Wayne Thogmartin | U.S. Geological Survey (original) (raw)
Papers by Wayne Thogmartin
Scientific Investigations Report, 2019
For more information on the USGS-the Federal source for science about the Earth, its natural and ... more For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit https://www.usgs.gov or call 1-888-ASK-USGS (1-888-275-8747). For an overview of USGS information products, including maps, imagery, and publications, visit https://store.usgs.gov. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.
Conservation Letters
Biodiversity conservation efforts have been criticized for generating inequitable socio‐economic ... more Biodiversity conservation efforts have been criticized for generating inequitable socio‐economic outcomes. These equity challenges are largely analyzed as place‐based problems affecting local communities directly impacted by conservation programs. The conservation of migratory species extends this problem geographically since people in one place may benefit while those in another bear the costs of conservation. The spatial subsidies approach offers an effective tool for analyzing such relationships between places connected by migratory species. Designed to quantify ecosystem services provided and received in specific locations across a migratory species’ range—and the disparities between them—the spatial subsidies approach highlights three axes of inequity: between indigenous and settler colonial societies, between urban and rural populations, and between the Global North and Global South. Recognizing these relationships is critical to achieving two mutually reinforcing policy goals...
Understanding the influence of specific habitats on the survival of a migratory species is an ess... more Understanding the influence of specific habitats on the survival of a migratory species is an essential part of making successful management decisions. Migration is a complicated process, and mathematical models of migratory networks offer a way to understand the importance of different parts of an organism’s annual cycle. The National Institute for Mathematical and Biological Symbiosis (NIMBioS) “Habitat for Migratory Species” working group has developed several approaches to study this problem. We will present three different approaches. The first method yields a per-capita metric for the number of individuals produced or surviving during a one-year time step for any habitat, transition, or pathway in the migratory network. This metric ranks areas from the number of individuals produced or surviving during a one year time step. Next, we will introduce a generalized network framework to demonstrate how perturbation analysis can be used to determine the relative importance of habitats and movement pathways. Then we will present an extension of the network modeling approach: a continuous model that links energy resources, at the nodes and along the paths, to the movement and survival of the migrating species. All three frameworks are intended to be general, not species specific, so that they can be applied in a standard way to a wide range of species with different migration patterns
Ecosphere, 2021
A central challenge in applied ecology is understanding the effect of anthropogenic fatalities on... more A central challenge in applied ecology is understanding the effect of anthropogenic fatalities on wildlife populations and predicting which populations may be particularly vulnerable and in greatest need of management attention. We used three approaches to investigate the potential effects of fatalities from collisions with wind turbines on 14 raptor species for both current (106 GW) and anticipated future (241 GW) levels of installed wind energy capacity in the United States. Our goals were to identify species at relatively high vs low risk of experiencing population declines from turbine collisions and to also compare results generated from these approaches. Two of the approaches used a calculated turbine‐caused mortality rate to decrement population growth, where population trends were derived either from the North American Breeding Bird Survey or from a matrix model parameterized from literature‐derived demographic values. The third approach was potential biological removal, whi...
Ambio, 2021
Collaborative monitoring over broad scales and levels of ecological organization can inform conse... more Collaborative monitoring over broad scales and levels of ecological organization can inform conservation efforts necessary to address the contemporary biodiversity crisis. An important challenge to collaborative monitoring is motivating local engagement with enough buy-in from stakeholders while providing adequate top-down direction for scientific rigor, quality control, and coordination. Collaborative monitoring must reconcile this inherent tension between top-down control and bottom-up engagement. Highly mobile and cryptic taxa, such as bats, present a particularly acute challenge. Given their scale of movement, complex life histories, and rapidly expanding threats, understanding population trends of bats requires coordinated broad-scale collaborative monitoring. The North American Bat Monitoring Program (NABat) reconciles top-down, bottom-up tension with a hierarchical master sample survey design, integrated data analysis, dynamic data curation, regional monitoring hubs, and know...
The American Naturalist, 2020
The consequences of environmental disturbance and management are difficult to quantify for spatia... more The consequences of environmental disturbance and management are difficult to quantify for spatially structured populations because changes in one location carry through to other areas as a result of species movement. We develop a metric, G, for measuring the contribution of a habitat or pathway to network-wide population growth rate in the face of environmental change. This metric is different from other contribution metrics, as it quantifies effects of modifying vital rates for habitats and pathways in perturbation experiments. Perturbation treatments may range from small degradation or enhancement to complete habitat or pathway removal. We demonstrate the metric using a simple metapopulation example and a case study of eastern monarch butterflies. For the monarch case study, the magnitude of environmental change influences the ordering of node contribution. We find that habitats within which all individuals reside during one season are the most important to short-term network growth under complete removal scenarios, whereas the central breeding region contributes most to population growth over all but the strongest disturbances. The metric G provides for more efficient management interventions that proactively mitigate impacts of expected disturbances to spatially structured populations.
Ecosystem Services, 2018
Migratory species provide ecosystem goods and services throughout their annual cycles, often over... more Migratory species provide ecosystem goods and services throughout their annual cycles, often over long distances. Designing effective conservation solutions for migratory species requires knowledge of both species ecology and the socioeconomic context of their migrations. We present a framework built around the concept that migratory species act as carriers, delivering benefit flows to people throughout their annual cycle that are supported by the network of ecosystems upon which the species depend. We apply this framework to the monarch butterfly (Danaus plexippus) migration of eastern North America by calculating their spatial subsidies. Spatial subsidies are the net ecosystem service flows throughout a species' range and a quantitative measure of the spatial mismatch between the locations where people receive most benefits and the locations of habitats that most support the species. Results indicate cultural benefits provided by monarchs in the U.S. and Canada are subsidized by migration and overwintering habitat in Mexico. At a finer scale, throughout the monarch range, habitat in rural landscapes subsidizes urban residents. Understanding the spatial distribution of benefits derived from and ecological support provided to monarchs and other migratory species offers a promising means of understanding the costs and benefits associated with conservation across jurisdictional borders.
Ecological Economics, 2019
Using contingent valuation, we estimated willingness to pay (WTP) in Canada, Mexico, and the Unit... more Using contingent valuation, we estimated willingness to pay (WTP) in Canada, Mexico, and the United States to protect habitat for Northern Pintails (hereafter pintails), a migratory waterfowl species that provides benefits to and requires habitat in the three countries. Our study contributes to research on spatial subsidies by measuring the value of migratory species habitat. While WTP to protect pintail habitat is highest in the household's own country, there also is substantial WTP to protect pintail habitat in the other two countries. Canadian households' annual WTP is US$12
Ecology and Society, 2017
the telecoupling framework for migratory species using the spatial subsidies approach to examine ... more the telecoupling framework for migratory species using the spatial subsidies approach to examine ecosystem services provided by Mexican free-tailed bats. Ecology and Society 22(4):23.
Human Dimensions of Wildlife, 2018
Many economic studies value birdwatching in general and often do not account for potential differ... more Many economic studies value birdwatching in general and often do not account for potential differences in viewers' benefits from observing different species. But, how different are economic values of viewing various bird species? To answer that question, we surveyed Ducks Unlimited (DU) members using an online questionnaire to estimate trip expenditures and consumer surplus per trip for viewing pintail ducks, waterfowl in general, and other species of waterfowl.
Ecology and evolution, 2018
Variation in movement across time and space fundamentally shapes the abundance and distribution o... more Variation in movement across time and space fundamentally shapes the abundance and distribution of populations. Although a variety of approaches model structured population dynamics, they are limited to specific types of spatially structured populations and lack a unifying framework. Here, we propose a unified network-based framework sufficiently novel in its flexibility to capture a wide variety of spatiotemporal processes including metapopulations and a range of migratory patterns. It can accommodate different kinds of age structures, forms of population growth, dispersal, nomadism and migration, and alternative life-history strategies. Our objective was to link three general elements common to all spatially structured populations (space, time and movement) under a single mathematical framework. To do this, we adopt a network modeling approach. The spatial structure of a population is represented by a weighted and directed network. Each node and each edge has a set of attributes w...
Journal of Applied Ecology, 2017
Understanding and conserving migratory species requires a method for characterizing the seasonal ... more Understanding and conserving migratory species requires a method for characterizing the seasonal flow of animals among habitats. Source‐sink theory describes the metapopulation dynamics of species by classifying habitats as population sources (i.e. net contributors) or sinks (i.e. net substractors). Migratory species may have non‐breeding habitats important to the species (e.g. overwintering or stopover habitats) that traditional source‐sink theory would classify as sinks because these habitats produce no individuals. Conversely, existing migratory network models can evaluate the relative contribution of non‐breeding nodes, but these models make an equilibrium assumption that is difficult to meet when examining real migratory populations. We extend a pathway‐based metric allowing breeding habitats, non‐breeding habitats and migratory pathways connecting these habitats to be classified as sources or sinks. Rather than being based on whether place‐ or season‐specific births exceed dea...
Conservation biology : the journal of the Society for Conservation Biology, Jan 2, 2017
In July 2014, the U.S. Fish and Wildlife Service and National Marine Fisheries Service announced ... more In July 2014, the U.S. Fish and Wildlife Service and National Marine Fisheries Service announced a new policy interpretation for the Endangered Species Act. According to the Act, a species must be listed as threatened or endangered if it is determined to be threatened or endangered in a significant portion of its range. The 1973 law does not define "significant portion of its range," leading to concerns that interpretations of "significant" by federal agencies and the courts could be inconsistent. The 2014 policy seeks to provide consistency by establishing that a portion of the range should be considered significant if the associated individuals' "removal would cause the entire species to become endangered or threatened." Here, we review quantitative techniques to assess whether a portion of a species' range is significant according to the new guidance. Our assessments are based on the "3R" criteria - Redundancy (i.e., buffering from ...
Wind Energy and Wildlife Interactions, 2017
For this study, a methodology was developed for assessing impacts of wind energy generation on po... more For this study, a methodology was developed for assessing impacts of wind energy generation on populations of birds and bats at regional to national scales. The approach combines existing methods in applied ecology for prioritizing species in terms of their potential risk from wind energy facilities and estimating impacts of fatalities on population status and trend caused by collisions with wind energy infrastructure. Methods include a qualitative prioritization approach, demographic models, and potential biological removal. The approach can be used to prioritize species in need of more thorough study as well as to identify species with minimal risk. However, the components of this methodology require simplifying assumptions and the data required may be unavailable or of poor quality for some species. These issues should be carefully considered before using the methodology. The approach will increase in value as more data become available and will broaden the understanding of anthropogenic sources of mortality on bird and bat populations.
PeerJ, 2016
Wind energy generation holds the potential to adversely affect wildlife populations. Species-wide... more Wind energy generation holds the potential to adversely affect wildlife populations. Species-wide effects are difficult to study and few, if any, studies examine effects of wind energy generation on any species across its entire range. One species that may be affected by wind energy generation is the endangered Indiana bat (Myotis sodalis), which is found in the eastern and midwestern United States. In addition to mortality from wind energy generation, the species also faces range-wide threats from the emerging infectious fungal disease, white-nose syndrome (WNS). White-nose syndrome, caused byPseudogymnoascus destructans, disturbs hibernating bats leading to high levels of mortality. We used a spatially explicit full-annual-cycle model to investigate how wind turbine mortality and WNS may singly and then together affect population dynamics of this species. In the simulation, wind turbine mortality impacted the metapopulation dynamics of the species by causing extirpation of some of...
Ecological Indicators, 2016
Mobile species with complex spatial dynamicscan be difficult to manage because their population d... more Mobile species with complex spatial dynamicscan be difficult to manage because their population distributionsvary across space and time, and becausethe consequences of managing particular habitats are uncertain when evaluated at the level of the entire population. Metrics to assess the importance of habitats and pathways connecting habitatsin a network are necessary to guide a variety of management decisions. Given the many metrics developed for spatially structured models, it can be challenging to select the most appropriate one for a particular decision. To guide the management of spatially structured populations, we define three classes of metrics describing habitat and pathway quality based on their data requirements (graph-based, occupancy-based, and demographic-based metrics) and synopsize the ecological literature relating to these classes. Applying the first steps of a formal decision-making approach (problem framing, objectives, and management actions), we assess the utility of metrics for particular types of management decisions. Our framework can help managers with problem framing, choosing metrics of habitat and pathway quality, and to elucidate the data needs for a particular metric. Our goal is to help managers to narrow the range of suitable metrics for a management project, and aid in decision-making to make the best use of limited resources.
Ecosphere, 2015
Quantifying the impact of anthropogenic development on local populations is important for conserv... more Quantifying the impact of anthropogenic development on local populations is important for conservation biology and wildlife management. However, these local populations are often subject to demographic stochasticity because of their small population size. Traditional modeling efforts such as population projection matrices do not consider this source of variation whereas individual-based models, which include demographic stochasticity, are computationally intense and lack analytical tractability. One compromise between approaches is branching process models because they accommodate demographic stochasticity and are easily calculated. These models are known within some sub-fields of probability and mathematical ecology but are not often applied in conservation biology and applied ecology. We applied branching process models to quantitatively compare and prioritize species locally vulnerable to the development of wind energy facilities. Specifically, we examined species vulnerability using branching process models for four representative species: A cave bat (a long-lived, low fecundity species), a tree bat (short-lived, moderate fecundity species), a grassland songbird (a short-lived, high fecundity species), and an eagle (a long-lived, slow maturation species). Wind turbine-induced mortality has been observed for all of these species types, raising conservation concerns. We simulated different mortality rates from wind farms while calculating local extinction probabilities. The longer-lived species types (e.g., cave bats and eagles) had much more pronounced transitions from low extinction risk to high extinction risk than shortlived species types (e.g., tree bats and grassland songbirds). High-offspring-producing species types had a much greater variability in baseline risk of extinction than the lower-offspring-producing species types. Long-lived species types may appear stable until a critical level of incidental mortality occurs. After this threshold, the risk of extirpation for a local population may rapidly increase with only minimal increases in wind mortality. Conservation biologists and wildlife managers may need to consider this mortality pattern when issuing take permits and developing monitoring protocols for wind facilities. We also describe how our branching process models may be generalized across a wider range of species for a larger assessment project and then describe how our methods may be applied to other stressors in addition to wind.
Biological Conservation, 2015
Scientific Investigations Report, 2019
For more information on the USGS-the Federal source for science about the Earth, its natural and ... more For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit https://www.usgs.gov or call 1-888-ASK-USGS (1-888-275-8747). For an overview of USGS information products, including maps, imagery, and publications, visit https://store.usgs.gov. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.
Conservation Letters
Biodiversity conservation efforts have been criticized for generating inequitable socio‐economic ... more Biodiversity conservation efforts have been criticized for generating inequitable socio‐economic outcomes. These equity challenges are largely analyzed as place‐based problems affecting local communities directly impacted by conservation programs. The conservation of migratory species extends this problem geographically since people in one place may benefit while those in another bear the costs of conservation. The spatial subsidies approach offers an effective tool for analyzing such relationships between places connected by migratory species. Designed to quantify ecosystem services provided and received in specific locations across a migratory species’ range—and the disparities between them—the spatial subsidies approach highlights three axes of inequity: between indigenous and settler colonial societies, between urban and rural populations, and between the Global North and Global South. Recognizing these relationships is critical to achieving two mutually reinforcing policy goals...
Understanding the influence of specific habitats on the survival of a migratory species is an ess... more Understanding the influence of specific habitats on the survival of a migratory species is an essential part of making successful management decisions. Migration is a complicated process, and mathematical models of migratory networks offer a way to understand the importance of different parts of an organism’s annual cycle. The National Institute for Mathematical and Biological Symbiosis (NIMBioS) “Habitat for Migratory Species” working group has developed several approaches to study this problem. We will present three different approaches. The first method yields a per-capita metric for the number of individuals produced or surviving during a one-year time step for any habitat, transition, or pathway in the migratory network. This metric ranks areas from the number of individuals produced or surviving during a one year time step. Next, we will introduce a generalized network framework to demonstrate how perturbation analysis can be used to determine the relative importance of habitats and movement pathways. Then we will present an extension of the network modeling approach: a continuous model that links energy resources, at the nodes and along the paths, to the movement and survival of the migrating species. All three frameworks are intended to be general, not species specific, so that they can be applied in a standard way to a wide range of species with different migration patterns
Ecosphere, 2021
A central challenge in applied ecology is understanding the effect of anthropogenic fatalities on... more A central challenge in applied ecology is understanding the effect of anthropogenic fatalities on wildlife populations and predicting which populations may be particularly vulnerable and in greatest need of management attention. We used three approaches to investigate the potential effects of fatalities from collisions with wind turbines on 14 raptor species for both current (106 GW) and anticipated future (241 GW) levels of installed wind energy capacity in the United States. Our goals were to identify species at relatively high vs low risk of experiencing population declines from turbine collisions and to also compare results generated from these approaches. Two of the approaches used a calculated turbine‐caused mortality rate to decrement population growth, where population trends were derived either from the North American Breeding Bird Survey or from a matrix model parameterized from literature‐derived demographic values. The third approach was potential biological removal, whi...
Ambio, 2021
Collaborative monitoring over broad scales and levels of ecological organization can inform conse... more Collaborative monitoring over broad scales and levels of ecological organization can inform conservation efforts necessary to address the contemporary biodiversity crisis. An important challenge to collaborative monitoring is motivating local engagement with enough buy-in from stakeholders while providing adequate top-down direction for scientific rigor, quality control, and coordination. Collaborative monitoring must reconcile this inherent tension between top-down control and bottom-up engagement. Highly mobile and cryptic taxa, such as bats, present a particularly acute challenge. Given their scale of movement, complex life histories, and rapidly expanding threats, understanding population trends of bats requires coordinated broad-scale collaborative monitoring. The North American Bat Monitoring Program (NABat) reconciles top-down, bottom-up tension with a hierarchical master sample survey design, integrated data analysis, dynamic data curation, regional monitoring hubs, and know...
The American Naturalist, 2020
The consequences of environmental disturbance and management are difficult to quantify for spatia... more The consequences of environmental disturbance and management are difficult to quantify for spatially structured populations because changes in one location carry through to other areas as a result of species movement. We develop a metric, G, for measuring the contribution of a habitat or pathway to network-wide population growth rate in the face of environmental change. This metric is different from other contribution metrics, as it quantifies effects of modifying vital rates for habitats and pathways in perturbation experiments. Perturbation treatments may range from small degradation or enhancement to complete habitat or pathway removal. We demonstrate the metric using a simple metapopulation example and a case study of eastern monarch butterflies. For the monarch case study, the magnitude of environmental change influences the ordering of node contribution. We find that habitats within which all individuals reside during one season are the most important to short-term network growth under complete removal scenarios, whereas the central breeding region contributes most to population growth over all but the strongest disturbances. The metric G provides for more efficient management interventions that proactively mitigate impacts of expected disturbances to spatially structured populations.
Ecosystem Services, 2018
Migratory species provide ecosystem goods and services throughout their annual cycles, often over... more Migratory species provide ecosystem goods and services throughout their annual cycles, often over long distances. Designing effective conservation solutions for migratory species requires knowledge of both species ecology and the socioeconomic context of their migrations. We present a framework built around the concept that migratory species act as carriers, delivering benefit flows to people throughout their annual cycle that are supported by the network of ecosystems upon which the species depend. We apply this framework to the monarch butterfly (Danaus plexippus) migration of eastern North America by calculating their spatial subsidies. Spatial subsidies are the net ecosystem service flows throughout a species' range and a quantitative measure of the spatial mismatch between the locations where people receive most benefits and the locations of habitats that most support the species. Results indicate cultural benefits provided by monarchs in the U.S. and Canada are subsidized by migration and overwintering habitat in Mexico. At a finer scale, throughout the monarch range, habitat in rural landscapes subsidizes urban residents. Understanding the spatial distribution of benefits derived from and ecological support provided to monarchs and other migratory species offers a promising means of understanding the costs and benefits associated with conservation across jurisdictional borders.
Ecological Economics, 2019
Using contingent valuation, we estimated willingness to pay (WTP) in Canada, Mexico, and the Unit... more Using contingent valuation, we estimated willingness to pay (WTP) in Canada, Mexico, and the United States to protect habitat for Northern Pintails (hereafter pintails), a migratory waterfowl species that provides benefits to and requires habitat in the three countries. Our study contributes to research on spatial subsidies by measuring the value of migratory species habitat. While WTP to protect pintail habitat is highest in the household's own country, there also is substantial WTP to protect pintail habitat in the other two countries. Canadian households' annual WTP is US$12
Ecology and Society, 2017
the telecoupling framework for migratory species using the spatial subsidies approach to examine ... more the telecoupling framework for migratory species using the spatial subsidies approach to examine ecosystem services provided by Mexican free-tailed bats. Ecology and Society 22(4):23.
Human Dimensions of Wildlife, 2018
Many economic studies value birdwatching in general and often do not account for potential differ... more Many economic studies value birdwatching in general and often do not account for potential differences in viewers' benefits from observing different species. But, how different are economic values of viewing various bird species? To answer that question, we surveyed Ducks Unlimited (DU) members using an online questionnaire to estimate trip expenditures and consumer surplus per trip for viewing pintail ducks, waterfowl in general, and other species of waterfowl.
Ecology and evolution, 2018
Variation in movement across time and space fundamentally shapes the abundance and distribution o... more Variation in movement across time and space fundamentally shapes the abundance and distribution of populations. Although a variety of approaches model structured population dynamics, they are limited to specific types of spatially structured populations and lack a unifying framework. Here, we propose a unified network-based framework sufficiently novel in its flexibility to capture a wide variety of spatiotemporal processes including metapopulations and a range of migratory patterns. It can accommodate different kinds of age structures, forms of population growth, dispersal, nomadism and migration, and alternative life-history strategies. Our objective was to link three general elements common to all spatially structured populations (space, time and movement) under a single mathematical framework. To do this, we adopt a network modeling approach. The spatial structure of a population is represented by a weighted and directed network. Each node and each edge has a set of attributes w...
Journal of Applied Ecology, 2017
Understanding and conserving migratory species requires a method for characterizing the seasonal ... more Understanding and conserving migratory species requires a method for characterizing the seasonal flow of animals among habitats. Source‐sink theory describes the metapopulation dynamics of species by classifying habitats as population sources (i.e. net contributors) or sinks (i.e. net substractors). Migratory species may have non‐breeding habitats important to the species (e.g. overwintering or stopover habitats) that traditional source‐sink theory would classify as sinks because these habitats produce no individuals. Conversely, existing migratory network models can evaluate the relative contribution of non‐breeding nodes, but these models make an equilibrium assumption that is difficult to meet when examining real migratory populations. We extend a pathway‐based metric allowing breeding habitats, non‐breeding habitats and migratory pathways connecting these habitats to be classified as sources or sinks. Rather than being based on whether place‐ or season‐specific births exceed dea...
Conservation biology : the journal of the Society for Conservation Biology, Jan 2, 2017
In July 2014, the U.S. Fish and Wildlife Service and National Marine Fisheries Service announced ... more In July 2014, the U.S. Fish and Wildlife Service and National Marine Fisheries Service announced a new policy interpretation for the Endangered Species Act. According to the Act, a species must be listed as threatened or endangered if it is determined to be threatened or endangered in a significant portion of its range. The 1973 law does not define "significant portion of its range," leading to concerns that interpretations of "significant" by federal agencies and the courts could be inconsistent. The 2014 policy seeks to provide consistency by establishing that a portion of the range should be considered significant if the associated individuals' "removal would cause the entire species to become endangered or threatened." Here, we review quantitative techniques to assess whether a portion of a species' range is significant according to the new guidance. Our assessments are based on the "3R" criteria - Redundancy (i.e., buffering from ...
Wind Energy and Wildlife Interactions, 2017
For this study, a methodology was developed for assessing impacts of wind energy generation on po... more For this study, a methodology was developed for assessing impacts of wind energy generation on populations of birds and bats at regional to national scales. The approach combines existing methods in applied ecology for prioritizing species in terms of their potential risk from wind energy facilities and estimating impacts of fatalities on population status and trend caused by collisions with wind energy infrastructure. Methods include a qualitative prioritization approach, demographic models, and potential biological removal. The approach can be used to prioritize species in need of more thorough study as well as to identify species with minimal risk. However, the components of this methodology require simplifying assumptions and the data required may be unavailable or of poor quality for some species. These issues should be carefully considered before using the methodology. The approach will increase in value as more data become available and will broaden the understanding of anthropogenic sources of mortality on bird and bat populations.
PeerJ, 2016
Wind energy generation holds the potential to adversely affect wildlife populations. Species-wide... more Wind energy generation holds the potential to adversely affect wildlife populations. Species-wide effects are difficult to study and few, if any, studies examine effects of wind energy generation on any species across its entire range. One species that may be affected by wind energy generation is the endangered Indiana bat (Myotis sodalis), which is found in the eastern and midwestern United States. In addition to mortality from wind energy generation, the species also faces range-wide threats from the emerging infectious fungal disease, white-nose syndrome (WNS). White-nose syndrome, caused byPseudogymnoascus destructans, disturbs hibernating bats leading to high levels of mortality. We used a spatially explicit full-annual-cycle model to investigate how wind turbine mortality and WNS may singly and then together affect population dynamics of this species. In the simulation, wind turbine mortality impacted the metapopulation dynamics of the species by causing extirpation of some of...
Ecological Indicators, 2016
Mobile species with complex spatial dynamicscan be difficult to manage because their population d... more Mobile species with complex spatial dynamicscan be difficult to manage because their population distributionsvary across space and time, and becausethe consequences of managing particular habitats are uncertain when evaluated at the level of the entire population. Metrics to assess the importance of habitats and pathways connecting habitatsin a network are necessary to guide a variety of management decisions. Given the many metrics developed for spatially structured models, it can be challenging to select the most appropriate one for a particular decision. To guide the management of spatially structured populations, we define three classes of metrics describing habitat and pathway quality based on their data requirements (graph-based, occupancy-based, and demographic-based metrics) and synopsize the ecological literature relating to these classes. Applying the first steps of a formal decision-making approach (problem framing, objectives, and management actions), we assess the utility of metrics for particular types of management decisions. Our framework can help managers with problem framing, choosing metrics of habitat and pathway quality, and to elucidate the data needs for a particular metric. Our goal is to help managers to narrow the range of suitable metrics for a management project, and aid in decision-making to make the best use of limited resources.
Ecosphere, 2015
Quantifying the impact of anthropogenic development on local populations is important for conserv... more Quantifying the impact of anthropogenic development on local populations is important for conservation biology and wildlife management. However, these local populations are often subject to demographic stochasticity because of their small population size. Traditional modeling efforts such as population projection matrices do not consider this source of variation whereas individual-based models, which include demographic stochasticity, are computationally intense and lack analytical tractability. One compromise between approaches is branching process models because they accommodate demographic stochasticity and are easily calculated. These models are known within some sub-fields of probability and mathematical ecology but are not often applied in conservation biology and applied ecology. We applied branching process models to quantitatively compare and prioritize species locally vulnerable to the development of wind energy facilities. Specifically, we examined species vulnerability using branching process models for four representative species: A cave bat (a long-lived, low fecundity species), a tree bat (short-lived, moderate fecundity species), a grassland songbird (a short-lived, high fecundity species), and an eagle (a long-lived, slow maturation species). Wind turbine-induced mortality has been observed for all of these species types, raising conservation concerns. We simulated different mortality rates from wind farms while calculating local extinction probabilities. The longer-lived species types (e.g., cave bats and eagles) had much more pronounced transitions from low extinction risk to high extinction risk than shortlived species types (e.g., tree bats and grassland songbirds). High-offspring-producing species types had a much greater variability in baseline risk of extinction than the lower-offspring-producing species types. Long-lived species types may appear stable until a critical level of incidental mortality occurs. After this threshold, the risk of extirpation for a local population may rapidly increase with only minimal increases in wind mortality. Conservation biologists and wildlife managers may need to consider this mortality pattern when issuing take permits and developing monitoring protocols for wind facilities. We also describe how our branching process models may be generalized across a wider range of species for a larger assessment project and then describe how our methods may be applied to other stressors in addition to wind.
Biological Conservation, 2015
This software is a refined and generic implementation of IBmodel 3.0 (see Erickson et al.), with ... more This software is a refined and generic implementation of IBmodel 3.0 (see Erickson et al.), with improvements to code performance. U.S. Fish and Wildlife Service Recovery Unit coordinators for the Indiana bat are using this tool to assess impact of wind energy development, disease, and other stressors to the species.
Erickson, R. A., W. E. Thogmartin, and J. A. Szymanski. BatTool: an R package with GUI for assessing the effect of White-nose Syndrome and other take events on Myotis spp. of bats. Source Code for Biology and Medicine 9:9.
