and associations with salmon origin (wild vs. hatchery), sex, size, and migration timing were explored. Salmon had high survival to spawning grounds (>98%) and migrated throughout all hours of the day, with higher proportions of nighttime movements in a smaller spawning tributary than in the Yukon River mainstem. Migration rates were faster for larger salmon as well as late-arriving salmon, which was likely necessary to ensure they had sufficient time and suitable conditions on spawning grounds to reproduce. Non-direct homing movements (e.g. tributary exploration) were more common in male salmon and considerably increased migration distance through the study area. Findings from this study may help to inform the complex international and inter-nation management of these increasingly threatened Chinook salmon populations.
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Affiliation(s)
- William M. Twardek
- Canadian Wildlife Federation, 459458, Kanata, Canada, K2M 2W1
- Carleton University, 6339, Department of Biology, Ottawa, Canada, K1S 5B6
| | - K.L. Knight
- Carcross/ Tagish First Nation, Whitehorse, Yukon, Canada
| | - C.H. Reid
- Carleton University, 6339, Department of Biology, Ottawa, Canada
| | | | - S.J. Cooke
- Carleton University, 6339, Department of Biology, Ottawa, Canada
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Quinn TP. Time Required for Brown Bears to Capture and Consume Pacific Salmon. WEST N AM NATURALIST 2021. [DOI: 10.3398/064.081.0318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Thomas P. Quinn
- School of Aquatic and Fishery Sciences, Box 355020, University of Washington, Seattle, WA 98195
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Lincoln A, Wirsing A, Quinn T. Prevalence and patterns of scavenging by brown bears ( Ursus arctos) on salmon ( Oncorhynchus spp.) carcasses. CAN J ZOOL 2021. [DOI: 10.1139/cjz-2020-0104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Scavenging, an underappreciated mechanism of prey consumption for many predators, can contribute substantially to nutritional intake. Facultative scavengers such as brown bears (Ursus arctos Linnaeus, 1758) may both kill and scavenge Pacific salmon (genus Oncorhynchus Suckley, 1861), though the extent of scavenging and factors affecting this behavior are unclear. We tagged 899 sockeye salmon (Oncorhynchus nerka (Walbaum in Artedi, 1792)) carcasses and placed them on streambanks over 5 years at multiple sites in southwestern Alaska (USA) where brown bears annually prey on spawning sockeye salmon. Examination of carcasses revealed overall scavenging rates of 15% after 1 day and 54% after 3 days. Scavenging rate varied by site and year and increased throughout the salmon run. Contrary to predictions, scavenging was more frequent in senescent or bear-killed carcasses than ripe carcasses. Carcass consumption ranged from minimal to almost complete; body and brain tissues were most frequently consumed after 3 days (68% and 63% of carcasses, respectively). We also documented secondary scavenging (i.e., tissue consumption on two separate events) and delayed scavenging (i.e., scavenging observed after 3 days but not 1 day). Taken together, the results indicated that scavenging in these streams contributes significantly to total consumption of salmon by bears, with ramifications for other components of these salmon-dependent ecosystems.
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Affiliation(s)
- A.E. Lincoln
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle, WA 98195, USA
| | - A.J. Wirsing
- School of Environmental and Forest Sciences, University of Washington, 4000 15th Avenue NE, Seattle, WA 98195, USA
| | - T.P. Quinn
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle, WA 98195, USA
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Walsh JC, Pendray JE, Godwin SC, Artelle KA, Kindsvater HK, Field RD, Harding JN, Swain NR, Reynolds JD. Relationships between Pacific salmon and aquatic and terrestrial ecosystems: implications for ecosystem-based management. Ecology 2020; 101:e03060. [PMID: 32266971 PMCID: PMC7537986 DOI: 10.1002/ecy.3060] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/10/2020] [Accepted: 02/24/2020] [Indexed: 11/18/2022]
Abstract
Pacific salmon influence temperate terrestrial and freshwater ecosystems through the dispersal of marine‐derived nutrients and ecosystem engineering of stream beds when spawning. They also support large fisheries, particularly along the west coast of North America. We provide a comprehensive synthesis of relationships between the densities of Pacific salmon and terrestrial and aquatic ecosystems, summarize the direction, shape, and magnitude of these relationships, and identify possible ecosystem‐based management indicators and benchmarks. We found 31 studies that provided 172 relationships between salmon density (or salmon abundance) and species abundance, species diversity, food provisioning, individual growth, concentration of marine‐derived isotopes, nutrient enhancement, phenology, and several other ecological responses. The most common published relationship was between salmon density and marine‐derived isotopes (40%), whereas very few relationships quantified ecosystem‐level responses (5%). Only 13% of all relationships tended to reach an asymptote (i.e., a saturating response) as salmon densities increased. The number of salmon killed by bears and the change in biomass of different stream invertebrate taxa between spawning and nonspawning seasons were relationships that usually reached saturation. Approximately 46% of all relationships were best described with linear or curved nonasymptotic models, indicating a lack of saturation. In contrast, 41% of data sets showed no relationship with salmon density or abundance, including many of the relationships with stream invertebrate and biofilm biomass density, marine‐derived isotope concentrations, or vegetation density. Bears required the highest densities of salmon to reach their maximum observed food consumption (i.e., 9.2 kg/m2 to reach the 90% threshold of the relationship’s asymptote), followed by freshwater fish abundance (90% threshold = 7.3 kg/m2 of salmon). Although the effects of salmon density on ecosystems are highly varied, it appears that several of these relationships, such as bear food consumption, could be used to develop indicators and benchmarks for ecosystem‐based fisheries management.
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Affiliation(s)
- Jessica C Walsh
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Jane E Pendray
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Sean C Godwin
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kyle A Artelle
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.,Raincoast Conservation Foundation, P.O. Box 2429, Sidney, British Columbia, V8L 3Y3, Canada
| | - Holly K Kindsvater
- Department of Ecology, Evolution and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey, 08908, USA
| | - Rachel D Field
- Department of Biology, The Okanagan Institute for Biodiversity, Resilience and Ecosystem Services (BRAES), Irving K. Barber School of Arts and Sciences, University of British Columbia, Okanagan, SCI 133, 1177 Research Road, Kelowna, British Columbia, V1V 1V7, Canada
| | - Jennifer N Harding
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Noel R Swain
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - John D Reynolds
- Earth to Ocean Research Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
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Rogers MC, Hilderbrand GV, Gustine DD, Joly K, Leacock WB, Mangipane BA, Welker JM. Splitting hairs: dietary niche breadth modelling using stable isotope analysis of a sequentially grown tissue. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2020; 56:358-369. [PMID: 32631088 DOI: 10.1080/10256016.2020.1787404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
Stable isotope data from durable, sequentially grown tissues (e.g. hair, claw, and baleen) is commonly used for modelling dietary niche breadth. The use of tissues grown over multiple months to years, however, has the potential to complicate isotopic niche breadth modelling, as time-averaged stable isotope signals from whole tissues may obscure information available from chronologically resolved stable isotope signals in serially sectioned tissues. We determined if whole samples of brown bear guard hair produced different isotopic niche breadth estimates than those produced from subsampled, serially sectioned samples of the same tissue from the same set of individuals. We sampled guard hair from brown bears (Ursus arctos) in four regions of Alaska with disparate biogeographies and dietary resource availability. Whole hair and serially sectioned hair samples were used to produce paired isotopic dietary niche breadth estimates for each region in the SIBER Bayesian model framework in R. Isotopic data from serially sectioned hair consistently produced larger estimates of isotopic dietary niche breadth than isotope data from whole hair samples. Serial sampling captures finer-scale changes in diet and when cumulatively used to estimate isotopic niche breadth, the serially sampled isotope data more fully captures dietary variability and true isotopic niche breadth.
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Affiliation(s)
- Matthew C Rogers
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
- NOAA Alaska Fisheries Science Center, Auke Bay Laboratories, Juneau, AK, USA
| | | | - David D Gustine
- National Park Service, Grand Teton National Park, Moose, WY, USA
| | - Kyle Joly
- National Park Service, Gates of the Arctic National Park and Preserve, Fairbanks, AK, USA
| | - William B Leacock
- US Fish and Wildlife Service, Kodiak National Wildlife Refuge, Kodiak, AK, USA
| | - Buck A Mangipane
- National Park Service, Lake Clark National Park and Preserve, Port Alsworth, AK, USA
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA
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Lincoln AE, Hilborn R, Wirsing AJ, Quinn TP. Managing salmon for wildlife: Do fisheries limit salmon consumption by bears in small Alaskan streams? ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02061. [PMID: 31863535 DOI: 10.1002/eap.2061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 10/28/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
Ecosystem-based management requires consideration of overlapping resource use between humans and other consumers. Pacific salmon are an important resource for both fisheries and populations of wildlife around the Pacific rim, including coastal brown bears (Ursus arctos); salmon consumption has been positively linked to bear density, body size, and reproductive rate. As a case study within the broader context of human-wildlife competition for food, we used 16-22 yr of empirical data in four different salmon-bearing systems in southwestern Alaska to explore the relationship between sockeye salmon (Oncorhynchus nerka) availability and consumption by bears. We found a negative relationship between the annual biomass of salmon available to bears and the fraction of biomass consumed per fish, and a saturating relationship between salmon availability and the total annual biomass of salmon consumed by bears. Under modeled scenarios, bear consumption of salmon was predicted to increase only with dramatic (on the order of 50-100%) increases in prey availability. Even such large increases in salmon abundance were estimated to produce relatively modest increases in per capita salmon consumption by bears (2.4-4.8 kg·bear-1 ·d-1 , 15-59% of the estimated daily maximum per capita intake), in part because bears did not consume salmon entirely, especially when salmon were most available. Thus, while bears catching salmon in small streams may be limited by salmon harvest in some years, current management of the systems we studied is sufficient for bear populations to reach maximum salmon consumption every 2-4 yr. Consequently, allocating more salmon for brown bear conservation would unlikely result in an ecologically significant response for bears in these systems, though other ecosystem components might benefit. Our results highlight the need for documenting empirical relationships between prey abundance and consumption, particularly in systems with partial consumption, when evaluating the ecological response of managing prey resources for wildlife populations.
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Affiliation(s)
- Alexandra E Lincoln
- School of Aquatic and Fishery Sciences, University of Washington, 1122 Northeast Boat Street, Seattle, Washington, 98195, USA
| | - Ray Hilborn
- School of Aquatic and Fishery Sciences, University of Washington, 1122 Northeast Boat Street, Seattle, Washington, 98195, USA
| | - Aaron J Wirsing
- School of Environmental and Forest Sciences, University of Washington, 4000 15th Avenue Northeast, Seattle, Washington, 98195, USA
| | - Thomas P Quinn
- School of Aquatic and Fishery Sciences, University of Washington, 1122 Northeast Boat Street, Seattle, Washington, 98195, USA
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Luhring TM, Meckley TD, Johnson NS, Siefkes MJ, Hume JB, Wagner CM. A semelparous fish continues upstream migration when exposed to alarm cue, but adjusts movement speed and timing. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.08.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Deacy W, Leacock W, Armstrong JB, Stanford JA. Kodiak brown bears surf the salmon red wave: direct evidence from GPS collared individuals. Ecology 2016; 97:1091-8. [PMID: 27349087 DOI: 10.1890/15-1060.1] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A key constraint faced by consumers is achieving a positive energy balance in the face of temporal variation in foraging opportunities. Recent work has shown that spatial heterogeneity in resource phenology can buffer mobile consumers from this constraint by allowing them to track changes in resource availability across space. For example, salmon populations spawn asynchronously across watersheds, causing high-quality foraging opportunities to propagate across the landscape, prolonging the availability of salmon at the regional scale. However, we know little about how individual consumers integrate across phenological variation or the benefits they receive by doing so. Here, we present direct evidence that individual brown bears track spatial variation in salmon phenology. Data from 40 GPS collared brown bears show that bears visited multiple spawning sites in synchrony with the order of spawning phenology. The number of sites used was correlated with the number of days a bear exploited salmon, suggesting the phenological variation in the study area influenced bear access to salmon, a resource which strongly influences bear fitness. Fisheries managers attempting to maximize harvest while maintaining ecosystem function should strive to protect the population diversity that underlies the phenological variation used by wildlife consumers.
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Ekanayake KB, Weston MA, Dann P, Sutherland DR. Corvids congregate to breeding colonies of a burrow-nesting seabird. AUSTRAL ECOL 2015. [DOI: 10.1111/aec.12311] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kasun B. Ekanayake
- Centre for Integrative Ecology; School of Life and Environmental Sciences; Faculty of Science; Engineering and Built Environment; Deakin University; 221 Burwood Highway Burwood VIC 3125 Australia
| | - Michael A. Weston
- Centre for Integrative Ecology; School of Life and Environmental Sciences; Faculty of Science; Engineering and Built Environment; Deakin University; 221 Burwood Highway Burwood VIC 3125 Australia
| | - Peter Dann
- Research Department; Phillip Island Nature Parks; Cowes VIC 3922 Australia
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