1
|
Weterings MJA, Ebbinge EYC, Strijker BN, Spek G, Kuipers HJ. Insights from a 31-year study demonstrate an inverse correlation between recreational activities and red deer fecundity, with bodyweight as a mediator. Ecol Evol 2024; 14:e11257. [PMID: 38654717 PMCID: PMC11035974 DOI: 10.1002/ece3.11257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
Human activity is omnipresent in our landscapes. Animals can perceive risk from humans similar to predation risk, which could affect their fitness. We assessed the influence of the relative intensity of recreational activities on the bodyweight and pregnancy rates of red deer (Cervus elaphus) between 1985 and 2015. We hypothesized that stress, as a result of recreational activities, affects the pregnancy rates of red deer directly and indirectly via a reduction in bodyweight. Furthermore, we expected non-motorized recreational activities to have a larger negative effect on both bodyweight and fecundity, compared to motorized recreational activities. The intensity of recreational activities was recorded through visual observations. We obtained pregnancy data from female red deer that were shot during the regular hunting season. Additionally, age and bodyweight were determined through a post-mortem examination. We used two Generalized-Linear-Mixed Models (GLMM) to test the effect of different types of recreation on (1) pregnancy rates and (2) bodyweight of red deer. Recreation had a direct negative correlation with the fecundity of red deer, with bodyweight, as a mediator as expected. Besides, we found a negative effect of non-motorized recreation on fecundity and bodyweight and no significant effect of motorized recreation. Our results support the concept of humans as an important stressor affecting wild animal populations at a population level and plead to regulate recreational activities in protected areas that are sensitive. The fear humans induce in large-bodied herbivores and its consequences for fitness may have strong implications for animal populations.
Collapse
Affiliation(s)
- Martijn J. A. Weterings
- Van Hall Larenstein University of Applied SciencesLeeuwardenThe Netherlands
- Wildlife Ecology and Conservation GroupWageningen UniversityWageningenThe Netherlands
| | | | - Beau N. Strijker
- Van Hall Larenstein University of Applied SciencesLeeuwardenThe Netherlands
| | - Gerrit‐Jan Spek
- Vereniging Wildbeheer Veluwe/FBE Gelderland/Natuurlijk Fauna Advies MtsVaassenThe Netherlands
| | - Henry J. Kuipers
- Van Hall Larenstein University of Applied SciencesLeeuwardenThe Netherlands
| |
Collapse
|
2
|
Andrews CP. On the use of body mass measures in severity assessment in laboratory passerine birds. Anim Welf 2022. [DOI: 10.7120/09627286.31.1.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Criteria for assessing the severity of scientific procedures in laboratory rodents include the loss of body mass. However, guidance is limited for passerine birds and application of criteria developed for mammals risks poor welfare decisions. Here, I ask whether, and how, body mass
criteria could be incorporated into laboratory welfare assessment of passerines. Passerine birds strategically adjust their body mass to minimise combined mortality risk from starvation and predation. A systematic literature review found that strategic mass changes can be sizeable (sometimes
> 10%) even over short timescales. Many aspects of a bird's current or past environment, including husbandry and experimental procedures, may alter perceived starvation or predation risks and thus drive strategic mass change via evolved mechanisms. Therefore, body mass criteria used for
rodents may be too stringent for passerines, potentially leading to over-estimated severity. Strategic mass changes might obscure those stemming from experimental interventions yet could also offer insights into whether birds perceive an intervention or altered husbandry as a threat. Mass
criteria for severity assessment should be species- and context-specific in order to balance needs for refinement and reduction. To guide the development of appropriate criteria, a future research priority is for greater data collection and sharing based on standardised routine monitoring
of mass variation under a representative range of husbandry conditions and procedures.
Collapse
Affiliation(s)
- CP Andrews
- University of Stirling, Division of Psychology, Faculty of Natural Sciences, Stirling FK9 4LA, UK
| |
Collapse
|
3
|
Majchrzak YN, Peers MJL, Studd EK, Menzies AK, Walker PD, Shiratsuru S, McCaw LK, Boonstra R, Humphries M, Jung TS, Kenney AJ, Krebs CJ, Murray DL, Boutin S. Balancing food acquisition and predation risk drives demographic changes in snowshoe hare population cycles. Ecol Lett 2022; 25:981-991. [PMID: 35148018 DOI: 10.1111/ele.13975] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/08/2021] [Accepted: 01/04/2022] [Indexed: 11/28/2022]
Abstract
Snowshoe hare cycles are one of the most prominent phenomena in ecology. Experimental studies point to predation as the dominant driving factor, but previous experiments combining food supplementation and predator removal produced unexplained multiplicative effects on density. We examined the potential interactive effects of food limitation and predation in causing hare cycles using an individual-based food-supplementation experiment over-winter across three cycle phases that naturally varied in predation risk. Supplementation doubled over-winter survival with the largest effects occurring in the late increase phase. Although the proximate cause of mortality was predation, supplemented hares significantly decreased foraging time and selected for conifer habitat, potentially reducing their predation risk. Supplemented hares also lost less body mass which resulted in the production of larger leverets. Our results establish a mechanistic link between how foraging time, mass loss and predation risk affect survival and reproduction, potentially driving demographic changes associated with hare cycles.
Collapse
Affiliation(s)
- Yasmine N Majchrzak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Michael J L Peers
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Emily K Studd
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Allyson K Menzies
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Philip D Walker
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Shotaro Shiratsuru
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Laura K McCaw
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Murray Humphries
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Thomas S Jung
- Department of Environment, Government of Yukon, Whitehorse, Yukon, Canada.,Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Alice J Kenney
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dennis L Murray
- Department of Biology, Trent University, Peterborough, Ontario, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
4
|
Fear of predators in free-living wildlife reduces population growth over generations. Proc Natl Acad Sci U S A 2022; 119:2112404119. [PMID: 35131939 PMCID: PMC8851447 DOI: 10.1073/pnas.2112404119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2021] [Indexed: 11/22/2022] Open
Abstract
Accurately evaluating the total impact of predators on prey population growth rates is fundamental to forecasting the consequences of predator conservation and management. That the fear (antipredator responses) predators inspire could contribute to this total impact has only relatively recently been recognized. We experimentally demonstrate that fear itself can impact prey population growth rates in free-living wildlife, extending to transgenerational impacts reducing population growth beyond the parental generation. We report how fear may contribute considerably to the total impact of predators and why this may be the norm in birds and mammals. The critical significance of our work lies in experimentally establishing that inferring the effects of predators using data on direct killing alone risks dramatically underestimating their total impact. Correctly assessing the total impact of predators on prey population growth rates (lambda, λ) is critical to comprehending the importance of predators in species conservation and wildlife management. Experiments over the past decade have demonstrated that the fear (antipredator responses) predators inspire can affect prey fecundity and early offspring survival in free-living wildlife, but recent reviews have highlighted the absence of evidence experimentally linking such effects to significant impacts on prey population growth. We experimentally manipulated fear in free-living wild songbird populations over three annual breeding seasons by intermittently broadcasting playbacks of either predator or nonpredator vocalizations and comprehensively quantified the effects on all the components of population growth, together with evidence of a transgenerational impact on offspring survival as adults. Fear itself significantly reduced the population growth rate (predator playback mean λ = 0.91, 95% CI = 0.80 to 1.04; nonpredator mean λ = 1.06, 95% CI = 0.96 to 1.16) by causing cumulative, compounding adverse effects on fecundity and every component of offspring survival, resulting in predator playback parents producing 53% fewer recruits to the adult breeding population. Fear itself was consequently projected to halve the population size in just 5 years, or just 4 years when the evidence of a transgenerational impact was additionally considered (λ = 0.85). Our results not only demonstrate that fear itself can significantly impact prey population growth rates in free-living wildlife, comparing them with those from hundreds of predator manipulation experiments indicates that fear may constitute a very considerable part of the total impact of predators.
Collapse
|
5
|
Zanette LY, Clinchy M. Ecology and Neurobiology of Fear in Free-Living Wildlife. ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2020. [DOI: 10.1146/annurev-ecolsys-011720-124613] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The ecology of fear concerns the population-, community-, and ecosystem-level consequences of the behavioral interactions between predators and prey, i.e., the aggregate impacts of individual responses to life-threatening events. We review new experiments demonstrating that fear itself is powerful enough to affect the population growth rate in free-living wild birds and mammals, and fear of large carnivores—or the human super predator—can cause trophic cascades affecting plant and invertebrate abundance. Life-threatening events like escaping a predator can have enduring, even lifelong, effects on the brain, and new interdisciplinary research on the neurobiology of fear in wild animals is both providing insights into post-traumatic stress (PTSD) and reinforcing the likely commonality of population- and community-level effects of fear in nature. Failing to consider fear thus risks dramatically underestimating the total impact predators can have on prey populations and the critical role predator-prey interactions can play in shaping ecosystems.
Collapse
Affiliation(s)
- Liana Y. Zanette
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada;,
| | - Michael Clinchy
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada;,
| |
Collapse
|
6
|
Li GY, Zhang ZQ. Development, lifespan and reproduction of spider mites exposed to predator-induced stress across generations. Biogerontology 2019; 20:871-882. [DOI: 10.1007/s10522-019-09835-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 09/14/2019] [Indexed: 01/02/2023]
|
7
|
Dudeck BP, Clinchy M, Allen MC, Zanette LY. Fear affects parental care, which predicts juvenile survival and exacerbates the total cost of fear on demography. Ecology 2017; 99:127-135. [DOI: 10.1002/ecy.2050] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/24/2017] [Accepted: 10/02/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Blair P. Dudeck
- Department of Biology; Western University; London Ontario N6A 5B7 Canada
| | - Michael Clinchy
- Department of Biology; Western University; London Ontario N6A 5B7 Canada
| | - Marek C. Allen
- Department of Biology; Western University; London Ontario N6A 5B7 Canada
| | - Liana Y. Zanette
- Department of Biology; Western University; London Ontario N6A 5B7 Canada
| |
Collapse
|
8
|
Walters BT, Cheng TNN, Doyle J, Guglielmo CG, Clinchy M, Zanette LY. Too important to tamper with: predation risk affects body mass and escape behaviour but not escape ability. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12851] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Benjamin T. Walters
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Tin Nok Natalie Cheng
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Justin Doyle
- Department of Computer Science University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Chistopher G. Guglielmo
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Michael Clinchy
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| | - Liana Y. Zanette
- Department of Biology and Advanced Facility for Avian Research (AFAR) University of Western Ontario 1151 Richmond St. North London ONN6A 5B7 Canada
| |
Collapse
|
9
|
Suraci JP, Roberts DJ, Clinchy M, Zanette LY. Fearlessness towards extirpated large carnivores may exacerbate the impacts of naïve mesocarnivores. Behav Ecol 2016. [DOI: 10.1093/beheco/arw178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
10
|
Suraci JP, Clinchy M, Zanette LY, Currie CMA, Dill LM. Mammalian mesopredators on islands directly impact both terrestrial and marine communities. Oecologia 2014; 176:1087-100. [PMID: 25234377 DOI: 10.1007/s00442-014-3085-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 09/04/2014] [Indexed: 10/24/2022]
Abstract
Medium-sized mammalian predators (i.e. mesopredators) on islands are known to have devastating effects on the abundance and diversity of terrestrial vertebrates. Mesopredators are often highly omnivorous, and on islands, may have access not only to terrestrial prey, but to marine prey as well, though impacts of mammalian mesopredators on marine communities have rarely been considered. Large apex predators are likely to be extirpated or absent on islands, implying a lack of top-down control of mesopredators that, in combination with high food availability from terrestrial and marine sources, likely exacerbates their impacts on island prey. We exploited a natural experiment--the presence or absence of raccoons (Procyon lotor) on islands in the Gulf Islands, British Columbia, Canada--to investigate the impacts that this key mesopredator has on both terrestrial and marine prey in an island system from which all native apex predators have been extirpated. Long-term monitoring of song sparrow (Melospiza melodia) nests showed raccoons to be the predominant nest predator in the Gulf Islands. To identify their community-level impacts, we surveyed the distribution of raccoons across 44 Gulf Islands, and then compared terrestrial and marine prey abundances on six raccoon-present and six raccoon-absent islands. Our results demonstrate significant negative effects of raccoons on terrestrial, intertidal, and shallow subtidal prey abundance, and point to additional community-level effects through indirect interactions. Our findings show that mammalian mesopredators not only affect terrestrial prey, but that, on islands, their direct impacts extend to the surrounding marine community.
Collapse
Affiliation(s)
- Justin P Suraci
- Department of Biology, University of Victoria, P.O. Box 1700, Station CSC, Victoria, BC, V8W 2Y2, Canada,
| | | | | | | | | |
Collapse
|
11
|
Zanette LY, Clinchy M, Suraci JP. Diagnosing predation risk effects on demography: can measuring physiology provide the means? Oecologia 2014; 176:637-51. [PMID: 25234371 DOI: 10.1007/s00442-014-3057-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 08/18/2014] [Indexed: 11/30/2022]
Abstract
Predators kill prey thereby affecting prey survival and, in the traditional top-down view of predator limitation, that is their sole effect. Bottom-up food limitation alters the physiological condition of individuals affecting both fecundity and survival. Predators of course also scare prey inducing anti-predator defences that may carry physiological costs powerful enough to reduce prey fecundity and survival. Here, we consider whether measuring physiology can be used as a tool to unambiguously diagnose predation risk effects. We begin by providing a review of recent papers reporting physiological effects of predation risk. We then present a conceptual framework describing the pathways by which predators and food can affect prey populations and give an overview of predation risk effects on demography in various taxa. Because scared prey typically eat less the principal challenge we see will be to identify measures that permit us to avoid mistaking predator-induced reductions in food intake for absolute food shortage. To construct an effective diagnostic toolkit we advocate collecting multiple physiological measures and utilizing multivariate statistical procedures. We recommend conducting two-factor predation risk × food manipulations to identify those physiological effects least likely to be mistaken for responses to bottom-up food limitation. We suggest there is a critical need to develop a diagnostic tool that can be used when it is infeasible to experimentally test for predation risk effects on demography, as may often be the case in wildlife conservation, since failing to consider predation risk effects may cause the total impact of predators to be dramatically underestimated.
Collapse
Affiliation(s)
- Liana Y Zanette
- Department of Biology, University of Western Ontario, 1151 Richmond Street, London, ON, N6A 5B7, Canada,
| | | | | |
Collapse
|
12
|
Wheeler HC, Hik DS. Giving-up densities and foraging behaviour indicate possible effects of shrub encroachment on arctic ground squirrels. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2014.06.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|