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At least 757 records · Page 42Linked to original sources
USGS2022

A haploid pseudo-chromosome genome assembly for a keystone sagebrush species of western North American rangelands

Increased ecological disturbances, species invasions, and climate change are creating severe conservation problems for several plant species that are widespread and foundational. Understanding the genetic diversity of these species and how it relates to adaptation to these stressors are necessary for guiding conservation and restoration efforts. This need is particularly acute for big sagebrush ( Artemisia tridentata ; Asteraceae), which was once the dominant shrub over 1,000,000 km 2 in western North America but has since retracted by half and thus has become the target of one of the largest restoration seeding efforts globally. Here, we present the first reference-quality genome assembly for an ecologically important subspecies of big sagebrush ( A. tridentata subsp. tridentata ) based on short and long reads, as well as chromatin proximity ligation data analyzed using the HiRise pipeline. The final 4.2-Gb assembly consists of 5,492 scaffolds, with nine pseudo-chromosomal scaffolds (nine scaffolds comprising at least 90% of the assembled genome; n = 9). The assembly contains an estimated 43,377 genes based on ab initio gene discovery and transcriptional data analyzed using the MAKER pipeline, with 91.37% of BUSCOs being completely assembled. The final assembly was highly repetitive, with repeat elements comprising 77.99% of the genome, making the Artemisia tridentata subsp. tridentata genome one of the most highly repetitive plant genomes to be sequenced and assembled. This genome assembly advances studies on plant adaptation to drought and heat stress and provides a valuable tool for future genomic research.

Arizona, California, Colorado, Idaho, Montana, Neb↗
USGS2022

A sagebrush conservation design to proactively restore America’s sagebrush biome

A working group of experts with diverse professional backgrounds and disciplinary expertise was assembled to conceptualize a spatially explicit conservation design to support and inform the Sagebrush Conservation Strategy Part 2. The goal was to leverage recent advancements in remotely sensed landcover products to develop spatially and temporally explicit maps of sagebrush rangeland condition and landscape threats. In addition, the group sought to provide a common basis for understanding the state of sagebrush rangelands through time. First, the study team developed a spatially explicit model to assess geographic patterns in sagebrush ecological integrity and used this model to identify core sagebrush areas (CSAs), growth opportunity areas (GOAs), and other rangeland areas (ORAs) across the biome. Among the identified rangelands, 33.4 million acres were classified as CSAs; 84.3 million acres as GOAs; and 127.2 million acres as ORAs as of 2020. Second, the team sought to demonstrate the ecological relevance of the identified CSAs and GOAs by comparing these data with independent datasets for sagebrush obligate species of conservation concern. Geographical patterns in sagebrush ecological integrity were strongly associated with the occurrence of high-priority species and also displayed clear links to population performance for greater sage-grouse. Third, the team parsed out the type, location, and acres of primary threats within the different categories (CSAs, GOAs, and ORAs) to help focus active management by identifying places where multiagency and organization efforts can protect CSAs and GOAs that have higher levels of integrity with lower cumulative threats. The assessment of the condition of the sagebrush biome (that is, the location, amount, and conservation status) indicated that complex ecosystem function problems are driving ~73 percent of the demonstrated threats within the CSAs and GOAs (rather than point-source problems, such as human development). Fourth, the team developed trend estimates for the identified CSAs and GOAs and three selected primary threats (invasive annual grasses, conifer encroachment, and human modification) to the sagebrush biome from 2001 to 2020. Results showed that an average of 1.3 million acres per year have transitioned to ORAs at an annual rate of −1.34 percent. Fifth, the team developed an approach to integrate climate change effects into the threat-based landscape conservation design and conducted an initial assessment on the magnitude of near-term climate effects in the context of observed historical trends. The team’s analysis suggests that climate change alone is unlikely to be the dominant threat to sagebrush ecological integrity in the next few decades, although interactions of climate with wildfire and invasive annual grasses may be an important threat, especially in the longer term. A spatial overlap analysis was performed and highlighted 45.8 million acres of shared priorities among existing conservation frameworks to help anchor and guide collaborative landscape-scale conservation of areas that still have no to low threats. This information is critical to provide context for decisions about the volume and nature of conservation actions and funding requirements.

western United States↗
USGS2000

2nd interface between ecology and land development in California

The 2nd Interface Between Ecology and Land Development Conference was held in association with Earth Day 1997, five years after the first Interface Conference. Rapid population growth in California has intensified the inevitable conflict between land development and preservation of natural ecosystems. Sustainable development requires wise use of diminishing natural resources and, where possible, restoration of damaged landscapes. These Earth Week Celebrations brought together resource managers, scientists, politicians, environmental consultants, and concerned citizens in an effort to improve the communication necessary to maintain our natural biodiversity, ecosystem processes and general quality of life. As discussed by our keynote speaker, Michael Soule, the best predictor of habitat loss is population growth and nowhere is this better illustrated than in California. As urban perimeters expand, the interface between wildlands and urban areas increases. Few problems are more vexing than how to manage the fire prone ecosystems indigenous to California at this urban interface. Today resource managers face increasing challenges of dealing with this problem and the lead-off section of the proceedings considers both the theoretical basis for making decisions related to prescribed burning and the practical application. Habitat fragmentation is an inevitable consequence of development patterns with significant impacts on animal and plant populations. Managers must be increasingly resourceful in dealing with problems of fragmentation and the often inevitable consequences, including susceptibility to invasive oganisms. One approach to dealing with fragmentation problems is through careful landplanning. California is the national leader in the integration of conservation and economics. On Earth Day 1991, Governor Pete Wilson presented an environmental agenda that promised to create between land owners and environmentalists, agreements that would guarantee the protection of -endangered species and out of this grew the pioneering initiative, known as the Natural Communities Conservation Planning (NCCP) program. California's vast expanse of seemingly endless resources has traditionally been viewed as justification for abusive land use practices. The modem day recognition that resources are finite has led to greater concern, not only for conserving what is left, but for restoring abused landscapes. Ecological restoration is a new science devoted to returning disturbed environments to a semblance of their 'pristine' state. Based on principles of 'revegetation,' restoration goes far beyond simple replanting, rather the ambition of ecological restoration is to return landscapes to functioning ecosystems and is the focus of the last section.

Open-File Report↗
USGS2022

Ten-year ecological responses to fuel treatments within semiarid Wyoming big sagebrush ecosystems

Sagebrush ecosystems of western North America are threatened by invasive annual grasses and wildfires that can remove fire-intolerant shrubs for decades. Fuel reduction treatments are used ostensibly to aid in fire suppression, conserve wildlife habitat, and restore historical fire regimes, but long-term ecological impacts of these treatments are not clear. In 2006, we initiated fuel reduction treatments (prescribed fire, mowing, and herbicide applications [tebuthiuron and imazapic]) in six Artemisia tridentata ssp. wyomingensis communities. We evaluated long-term effects of these fuel treatments on: (1) magnitude and longevity of fuel reduction; (2) Greater Sage-grouse habitat characteristics; and (3) ecological resilience and resistance to invasive annual grasses. Responses were analyzed using repeated-measures linear mixed models. Response variables included plant biomass, cover, density and height, distances between perennial plants, and exposed soil cover. Prescribed fire produced the greatest reduction in woody fuel over time. Mowing initially reduced woody biomass, which recovered by year 10. Tebuthiuron did not significantly reduce woody biomass compared to controls. All woody fuel treatments reduced sagebrush cover to below 15% (recommended minimum for Greater Sage-grouse habitat), but only prescribed fire reduced cover to below controls. Median mowed sagebrush height remained above the recommended 30 cm. Cheatgrass ( Bromus tectorum ) cover increased to above the recommended maximum of 10% across all treatments and controls. Ecological resilience to woody fuel treatments was lowest with fire and greatest with mowing. Low resilience over the 10 posttreatment years was identified by: (1) poor perennial plant recovery posttreatment with sustained reductions in cover and density of some perennial plant species; (2) sustained reductions in lichen and moss cover; and (3) increases in cheatgrass cover. Although 10 years is insufficient to conclusively describe final ecological responses to fuel treatments, mowing woody fuels has the greatest potential to reduce woody fuel, minimize shrub mortality and soil disturbance, maintain lichens and mosses, and minimize long-term negative impacts on Greater Sage-grouse habitat. However, maintaining ecological resilience and resistance to invasion may be threatened by increases in cheatgrass cover, which are occurring regionally.

Idaho, Nevada, Oregon, Utah, Washington↗
USGS2019

Predicting species distributions: unifying model selection and scale optimization for multi-scale occupancy models

Geographic distributions are a basic component of a species’ ecology, and predicting distributions is a fundamental task of conservation and resource management. Reliable prediction depends on identification of appropriate scales of effect for environmental data, and scale-optimization techniques are thus desirable to identify optimal scales for predictor variables. Recent statistical developments have also advanced methods of model selection based explicitly on predictive ability, which differ from commonly-used methods that regulate model structures via anticipated predictive performance. Such methods are beginning to permeate into species distribution models (SDMs), yet there remains no consensus methodology for developing optimally-predictive multi-scale SDMs when covariate data are collected over a range of scales. Thus, we compared the performance of common approaches for scale optimization and model selection in terms of their ability to produce optimally predictive multi-scale Bayesian occupancy models for predicting a species distribution, using models of the breeding distribution for King Rails (Rallus elegans) as a case study. Our results demonstrate sizable gains in predictive performance for hierarchical occupancy models selected explicitly via their ability to predict out-of-sample data using the logarithmic scoring rule, as compared to models selected using information criteria (DIC and WAIC). Information criteria commonly selected individual covariates, as well as scales of effect for those covariates, with suboptimal predictive performance. Performance of models selected using the logarithmic scoring rule was robust across method of scale optimization, which was not true for models selected using DIC and WAIC. Thus, we empirically demonstrate benefits of study designs that enable covariate and scale selection based explicitly on predictive ability. Our results also imply that more careful consideration of what constitutes an optimal scale is warranted in many ecological studies, as the meaning of optimal is not independent of the technique used for scale selection.

Ecosphere↗
USGS2013

Fall diel diet composition of American eel (Anguilla rostrata) in a tributary of the Hudson River, New York, USA

American eel (Anguilla rostrata), a once common species, is now in decline throughout much of its native range in North America. There is little information on the role of American eel in river food webs. A better understanding of the diet and ecological role of American eel will help in the conservation of this important species. During autumn 2009, eel and aquatic invertebrate samples were collected from Hannacroix Creek, a tributary of the Hudson River, in Albany and Greene counties, New York, USA. Eel diet was analyzed by the eel size and time period (day or night). A high proportion of eel stomachs were empty (73%). Eel diets varied among size classes and day and night feeding periods (p = 0.001). Diet overlap was significant between small and medium eels caught both during the day (α = 0.71) and at night (α = 0.84). Nocturnal diet and nocturnal invertebrate samples were similar (α = 0.65), indicating a preference for bottom feeding during the night. Mayfly nymphs were the major prey consumed in each period by all size classes. Among eels that fed, night-feeding eels had the greatest stomach weight (as a percent of total body weight). The swim-bladder parasite, Anguillicoloides crassus, was also observed in eels of all size classes with nearly 50% afflicted.

New York↗
USGS2024

Molecular sexing of birds using quantitative PCR (qPCR) of sex-linked genes and logistic regression models

The ability to sex individuals is an important component of many behavioural and ecological investigations and provides information for demographic models used in conservation and species management. However, many birds are difficult to sex using morphological characters or traditional molecular sexing methods. In this study, we developed probabilistic models for sexing birds using quantitative PCR (qPCR) data. First, we quantified distributions of gene copy numbers at a set of six sex-linked genes, including the sex-determining gene DMRT1 , for individuals across 17 species and seven orders of birds ( n = 150). Using these data, we built predictive logistic models for sex identification and tested their performance with independent samples from 51 species and 13 orders ( n = 209). Models using the two loci most highly correlated with sex had greater accuracy than models using the full set of sex-linked loci, across all taxonomic levels of analysis. Sex identification was highly accurate when individuals to be assigned were of species used in model building. Our analytical approach was widely applicable across diverse neognath bird lineages spanning millions of years of evolutionary divergence. Unlike previous methods, our probabilistic framework incorporates uncertainty around qPCR measurements as well as biological variation within species into decision-making rules. We anticipate that this method will be useful for sexing birds, including those of high conservation concern and/or subsistence value, that have proven difficult to sex using traditional approaches. Additionally, the general analytical framework presented in this paper may also be applicable to other organisms with sex chromosomes.

Molecular Ecology Resources↗
USGS2020

Dynamic Habitat Disturbance and Ecological Resilience (DyHDER): Modeling population responses to habitat condition

Understanding how populations respond to spatially heterogeneous habitat disturbance is as critical to conservation as it is challenging. Here, we present a new, free, and open-source metapopulation model: Dynamic Habitat Disturbance and Ecological Resilience (DyHDER), which incorporates subpopulation habitat condition and connectivity into a population viability analysis framework. Modeling temporally dynamic and spatially explicit habitat disturbance of varying magnitude and duration is accomplished through the use of habitat time-series data and a mechanistic approach to adjusting subpopulation vital rates. Additionally, DyHDER uses a probabilistic dispersal model driven by site-specific habitat suitability, density dependence, and directionally dependent connectivity. In the first application of DyHDER, we explore how fragmentation and projected climate change are predicted to impact a well-studied Bonneville cutthroat trout metapopulation in the Logan River (Utah, USA). The DyHDER model predicts which subpopulations are most susceptible to disturbance, as well as the potential interactions between stressors. Further, the model predicts how populations may be expected to redistribute following disturbance. This information is valuable to conservationists and managers faced with protecting populations of conservation concern across landscapes undergoing changing disturbance regimes. The DyHDER model provides a valuable and generalizable new tool to explore metapopulation resilience to spatially and temporally dynamic stressors for a diverse range of taxa and ecosystems.

Ecosphere↗
USGS2019

Filling knowledge gaps in a threatened shorebird flyway through satellite tracking

Satellite‐based technologies that track individual animal movements enable the mapping of their spatial and temporal patterns of occurrence. This is particularly useful in poorly studied or remote regions where there is a need for the rapid gathering of relevant ecological knowledge to inform management actions. One such region is East Asia, where many intertidal habitats are being degraded at unprecedented rates and shorebird populations relying on these habitats show rapid declines. We examine the utility of satellite tracking to accelerate the identification of coastal sites of conservation importance in the East Asian–Australasian Flyway. In 2015–2017, we used solar‐powered satellite transmitters to track the migration of 32 great knots ( Calidris tenuirostris ), an “Endangered” shorebird species widely distributed in the Flyway and fully dependent on intertidal habitats for foraging during the non‐breeding season. From the great knot tracks, a total of 92 stopping sites along the Flyway were identified. Surprisingly, 63% of these sites were not known as important shorebird sites before our study; in fact, every one of the tracked individuals used sites that were previously unrecognized. Site knowledge from on‐ground studies in the Flyway is most complete for the Yellow Sea and generally lacking for Southeast Asia, Southern China and Eastern Russia. Synthesis and applications . Satellite tracking highlighted coastal habitats that are potentially important for shorebirds but lack ecological information and conservation recognition, such as those in Southern China and Southeast Asia. At the same time, the distributional data of tracked individuals can direct on‐ground surveys at the lesser known sites to collect information on bird numbers and habitat characteristics. To recognize and subsequently protect valuable coastal habitats, filling knowledge gaps by integrating bird tracking with ground‐based methods should be prioritized.

East Asian-Australasian Flyway↗
USGS2014

Extensive dispersal of Roanoke logperch ( Percina rex ) inferred from genetic marker data

The dispersal ecology of most stream fishes is poorly characterised, complicating conservation efforts for these species. We used microsatellite DNA marker data to characterise dispersal patterns and effective population size ( N e ) for a population of Roanoke logperch Percina rex , an endangered darter (Percidae). Juveniles and candidate parents were sampled for 2 years at sites throughout the Roanoke River watershed. Dispersal was inferred via genetic assignment tests (ATs), pedigree reconstruction (PR) and estimation of lifetime dispersal distance under a genetic isolation-by-distance model. Estimates of N e varied from 105 to 1218 individuals, depending on the estimation method. Based on PR, polygamy was frequent in parents of both sexes, with individuals spawning with an average of 2.4 mates. The sample contained 61 half-sibling pairs, but only one parent–offspring pair and no full-sib pairs, which limited our ability to discriminate natal dispersal of juveniles from breeding dispersal of their parents between spawning events. Nonetheless, all methods indicated extensive dispersal. The AT indicated unrestricted dispersal among sites ≤15 km apart, while siblings inferred by the PR were captured an average of 14 km and up to 55 km apart. Model-based estimates of median lifetime dispersal distance (6–24 km, depending on assumptions) bracketed AT and PR estimates, indicating that widely dispersed individuals do, on average, contribute to gene flow. Extensive dispersal of P. rex suggests that darters and other small benthic stream fishes may be unexpectedly mobile. Monitoring and management activities for such populations should encompass entire watersheds to fully capture population dynamics.

Ecology of Freshwater Fish↗
USGS2026

Spatial and temporal drivers of variability in abundance of two stream fishes

An understanding of how and why animal populations vary in space and time informs effective conservation and management. We used spatial and temporal flow metrics to explore flow-ecology relationships for two fish species, Mountain Sucker Pantosteus platyrhynchus (Cope, 1874) and Mottled Sculpin Cottus bairdii Girard, 1850, across 64 sites and 8 years in Wyoming, U.S.A. We found variation in Mottled Sculpin and Mountain Sucker abundance was driven to a greater extent by spatial flow metrics (e.g., drainage area, median summer flow) with differing direction of response between species. The opposing responses to spatial variation in median summer flow could reflect the ability of Mountain Sucker to persist in non-perennial habitats, likely due to their relatively high mobility and recolonization capacity. Responses to temporal flow metrics (e.g., previous year spring flow, previous year autumn flow) were weaker but consistent across species likely due to similar reproductive strategies and timing. The lack of stronger flow effects on population variability in both species likely corresponds to high variability in local habitat characteristics that are mediating population response. These findings underscore how considering spatial context informs conservation planning and suggest that flow-ecology relationships may be mediated by species-specific traits and local habitat conditions.

Wyoming↗
USGS2009

Area sensitivity in North American grassland birds: Patterns and processes

Grassland birds have declined more than other bird groups in North America in the past 35-40 years (Vickery and Herkert 2001, Sauer et al. 2008), prompting a wide variety of research aimed at understanding these declines, as well as conservation programs trying to reverse the declines (Askins et al. 2007). Area sensitivity, whereby the pattern of a species’ occurrence and density increases with patch area (Robbins et al. 1989), has been invoked as an important issue in grassland-bird conservation, and understanding the processes that drive area sensitivity in grassland birds is a major conservation need (Vickery and Herkert 2001). Here, we review the literature on North American grassland bird species that is relevant to the following questions: (1) What is the evidence for area sensitivity in grassland birds? (2) What are the historical explanations for area sensitivity? (3) What ecological processes could produce area sensitivity? And (5) what are the conservation implications of knowing the processes behind area sensitivity? Because of space limitations, we could not cite every paper we reviewed; the cited papers are given as examples of the literature in this field

The Auk↗
USGS2015

Scale-appropriate adaptation strategies and actions in the Northeast and Midwest United States

Climate Change Adaptation is a growing field within conservation and natural resource management. Actions taken toward climate change adaptation account for climate impacts and ecological responses, both current and projected into the future. These actions attempt to accomplish a number of goals, including the conservation of wildlife and ecosystems by reducing vulnerability and increasing resilience. Climate change adaptation strategies and approaches for natural resources can be thought of as part of a continuum of potential actions ranging from 1) options or goals to 2) strategies, 3) approaches, and 4) tactics. There are a range of decision support tools and processes to aid climate change adaptation. This document highlights several including the Adaptation Workbook, Climate Change Vulnerability Assessments, Structured Decision Making, Adaptive Resource Management, and Scenario Planning. It will also provide case studies on the application of these tools across the Northeast and Midwest. Improved, better-integrated, and increasingly coordinated monitoring systems would be helpful to detect, track, and attribute species and habitat shifts to climate change over spatiotemporal scales. We highlight regional examples of projects and programs addressing these challenges. Illustrative case studies of climate change adaptation efforts are presented across landscape/ecoregion, state, and local scales. Appendix 4.1 provides a synthesis of over 900 general, species and habitat-specific adaptation strategies and tactics from 9 regional studies being considered or implemented across the region. The study of climate change adaptation is a relatively new and rapidly growing field focused on preparing for and responding to the current and future impacts of climate change. The goal of this chapter is to highlight different approaches, processes, and tools currently being used across the region through illustrative case studies at varying scales. In addition, we provide a synthesis of numerous species and habitat-specific adaptation strategies and actions from existing assessment reports and management plans, which is intended to showcase a range of possibilities for natural resource management under future global change. This report does not prescribe one specific approach to taking action; instead, we outline a range of adaptation 5 tactics, which will require thoughtful consideration of the needs of the species, habitat, and location, the stakeholders and partners involved, the scale that a decision or policy is being implemented at, and the financial and personnel resources available to managers.

Connecticut, Delaware, Iowa, Illinois, Indiana, Ke↗
USGS2020

Highly variable rates of survival to metamorphosis in wild boreal toads (Anaxyrus boreas boreas)

Life history theory suggests that long‐lived, pond‐breeding amphibians should have low and highly variable early life‐stage survival rates, but this theoretical expectation is often untested and the causes of variation are usually unknown. We evaluated the impact of hydroperiod, presence of a pathogen ( Batrachochytrium dendrobatidis [Bd]), presence of a potential predator (cutthroat trout Oncorhychus clarki stomias) , and whether animals had been reintroduced into a site on survival of early life stages of boreal toads ( Anaxyrus boreas boreas ). We used a multistate mark‐recapture framework to estimate survival of boreal toad embryos from egg to metamorphosis at four sites over 5 years. We found substantial spatial and temporal variation in survival to metamorphosis and documented some evidence that monthly tadpole survival was lower in sites with Bd, without trout, and at permanent sites. Our results support theories of amphibian life history, aid in the management of this species of conservation concern, and contribute to our knowledge of the ecology of the species. Additionally, we present methodology that allows practitioners to account for different lengths of time between sampling periods when estimating survival probabilities which is especially applicable to organisms with distinct biological stages.

Population Ecology↗
USGS2014

Abdominally implanted satellite transmitters affect reproduction and survival rather than migration of large shorebirds

Satellite telemetry has become a common technique to investigate avian life-histories, but whether such tagging will affect fitness is a critical unknown. In this study, we evaluate multi-year effects of implanted transmitters on migratory timing and reproductive performance in shorebirds. Shorebirds increasingly are recognized as good models in ecology and evolution. That many of them are of conservation concern adds to the research responsibilities. In May 2009, we captured 56 female Black-tailed Godwits Limosa limosa limosa during late incubation in The Netherlands. Of these, 15 birds were equipped with 26-g satellite transmitters with a percutaneous antenna (7.8 % ± 0.2 SD of body mass), surgically implanted in the coelom. We compared immediate nest survival, timing of migration, subsequent nest site fidelity and reproductive behaviour including egg laying with those of the remaining birds, a comparison group of 41 females. We found no effects on immediate nest survival. Fledging success and subsequent southward and northward migration patterns of the implanted birds conformed to the expectations, and arrival time on the breeding grounds in 2010–2012 did not differ from the comparison group. Compared with the comparison group, in the year after implantation, implanted birds were equally faithful to the nest site and showed equal territorial behaviour, but a paucity of behaviours indicating nests or clutches. In the 3 years after implantation, the yearly apparent survival of implanted birds was 16 % points lower. Despite intense searching, we found only three eggs of two implanted birds; all were deformed. A similarly deformed egg was reported in a similarly implanted Whimbrel Numenius phaeopus returning to breed in central Alaska. The presence in the body cavity of an object slightly smaller than a normal egg may thus lead to egg malformation and, likely, reduced egg viability. That the use of implanted satellite transmitters in these large shorebirds reduced nesting propensity and might also lead to fertility losses argues against the use of implanted transmitters for studies on breeding biology, and for a careful evaluation of the methodology in studies of migration.

Friesl↗
USGS2020

Threshold responses of songbirds to forest loss and fragmentation across the Marcellus-Utica shale gas region

Context Since 2005, unconventional gas develop[1]ment has rapidly altered forests across the Marcellus[1]Utica shale basin in the central Appalachian region of the eastern United States, an area of high conservation value for biodiversity. Much is still unknown about ecological impacts of associated land cover change. Objectives Our goal was to identify threshold responses among bird species and habitat guilds to (1) overall forest loss and fragmentation in affected landscapes, and (2) distance from anthropogenic landscapes, and (2) distance from anthropogenic disturbance, both related and unrelated to shale gas. Methods We conducted 2589 bird surveys at 190 sites across this region, and quantified community[1]level and species-specific thresholds relating to forest cover and distance to anthropogenic disturbance, using Threshold Indicator Taxa Analysis (TITAN). Results Forest interior species decreased abruptly in abundance and frequency of occurrence above a threshold of 17.0% overall forest loss, while early successional and synanthropic species increased abruptly above 30.5–36.5% forest loss, respectively. Broad quantile intervals around responses to distance from anthropogenic disturbance suggest these were not sharp threshold responses, but more gradual or linear responses. Among forest interior species evaluated, 48.1% increased in abundance farther from shale gas development, while 55.6% of early successional and synanthropic species decreased. Conclusions We found evidence of avian threshold responses to overall forest loss and fragmentation in affected landscapes across the Marcellus-Utica shale region. Our results suggest that efforts to avoid shale gas development in regional core forests—particularly those still retaining C 83% forest cover—can reduce negative effects on area-sensitive, forest interior dependent species

Maryland, New York, Ohio, Pennsylvania, West Virgi↗
USGS2015

Individual heterogeneity in growth and age at sexual maturity: A gamma process analysis of capture–mark–recapture data

Knowledge of organisms’ growth rates and ages at sexual maturity is important for conservation efforts and a wide variety of studies in ecology and evolutionary biology. However, these life history parameters may be difficult to obtain from natural populations: individuals encountered may be of unknown age, information on age at sexual maturity may be uncertain and interval-censored, and growth data may include both individual heterogeneity and measurement errors. We analyzed mark–recapture data for Red-backed Salamanders ( Plethodon cinereus ) to compare sex-specific growth rates and ages at sexual maturity. Aging of individuals was made possible by the use of a von Bertalanffy model of growth, complemented with models for interval-censored and imperfect observations at sexual maturation. Individual heterogeneity in growth was modeled through the use of Gamma processes. Our analysis indicates that female P. cinereus mature earlier and grow more quickly than males, growing to nearly identical asymptotic size distributions as males.

Journal of Agricultural, Biological, and Environme↗
USGS2019

Ecosystem function and services of aquatic predators in the Anthropocene

Arguments for the need to conserve aquatic predator (AP) populations often focuses on the ecological and socio-economic roles they play. Here, we summarize the diverse ecosystem functions and services connected to APs, including regulating food webs, cycling nutrients, engineering habitat, transmitting diseases/parasites, mediating ecological invasions, effecting climate, supporting fisheries, generating tourism, and providing bioinspiration. In some cases, human-driven declines and increases in AP populations have altered these ecosystem functions and services. We present a Social Ecological Framework for supporting adaptive management decisions involving APs in response to social and environmental change. We also identify outstanding questions to guide future research on the ecological functions and ecosystem services of APs in a changing world

Trends in Ecology and Evolution↗