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Taylor LU, Hodge W, Shlepr KR, Anderson J. Interspecies conflict, precarious reasoning, and the gull problem in the Gulf of Maine. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2024:e14299. [PMID: 38766874 DOI: 10.1111/cobi.14299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 02/22/2024] [Accepted: 03/27/2024] [Indexed: 05/22/2024]
Abstract
Contemporary conservation science requires mediating conflicts among nonhuman species, but the grounds for favoring one species over another can be unclear. We examined the premises through which wildlife managers picked sides in an interspecies conflict: seabird conservation in the Gulf of Maine (GOM). Managers in the GOM follow a simple narrative dubbed the gull problem. This narrative assumes Larus gulls are overpopulated and unnatural in the region. In turn, these assumptions make gulls an easy target for culling and lethal control when the birds come into conflict with other seabirds, particularly Sterna terns. Surveying historical, natural historical, and ecological evidence, we found no scientific support for the claim that Larus gulls are overpopulated in the GOM. Claims of overpopulation originated from a historical context in which rising gull populations became a nuisance to humans. Further, we found only limited evidence that anthropogenic subsidies make gulls unnatural in the region, especially when compared with anthropogenic subsidies provided for other seabirds. The risks and consequences of leveraging precarious assumptions include cascading plans to cull additional gull populations, obfuscation of more fundamental environmental threats to seabirds, and the looming paradox of gull conservation-even if one is still inclined to protect terns in the GOM. Our close look at the regional history of a conservation practice thus revealed the importance of not only conservation decisions, but also conservation decision-making.
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Affiliation(s)
- Liam U Taylor
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
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Appel CL, Lesmeister DB, Duarte A, Davis RJ, Weldy MJ, Levi T. Using passive acoustic monitoring to estimate northern spotted owl landscape use and pair occupancy. Ecosphere 2023. [DOI: 10.1002/ecs2.4421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Affiliation(s)
- Cara L. Appel
- Pacific Northwest Research Station USDA Forest Service Corvallis Oregon USA
- Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University Corvallis Oregon USA
- Oak Ridge Institute for Science and Education Oak Ridge Tennessee USA
| | - Damon B. Lesmeister
- Pacific Northwest Research Station USDA Forest Service Corvallis Oregon USA
- Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University Corvallis Oregon USA
| | - Adam Duarte
- Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University Corvallis Oregon USA
- Pacific Northwest Research Station USDA Forest Service Olympia Washington USA
| | - Raymond J. Davis
- Pacific Northwest Region USDA Forest Service Corvallis Oregon USA
| | - Matthew J. Weldy
- Pacific Northwest Research Station USDA Forest Service Corvallis Oregon USA
- Oak Ridge Institute for Science and Education Oak Ridge Tennessee USA
- Department of Forest Ecosystems and Society Oregon State University Corvallis Oregon USA
| | - Taal Levi
- Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University Corvallis Oregon USA
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Rockweit JT, Jenkins JM, Hines JE, Nichols JD, Dugger KM, Franklin AB, Carlson PC, Kendall WL, Lesmeister DB, McCafferty C, Ackers SH, Andrews LS, Bailey LL, Burgher J, Burnham KP, Chestnut T, Conner MM, Davis RJ, Dilione KE, Forsman ED, Glenn EM, Gremel SA, Hamm KA, Herter DR, Higley JM, Horn RB, Lamphear DW, McDonald TL, Reid JA, Schwarz CJ, Simon DC, Sovern SG, Swingle JK, Wiens JD, Wise H, Yackulic CB. Range-wide sources of variation in reproductive rates of northern spotted owls. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2726. [PMID: 36053865 PMCID: PMC10078374 DOI: 10.1002/eap.2726] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 06/09/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
We conducted a range-wide investigation of the dynamics of site-level reproductive rate of northern spotted owls using survey data from 11 study areas across the subspecies geographic range collected during 1993-2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further insights into northern spotted owl population ecology and dynamics. Both nondetection and state misclassification were important, especially because factors affecting these sources of error also affected focal ecological parameters. Annual probabilities of site occupancy were greatest at sites with successful reproduction in the previous year and lowest for sites not occupied by a pair in the previous year. Site-specific occupancy transition probabilities declined over time and were negatively affected by barred owl presence. Overall, the site-specific probability of successful reproduction showed substantial year-to-year fluctuations and was similar for occupied sites that did or did not experience successful reproduction the previous year. Site-specific probabilities for successful reproduction were very small for sites that were unoccupied the previous year. Barred owl presence negatively affected the probability of successful reproduction by northern spotted owls in Washington and California, as predicted, but the effect in Oregon was mixed. The proportions of sites occupied by northern spotted owl pairs showed steep, near-monotonic declines over the study period, with all study areas showing the lowest observed levels of occupancy to date. If trends continue it is likely that northern spotted owls will become extirpated throughout large portions of their range in the coming decades.
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Affiliation(s)
- Jeremy T. Rockweit
- Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsColoradoUSA
| | - Julianna M. Jenkins
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - James E. Hines
- US Geological Survey, Eastern Ecological Science CenterLaurelMarylandUSA
| | - James D. Nichols
- Department of Wildlife Ecology and ConservationUniversity of FloridaGainesvilleFloridaUSA
| | - Katie M. Dugger
- US Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
| | - Alan B. Franklin
- US Department of Agriculture, Wildlife ServicesNational Wildlife Research CenterFort CollinsColoradoUSA
| | - Peter C. Carlson
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsColoradoUSA
| | - William L. Kendall
- US Geological Survey, Colorado Cooperative Fish and Wildlife Research UnitColorado State UniversityFort CollinsColoradoUSA
| | - Damon B. Lesmeister
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - Christopher McCafferty
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - Steven H. Ackers
- Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
| | - L. Steven Andrews
- Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
| | - Larissa L. Bailey
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsColoradoUSA
| | - Jesse Burgher
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - Kenneth P. Burnham
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsColoradoUSA
| | - Tara Chestnut
- National Park Service, Mount Rainier National ParkAshfordWashingtonUSA
| | - Mary M. Conner
- Department of Wildland ResourcesUtah State UniversityLoganUtahUSA
| | - Raymond J. Davis
- US Department of Agriculture, Forest Service, Pacific Northwest RegionCorvallisOregonUSA
| | - Krista E. Dilione
- US Geological Survey, Forest and Rangeland Ecosystem Science CenterCorvallisOregonUSA
| | - Eric D. Forsman
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - Elizabeth M. Glenn
- US Geological Survey, Northwest Climate Adaptation Science CenterCorvallisOregonUSA
| | - Scott A. Gremel
- National Park Service, Olympic National ParkPort AngelesWashingtonUSA
| | - Keith A. Hamm
- Green Diamond Resource Company, California Timberlands DivisionKorbelCaliforniaUSA
| | | | - J. Mark Higley
- Hoopa Tribal Council, Forestry DivisionHoopaCaliforniaUSA
| | - Rob B. Horn
- US Bureau of Land ManagementRoseburgOregonUSA
| | - David W. Lamphear
- Green Diamond Resource Company, California Timberlands DivisionKorbelCaliforniaUSA
| | | | - Janice A. Reid
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - Carl J. Schwarz
- Department of Mathematics and StatisticsSimon Fraser UniversityBurnabyBritish ColumbiaCanada
| | - David C. Simon
- US Geological Survey, Forest and Rangeland Ecosystem Science CenterCorvallisOregonUSA
| | - Stan G. Sovern
- Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - James K. Swingle
- US Department of Agriculture, Forest ServicePacific Northwest Research StationCorvallisOregonUSA
| | - J. David Wiens
- US Geological Survey, Forest and Rangeland Ecosystem Science CenterCorvallisOregonUSA
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Bird Communities in a Changing World: The Role of Interspecific Competition. DIVERSITY 2022. [DOI: 10.3390/d14100857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Significant changes in the environment have the potential to affect bird species abundance and distribution, both directly, through a modification of the landscape, habitats, and climate, and indirectly, through a modification of biotic interactions such as competitive interactions. Predicting and mitigating the consequences of global change thus requires not only a sound understanding of the role played by biotic interactions in current ecosystems, but also the recognition and study of the complex and intricate effects that result from the perturbation of these ecosystems. In this review, we emphasize the role of interspecific competition in bird communities by focusing on three main predictions derived from theoretical and empirical considerations. We provide numerous examples of population decline and displacement that appeared to be, at least in part, driven by competition, and were amplified by environmental changes associated with human activities. Beyond a shift in relative species abundance, we show that interspecific competition may have a negative impact on species richness, ecosystem services, and endangered species. Despite these findings, we argue that, in general, the role played by interspecific competition in current communities remains poorly understood due to methodological issues and the complexity of natural communities. Predicting the consequences of global change in these communities is further complicated by uncertainty regarding future environmental conditions and the speed and efficacy of plastic and evolutionary responses to fast-changing environments. Possible directions of future research are highlighted.
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Morin DJ, Lesmeister DB, Nielsen CK, Schauber EM. Asymmetrical intraguild interactions with coyotes, red foxes, and domestic dogs may contribute to competitive exclusion of declining gray foxes. Ecol Evol 2022; 12:e9074. [PMID: 35813925 PMCID: PMC9251843 DOI: 10.1002/ece3.9074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 11/07/2022] Open
Abstract
Species coexistence is governed by availability of resources and intraguild interactions including strategies to reduce ecological overlap. Gray foxes are dietary generalist mesopredators expected to benefit from anthropogenic disturbance, but populations have declined across the midwestern USA, including severe local extirpation rates coinciding with high coyote and domestic dog occurrence and low red fox occurrence. We used data from a large‐scale camera trap survey in southern Illinois, USA to quantify intraguild spatial and temporal interactions among the canid guild including domestic dogs. We used a two‐species co‐occurrence model to make pairwise assessments of conditional occupancy and detection rates. We also estimated temporal activity overlap among species and fit a fixed‐effects hierarchical community occupancy model with the four canid species. We partitioned the posterior distributions to compare gray fox occupancy probabilities conditional on estimated state of combinations of other species to assess support for hypothesized interactions. We found no evidence of broadscale avoidance among native canids and conclude that spatial and temporal segregation were limited by ubiquitous human disturbance. Mean guild richness was two canid species at a site and gray fox occupancy was greater when any combination of sympatric canids was also present, setting the stage for competitive exclusion over time. Domestic dogs may amplify competitive interactions by increasing canid guild size to the detriment of gray foxes. Our results suggest that while human activities can benefit some mesopredators, other species such as gray foxes may serve as bellwethers for habitat degradation with trophic downgrading and continued anthropogenic homogenization.
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Affiliation(s)
- Dana J. Morin
- Department of Wildlife, Fisheries and Aquaculture Mississippi State University Mississippi State Mississippi USA
| | - Damon B. Lesmeister
- Pacific Northwest Research Station, U.S. Forest Service and Department of Fisheries and Wildlife Oregon State University Corvallis Oregon USA
| | - Clayton K. Nielsen
- Cooperative Wildlife Research Laboratory and Forestry Program Southern Illinois University Carbondale Illinois USA
| | - Eric M. Schauber
- Illinois Natural History Survey, Prairie Research Institute University of Illinois Urbana‐Champaign Champaign Illinois USA
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Wiens JD, Bloom PH, Madden MC, Kolar PS, Tracey JA, Fisher RN. Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.665792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Golden eagles (Aquila chrysaetos) are of increasing conservation concern in western North America. Effective conservation measures for this wide-ranging, federally protected raptor species require monitoring frameworks that accommodate strong inference on the status of breeding populations across vast landscapes. We used a broad-scale sampling design to identify relationships between landscape conditions, detection rates, and site occupancy by territorial pairs of golden eagles in coastal southern California, United States. In 2016 and 2017, we surveyed 175 territory-sized sample sites (13.9-km2 randomly selected grid cells) up to four times each year and detected a pair of eagles at least once in 22 (12.6%) sites. The probability of detecting pairs of eagles varied substantially between years and declined with increasing amounts of forest cover at survey sites, which obscured observations of eagles during ground-based surveys. After accounting for variable detection, the mean estimate of expected site occupancy by eagle pairs was 0.156 (SE = 0.081). Site-level estimates of occupancy were greatest (>0.30) at sample sites with more rugged terrain conditions, <20% human development, and lower amounts of scrubland vegetation cover. The proportion of a sample site with open grassland or forest cover was not strongly correlated with occupancy. We estimated that approximately 16% of the 5,338-km2 sampling frame was used by resident pairs of golden eagles, corresponding to a sparsely distributed population of about 60 pairs (95% CI = 19 – 151 pairs). Our study provided baseline data for future surveys of golden eagles along with a widely applicable monitoring framework for identifying spatial conservation priorities in urbanizing landscapes.
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Mikkelsen AJ, Lesmeister DB, O’Reilly KM, Dugger KM. Feather corticosterone reveals developmental challenges in a long‐term study of juvenile northern spotted owls. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ashlee J. Mikkelsen
- USDA Forest Service Pacific Northwest Research Station Corvallis OR USA
- Oregon Cooperative Fish and Wildlife Research Unit Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University Corvallis OR USA
| | - Damon B. Lesmeister
- USDA Forest Service Pacific Northwest Research Station Corvallis OR USA
- Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University Corvallis OR USA
| | | | - Katie M. Dugger
- U.S. Geological Survey Oregon Cooperative Fish and Wildlife Research Unit Department of Fisheries, Wildlife, and Conservation Sciences Oregon State University Corvallis OR USA
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Jenkins JMA, Lesmeister DB, Forsman ED, Dugger KM, Ackers SH, Andrews LS, Gremel SA, Hollen B, McCafferty CE, Pruett MS, Reid JA, Sovern SG, Wiens JD. Conspecific and congeneric interactions shape increasing rates of breeding dispersal of northern spotted owls. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02398. [PMID: 34212458 PMCID: PMC9285767 DOI: 10.1002/eap.2398] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 01/11/2021] [Accepted: 02/22/2021] [Indexed: 06/13/2023]
Abstract
Breeding dispersal, the movement from one breeding territory to another, is rare for philopatric species that evolved within relatively stable environments, such as the old-growth coniferous forests of the Pacific Northwest. Although dispersal is not inherently maladaptive, the consequences of increased dispersal on population dynamics in populations whose historical dispersal rates are low could be significant, particularly for a declining species. We examined rates and possible causes of breeding dispersal based on a sample of 4,118 northern spotted owls (Strix occidentalis caurina) monitored in seven study areas over 28 yr, 1990-2017, in Oregon and Washington, USA. Using a multistate mark-resight analysis, we investigated the potential impacts of an emergent congeneric competitor (barred owl Strix varia) and forest alteration (extrinsic factors), and social and individual conditions (intrinsic factors) on 408 successive and 1,372 nonsuccessive dispersal events between years. The annual probability of breeding dispersal increased for individual owls that had also dispersed in the previous year and decreased for owls on territories with historically high levels of reproduction. Intrinsic factors including pair status, prior reproductive success, and experience at a site, were also associated with breeding dispersal movements. The percent of monitored owls dispersing each year increased from ˜7% early in the study to ˜25% at the end of the study, which coincided with a rapid increase in numbers of invasive and competitively dominant barred owls. We suggest that the results presented here can inform spotted owl conservation efforts as we identify factors contributing to changing rates of demographic parameters including site fidelity and breeding dispersal. Our study further shows that increasing rates of breeding dispersal associated with population declines contribute to population instability and vulnerability of northern spotted owls to extinction, and the prognosis is unlikely to change unless active management interventions are undertaken.
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Affiliation(s)
- Julianna M. A. Jenkins
- U.S. Forest ServicePacific Northwest Research Station3200 SW Jefferson WayCorvallisOregon97331USA
| | - Damon B. Lesmeister
- U.S. Forest ServicePacific Northwest Research Station3200 SW Jefferson WayCorvallisOregon97331USA
- Department of Fisheries and WildlifeOregon State University104 Nash HallCorvallisOregon97331‐3803USA
| | - Eric D. Forsman
- U.S. Forest ServicePacific Northwest Research Station3200 SW Jefferson WayCorvallisOregon97331USA
| | - Katie M. Dugger
- U.S. Geological SurveyOregon Cooperative Wildlife Research UnitDepartment of Fisheries and WildlifeOregon State University104 Nash HallCorvallisOregon97331‐3803USA
| | - Steven H. Ackers
- Department of Fisheries and WildlifeOregon State University104 Nash HallCorvallisOregon97331‐3803USA
| | - L. Steven Andrews
- Department of Fisheries and WildlifeOregon State University104 Nash HallCorvallisOregon97331‐3803USA
| | - Scott A. Gremel
- U.S. National Park ServiceOlympic National Park600 East Park AvenuePort AngelesWashingtonUSA
| | - Bruce Hollen
- Bureau of Land ManagementOregon State Office1220 SW 3rd AvenuePortlandOregon97204USA
| | - Chris E. McCafferty
- Department of Fisheries and WildlifeOregon State University104 Nash HallCorvallisOregon97331‐3803USA
| | - M. Shane Pruett
- Department of Fisheries and WildlifeOregon State University104 Nash HallCorvallisOregon97331‐3803USA
| | - Janice A. Reid
- U.S. Forest ServicePacific Northwest Research Station3200 SW Jefferson WayCorvallisOregon97331USA
| | - Stan G. Sovern
- Department of Fisheries and WildlifeOregon State University104 Nash HallCorvallisOregon97331‐3803USA
| | - J. David Wiens
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center3200 SW Jefferson WayCorvallisOregon97331USA
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A culture of conservation: How an ancient forest plantation turned into an old‐growth forest reserve – The story of the Wamulin forest. PEOPLE AND NATURE 2021. [DOI: 10.1002/pan3.10248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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10
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Abstract
Invasive species can cause extinctions of native species and widespread biodiversity loss. Invader removal is a common management response, but the use of long-term field experiments to characterize effectiveness of removals in benefitting impacted native species is rare. We used a large-scale removal experiment to investigate the demographic response of a threatened native species, the northern spotted owl, to removal of an invasive competitor species, the barred owl. Removal of barred owls had a strong, positive effect on survival of spotted owls, which arrested long-term population declines of spotted owls. The results demonstrate that the long-term persistence of spotted owls will depend heavily on reducing the negative impacts of barred owls while simultaneously addressing other threats, such as habitat loss. Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before–after control–impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl (Strix occidentalis caurina). Removal of barred owls had a strong, positive effect on survival of sympatric spotted owls and a weaker but positive effect on spotted owl dispersal and recruitment. After removals, the estimated mean annual rate of population change for spotted owls stabilized in areas with removals (0.2% decline per year), but continued to decline sharply in areas without removals (12.1% decline per year). The results demonstrated that the most substantial changes in population dynamics of northern spotted owls over the past two decades were associated with the invasion, population expansion, and subsequent removal of barred owls. Our study provides experimental evidence of the demographic consequences of competitive release, where a threatened avian predator was freed from restrictions imposed on its population dynamics with the removal of a competitively dominant invasive species.
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Wood CM, Kryshak N, Gustafson M, Hofstadter DF, Hobart BK, Whitmore SA, Dotters BP, Roberts KN, Keane JJ, Sawyer SC, Gutiérrez RJ, Peery MZ. Density dependence influences competition and hybridization at an invasion front. DIVERS DISTRIB 2021. [DOI: 10.1111/ddi.13240] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Connor M. Wood
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
| | - Nick Kryshak
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
| | - Michaela Gustafson
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
| | - Daniel F. Hofstadter
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
| | - Brendan K. Hobart
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
| | - Sheila A. Whitmore
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
| | | | | | - John J. Keane
- U.S. Forest Service Pacific Southwest Research Station Davis CA USA
| | | | - Rocky J. Gutiérrez
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
| | - M. Zachariah Peery
- Department of Forest and Wildlife Ecology University of Wisconsin – Madison Madison WI USA
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Yackulic CB, Dodrill M, Dzul M, Sanderlin JS, Reid JA. A need for speed in Bayesian population models: a practical guide to marginalizing and recovering discrete latent states. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02112. [PMID: 32112492 DOI: 10.1002/eap.2112] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/24/2020] [Indexed: 06/10/2023]
Abstract
Bayesian population models can be exceedingly slow due, in part, to the choice to simulate discrete latent states. Here, we discuss an alternative approach to discrete latent states, marginalization, that forms the basis of maximum likelihood population models and is much faster. Our manuscript has two goals: (1) to introduce readers unfamiliar with marginalization to the concept and provide worked examples and (2) to address topics associated with marginalization that have not been previously synthesized and are relevant to both Bayesian and maximum likelihood models. We begin by explaining marginalization using a Cormack-Jolly-Seber model. Next, we apply marginalization to multistate capture-recapture, community occupancy, and integrated population models and briefly discuss random effects, priors, and pseudo-R2 . Then, we focus on recovery of discrete latent states, defining different types of conditional probabilities and showing how quantities such as population abundance or species richness can be estimated in marginalized code. Last, we show that occupancy and site-abundance models with auto-covariates can be fit with marginalized code with minimal impact on parameter estimates. Marginalized code was anywhere from five to >1,000 times faster than discrete code and differences in inferences were minimal. Discrete latent states and fully conditional approaches provide the best estimates of conditional probabilities for a given site or individual. However, estimates for parameters and derived quantities such as species richness and abundance are minimally affected by marginalization. In the case of abundance, marginalized code is both quicker and has lower bias than an N-augmentation approach. Understanding how marginalization works shrinks the divide between Bayesian and maximum likelihood approaches to population models. Some models that have only been presented in a Bayesian framework can easily be fit in maximum likelihood. On the other hand, factors such as informative priors, random effects, or pseudo-R2 values may motivate a Bayesian approach in some applications. An understanding of marginalization allows users to minimize the speed that is sacrificed when switching from a maximum likelihood approach. Widespread application of marginalization in Bayesian population models will facilitate more thorough simulation studies, comparisons of alternative model structures, and faster learning.
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Affiliation(s)
- Charles B Yackulic
- Southwest Biological Science Center, U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, Arizona, 86001, USA
| | - Michael Dodrill
- Southwest Biological Science Center, U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, Arizona, 86001, USA
| | - Maria Dzul
- Southwest Biological Science Center, U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, Arizona, 86001, USA
| | - Jamie S Sanderlin
- USDA Forest Service, Rocky Mountain Research Station, Flagstaff, Arizona, 86001, USA
| | - Janice A Reid
- USDA Forest Service, Pacific Northwest Research Station, Roseburg Field Station, Roseburg, Oregon, 97331, USA
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