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Results for “Integrative Conservation”

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At least 631 records · Page 35Linked to original sources
USGS2012

Directional connectivity in hydrology and ecology

Quantifying hydrologic and ecological connectivity has contributed to understanding transport and dispersal processes and assessing ecosystem degradation or restoration potential. However, there has been little synthesis across disciplines. The growing field of ecohydrology and recent recognition that loss of hydrologic connectivity is leading to a global decline in biodiversity underscore the need for a unified connectivity concept. One outstanding need is a way to quantify directional connectivity that is consistent, robust to variations in sampling, and transferable across scales or environmental settings. Understanding connectivity in a particular direction (e.g., streamwise, along or across gradient, between sources and sinks, along cardinal directions) provides critical information for predicting contaminant transport, planning conservation corridor design, and understanding how landscapes or hydroscapes respond to directional forces like wind or water flow. Here we synthesize progress on quantifying connectivity and develop a new strategy for evaluating directional connectivity that benefits from use of graph theory in ecology and percolation theory in hydrology. The directional connectivity index (DCI) is a graph-theory based, multiscale metric that is generalizable to a range of different structural and functional connectivity applications. It exhibits minimal sensitivity to image rotation or resolution within a given range and responds intuitively to progressive, unidirectional change. Further, it is linearly related to the integral connectivity scale length—a metric common in hydrology that correlates well with actual fluxes—but is less computationally challenging and more readily comparable across different landscapes. Connectivity-orientation curves (i.e., directional connectivity computed over a range of headings) provide a quantitative, information-dense representation of environmental structure that can be used for comparison or detection of subtle differences in the physical-biological feedbacks driving pattern formation. Case-study application of the DCI to the Everglades in south Florida revealed that loss of directional hydrologic connectivity occurs more rapidly and is a more sensitive indicator of declining ecosystem function than other metrics (e.g., habitat area) used previously. Here and elsewhere, directional connectivity can provide insight into landscape drivers and processes, act as an early-warning indicator of environmental degradation, and serve as a planning tool or performance measure for conservation and restoration efforts.

Ecological Applications↗
USGS2019

Spatially-structured statistical network models for landscape genetics

A basic understanding of how the landscape impedes, or creates resistance to, the dispersal of organisms and hence gene flow is paramount for successful conservation science and management. Spatially structured ecological networks are often used to represent spatial landscape‐genetic relationships, where nodes represent individuals or populations and resistance to movement is represented using non‐binary edge weights. Weights are typically assigned or estimated by the user, rather than observed, and validating such weights is challenging. We provide a synthesis of current methods used to estimate edge weights and an overview of common model types, stressing the advantages and disadvantages of each approach and their ability to model landscape‐genetic data. We further explore a set of spatial‐statistical methods that provide ecologists with alternative approaches for modeling spatially explicit processes that may affect genetic structure. This includes an overview of spatial autoregressive models, with a particular focus on how correlation and partial correlation are used to represent neighborhood structure with the inverse of the covariance matrix (i.e., precision matrix). We then demonstrate how to model resistance by specifying an appropriate statistical model on the nodes, conditioned on the edge weights, through the precision matrix. This integration of network ecology and spatial statistics provides a practical analytical framework for landscape‐genetic studies. The results can be used to make statistical inferences about the relative importance of individual landscape characteristics, such as the vegetative cover, hillslope, or the presence of roads or rivers, on gene flow. In addition, the R code we include allows readers to explore landscape‐genetic structure in their own datasets, which will potentially provide new insights into the evolutionary processes that generated ecological networks, as well as valuable information about the optimal characteristics of conservation corridors.

Ecological Monographs↗
USGS2023

Machine-learning model to delineate sub-surface agricultural drainage from satellite imagery

Knowing subsurface drainage (tile-drain) extent is integral to understanding how landscapes respond to precipitation events and subsequent days of drying, as well as how soil characteristics and land management influence stream response. Consequently, a time series of tile-drain extent would inform one aspect of land management that complicates our ability to explain streamflow and water-quality as a function of climate variability or conservation management. We trained a UNet machine-learning model, a convolutional neural network designed to highlight objects of interest within an image, to delineate tile-drain networks in panchromatic satellite imagery without additional data on soils, topography, or historical tile-drain extent. This was done by training the model to match the accuracy of human experts manually tracing the surface representation of tile drains in satellite imagery. Our approach began with a library of images that were used to train and quantify the accuracy of the model, with model performance tested on imagery from two areas that were not used to train the model. Satellite imagery included acquisition dates from 2008 to 2020. Training imagery was from agricultural areas within the US Great Lakes basin. Validation imagery was from the upper Maumee River, tributary to western Lake Erie, and an Indiana, Ohio-River headwater tributary. Our analysis of the satellite imagery paired with meteorological and soil data found that during spring, a combination of relatively high solar radiation, intermediate soil-water content and bare fields enabled the best model performance. Each area of interest was heavily tile-drained, where better understanding the movement of water, nutrients, and sediment from fields to downstream water bodies is key to managing harmful algal blooms and hypoxia. The trained UNet model successfully identified tile drains visible in the validation imagery with an accuracy of 93%–96% and balanced accuracy of 52%–54%, similar to performance for training data (95% and 63%, respectively). Model performance will benefit from ongoing contributions to the training library.

Indiana, Michigan, Ohio, Wisconsin↗
USGS2014

Identifying polar bear resource selection patterns to inform offshore development in a dynamic and changing Arctic

Although sea ice loss is the primary threat to polar bears ( Ursus maritimus ), little can be done to mitigate its effects without global efforts to reduce greenhouse gas emissions. Other factors, however, could exacerbate the impacts of sea ice loss on polar bears, such as exposure to increased industrial activity. The Arctic Ocean has enormous oil and gas potential, and its development is expected to increase in the coming decades. Estimates of polar bear resource selection will inform managers how bears use areas slated for oil development and to help guide conservation planning. We estimated temporally-varying resource selection patterns for non-denning adult female polar bears in the Chukchi Sea population (2008–2012) at two scales (i.e., home range and weekly steps) to identify factors predictive of polar bear use throughout the year, before any offshore development. From the best models at each scale, we estimated scale-integrated resource selection functions to predict polar bear space use across the population's range and determined when bears were most likely to use the region where offshore oil and gas development in the United States is slated to occur. Polar bears exhibited significant intra-annual variation in selection patterns at both scales but the strength and annual patterns of selection differed between scales for most variables. Bears were most likely to use the offshore oil and gas planning area during ice retreat and growth with the highest predicted use occurring in the southern portion of the planning area. The average proportion of predicted high-value habitat in the planning area was >15% of the total high-value habitat for the population during sea ice retreat and growth and reached a high of 50% during November 2010. Our results provide a baseline on which to judge future changes to non-denning adult female polar bear resource selection in the Chukchi Sea and help guide offshore development in the region. Lastly, our study provides a framework for assessing potential impacts of offshore oil and gas development to other polar bear populations around the Arctic.

Ecosphere↗
USGS2009

U.S. Geological Survey (USGS) Western Region: Coastal and Ocean Science

USGS Western Region Coastal and Ocean Science is interdisciplinary, collaborative, and integrates expertise from all USGS Disciplines, and ten of its major Science Centers, in Alaska, Hawai'i, California, Washington, and Oregon. The scientific talent, laboratories, and research vessels in the Western Region and across the Nation, strategically position the USGS to address broad geographic and oceanographic research topics. USGS information products inform resource managers and policy makers who must balance conservation mandates with increasing demands for resources that sustain the Nation's economy. This fact sheet describes but a few examples of the breadth of USGS science conducted in coastal, nearshore, and ocean environments along our Nation's West Coast and Pacific Islands.

Fact Sheet↗
USGS2021

SMaRT: A science-based tiered framework for common ravens

Large-scale increases and expansion of common raven ( Corvus corax ; raven) populations are occurring across much of North America, leading to increased negative consequences for livestock and agriculture, human health and safety, and sensitive species conservation. We describe a science-based adaptive management framework that incorporates recent quantitative analyses and mapping products for addressing areas with elevated raven numbers and minimizing potential adverse impacts to sensitive species, agricultural damage, and human safety. The framework comprises 5 steps: (1) desktop analysis; (2) field assessments; (3) comparison of raven density estimates to an ecological threshold (in terms of either density or density plus distance to nearest active or previous nest); (4) prescribing management options using a 3-tiered process (i.e., habitat improvements, subsidy reductions, and direct actions using StallPOPd.V4 software); and (5) post-management monitoring. The framework is integrated within the Science-based Management of Ravens Tool (SMaRT), a web-based application outfitted with a user-friendly interface that guides managers through each step to develop a fully customized adaptive plan for raven management. In the SMaRT interface, users can: (1) interact with pre-loaded maps of raven occurrence and density and define their own areas of interest within the Great Basin to delineate proposed survey or treatment sites; (2) enter site-level density estimates from distance sampling methods or perform estimation of raven densities using the rapid assessment protocol that we provide; (3) compare site-level density estimates to an identified ecological threshold; and (4) produce a list of potential management options for their consideration. The SMaRT supports decision-making by operationalizing scientific products for raven management and facilitates realization of diverse management goals including sensitive species conservation, protection of livestock and agriculture, safeguarding human health, and addressing raven overabundance and expansion. We illustrate the use of the framework through SMaRT using an example of greater sage-grouse ( Centrocercus urophasianus ) conservation efforts within the Great Basin, USA.

California, Idaho, Nevada, Oregon, Utah↗
USGS2012

How well do the rosgen classification and associated "natural channel design" methods integrate and quantify fluvial processes and channel response?

Over the past 10 years the Rosgen classification system and its associated methods of "natural channel design" have become synonymous (to many without prior knowledge of the field) with the term "stream restoration" and the science of fluvial geomorphology. Since the mid 1990s, this classification approach has become widely, and perhaps dominantly adopted by governmental agencies, particularly those funding restoration projects. For example, in a request for proposals for the restoration of Trout Creek in Montana, the Natural Resources Conservation Service required "experience in the use and application of a stream classification system and its implementation." Similarly, classification systems have been used in evaluation guides for riparian areas and U.S. Forest Service management plans. Most notably, many highly trained geomorphologists and hydraulic engineers are often held suspect, or even thought incorrect, if their approach does not include reference to or application of a classification system. This, combined with the para-professional training provided by some involved in "natural channel design" empower individuals and groups with limited backgrounds in stream and watershed sciences to engineer wholesale re-patterning of stream reaches using 50-year old technology that was never intended for engineering design. At Level I, the Rosgen classification system consists of eight or nine major stream types, based on hydraulic-geometry relations and four other measures of channel shape to distinguish the dimensions of alluvial stream channels as a function of the bankfull stage. Six classes of the particle size of the boundary sediments are used to further sub-divide each of the major stream types, resulting in 48 or 54 stream types. Aside from the difficulty in identifying bankfull stage, particularly in incising channels, and the issue of sampling from two distinct populations (beds and banks) to classify the boundary sediments, the classification provides a consistent and reproducible means for practitioners to describe channel morphology although difficulties have been encountered in lower-gradient stream systems. Use of the scheme to communicate between users or as a conceptual model, however, has not justified its use for engineering design or for predicting river behavior; its use for designing mitigation projects, therefore, seems beyond its technical scope. Copyright ASCE 2005.

Conference Paper↗
USGS2015

Fire modulates climate change response of simulated aspen distribution across topoclimatic gradients in a semi-arid montane landscape

Content Changing aspen distribution in response to climate change and fire is a major focus of biodiversity conservation, yet little is known about the potential response of aspen to these two driving forces along topoclimatic gradients. Objective This study is set to evaluate how aspen distribution might shift in response to different climate-fire scenarios in a semi-arid montane landscape, and quantify the influence of fire regime along topoclimatic gradients. Methods We used a novel integration of a forest landscape succession and disturbance model (LANDIS-II) with a fine-scale climatic water deficit approach to simulate dynamics of aspen and associated conifer and shrub species over the next 150 years under various climate-fire scenarios. Results Simulations suggest that many aspen stands could persist without fire for centuries under current climate conditions. However, a simulated 2–5 °C increase in temperature caused a substantial reduction of aspen coverage at lower elevations and a modest increase at upper elevations, leading to an overall reduction of aspen range at the landscape level. Increasing fire activity may favor aspen increase at its upper elevation limits adjacent to coniferous forest, but may also favor reduction of aspen at lower elevation limits adjacent to xeric shrubland. Conclusions Our study highlights the importance of incorporating fine-scale terrain effects on climatic water deficit and ecohydrology when modeling species distribution response to climate change. This modeling study suggests that climate mitigation and adaptation strategies that use fire would benefit from consideration of spatial context at landscape scales.

Landscape Ecology↗
USGS2024

Propagating observation errors to enable scalable and rigorous enumeration of plant population abundance with aerial imagery

Estimating and monitoring plant population size is fundamental for ecological research, as well as conservation and restoration programs. High-resolution imagery has potential to facilitate such estimation and monitoring. However, remotely sensed estimates typically have higher uncertainty than field measurements, risking biased inference on population status. We present a model that accounts for false negative (missed plants) and false positive (misclassified or double-counted plants) error in counts from high-resolution imagery via integration with ground data. We apply it to estimate the abundance of a foundational shrub species in post-wildfire landscapes in the western United States. In these landscapes, plant recruitment is crucial for ecological recovery but locally patchy, motivating the use of spatially extensive measurements from unoccupied aerial systems (UAS). Integrating >16 ha of UAS imagery with >700 georeferenced field plots, we fit our model to generate insights into the prevalence and drivers of observation errors associated with classification algorithms used to distinguish individual plants, relationships between abundance and landscape context, and to generate spatially explicit maps of shrub abundance. Raw counts of plant abundance in high-resolution imagery resulted in substantial false negative and false positive observation errors. The probability of detecting ( p ) adult plants (≥0.25 m tall) varied between sites within 0.52 < p̂adult < 0.82, whereas the detection of smaller plants (<0.25 m) was lower, 0.03 < p̂small < 0.3. On average, we estimate that 19% of all detected plants were false positive errors, which varied spatially in relation to topographic predictors. Abundance declined toward the interior of previous wildfires and was positively associated with terrain roughness. Our study demonstrates that integrated models accounting for imperfect detection improve estimates of plant population abundance derived from inherently imperfect UAS imagery. We believe such models will further improve inference on plant population dynamics—relevant to restoration, wildlife habitat and related objectives—and echo previous calls for remote sensing applications to better differentiate between ecological and observational processes.

Methods in Ecology and Evolution↗
USGS2019

Clustering and ensembling approaches to support surrogate-based species management

Aim Surrogate species can provide an efficient mechanism for biodiversity conservation if they encompass the needs or indicate the status of a broader set of species. When species that are the focus of ongoing management efforts act as effective surrogates for other species, these incidental surrogacy benefits lead to additional efficiency. Assessing surrogate relationships often relies on grouping species by distributional patterns or by species traits, but there are few approaches for integrating outputs from multiple methods into summaries of surrogate relationships that can inform decision‐making. Location Prairie Pothole Region of the United States. Methods We evaluated how well five upland‐nesting waterfowl species that are a focus of management may act as surrogates for other wetland‐dependent birds. We grouped species by their patterns of relative abundance at multiple scales and by different sets of traits, and evaluated whether empirical validation could effectively select among the resulting species groupings. We used an ensemble approach to integrate the different estimated relationships among species and visualized the ensemble as a network diagram. Results Estimated relationships among species were sensitive to methodological decisions, with qualitatively different relationships arising from different approaches. An ensemble provided an effective tool for integrating across different estimates and highlighted the Sora ( Porzana carolina ), American Avocet ( Recurvirostra Americana ) and Black Tern ( Chlidonias niger ) as the non‐waterfowl species expected to show the strongest incidental surrogacy relationships with the waterfowl that are the focus of ongoing management. Main conclusions An ensemble approach integrated multiple estimates of surrogate relationship strength among species and allowed for intuitive visualizations within a network. By accounting for methodological uncertainty while providing a simple continuous metric of surrogacy, our approach is amenable to both further validation and integration into decision‐making.

Alberta, Iowa, Manitoba, Minnesota, Montana, North↗
USGS2013

Fort Collins Science Center Ecosystem Dynamics branch--interdisciplinary research for addressing complex natural resource issues across landscapes and time

The Ecosystem Dynamics Branch of the Fort Collins Science Center offers an interdisciplinary team of talented and creative scientists with expertise in biology, botany, ecology, geology, biogeochemistry, physical sciences, geographic information systems, and remote-sensing, for tackling complex questions about natural resources. As demand for natural resources increases, the issues facing natural resource managers, planners, policy makers, industry, and private landowners are increasing in spatial and temporal scope, often involving entire regions, multiple jurisdictions, and long timeframes. Needs for addressing these issues include (1) a better understanding of biotic and abiotic ecosystem components and their complex interactions; (2) the ability to easily monitor, assess, and visualize the spatially complex movements of animals, plants, water, and elements across highly variable landscapes; and (3) the techniques for accurately predicting both immediate and long-term responses of system components to natural and human-caused change. The overall objectives of our research are to provide the knowledge, tools, and techniques needed by the U.S. Department of the Interior, state agencies, and other stakeholders in their endeavors to meet the demand for natural resources while conserving biodiversity and ecosystem services. Ecosystem Dynamics scientists use field and laboratory research, data assimilation, and ecological modeling to understand ecosystem patterns, trends, and mechanistic processes. This information is used to predict the outcomes of changes imposed on species, habitats, landscapes, and climate across spatiotemporal scales. The products we develop include conceptual models to illustrate system structure and processes; regional baseline and integrated assessments; predictive spatial and mathematical models; literature syntheses; and frameworks or protocols for improved ecosystem monitoring, adaptive management, and program evaluation. The descriptions in this fact sheet provide snapshots of our three research emphases, followed by descriptions of select current projects.

Fact Sheet↗
USGS2007

Recommendations for a barrier island breach management plan for Fire Island National Seashore, including the Otis Pike High Dune Wilderness Area, Long Island, New York

The U.S Army Corps of Engineers, New York District is developing engineering plans, including economic costs and benefits, for storm damage reduction along an 83 mile stretch of the coastal barrier islands and beaches on the south shore of Long Island, NY from Fire Island Inlet east to the Montauk Point headland. The plan, expected to include various alternatives for storm protection and erosion mitigation, is referred to as the Fire Island to Montauk Point Reformulation Plan (FIMP). These plans are expected to follow the Corps of Engineers’ Environmental Operating Principles striving for long term environmental sustainability and balance between environmental protection and protection of human health and property. Fire Island National Seashore (FIIS), a 19,579 acre unit of the National Park System includes a 32 mile long coastal barrier island located within the FIMP project area. A seven-mile section of the park, Otis Pike Fire Island High Dune Wilderness Area, is also a designated Federal Wilderness Area. The FIIS includes not only the barrier island and sand dunes, but also several islands, sand flats and wetlands landward of the barrier, submerged parts of Great South Bay shoreface, extending approximately 4,000 feet into the bay with the inner shelf region extending approximately 1,000 feet seaward of the Fire Island shoreline. The Fire Island barrier islands, a sand-starved system dominated by highly dynamic processes, are struggling to maintain their integrity in the face of sea-level rise and storms. Adding to the dilemma is that development on the barriers and the mainland has increased greatly during the past 50 years. As such, managers and decision makers in federal agencies, state agencies and local governments are challenged to balance tradeoffs between protection of lives and property, public access and long term conservation of natural habitats and processes and the plants and animals that depend on these habitats. National Park Service (NPS) policy stipulates that natural coastal processes be maintained to the greatest extent possible and not be impeded so as to conserve landforms, habitats and natural ecosystem resources that reply on the landforms and processes for long-term sustainability of the national park. Storms and associated processes such as waves, tides, currents and relative sea-level change are critical elements for the formation and evolution of these barrier islands, sand dunes, back-barrier sand flats and lagoons and vegetated wetlands. Processes such as wave run-up, overwash and barrier beaching, which occur during elevated storm surge are all necessary processes in enabling the efficient transfer of sediments, nutrients and marine water from the Atlantic Ocean across barriers and into Great South Bay. A large body of scientific data and information published over the past 50 years shows that such transfers of sediment and water from the ocean to the bays are essential for the long-term maintenance of the barrier island and back-bay systems and their biologically diverse habitats an d ecosystems. Current relative sea-level rise (~12 in/century) is chronic and pervasive in driving Long Island coastal change and with the likelihood of accelerating sea level rise in the near future, coastal hazards such as erosion, inundation, and storm surge flooding will increase, with corresponding increased risk to life and property on both Fire Island and on the mainland. In addition, the cumulative effects over the past century and more, both direct and indirect, of human impacts on the Long Island coast have altered the barrier beach and dunes and sediment transport processes. These impacts have likely increased the potential for breaching and increased risk to life and property on the coast and the mainland. Examples of direct impacts are: the stone jetties at Moriches, Shinnecock, and Fire Island tidal inlets and groin field structures at Westhampton that alter littoral processes, armoring and erosion-control stabilization of the headlandds such as the Montauk Point headlands, and deepening of navigation channels by dredging through the tidal inlets and in the bays. Indirect impacts that have a bearing on decisions to deal with breaching are: high-risk development of the barrier islands and low-lying areas of the mainland vulnerable to flooding, and the dredging of nearshore sand shoals for beach nourishment. The NPS strives to employ a coastal management framework for decision making that is based on assessment of the physical and ecological properties of the shoreline as well as human welfare and property. In order to protect developed areas of Fire Island and the mainland from loss of life, flooding, and other economic and physical damage, the NPS will likely need to consider allowing artificial closure of some breaches within the FIIS under certain circumstances. The decision by the NPS to allow breaches to evolve naturally and possibly close or to allow artificially closing breaches is based on four criteria: 1. Volumes of sediment transported landward and exchange of water and nutrients; 2. Elevated water levels and flooding risk to mainland life and property; 3. Engineering processes of artificial closure; and 4. Economic costs and benefits of artificial closure. This report for breach management presents protocols which specify when breach closures within the FIIS might be desirable and necessary, as well as provides recommendations for structural breach closure engineering operations which are indented to minimize negative impacts to the natural wilderness values and cultural resources within the FIIS, particularly the Otis Pike Wilderness Area. The goal of the plan is to strike a balance between protecting natural resources and allowing natural processes to operate and avoiding loss of life and excessive property damage.

New York↗
USGS2026

Environmental and demographic mechanisms underlying population dynamics provide relative stability in an island songbird

Understanding demographic and ecological mechanisms underlying population dynamics is a key goal in population ecology and can inform effective conservation and management. Species may be well adapted to persist under normal ranges of environmental conditions, but increasingly novel conditions due to climate change may strain their demographic buffering mechanisms. Small isolated populations on islands are expected to be especially vulnerable to declines caused by novel environmental conditions, but the ecological drivers of population dynamics on islands are often unknown. We used an integrated population model to (1) examine ecological drivers of population growth and (2) assess global population trends of the Island Scrub-Jay ( Aphelocoma insularis ) from 2009 to 2019. Our results suggest that population size increased slightly over this interval despite declines during severe drought. We also found evidence that density dependence, precipitation, and food availability affected fecundity and the survival of nonbreeding individuals. Breeder survival was relatively stable and had a weak effect on population growth as expected for long-lived species. Overall, our results provide an optimistic snapshot for this species by demonstrating resilience to contemporary drought but also emphasize the species' potential vulnerability due to its small population size.

California↗
USGS2018

Quantification of the indirect use value of functional group diversity based on the ecological role of species in the ecosystem

An important issue in biodiversity valuation is gaining a better understanding of how biodiversity conservation affects economic activities and human welfare. Quantifying the economic benefits of biodiversity for human well-being is not straightforward. Here, we expand the ecosystem service cascade by (i) attributing a methodology to the different steps of the cascade to assess the effects of changes in functional group diversity on economic activities; (ii) including multiple attributes for defining functional diversity and (iii) integrating a dynamic ecological model simulating complex interactions and feedbacks between species with an economic model assessing the effects of changes in functional group diversity for gross revenues. The stepwise methodological framework integrates a production function approach with a market price-based approach in order to investigate the indirect use value of functional group diversity based on the ecological role of species in the ecosystem. The methodology is applied to estimate the relationship between the gross economic value of Chinook salmon (Pacific Northwest, United States) and the diversity of freshwater macroinvertebrates. The results of our analysis emphasize the importance of biological diversity for sustaining ecosystem goods and services. The analysis provides a tractable framework for quantitatively exploring the economic consequences of changes in functional group diversity.

Ecological Economics↗
USGS2021

Why disease ecology needs life-history theory: A host perspective

When facing an emerging infectious disease of conservation concern, we often have little information on the nature of the host‐parasite interaction to inform management decisions. However, it is becoming increasingly clear that the life‐history strategies of host species can be predictive of individual‐ and population‐level responses to infectious disease, even without detailed knowledge on the specifics of the host‐parasite interaction. Here, we argue that a deeper integration of life‐history theory into disease ecology is timely and necessary to improve our capacity to understand, predict and mitigate the impact of endemic and emerging infectious diseases in wild populations. Using wild vertebrates as an example, we show that host life‐history characteristics influence host responses to parasitism at different levels of organisation, from individuals to communities. We also highlight knowledge gaps and future directions for the study of life‐history and host responses to parasitism. We conclude by illustrating how this theoretical insight can inform the monitoring and control of infectious diseases in wildlife.

Ecology Letters↗
USGS2019

Evaluating community-level response to management actions across a diverse Hawaiian forest bird community

Although species‐specific approaches are necessary to understand the dynamics of individual species composing a community, they do not offer a framework for making optimal management decisions at the community level. Here, we present a simple framework for comparing the response of entire communities to multiple management scenarios. Our approach uses a weighted average of standardized species‐specific responses to produce a single integrative measure of the community response and employs mixed‐effect linear models to quantify the increase in the community response due to each management action, or combination of actions. We demonstrate our approach with a simulation study assessing the potential benefits of multiple management actions on the avian community of Hakalau Forest National Wildlife Refuge, Hawaiʻi, which is composed of eight native species with conservation status varying from endangered to least concern. Management actions considered included a reduction of avian malaria transmission risk, reducing rat predation, and increasing forest habitat. We used three different prioritization (weighting) schemes to assess whether the response to management actions differed along a conservation gradient (from endangered to least concern). We also investigated whether future changes in disease distribution as a result of climate change will alter the relationship between management practices and community response. Our community‐level analysis produced three important insights, highlighting the need to consider the response from multiple species to changing threats and management actions. First, increasing the amount of habitat always had the greatest positive impact on the avian community, regardless of the weighting scheme. Second, the community response to management was different under current vs. future conditions, with increased benefit in the future when disease risks were higher. Third, the response to management varied along the conservation gradient. Reducing malaria transmission risk in 2100 had the greatest benefit to endangered species, while increasing forest habitat had the greatest benefit to “least concern” species. However, reducing rat predation appeared to benefit a subset of species based on ecological factors unrelated to rarity, such as nest accessibility. Our approach is widely applicable using experimental, observational, or simulation‐based data, allowing managers to consider the response of all species while weighting their priority levels.

Hawaii↗
USGS2010

Multiscale habitat use and selection in cooperatively breeding Micronesian kingfishers

Information about the interaction between behavior and landscape resources is key to directing conservation management for endangered species. We studied multi-scale occurrence, habitat use, and selection in a cooperatively breeding population of Micronesian kingfishers (Todiramphus cinnamominus) on the island of Pohnpei, Federated States of Micronesia. At the landscape level, point-transect surveys resulted in kingfisher detection frequencies that were higher than those reported in 1994, although they remained 15-40% lower than 1983 indices. Integration of spatially explicit vegetation information with survey results indicated that kingfisher detections were positively associated with the amount of wet forest and grass-urban vegetative cover, and they were negatively associated with agricultural forest, secondary vegetation, and upland forest cover types. We used radiotelemetry and remote sensing to evaluate habitat use by individual kingfishers at the home-range scale. A comparison of habitats in Micronesian kingfisher home ranges with those in randomly placed polygons illustrated that birds used more forested areas than were randomly available in the immediate surrounding area. Further, members of cooperatively breeding groups included more forest in their home ranges than birds in pair-breeding territories, and forested portions of study areas appeared to be saturated with territories. Together, these results suggested that forest habitats were limited for Micronesian kingfishers. Thus, protecting and managing forests is important for the restoration of Micronesian kingfishers to the island of Guam (United States Territory), where they are currently extirpated, as well as to maintaining kingfisher populations on the islands of Pohnpei and Palau. Results further indicated that limited forest resources may restrict dispersal opportunities and, therefore, play a role in delayed dispersal and cooperative behaviors in Micronesian kingfishers.

Journal of Wildlife Management↗
USGS2025

Non-native prey availability and over-compensatory density dependence drive population dynamics of a native fish predator

Understanding the factors that regulate population dynamics is crucial for conserving imperiled species. Bull trout ( Salvelinus confluentus ), a piscivorous salmonid and one of North America's most threatened cold-water species, has declined significantly due to habitat loss, overfishing, invasive species, and climate change. While recovery efforts have primarily targeted these threats, the role of prey availability in influencing bull trout population dynamics under multiple stressors remains poorly understood. Using a stage-based integrated population model, we quantified the effects of non-native prey availability (kokanee; Oncorhynchus nerka ), angling pressure, climatic variation, and density-dependent processes on bull trout population dynamics in Lake Koocanusa, a transboundary reservoir and river system (United States and Canada), over a 40-year period (1980–2023). Our results show that bull trout populations are regulated by density-dependent processes, including over-compensation in sub-adult recruitment and reduced adult survival at high densities. Increased kokanee biomass and restricted harvest significantly enhanced bull trout survival and abundance, whereas reduced water availability had a limited negative effect on sub-adult production. Model simulations indicate that as kokanee biomass availability increases, the number of bull trout that can be sustainably harvested also increases. In fact, a modest annual fishery (300 individuals) can be sustained, especially under moderate to high kokanee biomass conditions. These results underscore the importance of prey availability, including non-native species, in supporting bull trout populations. Effective management of threatened apex fish predators like bull trout requires addressing the complex interplay between environmental threats, prey dynamics, and density-dependent mechanisms across all life stages.

British Columbia, Montana↗