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Krebs CJ, Boutin S, Boonstra R. Population and community ecology: past progress and future directions. Integr Zool 2024. [PMID: 38956827 DOI: 10.1111/1749-4877.12863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Population and community ecology as a science are about 100 years old, and we discuss here our opinion of what approaches have progressed well and which point to possible future directions. The three major threads within population and community ecology are theoretical ecology, statistical tests and models, and experimental ecology. We suggest that our major objective is to understand what factors determine the distribution and abundance of organisms within populations and communities, and we evaluate these threads against this major objective. Theoretical ecology is elegant and compelling and has laid the groundwork for achieving our overall objectives with useful simple models. Statistics and statistical models have contributed informative methods to analyze quantitatively our understanding of distribution and abundance for future research. Population ecology is difficult to carry out in the field, even though we may have all the statistical methods and models needed to achieve results. Community ecology is growing rapidly with much description but less understanding of why changes occur. Biodiversity science cuts across all these subdivisions but rarely digs into the necessary population and community science that might solve conservation problems. Climate change affects all aspects of ecology but to assume that everything in population and community ecology is driven by climate change is oversimplified. We make recommendations on how to advance the field with advice for present and future generations of population and community ecologists.
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Affiliation(s)
- Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
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Krebs CJ, Kenney AJ, Gilbert BS, Boonstra R. Long-term monitoring of cycles in Clethrionomys rutilus in the Yukon boreal forest. Integr Zool 2024; 19:27-36. [PMID: 36892189 DOI: 10.1111/1749-4877.12718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
Baseline studies of small rodent populations in undisturbed ecosystems are rare. We report here 50 years of monitoring and experimentation in Yukon of a dominant rodent species in the North American boreal forest, the red-backed vole Clethrionomys rutilus. These voles breed in summer, weigh 20-25 g, and reach a maximum density of 20 to 25 per ha. Their populations have shown consistent 3-4-year cycles for the last 50 years with the only change being that peak densities averaged 8/ha until 2000 and 18/ha since that year. During the last 25 years, we have measured food resources, predator numbers, and winter weather, and for 1-year social interactions, to estimate their contribution to changes in the rate of summer increase and the rate of overwinter decline. All these potential limiting factors could contribute to changes in density, and we measured their relative contributions statistically with multiple regressions. The rate of winter decline in density was related to both food supply and winter severity. The rate of summer increase was related to summer berry crops and white spruce cone production. No measure of predator numbers was related to winter or summer changes in vole abundance. There was a large signal of climate change effects in these populations. There is no density dependence in summer population growth and only a weak one in winter population declines. None of our results provide a clear understanding of what generates 3-4-year cycles in these voles, and the major missing piece may be an understanding of social interactions at high density.
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Affiliation(s)
- Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alice J Kenney
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - B Scott Gilbert
- Renewable Resources Management Program, Yukon University, Whitehorse, Yukon, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
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Poirier M, Gauthier G, Domine F, Fauteux D. Lemming winter habitat: the quest for warm and soft snow. Oecologia 2023:10.1007/s00442-023-05385-y. [PMID: 37351629 DOI: 10.1007/s00442-023-05385-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 05/08/2023] [Indexed: 06/24/2023]
Abstract
During the cold arctic winter, small mammals like lemmings seek refuge inside the snowpack to keep warm and they dig tunnels in the basal snow layer, usually formed of a soft depth hoar, to find vegetation on which they feed. The snowpack, however, is a heterogenous medium and lemmings should use habitats where snow properties favor their survival and winter reproduction. We determined the impact of snow physical properties on lemming habitat use and reproduction in winter by sampling their winter nests for 13 years and snow properties for 6 years across 4 different habitats (mesic, riparian, shrubland, and wetland) on Bylot Island in the Canadian High Arctic. We found that lemmings use riparian habitat most intensively because snow accumulates more rapidly, the snowpack is the deepest and temperature of the basal snow layer is the highest in this habitat. However, in the deepest snowpacks, the basal depth hoar layer was denser and less developed than in habitats with shallower snowpacks, and those conditions were negatively related to lemming reproduction in winter. Shrubland appeared a habitat of moderate quality for lemmings as it favored a soft basal snow layer and a deep snowpack compared with mesic and wetland, but snow conditions in this habitat critically depend on weather conditions at the beginning of the winter. With climate change, a hardening of the basal layer of the snowpack and a delay in snow accumulation are expected, which could negatively affect the winter habitat of lemmings and be detrimental to their populations.
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Affiliation(s)
- Mathilde Poirier
- Centre d'Études Nordiques, Université Laval, Pavillon Abitibi-Price, 2405, rue de la Terrasse, Québec, QC, Canada.
- Department of Biology, Université Laval, 1045 av. de la Médecine, Québec, QC, Canada.
- Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), 1045 av. de la Médecine, Québec, QC, Canada.
| | - Gilles Gauthier
- Centre d'Études Nordiques, Université Laval, Pavillon Abitibi-Price, 2405, rue de la Terrasse, Québec, QC, Canada
- Department of Biology, Université Laval, 1045 av. de la Médecine, Québec, QC, Canada
| | - Florent Domine
- Centre d'Études Nordiques, Université Laval, Pavillon Abitibi-Price, 2405, rue de la Terrasse, Québec, QC, Canada
- Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), 1045 av. de la Médecine, Québec, QC, Canada
- Department of Chemistry, Université Laval, 1045 av. de la Médecine, Québec, QC, Canada
| | - Dominique Fauteux
- Centre d'Études Nordiques, Université Laval, Pavillon Abitibi-Price, 2405, rue de la Terrasse, Québec, QC, Canada
- Centre for Arctic Knowledge and Exploration, Canadian Museum of Nature, Station D, P.O. Box 3443, Ottawa, ON, Canada
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Bolduc D, Fauteux D, Bharucha É, Trudeau JM, Legagneux P. Ultra-light photosensor collars to monitor Arctic lemming activity. ANIMAL BIOTELEMETRY 2022; 10:31. [PMID: 37521809 PMCID: PMC9552731 DOI: 10.1186/s40317-022-00302-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/27/2022] [Indexed: 08/01/2023]
Abstract
Background Studying the anti-predatory behavior of mammals represents an important challenge, especially for fossorial small mammals that hide in burrows. In the Arctic, such behaviors are critical to the survival of lemmings considering that predation risks are high every summer. Because detailed information about how lemmings use burrows as hideouts is still lacking, we developed a 1.59 g photosensitive collar to record any event of a small mammal moving between a dark area (e.g., burrow) and a bright area (e.g., outside the burrow). Tests of how collars affected lemming behavior were conducted in captivity in Cambridge Bay, Nunavut, Canada, in November 2019 and field tests were conducted on Bylot Island, Nunavut, Canada, in August 2021. Results The device was made of two chemical batteries and a printed circuit board (PCB) equipped with a photosensor and a real-time clock that recorded amplitude transient thresholds of light (lux) continuously. In accordance with ethical use of such devices, we verified that no abnormal loss of body mass was observed in captive or free-ranging lemmings, and no difference in recapture rates were observed between those with and without a collar, though we could not test this for periods longer than 108 h. Measurements of light intensities revealed consistent patterns with high lux levels at mid-day and lowest during the night. Lemmings showed clearly defined behavioral patterns alternating between periods outside and inside burrows. Despite 24-h daylight in the middle of the summer, August nighttime (i.e., 11 PM to 4 AM) lux levels were insufficient for amplitude transient thresholds to be reached. Conclusion By taking advantage of the long periods of daylight in the Arctic, such technology is very promising as it sets new bases for passive recording of behavioral parameters and builds on the prospect of further miniaturization of batteries and PCBs.
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Affiliation(s)
- David Bolduc
- Centre d’Études Nordiques, Université Laval, 1045, avenue de la Médecine, Québec, QC G1V 0A6 Canada
| | - Dominique Fauteux
- Centre d’Études Nordiques, Université Laval, 1045, avenue de la Médecine, Québec, QC G1V 0A6 Canada
- Centre for Arctic Knowledge and Exploration, Canadian Museum of Nature, P.O. Box 3443 station D, Ottawa, ON K1P 6P4 Canada
| | - Éric Bharucha
- Centre d’Études Nordiques, Université Laval, 1045, avenue de la Médecine, Québec, QC G1V 0A6 Canada
- Sentinel North Technological Instrument Development Platform, Université Laval, 2375 rue de la Terrasse, Québec, QC G1V 0A6 Canada
| | - Jean-Marie Trudeau
- Centre d’Études Nordiques, Université Laval, 1045, avenue de la Médecine, Québec, QC G1V 0A6 Canada
- Sentinel North Technological Instrument Development Platform, Université Laval, 2375 rue de la Terrasse, Québec, QC G1V 0A6 Canada
| | - Pierre Legagneux
- Centre d’Études Nordiques, Université Laval, 1045, avenue de la Médecine, Québec, QC G1V 0A6 Canada
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Fauteux D, Gauthier G. Density-dependent demography and movements in a cyclic brown lemming population. Ecol Evol 2022; 12:e9055. [PMID: 35813905 PMCID: PMC9251844 DOI: 10.1002/ece3.9055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/03/2022] [Accepted: 06/08/2022] [Indexed: 11/23/2022] Open
Abstract
Theoretical modeling predicts that both direct and delayed density-dependence are key factors to generate population cycles. Deciphering density-dependent processes that lead to variable population growth characterizing different phases of the cycles remains challenging. This is particularly the case for the period of prolonged low densities, which is inherently data deficient. However, demographic analyses based on long-term capture-mark-recapture datasets can help resolve this question. We relied on a 16-year (2004-2019) live-trapping program to analyze the summer demography and movements of a cyclic brown lemming population in the Canadian Arctic. More specifically, we examined if inversely density-dependent processes could explain why population growth can remain low during the prolonged low phase. We found that the proportion of females in the population was inversely density-dependent with a strong male-biased sex ratio at low densities but not at high densities. However, survival of adult females was higher than adult males, but both had lower survival at low densities than at high ones. Distances moved by both adult males and females were density-dependent, and proportion of females in reproductive condition was weakly density-dependent as it tended to increase at low density. Individual body condition, measured as monthly change in body mass, was not density-dependent. Overall, the strong male-biased sex ratio at very low densities suggests a loss of reproductive potential due to the rarity of females and appears to be the most susceptible demographic factor that could contribute to the prolonged low phase in cyclic brown lemmings. What leads to this sex-bias in the first place is still unclear, potentially owing to our trapping period limited to the summer, but we suggest that it could be due to high predation rate on breeding females in winter.
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Affiliation(s)
- Dominique Fauteux
- Canadian Museum of NatureOttawaOntarioCanada
- Centre d'Études Nordiques and Université LavalQuébecQuébecCanada
| | - Gilles Gauthier
- Centre d'Études Nordiques and Université LavalQuébecQuébecCanada
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Vigués J, Menci S, Wilkinson C, Le Vaillant M, Angerbjörn A, Norén K. A beacon of dung: using lemming (Lemmus lemmus) winter nests and DNA analysis of faeces to further understand predator–prey dynamics in Northern Sweden. Polar Biol 2021. [DOI: 10.1007/s00300-021-02958-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Abstract The hypothesis that predation is the cause of the regular small rodent population oscillations observed in boreal and Arctic regions has long been debated. Within this hypothesis, it is proposed that the most likely predators to cause these destabilizing effects are sedentary specialists, with small mustelids being possible candidates. One such case would be the highly specialized least weasel (Mustela nivalis) driving the Norwegian lemming (Lemmus lemmus) cycle in Fennoscandia. These predators are often elusive and therefore distribution data can only be based on field signs, which is problematic when various mustelid species are sympatric, such as weasels and stoats (Mustela erminea). Here we present the results of using mustelid faeces in predated winter lemming nests to correctly identify the predator and thus discern which species exerts the strongest predation pressure on lemming winter populations. Samples were obtained during different phases in the lemming cycle, spanning 6 years, to account for different prey densities. Faecal mitochondrial DNA extraction and amplification of a 400-bp fragment was successful in 92/114 samples (81%); the sequencing of these samples proved that most predation occurrences (83%) could be attributed to the least weasel. These findings support the hypothesis that weasels in particular show high specificity in predation and could therefore be candidates to driving the lemming cycle in this area. We conclude that DNA analysis of faecal remains around predated nests can be a useful tool for further investigations concerning predator–prey interactions in the tundra.
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Climate variability and density-dependent population dynamics: Lessons from a simple High Arctic ecosystem. Proc Natl Acad Sci U S A 2021; 118:2106635118. [PMID: 34504000 PMCID: PMC8449336 DOI: 10.1073/pnas.2106635118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2021] [Indexed: 11/18/2022] Open
Abstract
Whether the renowned population cycles of small mammals in northern food webs are driven by bottom-up (plant–herbivore) or top-down (predator–prey) interactions is still a debated question but crucial to our understanding of their ecological functions and response to climate change. A long-term study of a graminivorous vole population in an exceptionally simple High Arctic food web allowed us to identify which population dynamics features are present without top-down regulation. Unique features were high-amplitude, noncyclic population fluctuations driven by a combination of stochastic weather events and season-specific density dependence likely arising from plant–herbivore interactions. That such features are not present in more complex food webs points to the importance of top-down regulation in small mammal populations. Ecologists are still puzzled by the diverse population dynamics of herbivorous small mammals that range from high-amplitude, multiannual cycles to stable dynamics. Theory predicts that this diversity results from combinations of climatic seasonality, weather stochasticity, and density-dependent food web interactions. The almost ubiquitous 3- to 5-y cycles in boreal and arctic climates may theoretically result from bottom-up (plant–herbivore) and top-down (predator–prey) interactions. Assessing, empirically, the roles of such interactions and how they are influenced by environmental stochasticity has been hampered by food web complexity. Here, we take advantage of a uniquely simple High Arctic food web, which allowed us to analyze the dynamics of a graminivorous vole population not subjected to top-down regulation. This population exhibited high-amplitude, noncyclic fluctuations—partly driven by weather stochasticity. However, the predominant driver of the dynamics was overcompensatory density dependence in winter that caused the population to frequently crash. Model simulations showed that the seasonal pattern of density dependence would yield regular 2-y cycles in the absence of stochasticity. While such short cycles have not yet been observed in mammals, they are theoretically plausible if graminivorous vole populations are deterministically bottom-up regulated. When incorporating weather stochasticity in the model simulations, cyclicity became disrupted and the amplitude was increased—akin to the observed dynamics. Our findings contrast with the 3- to 5-y population cycles that are typical of graminivorous small mammals in more complex food webs, suggesting that top-down regulation is normally an important component of such dynamics.
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Duncan RJ, Andrew ME, Forchhammer MC. Snow mediates climatic impacts on Arctic herbivore populations. Polar Biol 2021. [DOI: 10.1007/s00300-021-02871-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AbstractArctic ecosystems are particularly vulnerable to impacts of climate change; however, the complex relationships between climate and ecosystems make incorporating effects of climate change into population management difficult. This study used structural equation modelling (SEM) and a 24-year multifaceted monitoring data series collected at Zackenberg, North-East Greenland, to untangle the network of climatic and local abiotic and biotic drivers, determining their direct and indirect effects on two herbivores: musk ox (Ovibos moschatus) and collared lemming (Dicrostonyx groenlandicus). Snow conditions were determined to be the central driver within the system, mediating the effects of climate on herbivore abundance. Under current climate change projections, snow is expected to decrease in the region. Snow had an indirect negative effect on musk ox, as decreased snow depth led to an earlier start to the Arctic willow growing season, shown to increase fecundity and decrease mortality. Musk ox are therefore expected to be more successful under future conditions, within a certain threshold. Snow had both positive and negative effects on lemming, with lemming expected to ultimately be less successful under climate change, as reduction in snow increases their vulnerability to predation. Through their capacity to determine effects of climatic and local drivers within a hierarchy, and the relative strength and direction of these effects, SEMs were demonstrated to have the potential to be valuable in guiding population management.
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Poulin M, Clermont J, Berteaux D. Extensive daily movement rates measured in territorial arctic foxes. Ecol Evol 2021; 11:2503-2514. [PMID: 33767817 PMCID: PMC7981234 DOI: 10.1002/ece3.7165] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 11/28/2020] [Accepted: 12/11/2020] [Indexed: 11/30/2022] Open
Abstract
An animal's movement rate is a central metric of movement ecology as it correlates with its energy acquisition and expenditure. Obtaining accurate estimates of movement rate is challenging, especially in small highly mobile species where GPS battery size limits fix frequency, and geolocation technology limits positions' precision. In this study, we used high GPS fix frequencies to evaluate movement rates in eight territorial arctic foxes on Bylot Island (Nunavut, Canada) in July-August 2018. We also assessed the effects of fix interval and location error on estimated movement rates. We obtained 96 fox-days of data with a fix interval of 4 min and 12 fox-days with an interval of 30 s. We subsampled the latter dataset to simulate six longer fix intervals ranging from 1 to 60 min and estimated daily distances traveled by adding linear distances between successive locations. When estimated with a fix interval of 4 min, daily distances traveled by arctic foxes averaged 51.9 ± 11.7 km and reached 76.5 km. GPS location error averaged 11 m. Daily distances estimated at fix intervals longer than 4 min were greatly underestimated as fix intervals increased, because of linear estimation of tortuous movements. Conversely, daily distances estimated at fix intervals as small as 30 s were likely overestimated due to location error. To our knowledge, no other territorial terrestrial carnivore was shown to routinely travel daily distances as large as those observed here for arctic foxes. Our results generate new hypotheses and research directions regarding the foraging ecology of highly mobile predators. Furthermore, our empirical assessment of the effects of fix interval and location error on estimated movement rates can guide the design and interpretation of future studies on the movement ecology of small opportunistic foragers.
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Affiliation(s)
- Marie‐Pier Poulin
- Canada Research Chair on Northern Biodiversity and Center for Northern StudiesUniversité du Québec à RimouskiRimouskiQCCanada
| | - Jeanne Clermont
- Canada Research Chair on Northern Biodiversity and Center for Northern StudiesUniversité du Québec à RimouskiRimouskiQCCanada
| | - Dominique Berteaux
- Canada Research Chair on Northern Biodiversity and Center for Northern StudiesUniversité du Québec à RimouskiRimouskiQCCanada
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10
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Seyer Y, Gauthier G, Fauteux D, Therrien JF. Resource partitioning among avian predators of the Arctic tundra. J Anim Ecol 2020; 89:2934-2945. [PMID: 32965060 DOI: 10.1111/1365-2656.13346] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/08/2020] [Indexed: 11/29/2022]
Abstract
Interspecific competition can play a key role in structuring ecological communities. The Arctic tundra is a low productivity ecosystem supporting simple food webs, but several predators often feed on the same prey species, lemmings, known for their large-amplitude population fluctuations. We examined mechanisms involved in reducing intra-guild competition and allowing coexistence of four avian predators (snowy owls, glaucous gulls, rough-legged hawks and long-tailed jaegers) feeding on a pulsed resource (brown and collared lemmings). We compared the size and species of prey consumed by predators to see if resource partitioning occurred. We also verified if spatial segregation in nesting areas could be another mechanism allowing coexistence. Finally, we tested if the absence of the snowy owl, a dominant and irruptive species, triggered a competitive release on the smallest predator, the jaeger, with respect to prey size and nesting area used. We monitored the breeding of predators and lemming abundance over a 14-year period on Bylot Island, Canada. We mapped their nesting sites and collected regurgitation pellets to recover lemming mandibles, which were used to infer prey species and size. The size of lemmings consumed varied among species with the largest predators consuming the largest lemmings and the smallest predators consuming the smallest lemmings. All predators consumed more collared than brown lemmings compared to their availability although owls and jaegers consumed relatively more brown lemmings compared to gulls and hawks. Jaegers consumed larger lemmings in the absence of owls than in their presence, suggestive of a short-term competitive release. We found moderate to low overlap in nesting areas among predators and no evidence of their expansion in the absence of owls, suggesting that spatial distribution is caused by species-specific habitat preferences. The main mechanism to partition food resources among these avian predators is spatial segregation, and secondarily prey size and species. However, we found evidence that food competition is still present and leads to a niche shift in the smallest predator of the guild. Interspecific competition may thus be a pervasive force in simple, low productivity food webs characterized by pulsed resources.
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Affiliation(s)
- Yannick Seyer
- Department of Biology and Centre d'études nordiques, Université Laval, Québec, QC, Canada
| | - Gilles Gauthier
- Department of Biology and Centre d'études nordiques, Université Laval, Québec, QC, Canada
| | - Dominique Fauteux
- Department of Biology and Centre d'études nordiques, Université Laval, Québec, QC, Canada.,Canadian Museum of Nature, Ottawa, ON, Canada
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11
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Dobson FS, Murie JO, Viblanc VA. Fitness Estimation for Ecological Studies: An Evaluation in Columbian Ground Squirrels. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00216] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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12
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Carreira DC, Brodie JF, Mendes CP, Ferraz KMPMB, Galetti M. A question of size and fear: competition and predation risk perception among frugivores and predators. J Mammal 2020. [DOI: 10.1093/jmammal/gyaa034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Mammalian spatial and temporal activity patterns can vary depending on foraging behavior or the perception of predation or competition risk among species. These behaviors may in turn be altered by human influences such as defaunation. Herein, we evaluate whether frugivores avoid areas with high visitation rates by potential predators or competitors, and whether this avoidance changes in areas with different degrees of defaunation. We installed 189 cameras under fruit trees in six areas of the Atlantic Forest, Brazil, that differ in the abundance of top predators and large frugivores. Small predators and small frugivores were more frequent at night while large frugivores were more frequent during the day, but small frugivores visited and spent less time at fruiting trees on brighter nights, unlike large predators and large frugivores. Small frugivores also were less frequent in areas with high visitation by large frugivores and more frequent in highly defaunated areas. Our results suggest that the dynamics among mammalian functional groups varied according to diel patterns, potential competitors, and defaunation. We highlight the importance of understanding how species interactions are changing in areas exposed to strong human impacts to mitigate the indirect effects of defaunation.
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Affiliation(s)
- Daiane Cristina Carreira
- Programa Interunidades de Pós Graduação em Ecologia Aplicada, Escola Superior de Agricultura “Luiz de Queiroz” - Universidade de São Paulo, Piracicaba, São Paulo, Brazil
- Fundação Hermínio Ometto - Uniararas, Araras, São Paulo, Brazil
| | - Jedediah F Brodie
- Division of Biological Sciences and Wildlife Biology Program, University of Montana, Missoula, MT, USA
| | - Calebe P Mendes
- Instituto de Biociências, Departamento de Ecologia, Universidade Estadual Paulista (UNESP), Rio Claro, São Paulo, Brazil
| | - Katia Maria P M B Ferraz
- Departamento de Ciências Florestais, ESALQ, Universidade de São Paulo, Piracicaba, São Paulo, Brazil
| | - Mauro Galetti
- Instituto de Biociências, Departamento de Ecologia, Universidade Estadual Paulista (UNESP), Rio Claro, São Paulo, Brazil
- Department of Biology, University of Miami, Coral Gables, FL, USA
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13
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Morris DW, Dupuch A, Moses M, Busniuk K, Otterman H. Differences in behavior help to explain lemming coexistence. J Mammal 2019. [DOI: 10.1093/jmammal/gyz103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Collared (Dicrostonyx groenlandicus) and brown (Lemmus trimucronatus) lemmings coexist in tundra habitats across much of the middle and lower Canadian arctic. Their coexistence, and response to predation risk, appears mediated by behavior. We analyzed field-collected videos of open-field tests to assess potential differences in innate behaviors between the two species. Collared lemmings were less active and exhibited less exploratory behavior than did brown lemmings, which were more active under cover than in the open. Similar behaviors scaling along axes of activity and curiosity were revealed by principal components analysis. Each axis defined different aspects of brown lemming personality, but repeated testing of the same individuals yielded a striking dependence of their behavioral response on open-field treatments. Even so, the differences between species in behavior correlate well with their habitat preferences that resolve competition and govern their coexistence.
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Affiliation(s)
- Douglas W Morris
- Department of Biology, Lakehead University, Thunder Bay, Ontario, Canada
| | - Angélique Dupuch
- Institut des Sciences de la Forêt Tempérée, Université du Québec en Outaouais, Ripon, Québec, Canada
| | - MaryJane Moses
- Ontario Ministry of Environment, Conservation and Parks, Thunder Bay, Ontario, Canada
| | - Kaylee Busniuk
- Cognitive and Behavioural Ecology Graduate Program, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada
| | - Helen Otterman
- Faculty of Health Sciences, Lakehead University, Thunder Bay, Ontario, Canada
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Kelt DA, Heske EJ, Lambin X, Oli MK, Orrock JL, Ozgul A, Pauli JN, Prugh LR, Sollmann R, Sommer S. Advances in population ecology and species interactions in mammals. J Mammal 2019. [DOI: 10.1093/jmammal/gyz017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
AbstractThe study of mammals has promoted the development and testing of many ideas in contemporary ecology. Here we address recent developments in foraging and habitat selection, source–sink dynamics, competition (both within and between species), population cycles, predation (including apparent competition), mutualism, and biological invasions. Because mammals are appealing to the public, ecological insight gleaned from the study of mammals has disproportionate potential in educating the public about ecological principles and their application to wise management. Mammals have been central to many computational and statistical developments in recent years, including refinements to traditional approaches and metrics (e.g., capture-recapture) as well as advancements of novel and developing fields (e.g., spatial capture-recapture, occupancy modeling, integrated population models). The study of mammals also poses challenges in terms of fully characterizing dynamics in natural conditions. Ongoing climate change threatens to affect global ecosystems, and mammals provide visible and charismatic subjects for research on local and regional effects of such change as well as predictive modeling of the long-term effects on ecosystem function and stability. Although much remains to be done, the population ecology of mammals continues to be a vibrant and rapidly developing field. We anticipate that the next quarter century will prove as exciting and productive for the study of mammals as has the recent one.
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Affiliation(s)
- Douglas A Kelt
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Edward J Heske
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM, USA
| | - Xavier Lambin
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Madan K Oli
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - John L Orrock
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Jonathan N Pauli
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI, USA
| | - Laura R Prugh
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
| | - Rahel Sollmann
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Stefan Sommer
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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15
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Oli MK. Population cycles in voles and lemmings: state of the science and future directions. Mamm Rev 2019. [DOI: 10.1111/mam.12156] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Madan K. Oli
- Department of Wildlife Ecology and ConservationUniversity of Florida 110 Newins‐Ziegler Hall Gainesville FL 32611 USA
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16
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Peers MJL, Majchrzak YN, Neilson E, Lamb CT, Hämäläinen A, Haines JA, Garland L, Doran-Myers D, Broadley K, Boonstra R, Boutin S. Quantifying fear effects on prey demography in nature. Ecology 2018; 99:1716-1723. [PMID: 29897623 DOI: 10.1002/ecy.2381] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/18/2018] [Accepted: 04/05/2018] [Indexed: 02/03/2023]
Abstract
In recent years, it has been argued that the effect of predator fear exacts a greater demographic toll on prey populations than the direct killing of prey. However, efforts to quantify the effects of fear have primarily relied on experiments that replace predators with predator cues. Interpretation of these experiments must consider two important caveats: (1) the magnitude of experimenter-induced predator cues may not be realistically comparable to those of the prey's natural sensory environment, and (2) given functional predators are removed from the treatments, the fear effect is measured in the absence of any consumptive effects, a situation which never occurs in nature. We contend that demographic consequences of fear in natural populations may have been overestimated because the intensity of predator cues applied by experimenters in the majority of studies has been unnaturally high, in some instances rarely occurring in nature without consumption. Furthermore, the removal of consumption from the treatments creates the potential situation that individual prey in poor condition (those most likely to contribute strongly to the observed fear effects via starvation or reduced reproductive output) may have been consumed by predators in nature prior to the expression of fear effects, thus confounding consumptive and fear effects. Here, we describe an alternative treatment design that does not utilize predator cues, and in so doing, better quantifies the demographic effect of fear on wild populations. This treatment substitutes the traditional cue experiment where consumptive effects are eliminated and fear is simulated with a design where fear is removed and consumptive effects are simulated through the experimental removal of prey. Comparison to a natural population would give a more robust estimate of the effect of fear in the presence of consumption on the demographic variable of interest. This approach represents a critical advance in quantifying the mechanistic pathways through which predation structures ecological communities. Discussing the merits of both treatments will motivate researchers to go beyond simply describing the existence of fear effects and focus on testing their true magnitude in wild populations and natural communities.
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Affiliation(s)
- Michael J L Peers
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Yasmine N Majchrzak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Eric Neilson
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Clayton T Lamb
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Anni Hämäläinen
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Jessica A Haines
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Laura Garland
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Darcy Doran-Myers
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Kate Broadley
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, M1C 1A4, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2M9, Canada
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17
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Fauteux D, Gauthier G, Berteaux D, Palme R, Boonstra R. High Arctic lemmings remain reproductively active under predator-induced elevated stress. Oecologia 2018; 187:657-666. [PMID: 29651661 DOI: 10.1007/s00442-018-4140-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 04/05/2018] [Indexed: 10/17/2022]
Abstract
Non-consumptive effects of predation have rarely been assessed in wildlife populations even though their impact could be as important as lethal effects. Reproduction of individuals is one of the most important demographic parameters that could be affected by predator-induced stress, which in turn can have important consequences on population dynamics. We studied non-consumptive effects of predation on the reproductive activity (i.e., mating and fertilization) of a cyclic population of brown lemmings exposed to intense summer predation in the Canadian High Arctic. Lemmings were live-trapped, their reproductive activity (i.e., testes visible in males, pregnancy/lactation in females) assessed, and predators were monitored during the summers of 2014 and 2015 within a 9 ha predator-reduction exclosure delimited by a fence and covered by a net, and on an 11 ha control area. Stress levels were quantified non-invasively with fecal corticosterone metabolites (FCM). We found that FCM levels of lemmings captured outside the predator exclosure (n = 50) were 1.6 times higher than inside (n = 51). The proportion of pregnant/lactating adult females did not differ between the two areas, nor did the proportion of adult scrotal males. We found that lemmings showed physiological stress reactions due to high predation risk, but had no sign of reduced mating activity or fertility. Thus, our results do not support the hypothesis of reproductive suppression by predator-induced stress.
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Affiliation(s)
- Dominique Fauteux
- Department of Biology and Centre d'études nordiques, Université Laval, 1045 Avenue de la Médecine, Quebec, QC, G1V 0A6, Canada. .,Canadian Museum of Nature, P.O. Box 3443, Station D, Ottawa, ON, K1P 6P4, Canada.
| | - Gilles Gauthier
- Department of Biology and Centre d'études nordiques, Université Laval, 1045 Avenue de la Médecine, Quebec, QC, G1V 0A6, Canada
| | - Dominique Berteaux
- Canada Research Chair on Northern Biodiversity and Centre d'études nordiques, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, QC, G5L 3A1, Canada
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
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18
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Fauteux D, Gauthier G, Mazerolle MJ, Coallier N, Bêty J, Berteaux D. Evaluation of invasive and non-invasive methods to monitor rodent abundance in the Arctic. Ecosphere 2018. [DOI: 10.1002/ecs2.2124] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Dominique Fauteux
- Canadian Museum of Nature and Centre d’Études Nordiques; P.O. Box 3443 Station D Ottawa Ontario K1P 6P4 Canada
| | - Gilles Gauthier
- Department of Biology and Centre d’Études Nordiques; Université Laval; 1045 Avenue de la Médecine Québec Quebec G1V 0A6 Canada
| | - Marc J. Mazerolle
- Department of Wood and Forest Science and Centre d’Étude de la Forêt; Université Laval; 2405 rue de la Terrasse Québec Quebec G1V 0A6 Canada
| | - Nicolas Coallier
- Department of Biology and Centre d’Études Nordiques; Université Laval; 1045 Avenue de la Médecine Québec Quebec G1V 0A6 Canada
| | - Joël Bêty
- Canada Research Chair on Northern Biodiversity and Centre d’Études Nordiques; Université du Québec à Rimouski; 300 Allée des Ursulines Rimouski Quebec G5L 3A1 Canada
| | - Dominique Berteaux
- Canada Research Chair on Northern Biodiversity and Centre d’Études Nordiques; Université du Québec à Rimouski; 300 Allée des Ursulines Rimouski Quebec G5L 3A1 Canada
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19
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Schmidt JH, McIntyre CL, Roland CA, MacCluskie MC, Flamme MJ. Bottom-up processes drive reproductive success in an apex predator. Ecol Evol 2018; 8:1833-1841. [PMID: 29435257 PMCID: PMC5792545 DOI: 10.1002/ece3.3800] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 11/14/2017] [Accepted: 12/11/2017] [Indexed: 11/10/2022] Open
Abstract
One of the central goals of the field of population ecology is to identify the drivers of population dynamics, particularly in the context of predator-prey relationships. Understanding the relative role of top-down versus bottom-up drivers is of particular interest in understanding ecosystem dynamics. Our goal was to explore predator-prey relationships in a boreal ecosystem in interior Alaska through the use of multispecies long-term monitoring data. We used 29 years of field data and a dynamic multistate site occupancy modeling approach to explore the trophic relationships between an apex predator, the golden eagle, and cyclic populations of the two primary prey species available to eagles early in the breeding season, snowshoe hare and willow ptarmigan. We found that golden eagle reproductive success was reliant on prey numbers, but also responded prior to changes in the phase of the snowshoe hare population cycle and failed to respond to variation in hare cycle amplitude. There was no lagged response to ptarmigan populations, and ptarmigan populations recovered quickly from the low phase. Together, these results suggested that eagle reproduction is largely driven by bottom-up processes, with little evidence of top-down control of either ptarmigan or hare populations. Although the relationship between golden eagle reproductive success and prey abundance had been previously established, here we established prey populations are likely driving eagle dynamics through bottom-up processes. The key to this insight was our focus on golden eagle reproductive parameters rather than overall abundance. Although our inference is limited to the golden eagle-hare-ptarmigan relationships we studied, our results suggest caution in interpreting predator-prey abundance patterns among other species as strong evidence for top-down control.
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Affiliation(s)
| | - Carol L. McIntyre
- Denali National Park and PreserveU.S. National Park ServiceFairbanksAKUSA
| | - Carl A. Roland
- Central Alaska NetworkU.S. National Park ServiceFairbanksAKUSA
- Denali National Park and PreserveU.S. National Park ServiceFairbanksAKUSA
| | | | - Melanie J. Flamme
- Yukon‐Charley Rivers Preserve and Gates of the Arctic National Park and PreserveU.S. National Park ServiceFairbanksAKUSA
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