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OUP accepted manuscript. J Mammal 2022. [DOI: 10.1093/jmammal/gyac009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Gigliotti LC, Diefenbach DR. Risky behavior and its effect on survival: snowshoe hare behavior under varying moonlight conditions. J Zool (1987) 2018. [DOI: 10.1111/jzo.12532] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- L. C. Gigliotti
- Pennsylvania Cooperative Fish and Wildlife Research Unit; Pennsylvania State University; University Park PA USA
| | - D. R. Diefenbach
- U.S. Geological Survey; Pennsylvania Cooperative Fish and Wildlife Research Unit; Pennsylvania State University; University Park PA USA
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Ellsworth E, Boudreau M, Nagy K, Rachlow J, Murray D. Differential sex-related winter energetics in free-ranging snowshoe hares ( Lepus americanus). CAN J ZOOL 2016. [DOI: 10.1139/cjz-2015-0074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Animals spend considerable time and energy acquiring food to meet their metabolic requirements, but if energetic or fitness costs are substantive, such as during winter, then some individuals may limit daily energy expenditure by reducing foraging duration. To date, the prevalence and magnitude of such compensatory foraging responses are poorly known. We examined energy balance compensation in free-ranging snowshoe hares (Lepus americanus Erxleben, 1777) via a food supplementation experiment to determine whether individuals reduced their daily energy expenditure (DEE) and activity periods in response to increased food availability. Overall, food supplementation had no effect on diel activity patterns, although males had higher DEE compared with females. During early and mid-winter, hares did not alter their activity periods in response to food supplementation, but during late winter, when natural food availability declined, food-supplemented females (but not males) were ∼11% less active compared with controls. Natural food likely was sufficient and could have been acquired at relatively low energetic cost, but because males likely have higher DEE due to mating behavior whereas females may limit their activity (and thus DEE) to reduce predation risk, we conclude that gender-specific life-history demands can over-ride predicted responses to supplemental food when baseline food abundance is adequate.
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Affiliation(s)
- E. Ellsworth
- Department of Fish and Wildlife Sciences, University of Idaho, 875 Perimeter Drive, MS 1136, Moscow, ID 83843-1136, USA
| | - M.R. Boudreau
- Department of Biology, Trent University, Peterborough, ON K97 7B8, Canada
| | - K. Nagy
- Department of Ecology and Evolutionary Biology, University of California, 621 Young Drive South, Los Angeles, CA 90095-1606, USA
| | - J.L. Rachlow
- Department of Fish and Wildlife Sciences, University of Idaho, 875 Perimeter Drive, MS 1136, Moscow, ID 83843-1136, USA
| | - D.L. Murray
- Department of Biology, Trent University, Peterborough, ON K97 7B8, Canada
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Abele SL, Wirsing AJ, Murray DL. Precommercial forest thinning alters abundance but not survival of snowshoe hares. J Wildl Manage 2012. [DOI: 10.1002/jwmg.426] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wirsing A, Murray D. Food supplementation experiments revisited: verifying that supplemental food is used by its intended recipients. CAN J ZOOL 2007. [DOI: 10.1139/z07-048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Field-based food supplementation experiments can determine whether populations are limited by natural food availability. However, they may yield spurious results if added food is hoarded by dominants, exploited by immigrants, or delivered ineffectively. Surprisingly, population-level approaches accounting for these potential sources of bias have not been established. We explored responses of free-ranging snowshoe hares ( Lepus americanus Erxleben, 1777) to food supplementation by contrasting per capita browsing rates on three study sites with added food with those on three control sites during two winters. Food augmentation reduced foraging pressure by hares; this reduction was significant when browse species of high dietary importance were considered. By implication, hares on manipulated sites switched from favored natural foods to supplemental food, meaning that the extra food found its mark and was not heavily exploited by immigrants or hoarded by dominants. Demographic responses to food addition were not detected on the manipulated sites, indicating that the study population was not food limited. Given the success with which we detected the signal of supplementation and eliminated potential confounding factors, we suggest that future studies using food addition in the context of herbivore population dynamics would benefit from a more mechanistic approach; this may involve measurement of browsing rates on manipulated and control sites.
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Affiliation(s)
- A.J. Wirsing
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - D.L. Murray
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada
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Rödel H, Völkl W, Kilias H. Winter browsing of brown hares: evidence for diet breadth expansion. Mamm Biol 2004. [DOI: 10.1078/1616-5047-00163] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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