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At least 631 records · Page 35Linked to original sources
USGS2008

Report of the Federal Advisory Committee on the Bird Banding Laboratory

In the fall of 2005, the Directors of the U.S. Geological Survey (USGS) and the U.S. Fish and Wildlife Service (FWS) determined that to ensure that the Bird Banding Laboratory (BBL) of the USGS maintains and continues its important support of conservation and management of birds, it should be guided by a clear vision for the future. In order to carry out this task, they impaneled a fourteen-member Federal Advisory Committee (FAC) on the Bird Banding Laboratory. It was made up of representatives of the broad bird-banding community, public and private, and was cochaired by a senior representative from each agency. The Committee met four times and a writing subgroup met three times over the course of its work. The Committee identified a new vision and mission for the BBL and identified six goals that it believes should be integral to the development of a strategic plan to achieve them. Those goals are: 1. Facilitate the identification of individual birds through marking. 2. Create automated, electronic systems that efficiently verify, accept, store, and manage data associated with individually marked birds. 3. Facilitate access to and use of data from marked birds for science, conservation, and management. 4. Administer permits in an efficient, timely, and modern manner, and use them to ensure that bird welfare and data quality remain top priorities. 5. Work closely with national and international partners to achieve the mission of the BBL. 6. Manage the BBL in an efficient, cost-effective manner to maximize use of available resources. Most of the report is structured around these goals. The Committee made 2 programmatic recommendations and identified 23 objectives and 58 specific recommendations. The programmatic recommendations are: (1) that the primary role of the BBL is and should continue to be to support the use of banding and banding data by researchers and managers engaged in science, conservation, and management of birds, and not to play a lead role in original research; and (2) that the BBL be managed nationally by USGS headquarters as a research and operational support unit and provided with the resources appropriate to its national and international functions and responsibilities; it should continue to be located physically at the Patuxent Wildlife Research Center (PWRC). In order to achieve its vision and mission, the Committee believes that the BBL must work towards achieving all of the recommendations in this report. Nevertheless, it identified five objectives that stand out as high priority, and they are as follows: *Objective 1.1?to ensure a continuing, adequate supply of high-quality, Federally issued numeric bands of required sizes, materials, and types; *Objective 2.1?to improve mechanisms for verifying, accepting, storing, and managing bird-banding data; *Objective 2.3?to accommodate recapture data; *Objective 4.1?to ensure through the permitting process that banders know how to safely handle birds, collect data accurately, and maintain birds in humane and healthful conditions; and *Objective 5.3?to encourage the development of banding programs in Latin America and the Caribbean. Finally, this Committee believes that the BBL will be well served if it continues to support a Federal Advisory Committee, composed similarly to this one, to continue offering guidance and direction from the broad bird-banding community.

Circular↗
USGS2013

Newly documented host fishes for the eastern elliptio mussel (Elliptio complanata)

The eastern elliptio Elliptio complanata is a common, abundant, and ecologically important freshwater mussel that occurs throughout the Atlantic Slope drainage in the United States and Canada. Previous research has shown E. complanata glochidia to be host fish generalists, parasitizing yellow perch Perca flavescens , banded killifish Fundulus diaphanus , banded sculpin Cottus carolinae , and seven centrarchid species. Past laboratory studies have been conducted in the Midwest; however, glochidia used in these studies were obtained from adult mussels in the Great Lakes or St. Lawrence River basins, or glochidia sources were not reported. The objective of this study was to identify host fishes for E. complanata from streams in the Mid-Atlantic region. We used artificial laboratory infections to test host suitability of 38 fish and 2 amphibian species with E. complanata glochidia from the Chesapeake Bay drainage. Glochidia successfully metamorphosed into juvenile mussels on five fish species: American eel Anguilla rostrata , brook trout Salvelinus fontinalis , lake trout Salvelinus namaycush , mottled sculpin Cottus bairdii , and slimy sculpin Cottus cognatus . American eel was the most effective host, yielding the highest overall metamorphosis success (percentage of attached glochidia that transformed into juvenile mussels; ≥0.90) and producing 13.2 juveniles per fish overall. No juvenile E. complanata metamorphosed on other fish or amphibian species tested, including many previously identified host fishes that appear in the literature. Reasons for discrepancies in published host fish could include geographic variation in host use across the species' range, differences in host use between lentic and lotic populations, or poorly resolved taxonomy within the genus Elliptio .

Journal of Fish and Wildlife Management↗
USGS2011

Setting limits: Using air pollution thresholds to protect and restore U.S. ecosystems

More than four decades of research provide unequivocal evidence that sulfur, nitrogen, and mercury pollution have altered, and will continue to alter, our nation's lands and waters. The emission and deposition of air pollutants harm native plants and animals, degrade water quality, affect forest productivity, and are damaging to human health. Many air quality policies limit emissions at the source but these control measures do not always consider ecosystem impacts. Air pollution thresholds at which ecological effects are observed, such as critical loads, are effective tools for assessing the impacts of air pollution on essential ecosystem services and for informing public policy. U.S. ecosystems can be more effectively protected and restored by using a combination of emissions-based approaches and science-based thresholds of ecosystem damage. Based on the results of a comprehensive review of air pollution thresholds, we conclude: ??? Ecosystem services such as air and water purification, decomposition and detoxification of waste materials, climate regulation, regeneration of soil fertility, production and biodiversity maintenance, as well as crop, timber and fish supplies are impacted by deposition of nitrogen, sulfur, mercury and other pollutants. The consequences of these changes may be difficult or impossible to reverse as impacts cascade throughout affected ecosystems. ??? The effects of too much nitrogen are common across the U.S. and include altered plant and lichen communities, enhanced growth of invasive species, eutrophication and acidification of lands and waters, and habitat deterioration for native species, including endangered species. ??? Lake, stream and soil acidification is widespread across the eastern United States. Up to 65% of lakes within sensitive areas receive acid deposition that exceeds critical loads. ??? Mercury contamination adversely affects fish in many inland and coastal waters. Fish consumption advisories for mercury exist in all 50 states and on many tribal lands. High concentrations of mercury in wildlife are also widespread and have multiple adverse effects. ??? Air quality programs, such as those stemming from the 1990 Clean Air Act Amendments, have helped decrease air pollution even as population and energy demand have increased. Yet, they do not adequately protect ecosystems from long-term damage. Moreover they do not address ammonia emissions. ??? A stronger ecosystem basis for air pollutant policies could be established through adoption of science-based thresholds. Existing monitoring programs track vital information needed to measure the response to policies, and could be expanded to include appropriate chemical and biological indicators for terrestrial and aquatic ecosystems and establishment of a national ecosystem monitoring network for mercury. The development and use of air pollution thresholds for ecosystem protection and management is increasing in the United States, yet threshold approaches remain underutilized. Ecological thresholds for air pollution, such as critical loads for nitrogen and sulfur deposition, are not currently included in the formal regulatory process for emissions controls in the United States, although they are now considered in local management decisions by the National Park Service and U.S. Forest Service. Ecological thresholds offer a scientifically sound approach to protecting and restoring U.S. ecosystems and an important tool for natural resource management and policy. ?? The Ecological Society of America.

Issues in Ecology↗
USGS2007

Overview of developmental, reproductive, and behavioral/ neurological effects of mercury exposures in wildlife

We review wildlife/mercury literature and our own research findings that demonstrate the relevance of wildlife toxicity data in protecting human health. Methylmercury affects wildlife through reduced adult survival and reproduction, aberrant behavior, immune system effects, and teratogenic effects. Methylmercury can readily cross the blood-brain barrier, is excreted into eggs in birds, and is transferred to young mammals across the placenta and in milk. Its principal effect on wildlife is on neurological functions. Wild mink (Mustela vison) and otter (Lutra canadensis) have died from methylmercury poisoning, with signs of poisoning including anorexia, loss of weight, incoordination, tremors, and convulsions, which are symptoms similar to those experienced by mercury-poisoned humans. Mammals also may experience tonic and clonic convulsions and an increase in fetal anomalies, again paralleling toxic problems in people. Antibody-producing cells can be suppressed by methylmercury. Microscopically, the most notable lesions are in the cerebrum. Extensive vacuolation of hepatocytes in the liver and necrosis and other changes in the appearance of the proximal convoluted tubules of the kidneys are often noted. When harp seals (Pagophilus groenlandicus) were dosed with methylmercury chloride the number of circulating erythrocytes decreased and white blood cell counts greatly increased. The poisoned seals also suffered from uremia, hyperproteinemia, hypercholesterolemia, hyperbilirubinemia, and elevations in lactic dehydrogenase and alkaline phosphatase. In birds, signs of methylmercury poisoning included emaciation and weakness in the extremities, which progressed until the birds died. Mercury poisoning in birds and mammals can be diagnosed from a combination of the signs of poisoning if the animal is still alive, the pathological effects seen in a gross necropsy, the histopathological effects seen with a microscope, and the concentrations of mercury in various tissues. Our studies with mallards (Anas platyrhynchos) suggest that the dietary concentrations of mercury that cause toxicity are lower than those set in fish consumption advisories to protect humans. Because wild mammals and birds are so sensitive to methylmercury poisoning and cannot escape dietary exposure the way humans can, guidelines set to protect wild birds and mammals may very well provide a margin of safety for human health.

Book chapter↗
USGS2017

Quantitative tools for implementing the new definition of significant portion of the range in the U.S. Endangered Species Act

In 2014, the Fish and Wildlife Service (FWS) and National Marine Fisheries Service announced a new policy interpretation for the U.S. Endangered Species Act (ESA). According to the act, a species must be listed as threatened or endangered if it is determined to be threatened or endangered in a significant portion of its range (SPR). The 2014 policy seeks to provide consistency by establishing that a portion of the range should be considered significant if the associated individuals’ “removal would cause the entire species to become endangered or threatened.” We reviewed 20 quantitative techniques used to assess whether a portion of a species’ range is significant according to the new guidance. Our assessments are based on the 3R criteria—redundancy (i.e., buffering from catastrophe), resiliency (i.e., ability to withstand stochasticity), and representation (i.e., ability to evolve)—that the FWS uses to determine if a species merits listing. We identified data needs for each quantitative technique and considered which methods could be implemented given the data limitations typical of rare species. We also identified proxies for the 3Rs that may be used with limited data. To assess potential data availability, we evaluated 7 example species by accessing data in their species status assessments, which document all the information used during a listing decision. In all species, an SPR could be evaluated with at least one metric for each of the 3Rs robustly or with substantial assumptions. Resiliency assessments appeared most constrained by limited data, and many species lacked information on connectivity between subpopulations, genetic variation, and spatial variability in vital rates. These data gaps will likely make SPR assessments for species with complex life histories or that cross national boundaries difficult. Although we reviewed techniques for the ESA, other countries require identification of significant areas and could benefit from this research.

Conservation Biology↗
USGS2026

Natomas basin giant gartersnake annual monitoring report 2024

The giant gartersnake ( Thamnophis gigas ) is a semi aquatic snake endemic to the Central Valley of California. After losing 95 percent of its historic wetland habitat (Frayer and others, 1989), giant gartersnakes became state and federally listed as a threatened species (California Fish and Game Commission, 1971; U.S. Fish and Wildlife Service 1993, 1999). Continued monitoring of current populations and implementation of suggested management actions is necessary to recover the species. The Natomas basin in Sacramento, California, supports a population of giant gartersnakes persisting in restored marshes and rice agriculture. This annual report summarizes the giant gartersnake monitoring project for 2024, focusing on the apparent survival, abundance, density, and distribution of the giant gartersnakes and the connectivity of habitat throughout the Natomas basin. In 2024, 131 giant gartersnakes were captured 216 times at 44 sites by hand or trap. The catch-per-unit effort decreased from 2023 to 2024 but was similar to other years of the study. Estimates of occupancy increased between 2023 and 2024, although the trend of occupancy from 2011 through 2024 is still decreasing overall at a mean annual rate of 3 percent per year. Apparent survival was much higher at Betts-Kismat-Silva from 2018 to 2019 and from 2021 to 2022 than in other years, but this may be partly attributed to different sampling efforts over the years. Trapping effort was more consistent in the Sills tract, and apparent survival was slightly higher in later years (2022–23 and 2023–24). Giant gartersnake populations appeared to remain stable in 2024, but abundance, density, survival, and distribution is highly variable across different sites and years of the study. Continued monitoring of the populations would allow for better trend estimates over time and assessment of the effects of management activities. Giant gartersnake populations throughout the basin and on reserve lands would likely benefit from the following: (1) creating more managed marsh; (2) increasing the amount of emergent tule vegetation in existing marshes (for example, Cummings, Natomas Farms, and Lucich South); (3) continuing to flood existing marshes in early spring; (4) maintaining rice agriculture; and (5) continuing research into conservation actions that target the giant gartersnake, such as habitat and water management and translocation.

California↗
USGS2014

The effects of harvest on waterfowl populations

Change in the size of populations over space and time is, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change in the abundance is the simple difference between the number of individuals entering the population and the number leaving the population, either or both of which may change in response to factors intrinsic and extrinsic to the population. While harvest of individuals from a population constitutes a clear extrinsic source of removal of individuals, the response of populations to harvest is frequently complex, reflecting an interaction of harvest with one or more population processes. Here we consider the role of these interactions, and factors influencing them, on the effective harvest management of waterfowl populations. We review historical ideas concerning harvest and discuss the relationship(s) between waterfowl life histories and the development and application of population models to inform harvest management. The influence of population structure (age, spatial) on derivation of optimal harvest strategies (with and without explicit consideration of various sources of uncertainty) is considered. In addition to population structure, we discuss how the optimal harvest strategy may be influenced by: 1) patterns of density-dependence in one or more vital rates, and 2) heterogeneity in vital rates among individuals within an age-sex-size class. Although derivation of the optimal harvest strategy for simple population models (with or without structure) is generally straightforward, there are several potential difficulties in application. In particular, uncertainty concerning the population structure at the time of harvest, and the ability to regulate the structure of the harvest itself, are significant complications. We therefore review the evidence of effects of harvest on waterfowl populations. Some of this evidence has focussed on correspondence of data with more phenomenological models and other evidence relates to specific mechanisms, including densitydependence and heterogeneity. An important part of this evidence is found in the evolution of model weights under various adaptive harvest management programmes of the U.S. Fish and Wildlife Service for North American waterfowl. Overall, there is substantial uncertainty about system dynamics, about the impacts of potential management and conservation decisions on those dynamics, and how to optimise management decisions in the presence of such uncertainties. Such relationships are unlikely to be stationary over space or time, and selective harvest of some individuals can potentially alter life history allocation of resources over time – both of which will potentially influence optimal harvest strategies. These sources of variation and uncertainty argue for the use of adaptive approaches to waterfowl harvest management.

Wildfowl↗
USGS2011

Effectiveness of post-fire seeding at the Fitzner-Eberhardt Arid Land Ecology Reserve, Washington

In August 2007, the Milepost 17 and Wautoma fires burned a combined total of 77,349 acres (31,302 hectares) of the Fitzner-Eberhardt Arid Land Ecology Reserve (ALE), part of the Hanford Reach National Monument administered by the U.S. Fish and Wildlife Service (USFWS) Mid-Columbia National Wildlife Refuge. In 2009, the USFWS implemented a series of seeding and herbicide treatments to mitigate potential negative consequences of these fires, including mortality of native vegetation, invasion of Bromus tectorum (cheatgrass), and soil erosion. Treatments included combinations of seeding (drill and aerial), herbicides, and one of six different mixtures of species. Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) also was planted by hand in a small area in the southern end of the fire perimeter. Due to differences in plant communities prior to the fire and the multiple treatments applied, treatments were grouped into five treatment associations including mid-elevation aerial seedings, low-elevation aerial seedings, low-elevation drill seedings, high-elevation drill seeding, and no seeding treatments. Data collected at the mid-elevation aerial seedings indicate that the seeding did not appear to increase the density of seedlings compared to the non-seeded area in 2010. At the low-elevation aerial seedings, there were significantly more seedlings at seeded areas as compared to non-seeded areas. Low densities of existing perennial plants probably fostered a low-competition environment enabling seeds to germinate and emerge in 2010 during adequate moisture. Low-elevation drill seedings resulted in significant emergence of seeded grasses in 2009 and 2010 and forbs in 2010. This was likely due to adequate precipitation and that the drill seeding assured soil-to-seed contact. At the high-elevation drill seeding, which was implemented in 2009, there were a high number of seedlings in 2010. Transplanting of A. tridentata following the fires resulted in variable survival rates that warrant further testing; however, transplants located closer to washes tended to have the highest survival rates. Overall, the low-elevation aerial and drill seedings, and the high-elevation drill seedings resulted in significant numbers of seedlings. Further research is needed on methods that provide land managers with critical information about whether or not to seed post-fire areas including status of pre-fire vegetation and estimates of plant mortality due to fire.

Open-File Report↗
USGS2018

Flooding tolerance of Sagittaria latifolia and Sagittaria rigida under controlled laboratory conditions

Pool‐scale growing‐season water‐level reductions (drawdowns) have been implemented on the Upper Mississippi River in an effort to improve fish and wildlife habitat. Aquatic vegetation is a key habitat component, with perennial emergent species, such as Sagittaria latifolia and Sagittaria rigida , especially important. River managers have assumed the need for continuous drawdown during the growing season with limited reflooding and used this guidance in assessing the potential for an ecologically successful drawdown. However, information on the effects of growing‐season flooding episodes on survival and growth of Sagittaria is limited. To assess the flooding tolerance of S. latifolia and S. rigida , we evaluated multiple levels of timing, duration, and depth on survival and productivity of plants. Plants were produced from S. latifolia and S. rigida seeds and S. latifolia tubers; all were reared under moist‐soil or shallow‐flooded rearing conditions. Mortality of plants was low (2%) among plants from large tubers, low (7%) among seedlings (and largely associated with early flooding treatments), and modest (11%) among plants from small tubers (with no clear effects of inundation). Flooding treatments generally had a positive effect on biomass production from seedlings, particularly when treatments occurred early, were relatively shallow, and were short in duration. There were no clear effects of depth, duration, or timing components of flooding treatments on plant biomass arising from tubers. This experiment indicates that S. latifolia and S. rigida are relatively tolerant of flooding events during the growing season and may actually benefit from some level of inundation.

River Research and Applications↗
USGS2006

2005 annual progress report: Elk and bison grazing ecology in the Great Sand Dunes complex of lands

In 2000 the U.S. Congress authorized the expansion of the former Great Sand Dunes National Monument by establishing a new Great Sand Dunes National Park and Preserve in its place, and establishing the Baca National Wildlife Refuge. The establishment of Great Sand Dunes National Park and Preserve and the new Baca National Wildlife Refuge in the San Luis Valley (SLV), Colorado was one of the most significant land conservation actions in the western U.S. in recent years. The action was a result of cooperation between the National Park Service (NPS), U.S. Fish and Wildlife Service (USFWS), Bureau of Land Management (BLM), U.S. Forest Service (USDA-FS), and The Nature Conservancy (TNC). The new national park, when fully implemented, will consist of 107,265 acres, the new national preserve 41,872 acres, and the new national wildlife refuge (USFWS lands) 92,180 acres (fig. 1). The area encompassed by this designation protects a number of natural wonders and features including a unique ecosystem of natural sand dunes, the entire watershed of surface and groundwaters that are necessary to preserve and recharge the dunes and adjacent wetlands, a unique stunted forest, and other valuable riparian vegetation communities that support a host of associated wildlife and bird species. When the National Park was initially established, there were concerns about overconcentrations and impacts on native plant communities of the unhunted segments of a large and possibly growing elk (Cervus elaphus) population. This led to the designation of the Preserve as a compromise solution, where the elk could be harvested. The Preserve Unit, however, will not address all the ungulate management challenges. In order to reduce the current elk population, harvests of elk may need to be aggressive. But aggressive special hunts of elk to achieve population reductions can result in elk avoidance of certain areas or elk seeking refuge in areas where they cannot be hunted, while removals of whole herd segments and abandonment or alterations of migration routes can occur (Smith and Robbins, 1994; Boyce and others, 1991). Elk may seek refuge from hunting in the newly expanded Park Unit and TNC lands where they might overconcentrate and impact unique vegetation communities. In these sites of refugia, or preferred loafing sites, elk and bison could accelerate a decline in woody riparian shrubs and trees. This decline may also be due to changes in hydrology, climatic, or dunal processes, but ungulate herbivory might exacerbate the effects of those processes. To address the questions and needs of local resource managers, a multi-agency research project was initiated in 2005 to study the ecology, forage relations, and habitat relations of elk and bison in the Great Sand Dunes–Sangre de Cristo–Baca complex of lands. Meetings and discussions of what this research should include were started in 2001 with representatives from NPS, USFWS, TNC, the Colorado Division of Wildlife (CDOW), and USDA-FS/BLM. The final study plan was successfully funded in 2004 with research scheduled to start in 2005. The research was designed to encompass three major study elements: (1) animal movements and population dynamics, (2) vegetation and nutrient effects from ungulate herbivory, and (3) development of ecological models, using empirical data collected from the first two components, that will include estimates of elk carrying capacity and management scenarios for resource managers.

Colorado↗
USGS2023

Interstate 15 wildlife crossing design considerations for focal wildlife species - Santa Ana-Palomar Mountains Linkage southern California

The Nature Conservancy (TNC) and the California Department of Transportation (Caltrans), along with landowners including San Diego State University, California Department of Fish and Wildlife, Western Riverside Regional Conservation Authority and Riverside County Flood Control District are developing wildlife crossing infrastructure projects along a 3-mile stretch of Interstate 15 (I-15) in the Santa Ana-Palomar Mountains Linkage (hereafter ‘Linkage’) in southern California. These crossings will provide a critical missing link that will help reconnect wildlife in the coastal Santa Ana Mountains west of I-15 with those in the interior Palomar and Eastern Peninsular ranges to the east of I-15. The Linkage supports intact and diverse habitats including coastal sage scrub, grasslands, chaparral, and oak and riparian woodlands, and has been a focus of regional conservation efforts for the last 30 years. The three wildlife crossing infrastructure projects include enhancement of the existing Temecula Creek I-15 Bridge, construction of a new vegetated wildlife overcrossing, and construction of a new stand-alone wildlife culvert. Given the challenges and level of financial investment required to secure wildlife crossings for I-15 in the Linkage, TNC and Caltrans proposed that planning efforts would benefit from input by taxonomic experts on design concepts that meet the needs of the broadest range of wildlife. While wildlife crossings are becoming more common, optimal designs that meet the needs of a variety of wildlife species are largely unknown and can be site specific. To address this challenge, we held a workshop in February 2022 that brought together over 50 wildlife experts to brainstorm and identify specific design considerations for various focal wildlife species groups (medium/large mammals, small animals, birds, bats, plants, and invertebrates) that might use the identified I-15 wildlife crossings (The Nature Conservancy 2022). Lead experts for each focal species group worked together to identify specific wildlife crossing features or attributes for each of the three proposed wildlife crossings. Specific attributes evaluated by experts for each crossing type and species group included, at a minimum: • Crossing Structure Attributes; o Habitat features? (cover, habitat structure, substrate, moisture, light and noise mitigation) • Crossing Approach Area Features; o Habitat features (cover type/density, substrate, water, light and noise mitigation) • Barrier design to reduce roadkill and/or to funnel wildlife to the crossing; • Additional research to resolve uncertainties related to crossing design Based on the design considerations for each potential crossing type, the experts then weighed in on the suitability of the existing location and probability of use by their focal species or groups of species. With proposed design features, Temecula Creek Bridge has moderate or high probability of use by 27 of the 36 focal wildlife species assessed, while the vegetated overcrossing could meet the needs of 26 of the 36 species. When combined, Temecula Creek Bridge and the vegetated overcrossing have a moderate or high probability of use for 34 of the 36 species. The wildlife culvert has a moderate or high level of expected use by 10 of the 36 focal species and could serve connectivity needs for representative species from all but the bird and plant species groups.

California↗
USGS2023

Estimating northern spotted owl (Strix occidentalis caurina) pair detection probabilities based on call-back surveys associated with long-term mark-recapture studies, 1993–2018

The northern spotted owl ( Strix occidentalis caurina ; hereinafter NSO) was listed as “threatened” under the Endangered Species Act in 1990 and population declines have continued since that listing. Given the species’ protected status, any proposed activities on Federal lands that might impact NSO require consultation with U.S. Fish and Wildlife Service and part of that consultation often includes surveys to determine presence and occupancy status of the species in the proposed activity area. The objective of this report is to present study-area specific estimates of the probability of detection for NSO pairs from twelve 2-week seasonal survey periods using data from a recent range-wide meta-analysis. These estimates were a by-product of pair occupancy modeling but might provide insight into potential changes in the effect of the invasive barred owl on NSO detection rates. We used two-species multi-season occupancy models to estimate the probability of detection for NSOs on each of 11 study areas for each 2-week survey period and relative to the range-wide effect of barred owl presence or absence. Detection probabilities within the season generally increased from the earliest surveys in March through mid-season, decreasing again in the late season on five study areas. For three other study areas, detection rates were highest during the earliest survey periods in late March or early April. Estimates of cumulative seasonal detection of NSO (across a maximum of six within-season surveys) were less than 0.90 when barred owls (BO) were present on all but one study area, regardless of when surveys were conducted within a season. However, despite low detection rates, the probability that a territory was occupied when an NSO pair was not detected over six within-season surveys was also very low. When BO are not present on a territory, a six-survey protocol had a high probability of detecting an NSO pair at least once during the season on all study areas, except for the very lowest per-survey estimates. Conducting most surveys earlier in the season, when the probability of detecting pairs is highest (through May on most areas) could improve seasonal detection rates. However, alternative methods of population monitoring—such as the use of passive acoustic recorders—may be needed to continue monitoring NSO for research and management.

California, Oregon, Washington↗
USGS2019

Defensible standardized ploidy assessments for Grass Carp (Ctenopharyngodon idella, Cyprinidae) intercepted from the commercial supply chain

Although methods are in place through the U.S. Fish and Wildlife (USFWS) program for ploidy testing of feral caught Grass Carp ( Ctenopharyngodon idella ) and black carp ( Mylopharyngodon piceus ), no guidelines exist for carp hauled across state lines. Using 1200 Grass Carp purchased by undercover Ohio law enforcement during 2015–2016, we developed a standardized protocol for discriminating ploidy by using two parameters, nuclear size and DNA content. Bead standards at 2 μm or 4 μm were used to establish nuclear size from Nile Tilapia ( Oreochromis niloticus ), known diploid ( n = 20) and triploid (n = 20) Grass Carp blood, and cells derived from eyeballs of purchased field carp. The control for establishing DNA content was cryopreserved or fresh tilapia blood (2.40 pg). Time postmortem indicated nuclear size was similar over 4 days, but DNA quality from triploids was best at 24 h. Occasionally, only size or DNA content was measurable. Tilapia mean nuclear size ( n = 501 samples) was 4.61 μm (SE 0.05) (R 2 = 0.94). Known diploid and triploid blood nuclear sizes, compared with tilapia size, were 3.62 μm (SE 0.13) (R 2 = 0.96) and 7.58 μm (SE 0.27) (R 2 = 0.96), respectively. Mean field carp eye nuclear size was 5.83 μm (SE 0.13). Mean DNA content of cells from field carp eyes ( n = 698 fish) was 3.51 pg (SE 0.06). No diploid Grass Carp were detected in the USFWS certified triploid Grass Carp transports. This standard protocol reliably discriminates ploidy and can be used for enforcement of regulations that differ among state jurisdictions.

Journal of Great Lakes Research↗
USGS2017

Effects of tow transit on the efficacy of the Chicago Sanitary and Ship Canal Electric Dispersal Barrier System

In 2016, the U.S. Fish and Wildlife Service, U.S. Geological Survey, and U.S. Army Corps of Engineers undertook a field study in the Chicago Sanitary and Ship Canal near Romeoville, Illinois to determine the influence of tow transit on the efficacy of the Electric Dispersal Barrier System (EDBS) in preventing the passage of juvenile fish (total length < 100 millimeters (mm)). Dual-frequency identification sonar data showed that large schools of juvenile fish (mean school size of 120 fish; n = 19) moved upstream and crossed the electric field of an array in the EDBS concurrent with downstream-bound (downbound) loaded tows in 89.5% of trials. Smaller schools of juvenile fish (mean school size of 98 fish; n = 15) moved downstream and crossed the electric field of an array in the EDBS concurrent with upstream-bound (upbound) loaded tows in 73.3% of trials. Observed fish passages through the EDBS were always opposite to the direction of tow movement, and not associated with propeller wash. These schools were not observed to breach the EDBS in the absence of a tow and showed no signs of incapacitation in the barrier during tow passage. Loaded tows transiting the EDBS create a return current of water flowing between the tow and the canal wall that typically travels opposite the direction of tow movement, and cause a decrease in the voltage gradient of the barrier of up to 88%. Return currents and decreases in voltage gradients induced by tow passage likely contributed to the observed fish passage through the EDBS. The efficacy of the EDBS in preventing the passage of small, wild fish is compromised while tows are moving across the barrier system. In particular, downbound tows moving through the EDBS create a pathway for the upstream movement of small fish, and therefore may increase the risk of transfer of invasive fishes from the Mississippi River Basin to the Great Lakes Basin.

Illinois↗
USGS2020

Reconnaissance of surface water estrogenicity and the prevalence of intersex in smallmouth bass (Micropterus dolomieu) inhabiting New Jersey

The observation of testicular oocytes in male fishes has been utilized as a biomarker of estrogenic endocrine disruption. A reconnaissance project led in the Northeastern United States (US) during the period of 2008–2010 identified a high prevalence of intersex smallmouth bass on or near US Fish & Wildlife Service National Wildlife Refuges that included the observation of 100% prevalence in smallmouth bass males collected from the Wallkill River, NJ, USA. To better assess the prevalence of intersex smallmouth bass across the state of New Jersey, a tiered reconnaissance approach was initiated during the fall of 2016. Surface water samples were collected from 101 (85 river, 16 lake/reservoir) sites across the state at base-flow conditions for estrogenicity bioassay screening. Detectable estrogenicity was observed at 90% of the sites and 64% were above the US Environmental Protection Agency trigger level of 1 ng/L. Median surface water estrogenicity was 1.8 ng/L and a maximum of 6.9 ng/L E2EqBLYES was observed. Adult smallmouth bass were collected from nine sites, pre-spawn during the spring of 2017. Intersex was identified in fish at all sites, and the composite intersex prevalence was 93.8%. Prevalence across sites ranged from 70.6% to 100%. In addition to intersex, there was detectable plasma vitellogenin in males at all sites. Total estrogenicity in surface water was determined at these fish collection sites, and notable change over time was observed. Correlation analysis indicated significant positive correlations between land use (altered land; urban + agriculture) and surface water estrogenicity. There were no clear associations between land use and organismal metrics of estrogenic endocrine disruption (intersex or vitellogenin). This work establishes a baseline prevalence of intersex in male smallmouth bass in the state of New Jersey at a limited number of locations and identifies a number of waterbodies with estrogenic activity above an effects-based threshold.

New Jersey↗
USGS2020

Recent planform changes in the Upper Mississippi River

Geomorphic changes in the Upper Mississippi River (UMR) have long been a concern of river agencies charged with maintaining and restoring river habitat (GREAT 1980; Jackson et al. 1981; USFWS 1992). Large meandering alluvial rivers like the UMR are expected to constantly change and adjust their fluvial landforms within their riparian corridors as a result of the natural interaction of hydrologic processes, sediment movement, and vegetation over time. However, present geomorphic changes in the UMR reflect altered hydrologic, hydraulic, and sediment conditions caused by regulated flows, constructed agricultural levees and navigation dams, altered land use in the watershed, and climate change. Levees reduce lateral hydrologic and sediment connectivity between channels and floodplains on many tributaries and on the Mississippi River downstream of Pool 13. Between each of the dams are a repeating series of landforms associated with tailwater, intermediate, and impounded conditions. The dams maintain a minimum water level, thus creating many off-channel areas that act as sediment traps. Whereas high-head dams cut off sedimentological connectivity longitudinally through the river corridor (Skalak et al., 2013), low head dams on the UMR only slightly altered transport longitudinally. Deltaic-like sedimentation can be common in the impounded sections of dammed rivers. Erosion of relict land surfaces that remained above the raised impounded water levels has been the dominant change in UMR impounded sections due to increased wind fetch leading to increased wave action. Even though upland sources of sediment from tributaries have decreased over the middle to late 20th century, increased annual precipitation, the interplay of increased variability in flood magnitudes from year to year, and more fall and winter flooding have likely changed erosion and sedimentation patterns in the UMR (Belby, et al., 2019). Paradoxically, monitoring and research indicates that the concentration of some water column constituents like total suspended solids and phosphorous has decreased during the 1991 to 2014 time period (Kreiling and Houser, 2016). In areas prone to increased sedimentation, bed elevations rise and thereby water depths are reduced at a given discharge, resulting in loss of fish habitat. Sediment deposition or erosion further influences water exchange rates between main channel and off-channel areas in the river by increasing resistance in connecting channels or enlarging existing connecting channels. Water depth and water exchange rates are the most prominent features describing habitat quality in the UMR (De Jager et al. 2018), and in some cases, the trajectory of planform change from heightened deposition promises to threaten deep backwater habitats particularly important for overwintering fish. Although information on the rate of vertical change in bed elevation is needed for a complete assessment of geomorphic change associated with the loss of deep backwater habitats, mapping planform changes over time (i.e., lateral changes between the land-water boundary) provide needed information on the location, potential cause, and progressive direction of deposition, especially in the mid sections between dams where deltaic processes are the most pronounced. Several types of planform changes have been observed and identified as concerns. For example, island loss in the large impounded areas of the upper part of the UMR was one of the concerns identified by river managers in the 1980s and 90s, and subsequently island construction became a common form of restoration implemented by the Upper Mississippi River Restoration (UMRR) Program (USACE 2012). Other subtler planform changes, such as channel bank erosion and delta formation in backwaters, are perceived to be important, but have largely gone unquantified. A systemwide reconnaissance of the UMR and IWW conducted in 1998 concluded that 14-percent of the river banks were eroding (Nakato and Anderson 1998). However, stabilization of existing river banks has never been widely pursued as a restoration measure, due to the high cost and uncertain benefits. Delta formation reduces the amount of backwater habitat; however, the deltas maintain and create a mix of riparian and aquatic habitats, and that is generally considered to be beneficial for wildlife and fish. If recent hydrologic trends of more frequent and longer duration flood events continue, a better understanding of planform changes can help in describing past changes, and then be used to forecast potential future trajectories of change. If UMR resource managers determine that past and forecasted conditions are undesirable, then UMRR projects could be identified and prioritized to address those concerns. Vegetative cover associations with landform changes have been used to detect and quantify planform changes in many rivers (Johnson 1985; Hiatt 2015; Volte et al. 2015). Freyer and Jefferson (2013) completed such a study in Pool 6 of the UMR using the landcover data from 12 dates over a 115-yr period, including the 1989, 2000, and 2010/2011 landcover/use (LCU) data from the UMRR Program. Planform change detected over the last 20 years represented by the UMRR Program data best reflect present-day geomorphic patterns, rates and processes. Changes occurring prior to dam construction and changes occurring soon after dam construction are likely not the same as those happening now, 50-70 years after dam construction and creation of the impoundments (McHenry et al., 1984; Bhowmik and Adams, 1986; WEST Consultants, 2000). The LCU data from each of the 1989, 2000, and 2010/2011 imagery was developed using similar methods and is available in a Geographical Information System (GIS) for the entire UMR and therefore provides the opportunity for a more comprehensive planform change analysis. This study used GIS overlays of LCU classes to map and quantify changes in planform features over two periods, looking specifically for depositional areas where terrestrial and wetland vegetation expanded at the expense of open water. The land expansion was grouped into four possible process-based types common in large floodplain rivers, some following that used by Lewin et al. (2017). The four types include: crevasse deltas emanating from a breach from a main channel through a natural levee or narrow floodplain into backwaters (crevasse deltas), tributary deltas expanding into backwaters (tributary deltas), deltaic bars at the upstream end of impoundments (impounded deltas), and linear-like bars extending from the downstream ends of narrow levees and remnant floodplains (bar-tail limbs). The methods deployed for change detection addressed possible errors from a variety of sources.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗
USGS1993

Species richness and relative abundance of breeding birds in forests of the Mississippi Alluvial Valley

In 1992, the Vicksburg Field Research Station of the National Wetlands Research Center initiated research on the ecology of migratory birds within forests of the Mississippi Alluvial Valley (MAV). The MAV was historically a nearly contiguous bottomland hardwood forest, however, only remnants remain. These remnants are fragmented and often influenced by drainage projects, silviculture, agriculture, and urban development. Our objectives are to assess species richness and relative abundance, and to relate these to the size, quality, and composition of forest stands. Species richness and relative abundance were estimated for 53 randomly selected forest sites using 1 to 8 point counts per site, depending on the size of the forest fragment. However, statistical comparisons among sites will be restricted to an equal number ofpoint counts within the sites being compared. Point counts, lasting five minutes, were conducted from 11 May to 29 June 1992, foltowing Ralph, Sauer, and Droege (Point Count Standards; memo dated 9 March 1992). Vegetation was measured at the first three points on each site using a modification of the methods employed by Martin and Roper (Condor 90: 5 1-57; 1988). During 252 counts, 7 1 species were encountered, but only 62 species were encountered within a 50-m radius of point center. The mean number of species encountered within 50 m of a point, was 7.3 (s.d. = 2.7) and the mean number of individuals was 11.2 (s.d. = 4.2). The mean number of species detected at any distance was 9.6 (s.d, = 2.8) and the mean number of individuals was 15.6 (s.d. = 7.9). The most frequently encountered warblers in the MAV were Prothonotary Warbler and Northern Parula. Rarely encountered warblers were American Redstart and Worm-eating Warbler. The genera, Quercus, Ulmus, Carya, and Celtis were each encountered at 80 or more of the 152 points at which vegetation was sampled. Species most frequentlyencountered were: sugarberry (Celtis laevagata), water hickory (Caqa aquatica), American elm (Ulmus arnericana), sweetgum (Liquidambar styraciflua) and willow oak (Quercus phellos) The mean basal area of all trees 10 cm diameter-at-breast height (dbh) was 28 m2 /ha (range 7-70). The mean canopy cover was 87 percent, mean canopy height was 20 m, ground cover was 60 percent, and vegetation density (2-7 m) was 47 percent. The most frequently encountered understory species were sugarberry, ash (Fraxinus spp.), maple (Acer spp.), and elm (Ulnrus spp.). A cooperative GIs effort among the U.S. Fish and Wildlife Service, the Nature Conservancy, and the University of Arkansas is currently classifying forested habitats within the MAV. This effort will provide information on stand size and topology which will be used in concert with our current data, and data from visits to additional forest stands in 1993, to assess the relationship between the size, quatity, and composition of forests within the MAV and their breeding bird community.

Book chapter↗
USGS2025

Multiscale framework for assessing land cover change on barrier islands from extreme storms and restoration

Often found along the estuarine-marine interface, barrier islands and mainland coastal zones are shaped by tides, currents, extreme storms, and relative sea-level rise. These systems provide ecosystem services such as storm surge and wave attenuation, erosion protection to inland areas, habitat for fish and wildlife, recreation, and tourism. Given the importance of these ecosystems coupled with their dynamic nature, information on how these coastal systems are changing can help to inform natural resource management. Remote sensing advancements have led to an abundance of data for monitoring change in coastal settings. This study developed a multiscale framework that can provide trajectory information from screening-level analyses by using existing or custom moderate spatial resolution land cover maps. Using the north-central Gulf Coast as a case study, the trajectory of land cover area for barrier islands and mainland coastal zones was assessed using several geospatial data sets, including: (1) long-term moderate-resolution remote sensing products with an annual (or more frequent) temporal frequency; (2) a restoration database ( e.g. , beach/dune restoration, sediment placement, and dune enhancement); and (3) a tropical storm database. Due to the coarser spatial resolution of data sets used for screening-level analyses, detailed or application-specific analyses are often needed to reduce uncertainty in smaller changes that may not be captured. These may include land cover change analyses ( i.e. this study), periodic land cover maps with higher spatial resolution and more detailed land cover classes, or elevation-related analyses ( e.g. , dune change or inundation change). Using this framework, abrupt changes in land cover on Dauphin Island, Alabama, resulting from extreme storms were detected using moderate spatial resolution screening-level data, while restoration impact analyses may require higher resolution data. Further, land cover change analyses that incorporate change allocation provide robust information for understanding land cover change in dynamic coastal settings.

Alabama, Florida↗