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Richmond IC, Balluffi-Fry J, Vander Wal E, Leroux SJ, Rizzuto M, Heckford TR, Kennah JL, Riefesel GR, Wiersma YF. Individual snowshoe hares manage risk differently: integrating stoichiometric distribution models and foraging ecology. J Mammal 2021. [DOI: 10.1093/jmammal/gyab130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Herbivores making space use decisions must consider the trade-off between perceived predation risk and forage quality. Herbivores, specifically snowshoe hares (Lepus americanus), must constantly navigate landscapes that vary in predation risk and food quality, providing researchers with the opportunity to explore the factors that govern their foraging decisions. Herein, we tested predictions that intersect the risk allocation hypothesis (RAH) and optimal foraging theory (OFT) in a spatially explicit ecological stoichiometry framework to assess the trade-off between predation risk and forage quality. We used individual and population estimates of snowshoe hare (n = 29) space use derived from biotelemetry across three summers. We evaluated resource forage quality for lowbush blueberry (Vaccinium angustifolium), a common and readily available forage species within our system, using carbon:nitrogen and carbon:phosphorus ratios. We used habitat complexity to proxy perceived predation risk. We analyzed how forage quality of blueberry, perceived predation risk, and their interaction impact the intensity of herbivore space use. We used generalized mixed effects models, structured to enable us to make inferences at the population and individual home range level. We did not find support for RAH and OFT. However, variation in the individual-level reactions norms in our models showed that individual hares have unique responses to forage quality and perceived predation risk. Our finding of individual-level responses indicates that there is fine-scale decision-making by hares, although we did not identify the mechanism. Our approach illustrates spatially explicit empirical support for individual behavioral responses to the food quality–predation risk trade-off.
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Affiliation(s)
- Isabella C Richmond
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Juliana Balluffi-Fry
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Eric Vander Wal
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Shawn J Leroux
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Matteo Rizzuto
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Travis R Heckford
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Joanie L Kennah
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Gabrielle R Riefesel
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Yolanda F Wiersma
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL, Canada
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Doyle S, Cabot D, Walsh A, Inger R, Bearhop S, McMahon BJ. Temperature and precipitation at migratory grounds influence demographic trends of an Arctic-breeding bird. GLOBAL CHANGE BIOLOGY 2020; 26:5447-5458. [PMID: 32677737 DOI: 10.1111/gcb.15267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
Anthropogenic climate disruption, including temperature and precipitation regime shifts, has been linked to animal population declines since the mid-20th century. However, some species, such as Arctic-breeding geese, have thrived during this period. An increased understanding of how climate disruption might link to demographic rates in thriving species is an important perspective in quantifying the impact of anthropogenic climate disruption on the global state of nature. The Greenland barnacle goose (Branta leucopsis) population has increased tenfold in abundance since the mid-20th century. A concurrent weather regime shift towards warmer, wetter conditions occurred throughout its range in Greenland (breeding), Ireland and Scotland (wintering) and Iceland (spring and autumn staging). The aim of this study was to determine the relationship between weather and demographic rates of Greenland barnacle geese to discern the role of climate shifts in the population trend. We quantified the relationship between temperature and precipitation and Greenland barnacle goose survival and productivity over a 50 year period from 1968 to 2018. We detected significant positive relationships between warmer, wetter conditions on the Icelandic spring staging grounds and survival. We also detected contrasting relationships between warmer, wetter conditions during autumn staging and survival and productivity, with warm, dry conditions being the most favourable for productivity. Survival increased in the latter part of the study period, supporting the possibility that spring weather regime shifts contributed to the increasing population trend. This may be related to improved forage resources, as warming air temperatures have been shown to improve survival rates in several other Arctic and northern terrestrial herbivorous species through indirect bottom-up effects on forage availability.
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Affiliation(s)
- Susan Doyle
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - David Cabot
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Alyn Walsh
- Department of Culture, Heritage and the Gaeltacht, Scientific Unit, Wildfowl Reserve, Wexford, Ireland
| | - Richard Inger
- College of Life and Environmental Sciences, University of Exeter, Cornwall, UK
| | - Stuart Bearhop
- College of Life and Environmental Sciences, University of Exeter, Cornwall, UK
| | - Barry J McMahon
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
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Hutchen J, Hodges K. Foraging behaviour of snowshoe hares ( Lepus americanus) in conifer forests regenerating after fire. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Wildfires in conifer forests create patchy, heterogeneous landscapes. For many animal species, this post-fire variability means having to navigate quite different habitat patches to locate adequate cover and food. For snowshoe hares (Lepus americanus Erxleben, 1777), post-fire landscapes could include risky open patches, as well as dense regenerating stands rich in food and cover. We analyzed snowshoe hare tortuosity, speed of movement, and amount of browse along winter foraging pathways in unburned mature forest and in dense regenerating stands or open areas with sparse regeneration 12–13 years after the Okanagan Mountain Park fire (>25 000 ha near Kelowna, British Columbia, Canada) to determine whether hares change foraging behaviour in relation to cover type. Hares moved the fastest and browsed the least in open habitats. Hares browsed most often in areas where sapling regeneration was dense; their main forage was lodgepole pine (Pinus contorta Douglas ex Loudon). No differences were found in pathway tortuosity in relation to cover type (open, regenerating, or mature patches). When hares moved slower along foraging pathways, they also moved slightly more tortuously and ate more. These results suggest that hares prefer post-fire areas with dense tree regeneration.
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Affiliation(s)
- J. Hutchen
- Department of Biology, The University of British Columbia Okanagan, 1177 Research Road, Kelowna, BC V1V 1V7, Canada
- Department of Biology, The University of British Columbia Okanagan, 1177 Research Road, Kelowna, BC V1V 1V7, Canada
| | - K.E. Hodges
- Department of Biology, The University of British Columbia Okanagan, 1177 Research Road, Kelowna, BC V1V 1V7, Canada
- Department of Biology, The University of British Columbia Okanagan, 1177 Research Road, Kelowna, BC V1V 1V7, Canada
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Thomas JP, Reid ML, Barclay RM, Jung TS. Salvage logging after an insect outbreak reduces occupancy by snowshoe hares (Lepus americanus) and their primary predators. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00562] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Gigliotti LC, Jones BC, Lovallo MJ, Diefenbach DR. Snowshoe hare multi-level habitat use in a fire-adapted ecosystem. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21375] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Laura C. Gigliotti
- Pennsylvania Cooperative Fish and Wildlife Research Unit; Pennsylvania State University, 435 Forest Resources Building; University Park PA 16802 USA
| | | | | | - Duane R. Diefenbach
- U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit; Pennsylvania State University; 404 Forest Resources Building, University Park PA 16802 USA
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Olnes J, Kielland K, Juday GP, Mann DH, Genet H, Ruess RW. Can snowshoe hares control treeline expansions? Ecology 2017; 98:2506-2512. [PMID: 28766697 DOI: 10.1002/ecy.1968] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/11/2017] [Accepted: 07/24/2017] [Indexed: 11/11/2022]
Abstract
Treelines in Alaska are advancing in elevation and latitude because of climate warming, which is expanding the habitat available for boreal wildlife species, including snowshoe hares (Lepus americanus). Snowshoe hares are already present in tall shrub communities beyond treeline and are the main browser of white spruce (Picea glauca), the dominant tree species at treeline in Alaska. We investigated the processes involved in a "snowshoe hare filter" to white spruce establishment near treeline in Denali National Park, Alaska, USA. We modeled the pattern of spruce establishment from 1970 to 2009 and found that fewer spruce established during periods of high hare abundance. Multiple factors interact to influence browsing of spruce, including the hare cycle, snow depth and the characteristics of surrounding vegetation. Hares are abundant at treeline and may exclude spruce from otherwise optimal establishment sites, particularly floodplain locations with closed shrub canopies. The expansion of white spruce treeline in response to warming climate will be strongly modified by the spatial and temporal dynamics of the snowshoe hare filter.
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Affiliation(s)
- Justin Olnes
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA
| | - Knut Kielland
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA.,Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA
| | - Glenn P Juday
- School of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA
| | - Daniel H Mann
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA.,Department of Geosciences, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA
| | - Hélène Genet
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA
| | - Roger W Ruess
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA.,Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA
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Non-invasive genetic population density estimation of mountain hares (Lepus timidus) in the Alps: systematic or opportunistic sampling? EUR J WILDLIFE RES 2016. [DOI: 10.1007/s10344-016-1053-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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The seasonal trade-off between food and cover in the Alpine mountain hare (Lepus timidus). EUR J WILDLIFE RES 2015. [DOI: 10.1007/s10344-015-0963-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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