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Frank SC, Blaalid R, Mayer M, Zedrosser A, Steyaert SMJG. Fear the reaper: ungulate carcasses may generate an ephemeral landscape of fear for rodents. R Soc Open Sci 2020; 7:191644. [PMID: 32742677 PMCID: PMC7353961 DOI: 10.1098/rsos.191644] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Animal carcasses provide an ephemeral pulse of nutrients for scavengers that use them. Carcass sites can increase species interactions and/or ephemeral, localized landscapes of fear for prey within the vicinity. Few studies have applied the landscape of fear to carcasses. Here, we use a mass die-off of reindeer caused by lightning in Norway to test whether rodents avoided larger scavengers (e.g. corvids and fox). We used the presence and abundance of faeces as a proxy for carcass use over the course of 2 years and found that rodents showed the strongest avoidance towards changes in raven abundance (β = -0.469, s.e. = 0.231, p-value = 0.0429), but not fox, presumably due to greater predation risk imposed by large droves of raven. Moreover, the emergence of rodent occurrence within the carcass area corresponded well with the disappearance of raven during the second year of the study. We suggest that carcasses have the potential to shape the landscape of fear for prey, but that the overall effects of carcasses on individual fitness and populations of species ultimately depend on the carcass regime, e.g. carcass size, count, and areal extent, frequency and the scavenger guild. We discuss conservation implications and how carcass provisioning and landscapes of fear could be potentially used to manage populations and ecosystems, but that there is a gap in understanding that must first be bridged.
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Affiliation(s)
- S. C. Frank
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
| | - R. Blaalid
- Norwegian Institute for Nature Research, Thormøhlensgate 55, 5006 Bergen
| | - M. Mayer
- Department of Bioscience, Aarhus University, 8410 Rønde, Denmark
| | - A. Zedrosser
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
- Department of Integrative Biology, Institute of Wildlife Biology and Game Management, University of Natural Resources and Applied Life Sciences, Vienna, Austria
| | - S. M. J. G. Steyaert
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
- Faculty of Biosciences and Aquaculture, Nord University, 7711 Steinkjer, Norway
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Steyaert SMJG, Frank SC, Puliti S, Badia R, Arnberg MP, Beardsley J, Økelsrud A, Blaalid R. Special delivery: scavengers direct seed dispersal towards ungulate carcasses. Biol Lett 2019; 14:rsbl.2018.0388. [PMID: 30111659 DOI: 10.1098/rsbl.2018.0388] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 07/24/2018] [Indexed: 11/12/2022] Open
Abstract
Cadaver decomposition islands around animal carcasses can facilitate establishment of various plant life. Facultative scavengers have great potential for endozoochory, and often aggregate around carcasses. Hence, they may disperse plant seeds that they ingest across the landscape towards cadaver decomposition islands. Here, we demonstrate this novel mechanism along a gradient of wild tundra reindeer carcasses. First, we show that the spatial distribution of scavenger faeces (birds and foxes) was concentrated around carcasses. Second, faeces of the predominant scavengers (corvids) commonly contained viable seeds of crowberry, a keystone species of the alpine tundra with predominantly vegetative reproduction. We suggest that cadaver decomposition islands function as endpoints for directed endozoochory by scavengers. Such a mechanism could be especially beneficial for species that rely on small-scale disturbances in soil and vegetation, such as several Nordic berry-producing species with cryptic generative reproduction.
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Affiliation(s)
- S M J G Steyaert
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway .,Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432 Ås, Norway
| | - S C Frank
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
| | - S Puliti
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432 Ås, Norway.,Norwegian Institute of Bioeconomy Research, 1431 Ås, Norway
| | - R Badia
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432 Ås, Norway
| | - M P Arnberg
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
| | - J Beardsley
- Surveying and Spatial Sciences Group, College of Sciences and Engineering, University of Tasmania, Sandy Bay Tasmania, Hobart TAS-7001, Australia
| | - A Økelsrud
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, 3800 Bø i Telemark, Norway
| | - R Blaalid
- Norwegian Institute for Nature Research, 5006 Bergen, Norway
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Steyaert SMJG, Leclerc M, Pelletier F, Kindberg J, Brunberg S, Swenson JE, Zedrosser A. Human shields mediate sexual conflict in a top predator. Proc Biol Sci 2017; 283:rspb.2016.0906. [PMID: 27335423 PMCID: PMC4936045 DOI: 10.1098/rspb.2016.0906] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 05/25/2016] [Indexed: 11/12/2022] Open
Abstract
Selecting the right habitat in a risky landscape is crucial for an individual's survival and reproduction. In predator-prey systems, prey often can anticipate the habitat use of their main predator and may use protective associates (i.e. typically an apex predator) as shields against predation. Although never tested, such mechanisms should also evolve in systems in which sexual conflict affects offspring survival. Here, we assessed the relationship between offspring survival and habitat selection, as well as the use of protective associates, in a system in which sexually selected infanticide (SSI), rather than interspecific predation, affects offspring survival. We used the Scandinavian brown bear (Ursus arctos) population with SSI in a human-dominated landscape as our model system. Bears, especially adult males, generally avoid humans in our study system. We used resource selection functions to contrast habitat selection of GPS-collared mothers that were successful (i.e. surviving litters, n = 19) and unsuccessful (i.e. complete litter loss, n = 11) in keeping their young during the mating season (2005-2012). Habitat selection was indeed a predictor of litter survival. Successful mothers were more likely to use humans as protective associates, whereas unsuccessful mothers avoided humans. Our results suggest that principles of predator-prey and fear ecology theory (e.g. non-consumptive and cascading effects) can also be applied to the context of sexual conflict.
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Affiliation(s)
- S M J G Steyaert
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, 1432 Ås, Norway Faculty of Arts and Sciences, Department of Environmental and Health Studies, University College of Southeast Norway, 3800 Bø, Norway
| | - M Leclerc
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - F Pelletier
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1
| | - J Kindberg
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden Norwegian Institute for Nature Research, 7485 Trondheim, Norway
| | - S Brunberg
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, 1432 Ås, Norway
| | - J E Swenson
- Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, 1432 Ås, Norway Norwegian Institute for Nature Research, 7485 Trondheim, Norway
| | - A Zedrosser
- Faculty of Arts and Sciences, Department of Environmental and Health Studies, University College of Southeast Norway, 3800 Bø, Norway Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, 1180 Vienna, Austria
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Steyaert SMJG, Reusch C, Brunberg S, Swenson JE, Hackländer K, Zedrosser A. Infanticide as a male reproductive strategy has a nutritive risk effect in brown bears. Biol Lett 2013; 9:20130624. [PMID: 24088563 PMCID: PMC3971711 DOI: 10.1098/rsbl.2013.0624] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Behavioural strategies to reduce predation risk can incur costs, which are often referred to as risk effects. A common strategy to avoid predation is spatio-temporal avoidance of predators, in which prey typically trade optimal resources for safety. Analogous with predator–prey theory, risk effects should also arise in species with sexually selected infanticide (SSI), in which females with dependent offspring avoid infanticidal males. SSI can be common in brown bear (Ursus arctos) populations and explains spatio-temporal segregation among reproductive classes. Here, we show that in a population with SSI, females with cubs-of-the-year had lower quality diets than conspecifics during the SSI high-risk period, the mating season. After the mating season, their diets were of similar quality to diets of their conspecifics. Our results suggest a nutritive risk effect of SSI, in which females with cubs-of-the-year alter their resource selection and trade optimal resources for offspring safety. Such risk effects can add to female costs of reproduction and may be widespread among species with SSI.
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Affiliation(s)
- S M J G Steyaert
- Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, , Vienna 1180, Austria
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