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USGS2021

Seasonal activity and diets of bats at uranium mines and adjacent areas near the Grand Canyon

Little information exists on the habitat use and feeding ecology of insectivorous bats in arid ecosystems, especially at and near uranium mines in northern Arizona, within the Grand Canyon watershed. In 2015–2016, we conducted mist-netting, nightly acoustic monitoring (>1 year), and diet analyses of bats, as well as insect sampling, at 2 uranium mines (Pinenut and Arizona 1) with water containment ponds. Because of physical barriers and limited general access to areas within the mine yard, mist-netting was limited to outside of the perimeter fence and away from the containment ponds. Mist-netting also occurred at 2 nearby sites that served as proxies to the mines. Bats captured directly at the mines included one pregnant Antrozous pallidus and 3 adult male Parastrellus hesperus . At the proxy sites, we captured 45 individuals identified as A. pallidus , Corynorhinus townsendii , Eptesicus fuscus , Euderma maculatum , Lasionycteris noctivagans , Myotis californicus , Myotis ciliolabrum , P. hesperus , and Tadarida brasiliensis . The nightly and seasonal presence of bats, as shown through acoustic recordings at each mine, coincided with the seasonal migratory and hibernation behaviors of the bat species. Statistical comparisons of acoustic recordings with precipitation data collected over one year show that seasonal monsoon rains generally had a negative effect on the nightly activity and presence of bats. Diets of P. hesperus from both mines were comprised mostly of coleopterans but also included smaller volumes of Hymenoptera, Hemiptera, Lepidoptera, Diptera, and Neuroptera. The diet of A. pallidus was comprised solely of Coleoptera. Diets of bat species from the proxy sites were characteristic of their known feeding ecology, which ranged from the consumption of soft-bodied insects (e.g., moths) by C. townsendii to the consumption of hard-bodied insects (e.g., beetles) by E. fuscus . Ultimately, the increased knowledge of the natural history of bats through multiple methods of data collection allows for a better understanding of complex arid ecosystems. It also provides resources needed for the management of habitat associated with alternative energy, such as uranium mining.

Arizona↗

USGS2024

Effectiveness of canine-assisted surveillance and human searches for early detection of invasive spotted lanternfly

Prevention and early detection of invasive species are championed as the most cost-effective and efficient strategies for reducing or preventing negative impacts on ecosystems. Spotted lanternfly (SLF), Lycorma delicatula , is a recently introduced invasive insect whose range in the United States has been expanding rapidly since it was first discovered in Pennsylvania in 2014. Feeding by this planthopper can cause severe impacts on agricultural production, particularly grapes ( Vitis spp.). Human visual surveys are the most common search method employed for detection but can be ineffective due to the insect's cryptic egg masses and low density during early stages of infestation. Therefore, finding alternative early detection methods has become a priority for agencies tasked with addressing SLF management. This study experimentally tested whether trained detector dogs could improve the probability of detecting SLF in both agricultural and forest settings. We surveyed transects in 20 vineyards and their adjacent wooded areas in Pennsylvania and New Jersey, USA, and used a multiscale occupancy model to estimate detection probability achieved by human observers and detection dogs as a function of SLF infestation level, weather, and habitat covariates. We modeled transect-level occupancy of SLF as a function of infestation level, habitat type, topographic position index, and distance to forests. Occupancy probability of SLF was higher on vines within vineyards than in forests, and occupancy declined with increasing distance from forests, which is informative for future search efforts. Detection probability of SLF was lower at forested sites but was higher at high infestation sites. Detection dogs had a lower detection probability than humans in the vineyards, but the detection probability of dogs was >3× greater than that of humans in forested sites. Our study suggests that detection dogs are more effective than human visual searches as an early detection method for SLF in forested areas, and utilizing detector dogs could strengthen SLF early detection efforts. This study demonstrates the potential applicability of using canine-assisted search strategies combined with occupancy models to enhance the surveillance and prevention of other difficult-to-detect invasive species.

New Jersey, Pennsylvania↗

USGS2016

Hydrologic exchange flows and their ecological consequences in river corridors

The actively flowing waters of streams and rivers remain in close contact with surrounding off-channel and subsurface environments. These hydrologic linkages between relatively fast flowing channel waters, with more slowly flowing waters off-channel and in the subsurface, are collectively referred to as hydrologic exchange flows (HEFs). HEFs include surface exchange with a channel’s marginal areas and subsurface flow through the streambed (hyporheic flow), as well as storm-driven bank storage and overbank flows onto floodplains. HEFs are important, not only for storing water and attenuating flood peaks, but also for their role in influencing water conservation, water quality improvement, and related outcomes for ecological values and services of aquatic ecosystems. Biogeochemical opportunities for chemical transformations are increased by HEFs as a result of the prolonged contact between flowing waters and geochemically and microbially active surfaces of sediments and vegetation. Chemical processing is intensified and water quality is often improved by removal of excess nutrients, metals, and organic contaminants from flowing waters. HEFs also are important regulators of organic matter decomposition, nutrient recycling, and stream metabolism that helps establish a balanced and resilient aquatic food web. The shallow and protected storage zones associated with HEFs support nursery and feeding areas for aquatic organisms that sustain aquatic biological diversity. Understanding of these varied roles for HEFs has been driven by the related disciplines of stream ecology, fluvial geomorphology, surface-water hydraulics, and groundwater hydrology. A current research emphasis is on the role that HEFs play in altered flow regimes, including restoration to achieve diverse goals, such as expanding aquatic habitats and managing dissolved and suspended river loads to reduce over-fertilization of coastal waters and offset wetland loss. New integrative concepts and models are emerging (eg, hydrologic connectivity) that emphasize HEF functions in river corridors over a wide range of spatial and temporal scales.

Book chapter↗

USGS2002

Spent shot availability and ingestion on areas managed for mourning doves

Mourning dove (Zenaida macroura) hunting is becoming increasingly popular, especially in managed shooting fields. Given the possible increase in the availability of lead (Pb) shot on these areas, our objective was to estimate availability and ingestion of spent shot at the Eagle Bluffs Conservation Area (EBCA, hunted with nontoxic shot) and the James A. Reed Memorial Wildlife Area (JARWA, hunted with Pb shot) in Missouri. During 1998, we collected soil samples one or 2 weeks prior to the hunting season (prehunt) and after 4 days of dove hunting (posthunt). We also collected information on number of doves harvested, number of shots fired, shotgun gauge, and shotshell size used. Dove carcasses were collected on both areas during 1998-99. At EBCA, 60 hunters deposited an estimated 64,775 pellets/ha of nontoxic shot on or around the managed field. At JARWA, approximately 1,086,275 pellets/ha of Pb shot were deposited by 728 hunters. Our posthunt estimates of spent-shot availability from soil sampling were 0 pellets/ha for EBCA and 6,342 pellets/ha for JARWA. Our findings suggest that existing soil sampling protocols may not provide accurate estimates of spent-shot availability in managed dove shooting fields. During 1998-99, 15 of 310 (4.8%) mourning doves collected from EBCA had ingested nontoxic shot. Of those doves, 6 (40.0%) contained a?Y7 shot pellets. In comparison, only 2 of 574 (0.3%) doves collected from JARWA had ingested Pb shot. Because a greater proportion of doves ingested multiple steel pellets compared to Pb pellets, we suggest that doves feeding in fields hunted with Pb shot may succumb to acute Pb toxicosis and thus become unavailable to harvest, resulting in an underestimate of ingestion rates. Although further research is needed to test this hypothesis, our findings may partially explain why previous studies have shown few doves with ingested Pb shot despite their feeding on areas with high Pb shot availability.

Missouri↗

USGS2018

Methods to reduce conflicts between cranes and farmers

Alternative methods to reduce conflicts between cranes and farmers range from relatively simple, inexpensive disturbance methods to changes in land use at a landscape scale. Visual and acoustics disturbance methods can be useful for small fields or gardens but require frequent changes to prevent habituation by the cranes. Changes in farming practices can be implemented by individual farmers and matched to the local situation. By altering timing of seeding and harvest, harvest methods, and other management practices, farmers can minimize the vulnerability of the crop or its attractiveness to cranes. Crop damage can be reduced by strategically locating high-risk crops away from crane roosts or high-use areas. Diversionary fields, where cranes can forage on nutritious, preferred foods near their roost without disturbance, are one of the more effective methods to reduce crop damage. Artificial feeding may be appropriate as a temporary measure but its long-term use should only be a last option where no alternative wintering areas or food resources are available or restorable. Chemical treatment of seeds can deter cranes from taking newly sown seeds and seedlings. Conflicts with farmers can be mitigated by financial or other compensation, or through conservation approaches. Financial mechanisms should be used cautiously as they can dilute or corrupt local traditions of tolerance. An integrated approach, using several methods, is more likely to be effective in the long term. Farmers and communities are more likely to embrace alternative measures if they understand basic crane ecology and if the measures are clearly beneficial to the farmers. Developing a broader range of tools to better understand the conflict, to understand farmer perceptions of cranes, and to help implement strategies to improve positivist attitudes is necessary. Multi-disciplinary approaches that incorporate social, economic as well as ecological aspects of the issue are very rare, and much needed to develop workable solutions.

Book chapter↗

USGS2020

Effects of density reduction on age-specific growth of stream-dwelling Brown Trout

Density-dependent growth has been well documented among stream-dwelling Brown Trout Salmo trutta populations. In Spearfish Creek, South Dakota, biomass of adult Brown Trout (>200 mm) is about three times greater than that reported for similar Black Hills streams, whereas the mean length of adult fish is about 30% less. Here, we evaluate density reduction as a management tool for improving the growth rate of stream-dwelling Brown Trout. We compared age-specific growth of wild Brown Trout in stream sections receiving 50% reductions in fish abundance (removal sections) to that of fish in sections containing natural densities (control sections). Annual growth in length and weight of older Brown Trout (age > 2) was greater in removal sections compared to control sections, particularly among fish between 230 and 280 mm TL (ages 3–4). We attribute the growth response to constraints imposed by food availability and the strong feeding hierarchies, characteristic of larger (older) Brown Trout. Data collected from PIT-tagged fish that were recaptured 2 years after fish removal efforts revealed that growth responses owing to density reduction likely did not extend beyond 1 year. Nonetheless, among cohorts that showed improved growth after the first year, we found that their growth advantage was sustained into the second year. At removal sections, age-3 and older Brown Trout that experienced greater growth after 1 year were larger than fish from control sections 2 years later at age 5 and older. Identification of cohort(s) for which density-dependent growth is most pronounced could help to focus efforts on targeted reduction of specific fish sizes/ages that minimize the cost–benefit ratio of fish removal efforts.

South Dakota↗

USGS2014

Space use of wintering waterbirds in India: Influence of trophic ecology on home-range size

Relationship between species' home range and their other biological traits remains poorly understood, especially in migratory birds due to the difficulty associated with tracking them. Advances in satellite telemetry and remote sensing techniques have proved instrumental in overcoming such challenges. We studied the space use of migratory ducks through satellite telemetry with an objective of understanding the influence of body mass and feeding habits on their home-range sizes. We marked 26 individuals, representing five species of migratory ducks, with satellite transmitters during two consecutive winters in three Indian states. We used kernel methods to estimate home ranges and core use areas of these waterfowl, and assessed the influence of body mass and feeding habits on home-range size. Feeding habits influenced the home-range size of the migratory ducks. Carnivorous ducks had the largest home ranges, herbivorous ducks the smallest, while omnivorous species had intermediate home-ranges. Body mass did not explain variation in home-range size. To our knowledge, this is the first study of its kind on migratory ducks, and it has important implications for their conservation and management.

Current Zoology↗

USGS2016

Growth of juvenile steelhead Oncorhynchus mykiss under size-selective pressure limited by seasonal bioenergetic and environmental constraints

Increased freshwater growth of juvenile steelhead Oncorhynchus mykiss improved survival to smolt and adult stages, thus prompting an examination of factors affecting growth during critical periods that influenced survival through subsequent life stages. For three tributaries with contrasting thermal regimes, a bioenergetics model was used to evaluate how feeding rate and energy density of prey influenced seasonal growth and stage-specific survival of juvenile O. mykiss . Sensitivity analysis examined target levels for feeding rate and energy density of prey during the growing season that improved survival to the smolt and adult stages in each tributary. Simulated daily growth was greatest during warmer months (1 July to 30 September), whereas substantial body mass was lost during cooler months (1 December to 31 March). Incremental increases in annual feeding rate or energy density of prey during summer broadened the temperature range at which faster growth occurred and increased the growth of the average juvenile to match those that survived to smolt and adult stages. Survival to later life stages could be improved by increasing feeding rate or energy density of the diet during summer months, when warmer water temperatures accommodated increased growth potential. Higher growth during the summer period in each tributary could improve resiliency during subsequent colder periods that lead to metabolic stress and weight loss. As growth and corresponding survival rates in fresh water are altered by shifting abiotic regimes, it will be increasingly important for fisheries managers to better understand the mechanisms affecting growth limitations in rearing habitats and what measures might maintain or improve growth conditions and survival.

Washington↗

USGS2020

Intrinsic prey preference and selection of the giant gartersnake: A threatened predator in a nonnative prey-dominated community

The introduction of exotic species into an environment can introduce great change in the trophic dynamics of native species. This is of even greater concern if the native species is of conservation concern. The giant gartersnake, Thamnophis gigas , an endemic predator of the Central Valley of California and a species of conservation concern at the state and federal levels, has declined as a result of conversion of its once vast wetland habitat to agriculture. Another anthropogenic factor contributing to this snake's changing ecology is the introduction of nonnative prey into the species' habitats. These introductions have resulted in a prey community that is almost completely composed of exotic species and have potential for considerable effects. In order to assess prey preference and selection we performed three sets of behavioral trials on naïve neonates. We examined 1) neonate prey preference in response to olfactory cues of prepared prey extracts, 2) neonate consumption of different live prey items presented simultaneously; and 3) terrestrial feeding behavior and/or latency to successful attack. Results from the olfactory study suggest that native Sierran treefrogs, Pseudacris sierra, are preferred by neonates. Results from consumption trials suggest that neonates are more likely to select frog species than fish species. This is the first study that we are aware of that examines prey selection of this threatened species and serves to inform its conservation and management.

Journal of Fish and Wildlife Management↗

USGS2004

Mute swans: Natural (?) environmental indicators

The rapid expansion of the Chesapeake Bay's population of feral mute swans (Cygnus olar), coupled with a dramatic Bay-wide decline in submerged aquatic vegetation (SAV), has fueled much of the current debate surrounding the need for a management plan to protect the aquatic food resources that are critical to many species native to the Bay. Crucial to this decision process is a sound understanding of the ecological ramifications of having the year-round presence of a large, nonnative, aquatic herbivore on the Bay. Ultimately, this will require a quantitative assessment of the ecological harm currently posed by mute swans before a biologically defensible management strategy can be developed. Unfortunately, very little new information specific to the Bay's mute swan population has been gathered since Reese first studied them in the late 1960s and 1970s. While the debate over what to do about the rapidly expanding mute swan population continues, there is much that can be gained from study of this beautiful intruder. Several recent studies of the feeding habits of mute swans have shown that mutes can provide a unique barometer, or indicator, of environmental conditions. Because of their reliance on SAV as a primary food source, monitoring the density of swans utilizing a particular area can give some indication of the status of the area's grass beds. This phenomenon was clearly demonstrated during the summer of 1999 when there was a dramatic decline in the number of swans observed around the Eastern Neck NWR, a traditional population stronghold. The shift in bird use was precipitated by a rapid, large-scale collapse of the area's aquatic grass beds, possibly the result of a prolonged drought. During the winter of 2000/2001, a similar ecological assessment was conducted by comparing body weights of swans collected from Tangier Sound, an area with relatively abundant grass beds, and swans from the waters adjacent to Eastern Neck Island. Swans weights tended to reflect the conditions of their surroundings, with the Tangier Sound birds being slightly heavier at the onset of the breeding season. Interestingly, the birds at Eastern Neck showed a 1 kg decline in weight after dispersal from their wintering locations and entered the breeding season with noticeably less subcutaneous fat than the birds sampled in Tangier Sound. The fact that mute swans are nonmigratory and feed exclusively on benthic food items makes them an ideal organ-ism to monitor the degree of contamination of sediments within the Bay. In 1995, we compared the accumulation of metals by mute swans and other waterfowl and related it to metal concentrations in the sediments from the areas where the birds were collected. This study led to the development of an exposure model that more accurately assesses the risk of exposure to environmental contaminants through incidental ingestion of sediments, as opposed to the traditional assessment of contaminant accumulation through the food chain. This sediment exposure pathway was subsequently shown to be the primary route of exposure of swans to metals in risk assessments conducted at two Superfund sites.

Book chapter↗

USGS2022

Quantitative method development to determine feed consumption using a dye

Although there are many methods to determine ingestion and absorption of aquafeeds, none exist that are simple, cost-effective, and quantitative and that can mark fish with a long-lasting, visible indicator. In addition to aquafeed development, selective baits are needed that can be used for aquatic invasive species removal efforts, including for Grass Carp Ctenopharyngodon idella . Bait incorporated with a pesticide would allow for selective removal of targeted species. A method to quickly assess multiple bait formulations was developed to expediate development for invasive species management. Incorporation of Sudan Black B (SBB) in aquafeeds at concentrations greater than 75 and 120 mg SBB/kg fish resulted in pigmented external soft tissues of Largemouth Bass Micropterus salmoides and Rainbow Trout Oncorhynchus mykiss , respectively, 24 h after consumption. Visual confirmation of consumption was detectable in the gastrointestinal tract at all concentrations tested (≥10 mg SBB/kg) and quantifiable by absorbance measured at 601 nm from extracted SBB in tissues at concentrations less than those required for visual pigmentation. Although SBB was detectable in multiple tissues, fin and mandible tissues yielded the greatest accuracy in estimating consumption from extracted SBB. Compared with other tissues tested, liver tissue accumulated the highest level of SBB but had the greatest variability, while muscle tissue accumulated little detectable SBB. We used the SBB analytical method to compare consumption of six novel baits that were in the initial developmental stages to produce a palatable bait formulation designed to attract Grass Carp for management control. Overwhelming preference of a rapeseed bait formulation was confirmed using SBB as a tracer of consumption in the laboratory; however, use of SBB under natural conditions may be valuable for answering additional questions. Baits incorporated with SBB allowed for the rapid, simultaneous assessment of multiple formulations and could allow for future refinement of management baits, with results available as quickly as 24–72 h after application.

North American Journal of Aquaculture↗

USGS2006

Tetracycline residues and tetracycline resistance genes in groundwater impacted by swine production facilities

Antibiotics are used at therapeutic levels to treat disease; at slightly lower levels as prophylactics; and at low, subtherapeutic levels for growth promotion and improvement of feed efficiency. Over 88% of swine producers in the United States gave antimicrobials to grower/finisher pigs in feed as a growth promoter in 2000. It is estimated that ca . 75% of antibiotics are not absorbed by animals and are excreted in urine and feces. The extensive use of antibiotics in swine production has resulted in antibiotic resistance in many intestinal bacteria, which are also excreted in swine feces, resulting in dissemination of resistance genes into the environment. To assess the impact of manure management on groundwater quality, groundwater samples have been collected near two swine confinement facilities that use lagoons for manure storage and treatment. Several key contaminant indicators-including inorganic ions, antibiotics, and antibiotic resistance genes-were analyzed in groundwater collected from the monitoring wells. Chloride, ammonium, potassium, and sodium were predominant inorganic constituents in the manure samples and served as indicators of groundwater contamination. Based on these analyses, shallow groundwater has been impacted by lagoon seepage at both sites. Liquid chromatography-mass spectroscopy (LC-MS) was used to measure the dissolved concentrations of tetracycline, chlortetracycline, and oxytetracycline in groundwater and manure. Although tetracyclines were regularly used at both facilities, they were infrequently detected in manure samples and then at relatively trace concentrations. Concentrations of all tetracyclines and their breakdown products in the groundwater sampled were generally less than 0.5 ??g/L.</ p> Bacterial tetracycline resistance genes served as distinct genotypic markers to indicate the dissemination and mobility of antibiotic resistance genes that originated from the lagoons. Applying PCR to genomic DNA extracted from the lagoon and groundwater samples, four commonly occurring tetracycline (tet) resistance genes-tet(M), tet(O), tet(Q), and tet(W)-were detected. The detection frequency of tet genes was much higher in wells located closer to and down-gradient from the lagoons than in wells more distant from the lagoons. These results suggested that in the groundwater underlying both facilities tetracycline resistance genes exist and are somewhat persistent, but that the distribution and potentially the flux for each tet gene varied throughout the study period.

Animal Biotechnology↗

USGS2025

Burbot population dynamics in northern Lake Michigan, 2001–2023, and predation on newly stocked lake trout by burbot

Although the worldwide status of burbot ( Lota lota ) across its Holarctic distribution has recently been assessed, adverse effects of dreissenid mussels on burbot abundance in waters invaded by mussels have not been investigated. We analyzed data from an annual spring gillnet survey to characterize burbot population dynamics in northern Lake Michigan during 2001–2023. Adult burbot abundance in northern Lake Michigan trended neither significantly upward nor downward during 2001–2023. Thus, expansion of the quagga mussel ( Dreissena rostriformis bugensis ) population into deeper waters of Lake Michigan during 2003–2008 had no detectable negative effects on burbot abundance. Burbot continued to feed on lake trout ( Salvelinus namaycush ) stocked in the Northern Refuge of Lake Michigan through 2023, which supported a hypothesis that the burbot population potentially impeded lake trout restoration in the refuge.

Michigan↗

USGS1974

Feeding Ecology of Breeding Blue-Winged Teals

A 5-year investigation of factors influencing the selection of foods consumed by blue-winged teals ( Anas discors ) during the breeding season in the glaciated prairie region of south-central North Dakota showed that birds first arriving on the breeding grounds consumed a diet consisting of 45 percent invertebrates. The proportion of animal foods in the diet increased to 95 percent at the onset of the nesting season. The quality and quantity of foods selected at any given time were influenced by the biological demands and morphological adaptations of the bird, the behavior and ecology of the invertebrates selected as foods, and the general nature of the aquatic ecosystems as determined by the hydrology and geology of the area and modified by land use and weather. Feeding activities changed significantly when food availability within the aquatic ecosystem changed. During the spring and early summer, temporary and seasonal wetlands, if not severely disturbed, were of paramount importance to breeding blue-winged teals since they provided abundant and readily available, high protein, animal foods. Later in the summer when seasonal wetlands began to dry up, insects began to emerge in the semipermanent ponds and lakes, and feeding intensity shifted to these more permanent waters. This trend, however, was often reversed temporarily during the early summer following heavy precipitation that refilled shallow water areas and again stimulated invertebrate development.

North Dakota↗

USGS2013

Real-time continuous nitrate monitoring in Illinois in 2013

Many sources contribute to the nitrogen found in surface water in Illinois. Illinois is located in the most productive agricultural area in the country, and nitrogen fertilizer is commonly used to maximize corn production in this area. Additionally, septic/wastewater systems, industrial emissions, and lawn fertilizer are common sources of nitrogen in urban areas of Illinois. In agricultural areas, the use of fertilizer has increased grain production to meet the needs of a growing population, but also has resulted in increases in nitrogen concentrations in many streams and aquifers (Dubrovsky and others, 2010). The urban sources can increase nitrogen concentrations, too. The Federal limit for nitrate nitrogen in water that is safe to drink is 10 milligrams per liter (mg/L) (http://water.epa.gov/drink/contaminants/basicinformation/nitrate.cfm, accessed on May 24, 2013). In addition to the concern with nitrate nitrogen in drinking water, nitrogen, along with phosphorus, is an aquatic concern because it feeds the intensive growth of algae that are responsible for the hypoxic zone in the Gulf of Mexico. The largest nitrogen flux to the waters feeding the Gulf of Mexico is from Illinois (Alexander and others, 2008). Most studies of nitrogen in surface water and groundwater include samples for nitrate nitrogen collected weekly or monthly, but nitrate concentrations can change rapidly and these discrete samples may not capture rapid changes in nitrate concentrations that can affect human and aquatic health. Continuous monitoring for nitrate could inform scientists and water-resource managers of these changes and provide information on the transport of nitrate in surface water and groundwater.

Illinois↗

USGS2015

Environmental predictors of shrubby cinquefoil ( Dasiphora fruticosa ) habitat and quality as host for Maine’s endangered Clayton’s copper butterfly ( Lycaena dorcas claytoni )

Population size of habitat-specialized butterflies is limited in part by host plant distribution and abundance. Effective conservation for host-specialist species requires knowledge of host-plant habitat conditions and relationships with the specialist species. Clayton’s copper butterfly ( Lycaena dorcas claytoni ) is a Maine state-endangered species that relies exclusively on shrubby cinquefoil ( Dasiphora fruticosa ) as its host. Dasiphora fruticosa occurs in 28 wetlands in Maine, ten of which are occupied by L. d. claytoni. Little is known about environmental conditions that support large, persistent stands of D. fruticosa in Maine. We evaluated the environment (hydrology, pore water and peat nutrients) associated with D. fruticosa distribution, age, and condition in Maine wetlands supporting robust stands of D. fruticosa to compare with L. d. claytoni occurrence. Although dominant water source in D. fruticosa —containing wetlands included both groundwater discharge and surface-flow, D. fruticosa coverage was greater in wetlands with consistent growing season water levels that dropped into or below the root zone by late season, and its distributions within wetlands reflected pore water hydrogen ion and conductivity gradients. Flooding magnitude and duration were greatest during the L.d. claytoni larval feeding period, whereas, mean depth to water table and upwelling increased and were most variable following the L. d. claytoni egg-laying period that precedes D. fruticosa senescence. Oldest sampled shrubs were 37 years, and older shrubs were larger and slower-growing. Encounter rates of L. d. claytoni were greater in wetlands with larger D. fruticosa plants of intermediate age and greater bloom density. Wetland management that combines conditions associated with D. fruticosa abundance (e.g., non-forested, seasonally consistent water levels with high conductivity) and L. d. claytoni occurrence (e.g., drawdown below the root zone following egg-laying, abundant blooms on intermediate-aged D. fruticosa, nearby D. fruticosa -containing wetlands) will aid L. d. claytoni conservation.

Wetlands Ecology and Management↗

USGS2025

Workshop: Nature-based solutions to ecological and economic problems caused by extreme precipitation events in the Upper Mississippi River Basin

Future climate conditions in the Upper Mississippi River Basin are projected to include many more extreme precipitation events. These intense periods of rain can lead to flooding of the Mississippi River itself, as well the small streams and rivers that feed it. This flooding presents a challenge for local communities, farmers, small businesses, river users, and the ecosystems and wildlife in the area. To reduce the damage done by these extreme rainfall events, ‘natural solutions’ are often helpful. This might include preserving forests and grasslands to absorb rainwater before it arrives at streams or restoring wetlands to slow and clean runoff water. For river and natural resource managers to adapt to future climate by using these natural solutions, however, they require accurate information about the projected increase in extreme rainfall events and the effectiveness and costs of a variety of solutions. To provide this information, researchers must understand the decisions that managers are making and the challenges they face. In this project, researchers will host a workshop to facilitate knowledge sharing between natural resource managers, climate modelers, and scientists studying natural solutions. Participants will discuss climate projections related to extreme precipitation events in the region, as well as the management implications and decision-making challenges associated with these events. These conversations will cultivate collaborative relationships between managers and researchers to address critical knowledge gaps and improve future management efforts in the Upper Mississippi River Basin.

Upper Mississippi River basin↗

USGS2024

Detection of prions from spiked and free-ranging carnivore feces

Chronic wasting disease (CWD) is a highly contagious, fatal neurodegenerative disease caused by infectious prions (PrP CWD ) affecting wild and captive cervids. Although experimental feeding studies have demonstrated prions in feces of crows ( Corvus brachyrhynchos ), coyotes ( Canis latrans ), and cougars ( Puma concolor ), the role of scavengers and predators in CWD epidemiology remains poorly understood. Here we applied the real-time quaking-induced conversion (RT-QuIC) assay to detect PrP CWD in feces from cervid consumers, to advance surveillance approaches, which could be used to improve disease research and adaptive management of CWD. We assessed recovery and detection of PrP CWD by experimental spiking of PrP CWD into carnivore feces from 9 species sourced from CWD-free populations or captive facilities. We then applied this technique to detect PrP CWD from feces of predators and scavengers in free-ranging populations. Our results demonstrate that spiked PrP CWD is detectable from feces of free-ranging mammalian and avian carnivores using RT-QuIC. Results show that PrP CWD acquired in natural settings is detectable in feces from free-ranging carnivores, and that PrP CWD rates of detection in carnivore feces reflect relative prevalence estimates observed in the corresponding cervid populations. This study adapts an important diagnostic tool for CWD, allowing investigation of the epidemiology of CWD at the community-level.

Scientific Reports↗