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Fryxell JM, Mduma S, Masoy J, Sinclair ARE, Hopcraft GJC, Packer C. Stabilizing effects of group formation by Serengeti herbivores on predator-prey dynamics. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.981842] [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
Predator-prey theory often assumes that potential prey individuals are solitary and evenly distributed in space. This assumption is violated in social, mobile prey, such as many ungulates. Here we use data from 80 monthly field censuses to estimate the parameters for a power relationship between herd density and population density for eight species of large herbivores commonly found in the diet of Serengeti lions, confirming a power relationship proposed from a preliminary Serengeti dataset. Here we extend our analysis of that model to demonstrate how parameters of the power function relate to average herd size and density-dependent changes in herd size and evaluate how interspecific variation in these parameters shapes the group-dependent functional response by Serengeti lions for eight prey species. We apply the different prey-specific functional response models in a Rosenzweig-MacArthur framework to compare their impact on the stability of predator–prey dynamics. Model outcomes suggest that group formation plays a strong role in stabilizing lion–herbivore interactions in Serengeti by forcing lions to search over a larger area before each prey encounter. As a consequence of grouping by their prey, our model also suggests that Serengeti lions are forced to broaden their diets to include multiple species of prey in order to persist, potentially explaining the generalist foraging by lions routinely recorded across multiple ecosystems.
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2
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Wan X, Holyoak M, Yan C, Le Maho Y, Dirzo R, Krebs CJ, Stenseth NC, Zhang Z. Broad-scale climate variation drives the dynamics of animal populations: a global multi-taxa analysis. Biol Rev Camb Philos Soc 2022; 97:2174-2194. [PMID: 35942895 DOI: 10.1111/brv.12888] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 01/07/2023]
Abstract
Climate is a major extrinsic factor affecting the population dynamics of many organisms. The Broad-Scale Climate Hypothesis (BSCH) was proposed by Elton to explain the large-scale synchronous population cycles of animals, but the extent of support and whether it differs among taxa and geographical regions is unclear. We reviewed publications examining the relationship between the population dynamics of multiple taxa worldwide and the two most commonly used broad-scale climate indices, El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). Our review and synthesis (based on 561 species from 221 papers) reveals that population changes of mammals, birds and insects are strongly affected by major oceanic shifts or irregular oceanic changes, particularly in ENSO- and NAO-influenced regions (Pacific and Atlantic, respectively), providing clear evidence supporting Elton's BSCH. Mammal and insect populations tended to increase during positive ENSO phases. Bird populations tended to increase in positive NAO phases. Some species showed dual associations with both positive and negative phases of the same climate index (ENSO or NAO). These findings indicate that some taxa or regions are more or less vulnerable to climate fluctuations and that some geographical areas show multiple weather effects related to ENSO or NAO phases. Beyond confirming that animal populations are influenced by broad-scale climate variation, we document extensive patterns of variation among taxa and observe that the direct biotic and abiotic mechanisms for these broad-scale climate factors affecting animal populations are very poorly understood. A practical implication of our research is that changes in ENSO or NAO can be used as early signals for pest management and wildlife conservation. We advocate integrative studies at both broad and local scales to unravel the omnipresent effects of climate on animal populations to help address the challenge of conserving biodiversity in this era of accelerated climate change.
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Affiliation(s)
- Xinru Wan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Marcel Holyoak
- Department of Environmental Science and Policy, University of California, California, Davis, 95616, USA
| | - Chuan Yan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yvon Le Maho
- Institut Pluridisciplinaire Hubert Curien (IPHC), Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, 67000, France.,Centre Scientifique de Monaco, Monaco, 98000, Monaco
| | - Rodolfo Dirzo
- Department of Biology and Woods Institute for the Environment, Stanford University, Stanford, California, 94305, USA
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, N-0316, Norway
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
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3
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Barraquand F, Picoche C, Aluome C, Carassou L, Feigné C. Looking for compensation at multiple scales in a wetland bird community. Ecol Evol 2022; 12:e8876. [PMID: 35784078 PMCID: PMC9163198 DOI: 10.1002/ece3.8876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 11/21/2021] [Accepted: 12/09/2021] [Indexed: 11/30/2022] Open
Abstract
Compensatory dynamics, during which community composition shifts despite a near‐constant total community size, are usually rare: Synchronous dynamics prevail in natural communities. This is a puzzle for ecologists, because of the key role of compensation in explaining the relation between biodiversity and ecosystem functioning. However, most studies so far have considered compensation in either plants or planktonic organisms, so that evidence for the generality of such synchrony is limited. Here, we extend analyses of community‐level synchrony to wetland birds. We analyze a 35‐year monthly survey of a community where we suspected that compensation might occur due to potential competition and changes in water levels, favoring birds with different habitat preferences. We perform both year‐to‐year analyses by season, using a compensation/synchrony index, and multiscale analyses using a wavelet‐based measure, which allows for both scale‐ and time‐dependence. We analyze synchrony both within and between guilds, with guilds defined either as tightknit phylogenetic groups or as larger functional groups. We find that abundance and biomass compensation are rare, likely due to the synchronizing influence of climate (and other drivers) on birds, even after considering several temporal scales of covariation (during either cold or warm seasons, above or below the annual scale). Negative covariation in abundance at the guild or community level did only appear at the scale of a few months or several years. We also found that synchrony varies with taxonomic and functional scale: The rare cases where compensation appeared consistently in year‐to‐year analyses were between rather than within functional groups. Our results suggest that abundance compensation may have more potential to emerge between broad functional groups rather than between species, and at relatively long temporal scales (multiple years for vertebrates), above that of the dominant synchronizing driver.
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Affiliation(s)
- Frédéric Barraquand
- Institute of Mathematics of Bordeaux University of Bordeaux and CNRS Talence France
- Integrative and Theoretical Ecology LabEx COTE University of Bordeaux Pessac France
| | - Coralie Picoche
- Institute of Mathematics of Bordeaux University of Bordeaux and CNRS Talence France
- Integrative and Theoretical Ecology LabEx COTE University of Bordeaux Pessac France
| | - Christelle Aluome
- Integrative and Theoretical Ecology LabEx COTE University of Bordeaux Pessac France
- ISPA Bordeaux Sciences Agro & INRAE Villenave d'Ornon France
| | - Laure Carassou
- Integrative and Theoretical Ecology LabEx COTE University of Bordeaux Pessac France
- EABX INRAE Cestas France
| | - Claude Feigné
- Teich Ornithological Reserve PNR Landes Gascogne Le Teich France
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4
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Shogren EH, Jones MA, Boyle WA. Dancing in the rain: how do abiotic conditions influence sexually selected behaviors in the White-ruffed Manakin? Integr Comp Biol 2021; 61:1329-1342. [PMID: 34015118 DOI: 10.1093/icb/icab085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Tropical animals respond to rainfall in population-specific ways. In extremely wet regions, endotherms experience heavy rains as stressors with consequences for behavior and demography. Ultimately, such stressors can affect the relative strength of abiotic selection, reducing the scope for sexual selection and other biotic sources of selection. We studied population-level differences in the response to rainfall in White-ruffed Manakins (Corapipo altera) on the Caribbean slope of Costa Rica, a species having a lek mating system subject to strong sexual selection. Between 2008 and 2013, we studied reproductive behavior in a population inhabiting an extremely wet site; estimates of apparent survival were low, and the turnover of display courts and dominant males was high. Males also engaged in coordinated display, and sub-adult males practiced in the presence of adults. Over three breeding seasons (2017-2019), we studied a population of the same species at a site only 110 km away, but in a location receiving roughly half as much rain. We tested behavioral predictions of three alternative mechanisms-indirect abiotic effects, direct mortality effects, and direct behavioral effects-linking rainfall to sexual selection in these two populations. Data derived from over 4300 hr of observations at 105 display sites revealed high interannual variation in nearly all response variables, including turnover of display sites, retention of alpha status, male display behavior, and time females spent assessing male display. Additionally, we detected spatial differences in drivers of display site turnover. Notably, age distribution of males was skewed toward older individuals at the drier location. Based on these findings we infer that indirect abiotic effects on forest structure leading to display site transience and direct effects of mortality increasing turnover in the male population likely underlie links between rain and the spatial and temporal differences we documented. Our results are consistent with rain constituting an important source of abiotic selection for tropical endotherms and modulating the scope for sexual selection near the extremes of a species' hygric niche.
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Affiliation(s)
- Elsie H Shogren
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | | | - W Alice Boyle
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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5
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Rogy P, Sinclair ARE. Long-term surveys of age structure in 13 ungulate and one ostrich species in the Serengeti, 1926-2018. Sci Data 2020; 7:359. [PMID: 33087720 PMCID: PMC7577988 DOI: 10.1038/s41597-020-00701-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/29/2020] [Indexed: 11/24/2022] Open
Abstract
The Serengeti ecosystem spans an extensive network of protected areas in Tanzania, eastern Africa, and a UNESCO Wold Heritage Site. It is home to some of the largest animal migrations on the planet. Here, we describe a dataset consisting of the sample counts of three age classes (infant, juvenile and adult) of 13 ungulate and one ostrich species. Sample counts were tallied visually from the ground, or, in some instances, aerial photographs, during a period extending from 1926 to 2018. Observed animals were assigned to age classes based on specific criteria for each species. For nine of the 14 species of this dataset, the number of sampling years is over 30. This resulted in a total of 533 different records of count across age classes. By computing age-class ratios, these data can be used to measure long-term recruitment success at different ages of the tallied species. In particular, the temporal extent of these data allows comparison of patterns to other long-term processes, such as the El Niño-Southern Oscillation (ENSO).
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Affiliation(s)
- Pierre Rogy
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada.
| | - Anthony R E Sinclair
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada
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6
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Boyle WA, Shogren EH, Brawn JD. Hygric Niches for Tropical Endotherms. Trends Ecol Evol 2020; 35:938-952. [PMID: 32693967 DOI: 10.1016/j.tree.2020.06.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022]
Abstract
Biotic selective pressures dominate explanations for the evolutionary ecology of tropical endotherms. Yet, abiotic factors, principally precipitation regimes, shape biogeographical and phenological patterns in tropical regions. Despite its importance, we lack a framework for understanding when, why, and how rain affects endotherms. Here, we review how tropical birds and mammals respond to rain at individual, population, and community levels, and propose a conceptual framework to interpret divergent responses. Diverse direct and indirect mechanisms underlie responses to rainfall, including physiological, top-down, and food-related drivers. Our framework constitutes a roadmap for the empirical studies required to understand the consequences of rainfall variability. Identifying the patterns and mechanisms underpinning responses to temporal variation in precipitation is crucial to anticipate consequences of anthropogenic climate change.
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Affiliation(s)
- W Alice Boyle
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Elsie H Shogren
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Jeffrey D Brawn
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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7
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Archibald H. Relating the 4-year lemming (Lemmus spp. and Dicrostonyx spp.) population cycle to a 3.8-year lunar cycle and ENSO. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reported peak years of lemming (Lemmus spp. and Dicrostonyx spp.) and Arctic fox (Vulpes lagopus (Linnaeus, 1758)) abundance were compiled from the literature for 12 locations spanning 127 years. The mean period of the 34 reported lemming and Arctic fox cycles from 1868 to 1994 was 3.8 years, suggesting that the period of the 4-year cycle is actually 3.8 years. Peak population years were predicted using a simple model based on a 3.8-year lunar cycle. For nearly 130 years, reported years of peak abundance of lemmings and Arctic foxes were significantly correlated with and have persistently stayed in phase with predicted peak years of abundance. Over the same period, predicted peak years of lemming abundance have been closely aligned with peak (i.e., La Niña) years of the January–March Southern Oscillation Index (SOI). From 1952 to 1995, peak flowering in Norway tended to occur close to trough June–August SOI (El Niño) years. The hypothesis proposed is that the 3.8-year lunar cycle governs the timing of the lemming cycle, but it does not cause the population cycling itself. If this hypothesis is true, then the heretofore unexplained source of the persistent periodicity and quasi-metronomic regularity of the lemming cycle is identified.
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Affiliation(s)
- H.L. Archibald
- 632 Tee Hi Place, Medford, WI 54451, USA
- 632 Tee Hi Place, Medford, WI 54451, USA
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8
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Durant SM, Groom R, Kuloba B, Samna A, Muzuma U, Gadimang P, Mandisodza-Chikerema R, Ipavec A, Mitchell N, Ikanda D, Msuha M. Bridging the divide between scientists and decision-makers: how behavioural ecologists can increase the conservation impact of their research? Philos Trans R Soc Lond B Biol Sci 2019; 374:20190011. [PMID: 31352894 DOI: 10.1098/rstb.2019.0011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Effective conservation management is underpinned by science. Yet, there are often barriers against the incorporation of up-to-date scientific research into decision-making and policy. Here, we draw on experience from a multi-nation approach to conserve cheetah and African wild dogs across Africa, using relationships between scientists and managers established over more than a decade, to better understand scientific information needs of managers. While our analysis focuses on Africa, many of our findings are likely to be relevant to other regions. Managers view science as critical to their decision-making processes and strongly support scientific research, particularly when research directly addresses their information needs. However, managers reported problems in accessing final results and highlighted the need to access raw ecological data from research undertaken within protected areas. Fundamental to improving the management relevance of scientific research is the need for scientists to engage with managers through all steps of the research process, from project design and implementation through to scientific publication and end-of-project agreements. Effective engagement requires open and clear communication; including agreed processes for access to biodiversity data and submission of final results. In order to foster future scientific endeavours and collaborations, systems should be established to better facilitate information exchange, while also safeguarding the rights of scientists to publish their data and protect their academic freedom. Our analysis also calls for a greater awareness of the geo-political context under which science is undertaken, and for increased scientific participation through an inclusive approach that recognizes, and gives credit to, a wider diversity of scientific contributions and expertise. This article is part of the theme issue 'Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation'.
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Affiliation(s)
- Sarah M Durant
- Institute of Zoology, Zoological Society of London, London, UK.,Wildlife Conservation Society, New York, NY, USA
| | - Rosemary Groom
- Institute of Zoology, Zoological Society of London, London, UK
| | | | | | | | - Phemelo Gadimang
- Republic of Botswana Department of Wildlife and National Parks, 439808 Gaborone, Botswana
| | | | - Audrey Ipavec
- Institute of Zoology, Zoological Society of London, London, UK
| | | | - Dennis Ikanda
- Tanzania Wildlife Research Institute, Arusha, United Republic of Tanzania
| | - Maurus Msuha
- Wildlife Division, Ministry of Natural Resources and Tourism, 119143 Dar es Salaam, Arusha, United Republic of Tanzania
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9
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Fountain-Jones NM, Packer C, Jacquot M, Blanchet FG, Terio K, Craft ME. Endemic infection can shape exposure to novel pathogens: Pathogen co-occurrence networks in the Serengeti lions. Ecol Lett 2019; 22:904-913. [PMID: 30861289 PMCID: PMC7163671 DOI: 10.1111/ele.13250] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/12/2018] [Accepted: 02/11/2019] [Indexed: 11/30/2022]
Abstract
Pathogens are embedded in a complex network of microparasites that can collectively or individually alter disease dynamics and outcomes. Endemic pathogens that infect an individual in the first years of life, for example, can either facilitate or compete with subsequent pathogens thereby exacerbating or ameliorating morbidity and mortality. Pathogen associations are ubiquitous but poorly understood, particularly in wild populations. We report here on 10 years of serological and molecular data in African lions, leveraging comprehensive demographic and behavioural data to test if endemic pathogens shape subsequent infection by epidemic pathogens. We combine network and community ecology approaches to assess broad network structure and characterise associations between pathogens across spatial and temporal scales. We found significant non‐random structure in the lion‐pathogen co‐occurrence network and identified both positive and negative associations between endemic and epidemic pathogens. Our results provide novel insights on the complex associations underlying pathogen co‐occurrence networks.
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Affiliation(s)
- Nicholas M Fountain-Jones
- Department of Veterinary Population Medicine, University of Minnesota, 1365 Gortner Avenue, St Paul, MN, 55108, USA
| | - Craig Packer
- Department of Ecology Evolution and Behavior, University of Minnesota, St Paul, MN, 55408, USA
| | - Maude Jacquot
- INRA, UMR346 EPIA, Epidémiologie des maladies Animales et zoonotiques, 63122, Saint-Genès-Champanelle, France
| | - F Guillaume Blanchet
- Département de biologie, Université de Sherbrooke, 2500 Boulevard Université, Sherbrooke, QC, Canada, J1K 2R1
| | - Karen Terio
- Zoological Pathology Program, University of Illinois, Urbana-Champaign, IL, USA
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, 1365 Gortner Avenue, St Paul, MN, 55108, USA
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10
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Borrego N, Ozgul A, Slotow R, Packer C. Lion population dynamics: do nomadic males matter? Behav Ecol 2018. [DOI: 10.1093/beheco/ary018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Natalia Borrego
- School of Life Sciences, University of KwaZulu-Natal, University Rd, Westville, South Africa
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Falcon Heights, St. Paul, MN, USA
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurestrasse, Zurich, Switzerland
| | - Rob Slotow
- School of Life Sciences, University of KwaZulu-Natal, University Rd, Westville, South Africa
| | - Craig Packer
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Falcon Heights, St. Paul, MN, USA
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11
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Ward CL, McCann KS. A mechanistic theory for aquatic food chain length. Nat Commun 2017; 8:2028. [PMID: 29229910 PMCID: PMC5725575 DOI: 10.1038/s41467-017-02157-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/08/2017] [Indexed: 11/10/2022] Open
Abstract
Multiple hypotheses propose an ostensibly disparate array of drivers of food chain length (FCL), with contradictory support from natural settings. Here we posit that the magnitude of vertical energy flux in food webs underlies several drivers of FCL. We show that rising energy flux fuels top-heavy biomass pyramids, promoting omnivory, thereby reducing FCL. We link this theory to commonly evaluated hypotheses for environmental drivers of FCL (productivity, ecosystem size) and demonstrate that effects of these drivers should be context-dependent. We evaluate support for this theory in lake and marine ecosystems and demonstrate that ecosystem size is the most important driver of FCL in low-productivity ecosystems (positive relationship) while productivity is most important in large and high-productivity ecosystems (negative relationship). This work stands in contrast to classical hypotheses, which predict a positive effect of productivity on FCL, and may help reconcile the contradictory nature of published results for drivers of FCL.
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Affiliation(s)
- Colette L Ward
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada.
- National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, 735 State Street, Suite 300, Santa Barbara, CA, 93101-5504, USA.
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
| | - Kevin S McCann
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
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12
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Anderson TM, White S, Davis B, Erhardt R, Palmer M, Swanson A, Kosmala M, Packer C. The spatial distribution of African savannah herbivores: species associations and habitat occupancy in a landscape context. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0314. [PMID: 27502379 DOI: 10.1098/rstb.2015.0314] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2016] [Indexed: 11/12/2022] Open
Abstract
Herbivores play an important role in determining the structure and function of tropical savannahs. Here, we (i) outline a framework for how interactions among large mammalian herbivores, carnivores and environmental variation influence herbivore habitat occupancy in tropical savannahs. We then (ii) use a Bayesian hierarchical model to analyse camera trap data to quantify spatial patterns of habitat occupancy for lions and eight common ungulates of varying body size across an approximately 1100 km(2) landscape in the Serengeti ecosystem. Our results reveal strong positive associations among herbivores at the scale of the entire landscape. Lions were positively associated with migratory ungulates but negatively associated with residents. Herbivore habitat occupancy differed with body size and migratory strategy: large-bodied migrants, at less risk of predation and able to tolerate lower quality food, were associated with high NDVI, while smaller residents, constrained to higher quality forage, avoided these areas. Small herbivores were strongly associated with fires, likely due to the subsequent high-quality regrowth, while larger herbivores avoided burned areas. Body mass was strongly related to herbivore habitat use, with larger species more strongly associated with riverine and woodlands than smaller species. Large-bodied migrants displayed diffuse habitat occupancy, whereas smaller species demonstrated fine-scale occupancy reflecting use of smaller patches of high-quality habitat. Our results demonstrate the emergence of strong positive spatial associations among a diverse group of savannah herbivores, while highlighting species-specific habitat selection strongly determined by herbivore body size.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.
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Affiliation(s)
- T Michael Anderson
- Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Staci White
- Department of Mathematics and Statistics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Bryant Davis
- Department of Mathematics and Statistics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Rob Erhardt
- Department of Mathematics and Statistics, Wake Forest University, Winston-Salem, NC 27109, USA
| | - Meredith Palmer
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
| | - Alexandra Swanson
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
| | - Margaret Kosmala
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
| | - Craig Packer
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
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13
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Gustine D, Barboza P, Adams L, Griffith B, Cameron R, Whitten K. Advancing the match-mismatch framework for large herbivores in the Arctic: Evaluating the evidence for a trophic mismatch in caribou. PLoS One 2017; 12:e0171807. [PMID: 28231256 PMCID: PMC5322966 DOI: 10.1371/journal.pone.0171807] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 01/26/2017] [Indexed: 11/17/2022] Open
Abstract
Climate-induced shifts in plant phenology may adversely affect animals that cannot or do not shift the timing of their reproductive cycle. The realized effect of potential trophic "mismatches" between a consumer and its food varies with the degree to which species rely on dietary income and stored capital. Large Arctic herbivores rely heavily on maternal capital to reproduce and give birth near the onset of the growing season but are they vulnerable to trophic mismatch? We evaluated the long-term changes in the temperatures and characteristics of the growing seasons (1970-2013), and compared growing conditions and dynamics of forage quality for caribou at peak parturition, peak lactation, and peak forage biomass, and plant senescence between two distinct time periods over 36 years (1977 and 2011-13). Despite advanced thaw dates (7-12 days earlier), increased growing season lengths (15-21 days longer), and consistent parturition dates, we found no decline in forage quality and therefore no evidence within this dataset for a trophic mismatch at peak parturition or peak lactation from 1977 to 2011-13. In Arctic ungulates that use stored capital for reproduction, reproductive demands are largely met by body stores deposited in the previous summer and autumn, which reduces potential adverse effects of any mismatch between food availability and timing of parturition. Climate-induced effects on forages growing in the summer and autumn ranges, however, do correspond with the demands of female caribou and their offspring to gain mass for the next reproductive cycle and winter. Therefore, we suggest the window of time to examine the match-mismatch framework in Arctic ungulates is not at parturition but in late summer-autumn, where the multiplier effects of small changes in forage quality are amplified by forage abundance, peak forage intake, and resultant mass gains in mother-offspring pairs.
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Affiliation(s)
- David Gustine
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | - Perry Barboza
- Wildlife and Fisheries Science, Texas A&M University, College Station, Texas, United States of America
| | - Layne Adams
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, United States of America
| | - Brad Griffith
- U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Raymond Cameron
- Alaska Department of Fish and Game, Fairbanks, Alaska, United States of America
| | - Kenneth Whitten
- Alaska Department of Fish and Game, Fairbanks, Alaska, United States of America
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McMeans BC, McCann KS, Tunney TD, Fisk AT, Muir AM, Lester N, Shuter B, Rooney N. The adaptive capacity of lake food webs: from individuals to ecosystems. ECOL MONOGR 2016. [DOI: 10.1890/15-0288.1] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Bailey C. McMeans
- Department of Integrative Biology; University of Guelph; Guelph Ontario N1G 2W1 Canada
| | - Kevin S. McCann
- Department of Integrative Biology; University of Guelph; Guelph Ontario N1G 2W1 Canada
| | - Tyler D. Tunney
- Center for Limnology; University of Wisconsin-Madison; Madison Wisconsin 53706 USA
| | - Aaron T. Fisk
- Great Lakes Institute for Environmental Research; University of Windsor; Windsor Ontario N9B 3P4 Canada
| | - Andrew M. Muir
- Great Lakes Fisheries Commission; Ann Arbor Michigan 48105 USA
| | - Nigel Lester
- Harkness Laboratory of Fisheries Research; Aquatic Research and Monitoring Section; Ontario Ministry of Natural Resources; Peterborough Ontario K9J 7B8 Canada
| | - Brian Shuter
- Harkness Laboratory of Fisheries Research; Aquatic Research and Monitoring Section; Ontario Ministry of Natural Resources; Peterborough Ontario K9J 7B8 Canada
| | - Neil Rooney
- School of Environmental Sciences; University of Guelph; Guelph Ontario N1G 2W1 Canada
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15
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Food Web Structure in Temporally-Forced Ecosystems. Trends Ecol Evol 2015; 30:662-672. [DOI: 10.1016/j.tree.2015.09.001] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 09/01/2015] [Accepted: 09/02/2015] [Indexed: 01/20/2023]
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16
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Byrom AE, Nkwabi AJK, Metzger K, Mduma SAR, Forrester GJ, Ruscoe WA, Reed DN, Bukombe J, Mchetto J, Sinclair ARE. Anthropogenic stressors influence small mammal communities in tropical East African savanna at multiple spatial scales. WILDLIFE RESEARCH 2015. [DOI: 10.1071/wr14223] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Context Protection of natural ecosystems undoubtedly safeguards ecological communities, with positive benefits for ecosystem processes and function. However, ecosystems are under threat from anthropogenic stressors that reduce the resilience both of component species and the system as a whole. Aims To determine how anthropogenic stressors (land use and climate change) could impact the diversity and resilience of a small mammal community in the greater Serengeti ecosystem, an East African savanna comprising Serengeti National Park (SNP) and adjacent agro-ecosystems, at local (SNP) and Africa-wide geographic scales. Methods We recorded small mammal species in 10 habitats in the greater Serengeti ecosystem, including the agro-ecosystem, over 48 years (1962–2010). We calculated richness and diversity for each habitat type, and used an index of similarity to quantify differences in the community among habitats. Species accumulation curves were also generated for each habitat type. Key results We recorded 40 species of small mammals in the greater Serengeti ecosystem. At the local scale, restricted habitat types in SNP (each <1% of the total area) made a disproportionately large contribution to diversity. Agro-ecosystems had lower richness and were less likely to contain specialist species. At regional and Africa-wide scales, local endemics were less likely to be recorded in the agro-ecosystem (57% species loss) compared with those with regional (33% loss) or Africa-wide (31%) geographic distributions. Conclusions At the local scale, the variety of habitats in SNP contributed to overall diversity. However, the ability to maintain this diversity in the adjacent agro-ecosystem was compromised for localised endemics compared with species with Africa-wide ranges. Land use intensification adjacent to SNP and projected changes in rainfall patterns for East Africa under global climate scenarios may compromise the future resilience of the small mammal community in this tropical savanna ecosystem. Implications The loss of rare or specialised species from protected areas and human-modified ecosystems could be mitigated by: (1) increasing habitat complexity and maintaining specialist habitats in the agro-ecosystem; and (2) creating buffers at the boundary of protected natural ecosystems that accommodate regime shifts in response to climatic change. These measures would increase the resilience of this coupled human–natural savanna ecosystem.
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Bowler B, Krebs C, O'Donoghue M, Hone J. Climatic amplification of the numerical response of a predator population to its prey. Ecology 2014; 95:1153-61. [PMID: 25000747 DOI: 10.1890/13-0848.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We evaluated evidence of an effect of climate on the numerical response of a coyote (Canis latrans) population to their keystone prey, snowshoe hares (Lepus americanus), in a Canadian boreal forest. Six a priori hypotheses of the coyote numerical response were developed that postulated linear, nonlinear, additive, and interactive effects of prey and climate. Model selection procedures showed the North Atlantic Oscillation (NAO) had the strongest effect on the coyote numerical response via its interaction with snowshoe hare density, while other large-scale climate indices had very weak effects. For a given snowshoe hare density, a negative value of the NAO amplified the abundance of coyote and a positive NAO decreased coyote abundance. We hypothesize that the coyote numerical response is ultimately determined by the coyote functional response influenced by winter conditions determined by the NAO.
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18
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Byrom AE, Craft ME, Durant SM, Nkwabi AJK, Metzger K, Hampson K, Mduma SAR, Forrester GJ, Ruscoe WA, Reed DN, Bukombe J, Mchetto J, Sinclair ARE. Episodic outbreaks of small mammals influence predator community dynamics in an east African savanna ecosystem. OIKOS 2014. [DOI: 10.1111/oik.00962] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Meggan E. Craft
- Veterinary Population Medicine, University of Minnesota; 1988 Fitch Ave St Paul MN 55108 USA
| | - Sarah M. Durant
- Inst. of Zoology, Zoological Society of London, Regent's Park; London NW1 4RY UK
- Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
| | - Ally J. K. Nkwabi
- Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
- Serengeti Biodiversity Program, Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
| | - Kristine Metzger
- Beaty Biodiversity Centre, Univ. of British Columbia; Vancouver BC V6T 1Z4 Canada
| | - Katie Hampson
- Boyd Orr Centre for population and Ecosystem Health, Inst. for Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Univ. of Glasgow; Glasgow UK
| | - Simon A. R. Mduma
- Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
- Serengeti Biodiversity Program, Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
| | | | | | - Denne N. Reed
- Dept of Anthropology; Univ. of Texas Austin; 1 University Station C3200 Austin TX 78712 USA
| | - John Bukombe
- Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
- Serengeti Biodiversity Program, Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
| | - John Mchetto
- Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
- Serengeti Biodiversity Program, Tanzania Wildlife Research Inst.; PO Box 661 Arusha Tanzania
| | - A. R. E. Sinclair
- Beaty Biodiversity Centre, Univ. of British Columbia; Vancouver BC V6T 1Z4 Canada
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