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At least 1,441 records · Page 80Linked to original sources
USGS2019

Multi-resource analysis: A proof of concept study of natural resource tradeoffs in the Piceance Basin, Colorado, using the net resources assessment (NetRA) decision support tool

Executive Summary The U.S. Geological Survey (USGS) is developing a multi-resource analysis (MRA) line of products to inform land-use decision makers. Specifically, MRA products will integrate scientific information, include considerations for natural resource interrelations, and quantify the effects of resource management decisions in biophysical, economic, and societal terms. As part of the establishment of the MRA, the USGS, in collaboration with the University of New Mexico, has developed the Net Resources Assessment (NetRA) decision support tool. As a proof of concept analysis, the NetRA was applied to the Piceance basin in Colorado in a hypothetical example to illustrate how resource managers could use the NetRA to consider tradeoffs of natural resources among alternative development plans and land cover patterns within a geographic region. The NetRA is a policy-relevant approach to assess the availability of multiple natural resources. It is an analytical toolset that may be used to examine the spatiotemporal relations between development of energy and mineral resources and delivery of biological natural resources. The NetRA operates at multiple map scales and contains a set of integrated, compatible submodels with specific data requirements for natural resource stocks, engineering economics, biophysical, and ecological data for ecosystem services stocks, market prices, regulations, and nonmarket values. The NetRA includes an explicit process to consider the interdependence between development and conservation, which is a crucial consideration in land-management and land-use decisions. The NetRA is used to estimate an expected net resource value (NRV). The NRV is the expected, present value, economic benefit from the extraction of a resource (for example, natural gas) minus the total cost of production, which is the aggregation of the development, production, and social costs. Social costs include private costs plus any external costs. There can be external social benefits associated with natural gas production, such as increased demand for locally produced goods and increased employment in the local area through backward and forward linkages of natural gas production. The NRV is used to compare development outcomes (scenarios) from a range of exploration and development plans for cumulative energy production. The Piceance basin application of the NetRA uses the NRV to assess the tradeoff between continuous natural gas extraction and the effects to the local populations of Odocoileus hemionus (mule deer) and aquatic species and to consumptive water uses for an area the size and resolution of a USGS energy resource assessment unit. In the proof of concept simulation, the 2.9-square-mile-area of USGS oil and gas assessment unit 50200263 (Piceance basin continuous gas unit of the Mesaverde Total Petroleum System) was gridded into 588 cells. From this area, seven clusters with potential for development and three that cannot be developed were identified; the three clusters that cannot be developed were identified as wilderness study areas, areas of critical environmental concern, and national forests. On the basis of these criteria, there are 118 cells unsuitable for development in the oil and gas assessment unit: 84 are in national forests, 23 are areas of critical environmental concern, and 11 are wilderness study areas. The remaining cells in the oil and gas assessment unit can be developed on both private and public lands. Two scenarios were considered that are distinguished as plan 1 and plan 2. Plan 1 keeps the amount of land disturbance unchanged and limits the number of development locations to 140 grid cells for the production period, which constrains the amount of the energy resources available for development; the plan requires the usage of the Bureau of Land Management (BLM) unsuitability criteria. Plan 2 also limits the number of development locations to 140 grid cells for the production period but provides a constant volume of energy production by increasing the density of well pads within the cells. The effects of plan 2 to the NRV when there are five wells per pad and five pads per square mile happen mostly in the first 5 years of development, even though the effects on the population of mule deer continue in later years. This outcome is the result of the upfront development and investment costs and the initial effect to the ecosystem services.

Colorado↗
USGS2022

New frontiers in bird migration research

Bird migrations are impressive behavioral phenomena, representing complex spatiotemporal strategies to balance costs of living while maximizing fitness. The field of bird migration research has made great strides over the past decades, yet fundamental gaps remain. Technologies have sparked a transformation in the study of bird migration research by revealing remarkable insights into the underlying behavioral, cognitive, physiological and evolutionary mechanisms of these diverse journeys. Here, we aim to encourage broad discussions and promote future studies by highlighting research fields that are characterized by major knowledge gaps or conflicting evidence, namely the fields of navigation, social learning, individual development, energetics and conservation. We approach each topic by summarizing the current state of knowledge and provide a future outlook of ideas and state-of-the-art methods to further advance the field. Integrating knowledge across these disciplines will allow us to understand the adaptive abilities of different species and to develop effective conservation strategies in a rapidly changing world.

Current Biology↗
USGS2020

Analysis of genomic sequence data reveals the origin and evolutionary separation of Hawaiian hoary bat populations

We examine the genetic history and population status of Hawaiian hoary bats ( Lasiurus semotus ), the most isolated bats on Earth, and their relationship to northern hoary bats ( Lasiurus cinereus ), through whole-genome analysis of single-nucleotide polymorphisms mapped to a de novo-assembled reference genome. Profiles of genomic diversity and divergence indicate that Hawaiian hoary bats are distinct from northern hoary bats, and form a monophyletic group, indicating a single ancestral colonization event 1.34 Ma, followed by substantial divergence between islands beginning 0.51 Ma. Phylogenetic analysis indicates Maui is central to the radiation across the archipelago, with the southward expansion to Hawai‘i and westward to O‘ahu and Kaua‘i. Because this endangered species is of conservation concern, a clearer understanding of the population genetic structure of this bat in the Hawaiian Islands is of timely importance.

Hawaii↗
USGS2025

Not all who meander are lost: Migrating sea lamprey follow river thalwegs to facilitate safe and efficient passage upstream

Efficient navigation is crucial for the reproductive success of many migratory species, often driven by competing pressures to conserve energy and reduce predation risk. Little is known about how non-homing species achieve this balance. We show that sea lamprey ( Petromyzon marinus ), an ancient extant vertebrate, uses persistent patterns in hydro-geomorphology to quickly and efficiently navigate through complex ecosystems. Hydrodynamic flow models coupled with bathymetric mapping and fine-scale acoustic telemetry revealed movement paths that tracked thalweg scour channels, which are often the deepest and fastest-flowing sections of a river. These paths allow rapid and efficient upstream migration and suggest the existence of a bathymetric highway system. Near-substrate swimming along this path resulted in a median of 5.8% energy savings while also promoting improved safety from nocturnally active predators. We hypothesize sea lampreys use hydrostatic pressure-guided rheotaxis to achieve this navigation. It is likely this tactic relies on sensory information from the animal's primitive lateral line and perhaps the inner ear. Insights from this study can be used to redesign conservation practices to achieve improved control where the animal is invasive and improved fish passage within its native range.

Michigan↗
USGS1999

Le Conte's sparrows breeding in Conservation Reserve Program fields: precipitation and patterns of population change

The climate of the North American Great Plains is highly dynamic, with great year-to-year variability in precipitation and periodic, often extreme, wet and dry cycles (Bragg 1995). Drought is a major force of ecological disturbance on the Great Plains and has played a key role in directing the evolution of the grassland biota of this region (Knopf and Samson 1997). Although grassland birds may differ in their responses to enviromenental variations (Rotenberry and Wiens 1991), climatic variability and concomitant unpredictability of resources strongly influence populations of grassland birds across space and time (Wiens 1974, 1986; Cody 1985). Not surprisingly, breeding bird populations on the Great Plains are highly dynamic, exhibiting considerable annual variation in composition, abundance, and distribution (Johnson and Grier 1988, George et al. 1992, Zimmerman 1992, Igl and Johnson 1997). Recently, interest in grassland birds has increased with the recognition that many species are declining both continentally (Droege and Sauer 1994) and globally (Goriup 1988). Identification of the specific factors associated with grassland bird declines in North America, however, remains largely enigmatic (Herkert 1997), and it is complicated by the considerable annual fluctuations in grassland bird distribution and abundance (Igl and Johnson 1997). Although there is evidence that land-use changes on the breeding grounds may have contributed to grassland bird declines (e.g., Igl and Johnson 1997), there also is an indication that long-term drought conditions may have influenced recent population changes of some breeding birds on the Great Plains (Droege and Sauer 1989, Peterjohn and Sauer 1993, Bethke and Nudds 1995, Igl and Johnson 1997). Le Conte's Sparrow (Ammodramus leconteii) is a secretive grassland bird that breeds in central and southern Canada and the northcentral United States (Murray 1969). It winters primarily in the southern United States (Peterson 1980, 1990). Like populations of many grassland breeding birds in North America (Fretwell 1986, Igl and Johnson 1997), Le Conte's Sparrow populations exhibit numerical highs and lows depending on local moisture conditions (Peabody 1901, Stewart 1975, Knapton 1979, Zimmer 1979, Madden 1996). This observation, however, is based largely on anecdotal evidence or short-term observations. Long-term studies of Le Conte's Sparrow populations are limited. Le Conte's Sparrow is poorly represented on the North American Breeding Bird Survey (BBS) because of small sample sizes, poor coverage in the northern portion of its breeding range, and the species' furtive behavior (Sauer et al. 1995). Moreover, dramatic fluctuations in Le Conte's Sparrow abundance tend to obscure the species' long-term population trends on the BBS (Sauer et al. 1995). In this paper we examine long-term population changes of Le Conte's Sparrows breeding in perennial grassland fields enrolled in the Conservation Reserve Program (CRP) on the northern Great Plains. We discuss patterns of population change of Le Conte's Sparrows associated with changes in precipitation and moisture conditions.

Studies in Avian Biology↗
USGS2019

Successful molecular detection studies require clear communication among diverse research partners

Molecular detection techniques are powerful tools used in ecological applications ranging from diet analyses to pathogen surveillance. Research partnerships that use these tools often involve collaboration among professionals with expertise in field biology, laboratory techniques, quantitative modeling, wildlife disease, and natural resource management. However, in many cases, each of these collaborators lacks specific knowledge about the approaches, decisions, methods, and terminology used by their research partners, which can impede effective communication and act as a barrier to the efficient use of molecular data for ecological inferences and subsequent conservation decision making. We outline a collaborative framework to assist colleagues with diverse types of expertise to effectively translate their scientific and management needs to research partners from other specialties. The molecular techniques used to detect organisms will continue to advance both in sophistication and in the breadth of ecological applications. Our objective is to enable ecologists to harness the full utility of these methods by developing effective collaborative partnerships.

Frontiers in Ecology and the Environment↗
USGS2025

Potential for biological effects of per- and polyfluoroalkyl substances in Great Lakes tributaries and associations with land cover and wastewater effluent

Surface water concentrations of per- and polyfluoroalkyl substances (PFAS) and potential for resulting biological effects were estimated in a study using polar organic chemical integrative samplers (POCIS) from 60 tributary sites within 20 watersheds in the Great Lakes Basin in 2018. Sites represented a range of urban to agricultural, forested, and wetland land uses and included a gradient of wastewater treatment effluent from zero to 44% of annual streamflow. Several sites also had airport influence. Twenty-one of 32 targeted PFAS compounds were detected in POCIS samplers, of which, 16 had available POCIS sampling rates, enabling time-weighted water concentration estimates and comparison with available effects data. Estimated water concentrations were compared with published water quality guidelines (available for nine PFAS), effect concentrations reported in primary literature within the ECOTOX Knowledgebase for apical endpoints (10 PFAS) and nonapical endpoints (10 PFAS), and in vitro high-throughput screening data from the U.S. Environmental Protection Agency Toxicity Forecaster (ToxCast; 14 PFAS). Based on a conservative evaluation approach that was also weighted for persistence and limitations in available toxicological information, five individual PFAS, including perfluorooctanesulfonic acid, perfluorohexanesulfonic acid, perfluorobutanesulfonic acid, perfluorooctanoic acid, and perfluorononanoic acid were identified as warranting additional investigation. Possible increased potency of PFAS mixtures over individual chemical effects, estimated by summation of exposure-activity ratios (EARs) for chemicals that influence common ToxCast assays and specified gene targets, indicated that EAR values increased up to 5.6-fold over individual chemicals, with up to 14 chemicals contributing to mixture effect predictions. Potential for biological effects from PFAS, as estimated by summed exposure-activity ratios, were correlated with urban land use and the proportion of streamflow contributed by wastewater effluent.

Great Lakes tributaries↗
USGS2018

A full annual-cycle conservation strategy for Sprague’s Pipit, Chestnut-collared and McCown’s Longspurs, and Baird’s Sparrow

Sprague’s Pipit ( Anthus spragueii ), Chestnut-collared Longspur ( Calcarius ornatus ), McCown’s Longspur ( Rhynchophanes mccownii ), and Baird’s Sparrow ( Centronyx bairdii ) [hereafter, “the Species”] are North American grassland-obligate songbirds whose populations have experienced significant annual population declines and are the focus of increasing conservation concern. The purpose of this strategy is to summarize current knowledge of the Species and identify priority research, monitoring and conservation actions required to improve their population status. Grasslands are among the most threatened ecosystems in the world with historic losses of 61-70% converted to other land uses, primarily cropland agriculture. Losses continue, with current conversion in the northern Great Plains occurring several times faster than grasslands can be protected. The Partners in Flight North American Landbird Conservation Plan (PIF NALCP) estimates current global populations of 900,000, 3,000,000, 600,000, and 2,000,000 for Sprague’s Pipit, Chestnut-collared Longspur, McCown’s Longspur, and Baird’s Sparrow, respectively. Over the period of 1967-2015, these populations have declined at -3.1, -4.2, -5.9 and -2.2% annually for estimated total losses of 78, 87, 94 and 65%, respectively. Habitat associations of breeding birds, especially at the local scale, represent the majority of the existing scientific literature on the Species’ biology. Landscape-scale associations are more poorly understood, and few studies have linked habitat, at any scale, to population vital rates. Increasing effort is focused on nonbreeding season and very little is known about migration. Current knowledge identifies three primary threats: 1) loss of native grasslands, 2) degradation and fragmentation of remaining native grasslands, and 3) disturbance inconsistent with needs of the Species. Top priorities for future research include: identification of population limiting factors, links between breeding habitat and demographics, identification of migratory habitat requirements, and identification of conditions promoting winter survival. Implementation strategies must focus on the protection, restoration, and enhancement (i.e., management) of grassland communities. Most imperative is the protection of remaining native grasslands from conversion to other uses. Actions supporting grass-based agriculture on privately-owned, native grasslands are paramount. These include incentive-based tools to support livestock grazing that benefits both priority birds and healthy ranching communities, which in turn prevent the conversion of native grasslands to cropland. Where cropland conversion has already taken place, conservation partners should work to continue and improve programs such as the Conservation Reserve Program (CRP) to restore and maintain permanent native cover. This strategy adopts the PIF NALCP objective, which is to reduce the rate of the Species’ decline in the first 10 years, then stabilize and ultimately increase the 2016 population by 5-15% over the subsequent 20 years. Ongoing monitoring programs such as the Breeding Bird Survey, Integrated Monitoring of Bird Conservation Regions, and eBird are critical for informing broadscale demographic and geographic trends for the Species. However, to achieve PIF NALCP goals, there is additional need for monitoring that links habitat conservation accomplishments to population performance within a strategic habitat conservation framework.

Report↗
USGS2025

The functional traits behind fish rarity in an impounded river basin

Reservoirs alter flows and aquatic habitats, reordering rarity patterns of reservoir ichthyofauna by allowing certain fish traits to flourish while filtering others. We reviewed the composition of fish species in an impounded river basin (Tennessee River, USA) to identify traits that influence rarity. We delineate levels of rarity based on the number of occupied reservoirs and species distribution, compare traits across rarity levels, and pinpoint traits that influence species rarity inside reservoirs. Four rarity levels were designated to 212 fish species: absent from the reservoir, rare and restricted within the basin, rare and spread throughout the basin, and common throughout the basin. Common species had the most distinctive traits, suggesting highly filtered species. They exhibited higher fecundity, longevity, piscivory, potamodromy, and association with large woody debris, vegetation, slow current, and lacustrine habitats. Rare and spread and rare and restricted species were separated by a few macrohabitat traits, with the former tending to be more lowland, slow current, large river, and lacustrine-oriented whereas the latter more creek and lotic oriented. Only age at maturity, longevity, fecundity, and potamodromy—all of which were lower in absent species—separated the absent from the rare and restricted. About half of rare and restricted species were already rare and restricted pre-impoundment; the rest had wider distributions pre-impoundment denoting species vulnerable in reservoirs and needing conservation to prevent local extinctions. Signals gleaned from species traits and rarity analysis indicate that conservation of rare species may need to focus on enhancements to selected reservoir habitats and to basin-wide connectivity.

Alabama, Georgia, Kentucky, Tennessee↗
USGS2016

Mitigating amphibian chytridiomycosis in nature

Amphibians across the planet face the threat of population decline and extirpation caused by the disease chytridiomycosis. Despite consensus that the fungal pathogens responsible for the disease are conservation issues, strategies to mitigate their impacts in the natural world are, at best, nascent. Reducing risk associated with the movement of amphibians, non-amphibian vectors and other sources of infection remains the first line of defence and a primary objective when mitigating the threat of disease in wildlife. Amphibian-associated chytridiomycete fungi and chytridiomycosis are already widespread, though, and we therefore focus on discussing options for mitigating the threats once disease emergence has occurred in wild amphibian populations. All strategies have shortcomings that need to be overcome before implementation, including stronger efforts towards understanding and addressing ethical and legal considerations. Even if these issues can be dealt with, all currently available approaches, or those under discussion, are unlikely to yield the desired conservation outcome of disease mitigation. The decision process for establishing mitigation strategies requires integrated thinking that assesses disease mitigation options critically and embeds them within more comprehensive strategies for the conservation of amphibian populations, communities and ecosystems.

Philosophical Transactions of the Royal Society B:↗
USGS2018

Probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty from maximum temperature metric selection

Predictions of the projected changes in species distributions and potential adaptation action benefits can help guide conservation actions. There is substantial uncertainty in projecting species distributions into an unknown future, however, which can undermine confidence in predictions or misdirect conservation actions if not properly considered. Recent studies have shown that the selection of alternative climate metrics describing very different climatic aspects (e.g., mean air temperature vs. mean precipitation) can be a substantial source of projection uncertainty. It is unclear, however, how much projection uncertainty might stem from selecting among highly correlated, ecologically similar climate metrics (e.g., maximum temperature in July, maximum 30‐day temperature) describing the same climatic aspect (e.g., maximum temperatures) known to limit a species’ distribution. It is also unclear how projection uncertainty might propagate into predictions of the potential benefits of adaptation actions that might lessen climate change effects. We provide probabilistic measures of climate change vulnerability, adaptation action benefits, and related uncertainty stemming from the selection of four maximum temperature metrics for brook trout ( Salvelinus fontinalis ), a cold‐water salmonid of conservation concern in the eastern United States. Projected losses in suitable stream length varied by as much as 20% among alternative maximum temperature metrics for mid‐century climate projections, which was similar to variation among three climate models. Similarly, the regional average predicted increase in brook trout occurrence probability under an adaptation action scenario of full riparian forest restoration varied by as much as .2 among metrics. Our use of Bayesian inference provides probabilistic measures of vulnerability and adaptation action benefits for individual stream reaches that properly address statistical uncertainty and can help guide conservation actions. Our study demonstrates that even relatively small differences in the definitions of climate metrics can result in very different projections and reveal high uncertainty in predicted climate change effects.

Global Change Biology↗
USGS2018

Variation in DNA methylation is associated with migratory phenotypes of lake sturgeon (Acipenser fulvescens) in the St. Clair River

Lake sturgeon populations show a variety of movement patterns, but this variation is poorly understood. To compare two migratory phenotypes of lake sturgeon in the St. Clair River, multiple data types were analyzed. Individual fish were classified into migratory phenotypes based on acoustic telemetry data from 2012-2015. Lake sturgeon consistently showed movement from the St. Clair River upriver into Lake Huron or downriver into Lake St. Clair. The two migratory phenotypes were then compared for differences in morphometrics, genetics, and epigenetics. Morphological differences based on linear measurements were not detected between phenotypes. Microsatellite data from 11 loci suggested one population with no genetic differentiation between migratory phenotypes. Our epigenetic results indicated that the migratory phenotypes are differentially methylated (P=0.036), thus epigenetics may be associated with migratory differences in lake sturgeon. Only one restriction site was identified to be driving the differential methylation (P=0.012). While little evidence at neutral loci occurred for genetic differentiation of lake sturgeon, DNA methylation may play a role in the observed movement pattern variation. When combined with microsatellite and morphometric analyses, our results suggested that different migratory patterns may reflect phenotypic plasticity, allowing lake sturgeon to acclimate to short-term environmental variability. Without an integrated approach, the role of epigenetics in the migratory phenotype of lake sturgeon may have been overlooked. Further characterization of migratory phenotypes could be important for management to conserve behavioral variation across the distribution of lake sturgeon and for design of stocking guidelines.

Michigan↗
USGS2001

Cranes in East Asia; Proceedings of the symposium held in Harbin, People's Republic of China, June 9-18, 1998

Introductory Remarks (R.C. Stendell): I appreciate the opportunity to be in Harbin and participate in the International Scientific Workshop on Cranes in East Asia. I would like to provide some background information on how this meeting came to be. Almost one year ago, in July 1997, Dr. Kun John of the Seoul National University contacted the U.S. Geological Survey’s Midcontinent Ecological Science Center (MESC) requesting that we host a meeting of scientists from the Republic of Korea (ROK) and the Democratic People’s Republic of Korea (DPRK) to discuss the biology and ecology of cranes on the Korean peninsula. Dr. John and his colleagues expressed concern about three species of cranes that migrate up and down the Korean peninsula and use the Demilitarized Zone. The species of interest are the Red-crowned Crane, White-naped Crane, and the Hooded Crane. The primary question was the conservation of these species in this part of the world. Another concern involved exploring potential economic values and opportunities associated with these species. Richard Johnson, an economist at MESC, assumed responsibility as the primary MESC contact to help bring about this meeting.

Open-File Report↗
USGS2002

Analysis and Management of Animal Populations: Modeling, Estimation and Decision Making

This book deals with the processes involved in making informed decisions about the management of animal populations. It covers the modeling of population responses to management actions, the estimation of quantities needed in the modeling effort, and the application of these estimates and models to the development of sound management decisions. The book synthesizes and integrates in a single volume the methods associated with these themes, as they apply to ecological assessment and conservation of animal populations. KEY FEATURES * Integrates population modeling, parameter estimation and * decision-theoretic approaches to management in a single, cohesive framework * Provides authoritative, state-of-the-art descriptions of quantitative * approaches to modeling, estimation and decision-making * Emphasizes the role of mathematical modeling in the conduct of science * and management * Utilizes a unifying biological context, consistent mathematical notation, * and numerous biological examples

Book↗
USGS1994

Avian assemblages on altered grasslands

Grasslands comprise 17% of the North American landscape but provide primary habitat for only 5% of native bird species. On the Great Plains, grasslands include an eastern component of tall grasses and a western component of short grasses, both of which have been regionally altered by removing native grazers, plowing sod, draining wetlands, and encouraging woody vegetation. As a group, populations of endemic bird species of the grasslands have declined more than others (including neotropical migrants) in the last quarter century. Individually, populations of the Upland Sandpiper and McCown’s Longspur have increased; the wetlands-associated Marbled Godwit and Wilson’s Phalarope appear stable; breeding ranges are shifting for the Ferruginous Hawk, Mississippi Kite, Short-eared Owl, Upland Sandpiper, Horned Lark, Vesper, Savannah, and Henslow’s sparrows, and Western Meadowlark; breeding habitats are disappearing locally for Franklin’s Gull, Dickcissel, Henslow’s and Grasshopper sparrows. Lark Bunting, and Eastern Meadowlark; and populations are declining throughout the breeding ranges for Mountain Plover, and Cassin’s and Clay-colored sparrows. Declines of these latter three species, and also the Franklin’s Gull, presumably are due to ecological phenomena on their respective wintering areas. Unlike forest species that winter in the neotropics, most birds that breed in the North American grasslands also winter on the continent and problems driving declines in grassland species are associated almost entirely with North American processes. Contemporary programs and initiatives hold promise for the conservation of breeding habitats for these birds. Ecological ignorance of wintering habits and habitats clouds the future of the endemic birds of grasslands, especially those currently experiencing widespread declines across breeding locales.

Studies in Avian Biology↗
USGS1995

Southeastern freshwater fishes

North America has the richest fauna of temperate freshwater fishes in the world, with about 800 native species in the waters of Canada and the United States. The center of this diversity is in the southeastern United States, where as many as 500 species may exist (62% of the continental fauna north of Mexico). Many coastal marine species also enter fresh waters of the Southeast, and at least 34 foreign fish species are established in the region. Although freshwater fishes of the United States are better studied than any fish fauna of comparable scope in the world (Lee et al. 1980; Hocutt and Wiley 1986; Matthews and Heins 1987; Page and Burr 1991; Mayden 1992), large gaps exist in scientific knowledge about the biology and ecology of most species. New species are still being discovered, and the taxonomy of other species is being refined. Seriously declining populations of freshwater fishes in the United States concern the scientific community (Deacon et al. 1979; Williams et al. 1989; Moyle and Leidy 1992; Warren and Burr 1994). This article briefly summarizes the current conservation status of southeastern freshwater fishes; the Southeast is emphasized because of its important fish biodiversity and to focus attention on the growing problem of adverse human impacts on the region's aquatic habitats (Mount 1986; Burkhead and Jenkins 1991; Etnier and Starnes 1991; Warren and Burr 1994).

Book chapter↗
USGS2024

Climate change

Amphibian ecology and distribution are strongly correlated with climate. Regional patterns of amphibian biodiversity are intimately linked to temperature, evapotranspiration rate, and clines in humidity. While amphibians are and will continue to be adversely affected by recent and projected changes in climate, research suggests that adaptation may happen more slowly than the expected rate of environmental shifts. Here, we review conservation-relevant aspects of both realised and potential impacts of climate change, and outline options for amphibian conservation planning and management. Recent advances in our understanding of climate change impacts on amphibians have primarily stemmed from ecological modelling and direct assessment of climatic tolerances and dispersal capacities through physiological assays, landscape genetics, and dispersal tracking. Anthropogenic climate change has already altered amphibian assemblages and their impacts on ecosystem functioning and services. Because of known and hypothesised ecological tolerances, many amphibians might have reached or exceeded most limits in their ability to adapt to or tolerate further climate change, however the uncertainties are substantial. Implementation of conservation planning and action can help to forestall severe impacts of environmental shifts. Scientific research and science-based decision-making and policy development have already lagged; the current pace of conservation planning and action may not allow for effective identification of threats and mitigation. An increased response rate could help to avert further loss of amphibian biodiversity and decay of ecosystem services. The lack of basic field research in natural habitats continues to be an underlying challenge. We suggest priority areas of research to include the development of biologically realistic predictive models of amphibian response to climate change, field verification of model estimates and key parameters, population monitoring across multiple sites and taxa, and a combination of efforts within and across ecosystems to understand how impacts of climate change can be better mitigated.

Book chapter↗
USGS2014

North American amphibians: Distribution and diversity

Some 300 species of amphibians inhabit North America. The past two decades have seen an enormous growth in interest about amphibians and an increased intensity of scientific research into their fascinating biology and continent-wide distribution. This atlas presents the spectacular diversity of North American amphibians in a geographic context. It covers all formally recognized amphibian species found in the United States and Canada, many of which are endangered or threatened with extinction. Illustrated with maps and photos, the species accounts provide current information about distribution, habitat, and conservation. Researchers, professional herpetologists, and anyone intrigued by amphibians will value North American Amphibians as a guide and reference.

Book↗