1
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Ellis SL, Lohman MG, Sedinger JS, Williams PJ, Riecke TV. Long-term trends and drought: Spatiotemporal variation in juvenile sex ratios of North American ducks. Ecol Evol 2022; 12:e9099. [PMID: 35845362 PMCID: PMC9280441 DOI: 10.1002/ece3.9099] [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: 10/30/2021] [Revised: 06/12/2022] [Accepted: 06/20/2022] [Indexed: 11/30/2022] Open
Abstract
Sex ratios affect population dynamics and individual fitness, and changing sex ratios can be indicative of shifts in sex-specific survival at different life stages. While climate and landscape changes alter sex ratios of wild bird populations, long-term, landscape scale assessments of sex ratios are rare. Further, little work has been done to understand changes in sex ratios in avian communities. In this manuscript, we analyze long-term (1961-2015) data on five species of ducks across five broad climatic regions of the United States to estimate the effects of drought and long-term trends on the proportion of juvenile females captured at banding. As waterfowl have a 1:1 sex ratio at hatch, we interpret changes in sex ratios of captured juveniles as changes in sex-specific survival rates during early life. Seven of 12 species-region pairs exhibited evidence for long-term trends in the proportion of juvenile females at banding. The proportion of juvenile females at banding increased for duck populations in the western United States and typically declined for duck populations in the eastern United States. We only observed evidence for an effect of drought in two of the 12 species-region pairs, where the proportion of females declined during drought. As changes to North American landscapes and climate continue and intensify, we expect continued changes in sex-specific juvenile survival rates. More broadly, we encourage further research examining the mechanisms underlying long-term trends in juvenile sex ratios in avian communities.
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Affiliation(s)
- Sage L. Ellis
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
| | - Madeleine G. Lohman
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
- Program in Ecology, Evolution, and Conservation BiologyUniversity of NevadaRenoNevadaUSA
| | - James S. Sedinger
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
| | - Perry J. Williams
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
| | - Thomas V. Riecke
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
- Program in Ecology, Evolution, and Conservation BiologyUniversity of NevadaRenoNevadaUSA
- Swiss Ornithological InstituteSempachSwitzerland
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2
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Oro D, Sanz-Aguilar A, Carbonell F, Grajera J, Torre I. Multi-species prey dynamics influence local survival in resident and wintering generalist predators. Oecologia 2021; 197:437-446. [PMID: 34550444 PMCID: PMC8505301 DOI: 10.1007/s00442-021-05042-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/11/2021] [Indexed: 11/23/2022]
Abstract
Stochasticity in food availability influences vital rates such as survival and fertility. Life-history theory predicts that in long-lived organisms, survival should be buffered against environmental stochasticity showing little temporal variability. Furthermore, to optimize survival prospects, many animal species perform migrations to wintering areas where food availability is larger. Species with large latitudinal distribution ranges may show populations that migrate and others that are resident, and they may co-occur in winter. One example of these species is the predatory raptor buzzard Buteo buteo. Here, we test whether temporal variability in the density of five small mammal species of prey inhabiting different habitats (shrubland and forests) influences local annual survival of buzzards in a wintering area depending on their age and residency status (residents versus wintering individuals). We found that prey density explained a considerable amount of annual changes in local survival, which was higher for older and resident birds. This difference in local survival likely corresponded to philopatry to the wintering area, which was larger for residents and increased when prey density was larger. The total density of prey inhabiting open shrublands was the variable explaining more variance in temporal variability of local survival, even though the study area is mostly occupied by woodlands. Temporal population dynamics of the different small mammals inhabiting shrublands were not synchronous, which suggests that buzzards preyed opportunistically on the most abundant prey each winter. Generalist predation may buffer the impact of resource unpredictability for pulsed and asynchronous prey dynamics, typical of small mammals in winter.
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Affiliation(s)
- Daniel Oro
- Theoretical and Computational Ecology Group, Center for Advanced Studies of Blanes (CEAB-CSIC), Accés Cala Sant Francesc 14, 17300, Blanes, Spain.
| | - Ana Sanz-Aguilar
- Animal Demography and Ecology Unit, IMEDEA (CSIC-UIB), Miquel Marques 21, 07190, Esporles, Spain.,Applied Zoology and Conservation Group, University of the Balearic Islands, Crtra. Valldemossa s/n, 07122, Palma, Spain
| | | | - Joan Grajera
- Catalan Ornithological Institute, Girona 168, 08037, Barcelona, Spain
| | - Ignasi Torre
- BiBio Research Group, Natural Sciences Museum of Granollers, Francesc Macià 51, 08402, Granollers, Spain
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3
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Adde A, Darveau M, Barker N, Imbeau L, Cumming S. Environmental covariates for modelling the distribution and abundance of breeding ducks in northern North America: a review. ECOSCIENCE 2021. [DOI: 10.1080/11956860.2020.1802933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Antoine Adde
- Département des sciences du bois et de la forêt, Université Laval, Québec, QC, Canada
| | - Marcel Darveau
- Département des sciences du bois et de la forêt, Université Laval, Québec, QC, Canada
- Canards Illimités Canada, Québec, QC, Canada
| | - Nicole Barker
- Canadian Wildlife Service, Environment and Climate Change Canada, Edmonton, AB, Canada
| | - Louis Imbeau
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, Canada
| | - Steven Cumming
- Département des sciences du bois et de la forêt, Université Laval, Québec, QC, Canada
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4
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Johnson‐Bice SM, Ferguson JM, Erb JD, Gable TD, Windels SK. Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02198. [PMID: 32583507 PMCID: PMC7816246 DOI: 10.1002/eap.2198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 03/13/2020] [Accepted: 03/30/2020] [Indexed: 05/20/2023]
Abstract
Over the past two decades, there have been numerous calls to make ecology a more predictive science through direct empirical assessments of ecological models and predictions. While the widespread use of model selection using information criteria has pushed ecology toward placing a higher emphasis on prediction, few attempts have been made to validate the ability of information criteria to correctly identify the most parsimonious model with the greatest predictive accuracy. Here, we used an ecological forecasting framework to test the ability of information criteria to accurately predict the relative contribution of density dependence and density-independent factors (forage availability, harvest, weather, wolf [Canis lupus] density) on inter-annual fluctuations in beaver (Castor canadensis) colony densities. We modeled changes in colony densities using a discrete-time Gompertz model, and assessed the performance of four models using information criteria values: density-independent models with (1) and without (2) environmental covariates; and density-dependent models with (3) and without (4) environmental covariates. We then evaluated the forecasting accuracy of each model by withholding the final one-third of observations from each population and compared observed vs. predicted densities. Information criteria and our forecasting accuracy metrics both provided strong evidence of compensatory density dependence in the annual dynamics of beaver colony densities. However, despite strong within-sample performance by the most complex model (density-dependent with covariates) as determined using information criteria, hindcasts of colony densities revealed that the much simpler density-dependent model without covariates performed nearly as well predicting out-of-sample colony densities. The hindcast results indicated that the complex model over-fit our data, suggesting that parameters identified by information criteria as important predictor variables are only marginally valuable for predicting landscape-scale beaver colony dynamics. Our study demonstrates the importance of evaluating ecological models and predictions with long-term data and revealed how a known limitation of information criteria (over-fitting of complex models) can affect our interpretation of ecological dynamics. While incorporating knowledge of the factors that influence animal population dynamics can improve population forecasts, we suggest that comparing forecast performance metrics can likewise improve our knowledge of the factors driving population dynamics.
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Affiliation(s)
- Sean M. Johnson‐Bice
- Department of Biological SciencesUniversity of Manitoba50 Sifton RoadWinnipegManitobaR3T 2N2Canada
- Natural Resources Research InstituteUniversity of Minnesota Duluth5013 Miller Trunk HighwayDuluthMinnesota55812USA
| | - Jake M. Ferguson
- Department of BiologyUniversity of Hawai`i at Mānoa2538 McCarthy MallHonoluluHawaii96822USA
| | - John D. Erb
- Forest Wildlife Populations and Research GroupMinnesota Department of Natural Resources1201 E. highway 2Grand RapidsMinnesota55744USA
| | - Thomas D. Gable
- Department of Fisheries, Wildlife and Conservation BiologyUniversity of Minnesota Twin Cities2003 Upper Buford CircleSt. PaulMinnesota55108USA
| | - Steve K. Windels
- Natural Resources Research InstituteUniversity of Minnesota Duluth5013 Miller Trunk HighwayDuluthMinnesota55812USA
- Department of Fisheries, Wildlife and Conservation BiologyUniversity of Minnesota Twin Cities2003 Upper Buford CircleSt. PaulMinnesota55108USA
- Voyageurs National Park360 Highway 11 E.International FallsMinnesota56649USA
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5
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Adde A, Darveau M, Barker N, Cumming S. Predicting spatiotemporal abundance of breeding waterfowl across Canada: A Bayesian hierarchical modelling approach. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Antoine Adde
- Department of Wood and Forest Sciences Laval University Quebec QC Canada
| | - Marcel Darveau
- Department of Wood and Forest Sciences Laval University Quebec QC Canada
- Ducks Unlimited Canada Quebec QC Canada
| | - Nicole Barker
- Canadian Wildlife Service Environment and Climate Change Canada Edmonton AB Canada
| | - Steven Cumming
- Department of Wood and Forest Sciences Laval University Quebec QC Canada
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6
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Thurber BG, Roy C, Zimmerling JR. Long-term changes in the autumn migration phenology of dabbling ducks in southern Ontario and implications for waterfowl management. WILDLIFE BIOLOGY 2020. [DOI: 10.2981/wlb.00668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Bethany G. Thurber
- B. G. Thurber (https://orcid.org/0000-0002-6973-9810) ✉ , 5 Best Avenue, Dundas, ON, L9H 5Z1, Canada
| | - Christian Roy
- B. G. Thurber (https://orcid.org/0000-0002-6973-9810) ✉ , 5 Best Avenue, Dundas, ON, L9H 5Z1, Canada
| | - J. Ryan Zimmerling
- B. G. Thurber (https://orcid.org/0000-0002-6973-9810) ✉ , 5 Best Avenue, Dundas, ON, L9H 5Z1, Canada
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7
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Sedinger BS, Riecke TV, Nicolai CA, Woolstenhulme R, Henry WG, Stewart KM. Experimental harvest regulations reveal that water availability during spring, not harvest, affects change in a waterfowl population. Ecol Evol 2019; 9:12701-12709. [PMID: 31788208 PMCID: PMC6875577 DOI: 10.1002/ece3.5743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/09/2019] [Accepted: 09/15/2019] [Indexed: 11/09/2022] Open
Abstract
Population change is regulated by vital rates that are influenced by environmental conditions, demographic stochasticity, and, increasingly, anthropogenic effects. Habitat destruction and climate change threaten the future of many wildlife populations, and there are additional concerns regarding the effects of harvest rates on demographic components of harvested organisms. Further, many population managers strictly manage harvest of wild organisms to mediate population trends of these populations. The goal of our study was to decouple harvest and environmental variability in a closely monitored population of wild ducks in North America, where we experimentally regulated harvest independently of environmental variation over a period of 4 years. We used 9 years of capture-mark-recapture data to estimate breeding population size during the spring for a population of wood ducks in Nevada. We then assessed the effect of one environmental variable and harvest pressure on annual changes in the breeding population size. Climatic conditions influencing water availability were strongly positively related to population growth rates of wood ducks in our study system. In contrast, harvest regulations and harvest rates did not affect population growth rates. We suggest efforts to conserve waterfowl should focus on the effects of habitat loss in breeding areas and climate change, which will likely affect precipitation regimes in the future. We demonstrate the utility of capture-mark-recapture methods to estimate abundance of species which are difficult to survey and test the impacts of anthropogenic harvest and climate on populations. Finally, our results continue to add to the importance of experimentation in applied conservation biology, where we believe that continued experiments on nonthreatened species will be critically important as researchers attempt to understand how to quantify and mitigate direct anthropogenic impacts in a changing world.
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Affiliation(s)
- Benjamin S. Sedinger
- College of Natural ResourcesUniversity of Wisconsin – Stevens PointStevens PointWIUSA
- Program in Ecology, Evolution, and Conservation BiologyUniversity of NevadaRenoNVUSA
| | - Thomas V. Riecke
- Program in Ecology, Evolution, and Conservation BiologyUniversity of NevadaRenoNVUSA
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNVUSA
| | - Christopher A. Nicolai
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNVUSA
- Delta Waterfowl FoundationBismarckNDUSA
| | | | | | - Kelley M. Stewart
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNVUSA
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8
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Diet of Lesser Scaup Wintering on Lake Pontchartrain, Louisiana. JOURNAL OF FISH AND WILDLIFE MANAGEMENT 2019. [DOI: 10.3996/052019-jfwm-036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Abstract
The lesser scaup Aythya affinis has been a species of conservation concern since continental breeding populations began declining in the 1980s. The causes of this decline are likely multifaceted, but cross-seasonal effects are believed to play a prominent role: females unable to acquire sufficient nutrient reserves during winter and spring migration have poor survival and breeding success. Understanding scaup diet composition and prey selection can help managers not only diagnose mechanisms underlying wintering scaup distributions, but may also help direct management actions to increase forage availability and quality. We evaluated the diet of 60 scaup collected from a major wintering site in Louisiana, Lake Pontchartrain. Scaup consumed almost entirely mollusks, especially targeting medium-sized (6–16 mm) common rangia clams Rangia cuneata, which were strongly selected relative to their availability. Eighty-two percent of scaup consumed dark false mussels Mytilopsis leucophaeata and 57% consumed dwarf surf clams Mulinia lateralis; both foods were selected by scaup, but were uncommon in benthic samples. On the other hand, small snails Texadina sphinctostoma, Probythinella protera were common in dredge samples but were either avoided or consumed in proportion to their availability. We conclude that medium-sized common rangia clams and dark false mussels are the most consumed foods for scaup wintering on Lake Pontchartrain, and hypothesize that annual variation in prey populations may be an important proximate driver of scaup abundance.
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9
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Ross BE, Haukos DA, Walther P. Quantifying changes and influences on mottled duck density in Texas. J Wildl Manage 2018. [DOI: 10.1002/jwmg.21373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Beth E. Ross
- Division of Biology; Kansas State University; Manhattan KS 66506 USA
| | - David A. Haukos
- U.S. Geological Survey; Kansas Cooperative Fish and Wildlife Research Unit; Manhattan KS 66506 USA
| | - Patrick Walther
- U.S. Fish and Wildlife Service; Texas Chenier Plain National Wildlife Refuge Complex; Anahuac TX 77514 USA
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10
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Amburgey SM, Miller DAW, Campbell Grant EH, Rittenhouse TAG, Benard MF, Richardson JL, Urban MC, Hughson W, Brand AB, Davis CJ, Hardin CR, Paton PWC, Raithel CJ, Relyea RA, Scott AF, Skelly DK, Skidds DE, Smith CK, Werner EE. Range position and climate sensitivity: The structure of among-population demographic responses to climatic variation. GLOBAL CHANGE BIOLOGY 2018; 24:439-454. [PMID: 28833972 DOI: 10.1111/gcb.13817] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 06/26/2017] [Indexed: 05/28/2023]
Abstract
Species' distributions will respond to climate change based on the relationship between local demographic processes and climate and how this relationship varies based on range position. A rarely tested demographic prediction is that populations at the extremes of a species' climate envelope (e.g., populations in areas with the highest mean annual temperature) will be most sensitive to local shifts in climate (i.e., warming). We tested this prediction using a dynamic species distribution model linking demographic rates to variation in temperature and precipitation for wood frogs (Lithobates sylvaticus) in North America. Using long-term monitoring data from 746 populations in 27 study areas, we determined how climatic variation affected population growth rates and how these relationships varied with respect to long-term climate. Some models supported the predicted pattern, with negative effects of extreme summer temperatures in hotter areas and positive effects on recruitment for summer water availability in drier areas. We also found evidence of interacting temperature and precipitation influencing population size, such as extreme heat having less of a negative effect in wetter areas. Other results were contrary to predictions, such as positive effects of summer water availability in wetter parts of the range and positive responses to winter warming especially in milder areas. In general, we found wood frogs were more sensitive to changes in temperature or temperature interacting with precipitation than to changes in precipitation alone. Our results suggest that sensitivity to changes in climate cannot be predicted simply by knowing locations within the species' climate envelope. Many climate processes did not affect population growth rates in the predicted direction based on range position. Processes such as species-interactions, local adaptation, and interactions with the physical landscape likely affect the responses we observed. Our work highlights the need to measure demographic responses to changing climate.
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Affiliation(s)
- Staci M Amburgey
- Department of Ecosystem Sciences and Management, The Pennsylvania State University, University Park, PA, USA
- Intercollege Graduate Ecology Program, The Pennsylvania State University, University Park, PA, USA
| | - David A W Miller
- Department of Ecosystem Sciences and Management, The Pennsylvania State University, University Park, PA, USA
| | - Evan H Campbell Grant
- USGS Patuxent Wildlife Research Center, SO Conte Anadromous Fish Research Center, Turners Falls, MA, USA
| | - Tracy A G Rittenhouse
- Department of Natural Resources and the Environment, University of Connecticut, Storrs, CT, USA
| | - Michael F Benard
- Department of Biology, Case Western Reserve University, Cleveland, OH, USA
| | | | - Mark C Urban
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA
| | | | - Adrianne B Brand
- USGS Patuxent Wildlife Research Center, SO Conte Anadromous Fish Research Center, Turners Falls, MA, USA
| | - Christopher J Davis
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carmen R Hardin
- Forestry Division, Wisconsin Department of Natural Resources, Madison, WI, USA
| | - Peter W C Paton
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI, USA
| | - Christopher J Raithel
- Division of Fish and Wildlife, Rhode Island Department of Environmental Management, West Kingston, RI, USA
| | - Rick A Relyea
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - A Floyd Scott
- Department of Biology, Austin Peay State University, Clarksville, TN, USA
| | - David K Skelly
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, USA
| | - Dennis E Skidds
- Northeast Coastal and Barrier Network, National Parks Service, Kingston, RI, USA
| | - Charles K Smith
- Department of Biology, High Point University, High Point, NC, USA
| | - Earl E Werner
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
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11
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Arnold TW, Clark RG, Koons DN, Schaub M. Integrated population models facilitate ecological understanding and improved management decisions. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21404] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Todd W. Arnold
- Department of Fisheries, Wildlife and Conservation Biology; University of Minnesota; St. Paul MN 55108 USA
| | - Robert G. Clark
- Wildlife Research Division; Environment and Climate Change Canada; 115 Perimeter Road Saskatoon SK S7N 0X4 Canada
| | - David N. Koons
- Department of Wildland Resources and the Ecology Center; Utah State University; Logan UT 84322 USA
| | - Michael Schaub
- Swiss Ornithological Institute; 6204 Sempach Switzerland
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12
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Greenville AC, Wardle GM, Dickman CR. Desert mammal populations are limited by introduced predators rather than future climate change. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170384. [PMID: 29291051 PMCID: PMC5717625 DOI: 10.1098/rsos.170384] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 10/04/2017] [Indexed: 05/19/2023]
Abstract
Climate change is predicted to place up to one in six species at risk of extinction in coming decades, but extinction probability is likely to be influenced further by biotic interactions such as predation. We use structural equation modelling to integrate results from remote camera trapping and long-term (17-22 years) regional-scale (8000 km2) datasets on vegetation and small vertebrates (greater than 38 880 captures) to explore how biotic processes and two key abiotic drivers influence the structure of a diverse assemblage of desert biota in central Australia. We use our models to predict how changes in rainfall and wildfire are likely to influence the cover and productivity of the dominant vegetation and the impacts of predators on their primary rodent prey over a 100-year timeframe. Our results show that, while vegetation cover may decline due to climate change, the strongest negative effect on prey populations in this desert system is top-down suppression from introduced predators.
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Affiliation(s)
- Aaron C. Greenville
- Desert Ecology Research Group, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
- Long Term Ecological Research Network, Terrestrial Ecosystem Research Network, St Lucia, Australia
- Author for correspondence: Aaron C. Greenville e-mail:
| | - Glenda M. Wardle
- Desert Ecology Research Group, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
- Long Term Ecological Research Network, Terrestrial Ecosystem Research Network, St Lucia, Australia
| | - Chris R. Dickman
- Desert Ecology Research Group, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
- Long Term Ecological Research Network, Terrestrial Ecosystem Research Network, St Lucia, Australia
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13
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Koons DN, Arnold TW, Schaub M. Understanding the demographic drivers of realized population growth rates. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:2102-2115. [PMID: 28675581 DOI: 10.1002/eap.1594] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/08/2017] [Accepted: 06/15/2017] [Indexed: 06/07/2023]
Abstract
Identifying the demographic parameters (e.g., reproduction, survival, dispersal) that most influence population dynamics can increase conservation effectiveness and enhance ecological understanding. Life table response experiments (LTRE) aim to decompose the effects of change in parameters on past demographic outcomes (e.g., population growth rates). But the vast majority of LTREs and other retrospective population analyses have focused on decomposing asymptotic population growth rates, which do not account for the dynamic interplay between population structure and vital rates that shape realized population growth rates (λt=Nt+1/Nt) in time-varying environments. We provide an empirical means to overcome these shortcomings by merging recently developed "transient life-table response experiments" with integrated population models (IPMs). IPMs allow for the estimation of latent population structure and other demographic parameters that are required for transient LTRE analysis, and Bayesian versions additionally allow for complete error propagation from the estimation of demographic parameters to derivations of realized population growth rates and perturbation analyses of growth rates. By integrating available monitoring data for Lesser Scaup over 60 yr, and conducting transient LTREs on IPM estimates, we found that the contribution of juvenile female survival to long-term variation in realized population growth rates was 1.6 and 3.7 times larger than that of adult female survival and fecundity, respectively. But a persistent long-term decline in fecundity explained 92% of the decline in abundance between 1983 and 2006. In contrast, an improvement in adult female survival drove the modest recovery in Lesser Scaup abundance since 2006, indicating that the most important demographic drivers of Lesser Scaup population dynamics are temporally dynamic. In addition to resolving uncertainty about Lesser Scaup population dynamics, the merger of IPMs with transient LTREs will strengthen our understanding of demography for many species as we aim to conserve biodiversity during an era of non-stationary global change.
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Affiliation(s)
- David N Koons
- Department of Wildland Resources and the Ecology Center, Utah State University, 5230 Old Main Hill, Logan, Utah, 84322, USA
- James C. Kennedy Endowed Chair in Wetland and Waterfowl Conservation, Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado, 80523, USA
| | - Todd W Arnold
- Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, 135 Skok Hall, St. Paul, Minnesota, 55108, USA
| | - Michael Schaub
- Swiss Ornithological Institute, 6204, Sempach, Switzerland
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14
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Lindberg MS, Boomer GS, Schmutz JA, Walker JA. A comment on “temporal variation in survival and recovery rates of lesser scaup”. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21250] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mark S. Lindberg
- Institute of Arctic Biology; University of Alaska Fairbanks; Fairbanks AK 99775 USA
| | - G. Scott Boomer
- U.S. Fish and Wildlife Service; Division of Migratory Bird Management; 11510 American Holly Drive Laurel MD 20708 USA
| | - Joel A. Schmutz
- U.S. Geological Survey; Alaska Science Center, 4210 University Drive; Anchorage AK 99508 USA
| | - Johann A. Walker
- Great Plains Regional Office; Ducks Unlimited; 2525 River Road Bismarck ND 58503 USA
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15
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Zhao Q, Boomer GS, Silverman E, Fleming K. Accounting for the temporal variation of spatial effect improves inference and projection of population dynamics models. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2017.07.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Arnold TW, Afton AD, Anteau MJ, Koons DN, Nicolai CA. Temporal variation in survival and recovery rates of lesser scaup: A response. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21315] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Todd W. Arnold
- Department of Fisheries, Wildlife and Conservation Biology; University of Minnesota; 135 Skok Hall St. Paul MN 55108 USA
| | - Alan D. Afton
- School of Renewable Natural Resources; Louisiana State University; Baton Rouge LA 70803 USA
| | - Michael J. Anteau
- U.S. Geological Survey; Northern Prairie Wildlife Research Center; 8711 37th St SE Jamestown ND 58401 USA
| | - David N. Koons
- Department of Wildland Resources and the Ecology Center; Utah State University; 5230 Old Main Hill Logan UT 84322-5230 USA
| | - Chris A. Nicolai
- Department of Natural Resources and Environmental Science; University of Nevada Reno; 1664 North Virginia Street Reno NV 89557 USA
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Pöysä H, Rintala J, Johnson DH, Kauppinen J, Lammi E, Nudds TD, Väänänen VM. Environmental variability and population dynamics: do European and North American ducks play by the same rules? Ecol Evol 2017; 6:7004-7014. [PMID: 28725377 PMCID: PMC5513220 DOI: 10.1002/ece3.2413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/01/2016] [Accepted: 08/04/2016] [Indexed: 11/06/2022] Open
Abstract
Density dependence, population regulation, and variability in population size are fundamental population processes, the manifestation and interrelationships of which are affected by environmental variability. However, there are surprisingly few empirical studies that distinguish the effect of environmental variability from the effects of population processes. We took advantage of a unique system, in which populations of the same duck species or close ecological counterparts live in highly variable (north American prairies) and in stable (north European lakes) environments, to distinguish the relative contributions of environmental variability (measured as between-year fluctuations in wetland numbers) and intraspecific interactions (density dependence) in driving population dynamics. We tested whether populations living in stable environments (in northern Europe) were more strongly governed by density dependence than populations living in variable environments (in North America). We also addressed whether relative population dynamical responses to environmental variability versus density corresponded to differences in life history strategies between dabbling (relatively "fast species" and governed by environmental variability) and diving (relatively "slow species" and governed by density) ducks. As expected, the variance component of population fluctuations caused by changes in breeding environments was greater in North America than in Europe. Contrary to expectations, however, populations in more stable environments were not less variable nor clearly more strongly density dependent than populations in highly variable environments. Also, contrary to expectations, populations of diving ducks were neither more stable nor stronger density dependent than populations of dabbling ducks, and the effect of environmental variability on population dynamics was greater in diving than in dabbling ducks. In general, irrespective of continent and species life history, environmental variability contributed more to variation in species abundances than did density. Our findings underscore the need for more studies on populations of the same species in different environments to verify the generality of current explanations about population dynamics and its association with species life history.
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Affiliation(s)
- Hannu Pöysä
- Natural Resources Institute Finland Joensuu Finland
| | - Jukka Rintala
- Natural Resources Institute Finland Helsinki Finland
| | - Douglas H Johnson
- USGS Northern Prairie Wildlife Research Center St. Paul MN USA.,Fisheries, Wildlife, and Conservation Biology University of Minnesota St. Paul MN USA
| | | | - Esa Lammi
- Environmental Planning ENVIRO Espoo Finland
| | - Thomas D Nudds
- Department of Integrative Biology University of Guelph Guelph ON Canada
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Monroe AP, Aldridge CL, Assal TJ, Veblen KE, Pyke DA, Casazza ML. Patterns in Greater Sage-grouse population dynamics correspond with public grazing records at broad scales. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:1096-1107. [PMID: 28329422 DOI: 10.1002/eap.1512] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 01/09/2017] [Indexed: 06/06/2023]
Abstract
Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004-2014, we modeled population trends in response to grazing level (represented by a relative grazing index) and timing across a gradient in vegetation productivity as measured by the Normalized Vegetation Difference Index (NDVI). We found grazing can have both positive and negative effects on Sage-grouse populations depending on the timing and level of grazing. Sage-grouse populations responded positively to higher grazing levels after peak vegetation productivity, but populations declined when similar grazing levels occurred earlier, likely reflecting the sensitivity of cool-season grasses to grazing during peak growth periods. We also found support for the hypothesis that effects of grazing management vary with local vegetation productivity. These results illustrate the importance of broad-scale analyses by revealing patterns in Sage-grouse population trends that may not be inferred from studies at finer scales, and could inform sustainable grazing management in these ecosystems.
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Affiliation(s)
- Adrian P Monroe
- Natural Resource Ecology Laboratory and Department of Ecosystem Science and Sustainability, Colorado State University in cooperation with the US Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, 80526, USA
| | - Cameron L Aldridge
- Natural Resource Ecology Laboratory and Department of Ecosystem Science and Sustainability, Colorado State University in cooperation with the US Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, 80526, USA
| | - Timothy J Assal
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, 80526, USA
| | - Kari E Veblen
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, 84322, USA
| | - David A Pyke
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon, 97331, USA
| | - Michael L Casazza
- U.S. Geological Survey, Western Ecological Research Center, Dixon, California, 95620, USA
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Tredennick AT, Hooten MB, Aldridge CL, Homer CG, Kleinhesselink AR, Adler PB. Forecasting climate change impacts on plant populations over large spatial extents. Ecosphere 2016. [DOI: 10.1002/ecs2.1525] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Andrew T. Tredennick
- Department of Wildland Resources and the Ecology Center Utah State University 5230 Old Main Hill Logan Utah 84322 USA
| | - Mevin B. Hooten
- U.S. Geological Survey Colorado Cooperative Fish and Wildlife Research Unit Colorado State University Fort Collins Colorado 80523 USA
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado 80523 USA
- Department of Statistics Colorado State University Fort Collins Colorado 80523 USA
| | - Cameron L. Aldridge
- Department of Ecosystem Science and Sustainability Natural Resource Ecology Laboratory Colorado State University Fort Collins Colorado 80523 USA
- U.S. Geological Survey Fort Collins Science Center Fort Collins Colorado 80526 USA
| | - Collin G. Homer
- U.S. Geological Survey Earth Resources Observation and Science (EROS) Center Sioux Falls South Dakota 57198 USA
| | - Andrew R. Kleinhesselink
- Department of Wildland Resources and the Ecology Center Utah State University 5230 Old Main Hill Logan Utah 84322 USA
| | - Peter B. Adler
- Department of Wildland Resources and the Ecology Center Utah State University 5230 Old Main Hill Logan Utah 84322 USA
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21
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Arnold TW, Afton AD, Anteau MJ, Koons DN, Nicolai CA. Temporal variation in survival and recovery rates of lesser scaup. J Wildl Manage 2016. [DOI: 10.1002/jwmg.21074] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Todd W. Arnold
- Department of Fisheries; Wildlife and Conservation Biology; University of Minnesota; 135 Skok Hall St. Paul MN 55108 USA
| | - Alan D. Afton
- School of Renewable Natural Resources; Louisiana State University; Baton Rouge LA 70803 USA
| | - Michael J. Anteau
- U.S. Geological Survey; Northern Prairie Wildlife Research Center; 8711 37th St SE Jamestown ND 58401 USA
| | - David N. Koons
- Department of Wildland Resources and the Ecology Center; Utah State University; 5230 Old Main Hill Logan UT 84322-5230 USA
| | - Chris A. Nicolai
- Department of Natural Resources and Environmental Science; University of Nevada Reno; 1664 North Virginia Street Reno NV 89557 USA
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