Feasibility and accuracy of In Vivo and Ex Vivo XRF bone lead assessment wild birds: An example with black vultures, Coragyps atratus.

Background: Lead (Pb) contamination in wildlife remains a critical environmental concern, particularly for scavenger species, which are at high risk due to ingestion of lead-contaminated carrion. Portable XRF (pXRF) systems can be useful to evaluate lead concentration of wild animals in vivo. However, the accuracy of these systems has never been validated for living birds.

Age-dependent response to anthropogenic habitat during migration of an endangered raptor.

Decisions made by migrating animals can impact individual fitness and population dynamics. For avian migrants, these decisions can be affected by environmental and anthropogenic factors and by internal states. However, recent reviews have pointed to multiple gaps in our understanding of these decisions.

RAD (Resist-Accept-Direct) switch points and triggers for adaptation planning.

Climate change is transforming ecosystems globally. The Resist-Accept-Direct (RAD) framework has gained traction within many natural resource management institutions to help consider the decision space in response to this transformation. Because RAD helps manage for directional change, RAD choices entail considering which RAD pathway to implement and for how long.

A global dataset of terrestrial biological nitrogen fixation.

Biological nitrogen fixation (BNF) is the main natural source of new nitrogen inputs in terrestrial ecosystems, supporting terrestrial productivity, carbon uptake, and other Earth system processes. We assembled a comprehensive global dataset of field measurements of BNF in all major N-fixing niches across natural terrestrial biomes derived from the analysis of 376 BNF studies. The dataset comprises 32 variables, including site location, biome type, N-fixing niche, sampling year, quantification method, BNF rate (kg N ha y), the percentage of nitrogen derived from the atmosphere (%N), N fixer or N-fixing substrate abundance, BNF rate per unit of N fixer abundance, and species identity.

Aeroecology drives seasonal movements and predicts future distributions of a critically endangered terrestrial bird.

All terrestrial species interact with the airspace. The principles derived from the study of those interactions, i.e.

The Effects of Forest Harvesting on Total and Methylmercury Concentrations in Surface Waters Depend on Harvest Practices and Physical Site Characteristics.

Forest harvesting can lead to mercury (Hg) mobilization from soils to aquatic habitats and promote the transformation of inorganic Hg to highly neurotoxic and bioaccumulative methyl-Hg (MeHg). Multiple past studies reveal broad variation of stream water MeHg and total Hg (THg) concentration responses to forest harvesting, which has confounded messaging to forest and resource managers. To advance beyond divergent and sometimes contradictory findings, we synthesized information for 23 previously studied catchments in North America and Fennoscandia and compiled a uniform set of soil, landscape, and harvesting properties to identify forest management, riparian, and hillslope factors that influence responses of stream water MeHg and THg concentrations.

Global terrestrial nitrogen fixation and its modification by agriculture.

Biological nitrogen fixation (BNF) is the largest natural source of new nitrogen (N) that supports terrestrial productivity, yet estimates of global terrestrial BNF remain highly uncertain. Here we show that this uncertainty is partly because of sampling bias, as field BNF measurements in natural terrestrial ecosystems occur where N fixers are 17 times more prevalent than their mean abundances worldwide. To correct this bias, we develop new estimates of global terrestrial BNF by upscaling field BNF measurements using spatially explicit abundances of all major biogeochemical N-fixing niches.

Metabarcoding Analysis of Arthropod Pollinator Diversity: A Methodological Comparison of eDNA Derived From Flowers and DNA Derived From Bulk Samples of Insects.

Limitations of traditional insect sampling methods have motivated the development and optimisation of new non-lethal methods capable of quantifying diverse arthropod communities. Environmental DNA (eDNA) metabarcoding using arthropod-specific primers has recently been investigated as a novel way to characterise arthropod communities from the DNA they deposit on the surface of plants. This sampling method has had demonstrated success, but pollinators-especially bees-are oddly underrepresented in these studies.

Soil-microbial communities respond less than plant communities to synthetic- or bio-herbicides applied to address the exotic grass-fire cycle in rangelands.

The exotic grass-fire cycle is degrading semiarid rangelands, such as the vast areas of shrub-steppe in North America now invaded by fire-promoting cheatgrass. Chemical- or bio-herbicides are sprayed onto soils to inhibit the invaders, but information on chemical- or bio-herbicide impacts to soil microbial communities is limited. We asked how the soil-microbiome responded to the bioherbicide Pseudomonas fluorescens strain ACK55 in comparison to the separate and combined effects of a conventional pre-emergent chemical herbicide, imazapic, in two cheatgrass-invaded sagebrush-steppe sites.

Reliability of satellite-based vegetation maps for planning wildfire-fuel treatments in shrub steppe: Inferences from two contrasting national parks.

Protecting habitat threatened by increasing wildfire size and frequency requires identifying the spatial intersection of wildfire behavior and ecological conditions that favor positive management outcomes. In the perennial sagebrush steppe of Western North America, invasions by fire-prone annual grasses are a key concern, and management of them requires reliable maps of vegetation cover, fuels, and wildfire behavior. We compared commonly used, publicly available vegetation cover and fuels maps, specifically the Rangeland Analysis Platform (RAP) and LANDFIRE, with field-based assessments at two U.

Independent and interactive effects of disease and methylmercury on demographic rates across multiple amphibian populations.

Disease, alone or combined with other stressors such as habitat loss and contaminants, affects wildlife populations worldwide. However, interactions among stressors and how they affect demography and populations remain poorly understood. The amphibian chytrid fungus (Batrachochytrium dendrobatidis; Bd) is a sometimes-lethal pathogen linked with population declines and extirpations of amphibians globally.

New technology for an ancient fish: A lamprey life cycle modeling tool with an R Shiny application.

Lampreys (Petromyzontiformes) are an ancient group of fishes with complex life histories. We created a life cycle model that includes an R Shiny interactive web application interface to simulate abundance by life stage. This will allow scientists and managers to connect available demographic information in a framework that can be applied to questions regarding lamprey biology and conservation.

A partner-driven decision support model to inform the reintroduction of bull trout.

Assessments of species reintroductions involve a series of complex decisions that include human perspectives and ecological contexts. Here, we present a reintroduction assessment involving bull trout (Salvelinus confluentus) using a structured decision-making process. We approached this assessment by engaging partners representing public utilities, government agencies, and Tribes with shared interests in a potential reintroduction.

Ultrasonic deterrents provide no additional benefit over curtailment in reducing bat fatalities at an Ohio wind energy facility.

Wind energy is important for achieving net-zero greenhouse gas emissions but also contributes to global bat mortality. Current strategies to minimize bat mortality due to collision with wind-turbine blades fall broadly into two categories: curtailment (limiting turbine operation during high-risk periods) and deterrence (discouraging bat activity near turbines). Recently, there has been interest in combining these strategies to achieve greater reductions in bat fatalities than either strategy might achieve in isolation.

Mercury trophic transfer to a freshwater biosentinel: quantifying controlled bioaccumulation in larval dragonflies.

Mercury bioavailability and biomagnification in freshwater systems can be highly variable; thus, tissue data from biosentinel taxa can be useful to assess risk. Dragonfly larvae have emerged as biological indicators of mercury impairment, yet their mercury biodynamics over time and across exposure levels are not well understood. Evaluating these attributes using controlled experimental approaches is an important step to validate larval dragonflies as biosentinels for spatial and temporal trends in mercury risk.

Imperiled Great Basin terminal lakes: Synthesizing ecological and hydrological science gaps and research needs for waterbird conservation.

Terminal lakes are declining globally because of human water demands, drought, and climate change. Through literature synthesis and feedback from the resource and conservation community, we review the state of research for terminal lakes in the Great Basin of the United States, which support millions of waterbirds annually, to prioritize ecological and hydrologic information needs. From an ecological perspective, research priorities include measuring the underlying differences in waterbird resource selection and distribution, migratory connectivity, abiotic factors that interact with prey densities to affect prey availability, and waterbird fitness or demography.

Contrasting Magnitude and Timing of Pulsed Aqueous Methylmercury Bioaccumulation across a Reservoir Food Web.

Water column hypoxia is a key process influencing methylmercury (MeHg) production and availability in waterbodies worldwide. During seasonal destratification, large, short-lived pulses of aqueous MeHg may be released into the subsequently mixed water column, but little is known about the fate of these pulses, particularly whether there are concomitant increases in MeHg uptake into aquatic food webs. We examined the magnitude and timing of MeHg uptake across several trophic guilds relative to the reservoir stratification status using biweekly mercury data from water, zooplankton, and fish (Bluegill, and Smallmouth Bass, ).

How will we prepare for an uncertain future? The value of open data and code for unborn generations facing climate change.

As the impacts of climate change continue to intensify, humans face new challenges to long-term survival. Humans will likely be battling these problems long after 2100, when many climate projections currently end. A more forward-thinking view on our science and its direction may help better prepare for the future of our species.

Blended-red lighting partially mitigates the cost of light pollution for arthropods.

Light pollution disrupts the natural dark-light rhythmicity of the world and alters the spectral composition of the nocturnal sky, with far-reaching impacts on natural systems. While the costs of light pollution are now documented across scales and taxa, community-level mitigations for arthropods remain unclear. To test two light pollution mitigation strategies, we replaced all 32 streetlights in the largest visitor center in Grand Teton National Park (Wyoming, USA) to allow wireless control over each luminaries' color and brightness.

Methylmercury in subarctic amphibians: environmental gradients, bioaccumulation, and estimated flux.

Rapid warming in polar regions is causing large changes to ecosystems, including altering environmentally available mercury (Hg). Although subarctic freshwater systems have simple vertebrate communities, Hg in amphibians remains unexplored. We measured total Hg (THg) in wetland sediments and methylmercury (MeHg) in multiple life-stages (eggs to adults) of wood frogs (Rana sylvatica) and larval boreal chorus frogs (Pseudacris maculata) from up to 25 wetlands near Churchill, Manitoba (Canada), during the summers of 2018-2019.

Population Genomics Reveals Local Adaptation Related to Temperature Variation in Two Stream Frog Species: Implications for Vulnerability to Climate Warming.

Identifying populations at highest risk from climate change is a critical component of conservation efforts. However, vulnerability assessments are usually applied at the species level, even though intraspecific variation in exposure, sensitivity and adaptive capacity play a crucial role in determining vulnerability. Genomic data can inform intraspecific vulnerability by identifying signatures of local adaptation that reflect population-level variation in sensitivity and adaptive capacity.

Ecosystem Drivers of Freshwater Mercury Bioaccumulation Are Context-Dependent: Insights from Continental-Scale Modeling.

Significant variation in mercury (Hg) bioaccumulation is observed across the diversity of freshwater ecosystems in North America. While there is support for the major drivers of Hg bioaccumulation, the relative influence of different external factors can vary widely among waterbodies, which makes predicting Hg risk across large spatial scales particularly challenging. We modeled Hg bioaccumulation by coupling Hg concentrations in more than 21,000 dragonflies collected across the United States from 2008 to 2021 with a suite of chemical (e.

Nitrogen Deposition Weakens Soil Carbon Control of Nitrogen Dynamics Across the Contiguous United States.

Anthropogenic nitrogen (N) deposition is unequally distributed across space and time, with inputs to terrestrial ecosystems impacted by industry regulations and variations in human activity. Soil carbon (C) content normally controls the fraction of mineralized N that is nitrified (ƒ), affecting N bioavailability for plants and microbes. However, it is unknown whether N deposition has modified the relationships among soil C, net N mineralization, and net nitrification.