Mississippi River Region Research Articles

Economic consequences of inland waterway disruptions in the Upper Mississippi River region in a changing climate

Inland waterway locks have become significant bottlenecks in waterway networks worldwide due to the disruptions caused by aging infrastructure and climate change. While these locks have traditionally received attention for traffic issues, the disruptive impact on the regional economy remains unclear. This study addresses this knowledge gap by assessing the economic impacts of inland water transportation system failures, specifically focusing on disruptions in agricultural commodities within the Upper Mississippi River–Illinois River (UMR–IR) region. These disruptions encompass both unscheduled climate-induced extreme weather events and scheduled maintenance and repair work due to internal system failure. To capture the spatial interdependence between the regional economy and shipping rate changes caused by disruptions, we developed an integrated modeling approach. This approach combines spatial econometric modeling and multi-regional computable general equilibrium modeling techniques. Detailed weekly data from 2013 to 2021, including variations in inland barge rates and environmental conditions, were utilized. The assessment reveals that lock closure events in the UMR-IR region have severe economic consequences, impacting both the region itself and beyond. Conversely, transportation resilience achieved through modal substitution from barge to rail services during disruptive events can substantially reduce GDP losses. Specifically, such resilience measures can reduce GDP losses in the UMR-IR region by 6.6–24.2% and in the rest of the USA by 5.2–19.5%. Overall, these research findings carry significant implications for future planning and investment in inland waterway systems.

Population genetics of Nelumbo lutea (American lotus) near its northwestern range limit

Nelumbo lutea Wild. (American lotus) has a broad and changing geographical distribution that is influenced by human transplanting and changes to climate, hydrology, and habitat. Populations vary from extensive stands where the species appears to be an effective colonizer, to sites where the species has declined or appears to have been extirpated. Previous studies in apparently stable populations from central and southern United States revealed low genetic diversity within and between populations. In this study, we assess genetic diversity at the northern edge of N. lutea’s range where it is often imperiled. A total of 489 individuals in 25 populations collected in Upper Mississippi River regions in Minnesota and Wisconsin were amplified in 12 microsatellite loci. Ten microsatellite loci indicated significant deviation from Hardy-Weinberg principal and were utilized for further analysis. Generally, genetic diversity was low compared to the genetic studies from southern North America. Despite low levels of genetic differentiation (Fst range; 0.003–0.059), structure and UPGMA analysis indicated the possibility of two distinct clusters and slight admixture in some populations. Initial low genetic diversity in populations was likely caused by founder effect if few individuals were established at each site. Limited migration and clonal growth contribute to the continued low diversity. We provide recommendations and research suggestions for the conservation of this species.

Geographic Patterns in U.S. Lung Cancer Mortality and Cigarette Smoking.

Despite the success of smoking cessation campaigns, lung cancer remains the leading cause of cancer death in the U.S. Variations in smoking behavior and lung cancer mortality are evident by sex and region. Applying geospatial methods to lung cancer mortality data from the National Vital Statistics System and county-level estimates of smoking prevalences from the NCI's Small Area Estimates of Cancer-Related Measures, we evaluated patterns in lung cancer mortality rates (2005-2018) in relation to patterns in ever cigarette smoking prevalences (1997-2003). Overall, ever smoking spatial patterns were generally associated with lung cancer mortality rates, which were elevated in the Appalachian region and lower in the West for both sexes. However, we also observed geographic variation in mortality rates that is not explained by smoking. Using Lee's L statistic for assessing bivariate spatial association, we identified counties where the ever smoking prevalence was low and lung cancer rates were high. We observed a significant cluster of counties (n = 25; P values ranging from 0.001 to 0.04) with low ever smoking prevalence and high mortality rates among females around the Mississippi River region south of St. Louis, Missouri and a similar and smaller cluster among males in Western Mississippi (n = 12; P values ranging from 0.002 to 0.03) that has not been previously described. Our analyses identified U.S. counties where factors other than smoking may be driving lung cancer mortality. These novel findings highlight areas where investigation of environmental and other risk factors for lung cancer is needed.

S1857 Gastrointestinal Histoplasmosis in an Immunocompetent Adult in a Non-Endemic Region

Introduction: Histoplasma capsulatum is an endemic fungus and infection is rarely seen in the United States outside of the Ohio and Mississippi River regions. Disseminated infection is typically seen in immunocompromised patients and primary gastrointestinal involvement is rare. We report the case of an immunocompetent adult who was diagnosed with disseminated histoplasmosis with primarily gastrointestinal symptoms. Case description/methods: A 34-year-old male with history of developmental delay and prior seizures presented with seven months of intermittent bloody diarrhea, abdominal pain, fever and chills. He had a similar presentation previously at another hospital and underwent colonoscopy with evidence of multiple ulcers throughout the colon. He was empirically treated with antibiotics but re-presented due to persistent symptoms. Patient was intermittently febrile on admission. Exam showed diffuse abdominal tenderness to palpation. Labs were notable for Hgb 9.1 g/dL and, WBC 12.3 × 10^9 cells/L Stool calprotectin 1570 mcg/g. CT abdomen showed diffuse colonic thickening. Colonoscopy showed discontinuous scattered non-bleeding deep ulcers throughout the entire colon (Figure 1) which were biopsied. Pathology showed histiocytes with intracellular fungal elements. Even duodenal biopsies showed intracellular fungal elements though the duodenal mucosa appeared normal aside from some lymphoid aggregates on upper endoscopy. Urine histoplasma galactomannan antigen was positive. He had no evidence of pulmonary disease. Further history revealed that the patient had never traveled outside of California but did have some close contact with relatives from Minnesota prior to the onset of symptoms. Other infectious work-up including Aspergillus, HIV, CMV, Coccidiomycosis, Cryptococcus were all normal. He was initially treated with oral itraconazole with no improvement of his symptoms, however symptom resolved after initiating IV amphotericin. Genetic testing is pending for underlying immunodeficiency. Discussion: This unique case illustrates disseminated histoplasmosis with mainly gastrointestinal symptoms in a seemingly immunocompetent adult in a non-endemic area. The patient had diffuse small bowel and colonic involvement led to symptoms mimicking inflammatory bowel disease and he even had a markedly elevated calprotectin. Prior case series of disseminated histoplasmosis have reported 100% mortality when untreated. Endoscopic biopsies were crucial to help make the diagnosis and appropriate therapy.Figure 1.: Deep, non-bleeding ulcerations found in transverse colon on colonoscopy.Table 1.: EGD and colonoscopy biopsy results.

Comparative Proteomic Analysis of Histoplasma capsulatum Yeast and Mycelium Reveals Differential Metabolic Shifts and Cell Wall Remodeling Processes in the Different Morphotypes.

Histoplasma capsulatum is a thermally dimorphic fungus distributed worldwide, but with the highest incidence in the Americas within specific geographic areas, such as the Mississippi River Valley and regions in Latin America. This fungus is the etiologic agent of histoplasmosis, an important life-threatening systemic mycosis. Dimorphism is an important feature for fungal survival in different environments and is related to the virulence of H. capsulatum, and essential to the establishment of infection. Proteomic profiles have made important contributions to the knowledge of metabolism and pathogenicity in several biological models. However, H. capsulatum proteome studies have been underexplored. In the present study, we report the first proteomic comparison between the mycelium and the yeast cells of H. capsulatum. Liquid chromatography coupled to mass spectrometry was used to evaluate the proteomic profile of the two phases of H. capsulatum growth, mycelium, and yeast. In summary, 214 and 225 proteins were only detected/or preferentially abundant in mycelium or yeast cells, respectively. In mycelium, enzymes related to the glycolytic pathway and to the alcoholic fermentation occurred in greater abundance, suggesting a higher use of anaerobic pathways for energy production. In yeast cells, proteins related to the tricarboxylic acid cycle and response to temperature stress were in high abundance. Proteins related to oxidative stress response or involved with cell wall metabolism were identified with differential abundance in both conditions. Proteomic data validation was performed by enzymatic activity determination, Western blot assays, or immunofluorescence microscopy. These experiments corroborated, directly or indirectly, the abundance of isocitrate lyase, 2-methylcitrate synthase, catalase B, and mannosyl-oligosaccharide-1,2-alpha-mannosidase in the mycelium and heat shock protein (HSP) 30, HSP60, glucosamine-fructose-6-phosphate aminotransferase, glucosamine-6-phosphate deaminase, and N-acetylglucosamine-phosphate mutase in yeast cells. The proteomic profile-associated functional classification analyses of proteins provided new and interesting information regarding the differences in metabolism between the two distinct growth forms of H. capsulatum.

Stopover duration of spring migrating dabbling ducks in the Wabash river valley

ABSTRACTWaterfowl use stopover sites during spring migration to rest and replenish nutrient reserves prior to their arrival on breeding grounds. Estimating the extent to which an individual remains at a stopover site before dispersing (i.e., stopover duration) is essential for managers to develop wetland habitat objectives needed to ensure sufficient resources are available to meet the needs of migrating waterfowl. Our objectives were to determine average stopover duration of dabbling ducks in the Wabash River Valley (WRV) of Illinois and Indiana, USA, identify factors that may influence that duration, and evaluate how those duration values compare with those currently used by the Upper Mississippi River and Great Lakes Region Joint Venture (UMRGLRJV). We estimated stopover duration of 39 mallard (Anas platyrhynchos) and 62 green‐winged teal (A. crecca) between January and April 2016–2017 in the WRV. Estimated stopover duration for mallards and green‐winged teal was 17.0 days (95% CI = 12.6–22.9). Our estimate is substantially shorter than current estimates used by the UMRGLRJV for conservation planning and could affect conservation objectives for waterfowl. © 2019 The Wildlife Society.

Infection patterns of trematodes across size classes of an invasive snail species using field and laboratory studies

In the Upper Mississippi River Region, invasive faucet snails (Bithynia tentaculata) and their trematode parasites have been implicated in more than 182 000 waterfowl deaths since 1996. Estimating transmission potential depends on accurate assessments of susceptible host population size. However, little is known about the mechanisms underlying snail-host susceptibility in this system. Prior field studies suggest that very small, likely young, faucet snails are less suitable secondary intermediate hosts. Here, we test whether the patterns observed in the field are because small snails (1) are refractory to infection by cercariae, (2) die from infection and are removed from sampled populations, and/or (3) are not preferred by cercariae. Our own field collections were consistent with the observation that smaller faucet snails exhibit lower metacercarial infection prevalence and abundance than larger snails. However, laboratory-based experiments show that smaller snails were actually more susceptible to infection than larger snails. Moreover, the smallest snail size class had significantly higher mortality than larger snails following infection, which may explain their reduced infection levels observed in the field. Our study demonstrates the importance of pairing field and laboratory studies to better understand mechanisms underlying patterns of infection.

Mallard survival, movements, and habitat use during autumn in Illinois

ABSTRACTThe Illinois River Valley (IRV) in central Illinois, USA, provides migratory stopover habitat for millions of waterfowl during autumn and spring in the Mississippi Flyway. Mallards (Anas platyrhynchos) are the most abundant species of waterfowl during autumn migration and the most harvested duck in Illinois. We investigated mallard migration ecology in central Illinois, USA, to address information needs of biologists and managers in the Upper Mississippi River and Great Lake Region Joint Venture and Illinois Department of Natural Resources. Our objectives were to document daily movements and identify factors affecting inter‐wetland movements, investigate lengths of foraging flights, assess home range size during stopover, describe habitat use and identify factors associated with wetland use, estimate survival and cause specific mortality, and evaluate proportional use of refuges and areas open to hunting in and nearby the IRV by mallards. We employed standard radio‐telemetry techniques to achieve our objectives during autumns and early winters 2009 and 2010 (n = 86 F and 56 M mallards). The mean movement distance between locations collected on consecutive days was 2,822 ± 120 (SE) m (n = 1,862; max. = 56,966 m) across age, sex, and months. Female mallards (n = 35) traveled 2,708 ± 191 m during evening foraging flights (n = 145) to agricultural fields and emergent marshes. Mean home range size (95% minimum convex polygon) was 21,306 ± 1,925 ha across sex and age classes (n = 81 mallards). We documented 43 mortalities of 142 radio‐marked mallards (2009: 28.2%; 2010: 32.3%) with 85.0% and 69.6% of deaths attributed to hunting in 2009 and 2010, respectively. Body condition, hunting period, age, year, minimum daily temperature, and daily movement distance were important variables affecting survival, but differences were most pronounced for year and hunting period. Overall survival was greater in 2010 (Ŝi = 0.62) than 2009 (Ŝi = 0.39) and daily survival rates were 0.8% and 0.4% greater during closed than open hunting periods in 2009 and 2010, respectively. Mallards used open water most frequently across years (49.4% daily locations), followed by corn (dryland, flooded, standing, or harvested; 16.3%), herbaceous (10.6%), woody (10.5%), and other wetlands and upland cover types. Use of areas closed to hunting was low (18.7%) and most diurnal locations of mallards occurred in wetlands open to hunting (81.3%; i.e., not designated as refuge by statute). Similar to diurnal habitat use, female mallards returning from evening foraging flights (n = 138) used areas open to hunting (81.9%) more than refuges (18.1%). Refuges that were primarily composed of open water received low use by autumn‐migrating mallards in the IRV. Restoration or rehabilitation of moist‐soil and emergent wetlands within statutory refuges protected from unnatural flood regimes may improve foraging habitat quality and increase survival for mallards and other ducks during migration. © 2017 The Wildlife Society.

Disseminated Blastomycosis Involving the Pancreas

SESSION TITLE: Lung Infections 1 SESSION TYPE: Affiliate Case Report Slide PRESENTED ON: Sunday, October 29, 2017 at 10:45 AM - 12:00 PM INTRODUCTION: Presented is a rare case of disseminated blastomycosis involving the pancreas. CASE PRESENTATION: A 67 year-old African-American male with a history of chronic hepatitis C, diabetes mellitus and latent MTB presented with 2-3 months of dry cough, weight loss and anorexia and a new post-auricular superficial skin lesion. Computed Tomography (CT) revealed mass-like consolidations in the right lower lobe and pancreas [Figure 1]. Wet preparation of skin lesion was negative. He underwent bronchoscopy with bronchoalveolar lavage (BAL) of the right lower lobe and ultrasound-guided aspiration of the pancreatic mass. Pathology of pancreatic mass revealed granulomatous inflammation with hyphae. BAL revealed budding fungus consistent with Blastomycoses. Liposomal amphotericin was started and treatment transitioned to itraconazole after 14 days. Follow up CT revealed significant pulmonary improvement and near complete resolution of the pancreatic mass [Figure 2]. DISCUSSION: Blastomycoses is a dimorphic fungi endemic to the Mississippi and Ohio River regions. Clinical manifestations of infection are broad with pulmonary most common. Dissemination is seen in an estimated 20% of cases most commonly involving the lungs and skin; less commonly bone, genitourinary and CNS. Presented is a rare case of disseminated blastomycosis involving the pancreas. Culture provides definitive diagnosis however direct visualization of yeast form on clinical specimens can be helpful. Treatment depends on severity and presence of extra-pulmonary disease. CONCLUSIONS: Pancreatic involvement in disseminated blastomycosis is rare. Reference #1: Chapman SW, Lin AC, Hendricks KA, et al. Endemic blastomycosis in Mississippi: epidemiological and clinical studies. Semin Respir Infect. 1997;12(3):219-28. Reference #2: Chapman SW, Dismukes WE, Proia LA, et al. Clinical practice guidelines for the management of blastomycosis: 2008 update by the Infectious Diseases Society of America. Clin Infect Dis. 2008; 46(12):1801-12. Reference #3: Smith JA, Gauthier G. New Developments in Blastomycosis. Semin Respir Crit Care Med. 2015;36(5):715-28. DISCLOSURE: The following authors have nothing to disclose: Craig Schuring, Adnan Khan, Matt Rudd, Amik Sodhi, Dipen Kadaria No Product/Research Disclosure Information

Conjunctive water management to sustain agricultural economic returns and a shallow aquifer at the landscape level

Irrigated farming regions around the world face the problem of groundwater scarcity. We examine the economic effectiveness of conjunctive water management with on-farm reservoirs and tail-water recovery to address this scarcity in the Lower Mississippi River Region of Arkansas, United States. A landscape level economic model is used because groundwater use by one producer affects the groundwater available for other producers. The present value of farm net returns over 30 years on the agricultural landscape depends on the crop mix, reservoir adoption, and the groundwater depletion that are optimal using a spatial-dynamic programming problem. We find that reservoirs should be built when the depth to the aquifer exceeds 18.3 m (60 ft), and the average share of productive land in a reservoir should be about 2%. Rice (<i>Oryza sativa</i>) intensive areas use reservoirs to replace groundwater with reservoir surface water when the depth to groundwater increases. Soybean (<i>Glycine max</i>) intensive areas use reservoirs sparingly to support shallow groundwater pumping depths, but groundwater remains the primary source of irrigation.

Low downstream dispersal of young-of-year common carp from marshes into lakes in the Upper Mississippi River region and its implications for integrated pest management strategies

Low downstream dispersal of young-of-year common carp from marshes into lakes in the Upper Mississippi River region and its implications for integrated pest management strategies

Continental‐Scale River Flow Modeling of the Mississippi River Basin Using High‐Resolution NHDPlus Dataset

AbstractAs a key component of the National Flood Interoperability Experiment (NFIE), this article presents the continental scale river flow modeling of the Mississippi River Basin (MRB), using high‐resolution river data from NHDPlus. The Routing Application for Parallel computatIon of Discharge (RAPID) was applied to the MRB with more than 1.2 million river reaches for a 10‐year study (2005‐2014). Runoff data from the Variable Infiltration Capacity (VIC) model was used as input to RAPID. This article investigates the effect of topography on RAPID performance, the differences between the VIC‐RAPID streamflow simulations in the HUC‐2 regions of the MRB, and the impact of major dams on the streamflow simulations. The model performance improved when initial parameter values, especially the Muskingum K parameter, were estimated by taking topography into account. The statistical summary indicates the RAPID model performs better in the Ohio and Tennessee Regions and the Upper and Lower Mississippi River Regions in comparison to the western part of the MRB, due to the better performance of the VIC model. The model accuracy also increases when lakes and reservoirs are considered in the modeling framework. In general, results show the VIC‐RAPID streamflow simulation is satisfactory at the continental scale of the MRB.

Validation of landscape suitability indices for Black Terns (Chlidonias niger) in the U.S. Great Lakes region

ABSTRACT Remotely sensed land cover data enable characterization of avian habitat over large spatial scales, which can be applied to regional conservation planning. Black Terns (Chlidonias niger) have been declining in the U.S. Great Lakes region for decades. Although causes of the decline are not well understood, habitat loss and degradation are viewed as major barriers to recovery. The Upper Mississippi River and Great Lakes Region Joint Venture, a partnership for bird conservation in the Upper Midwest, developed a landscape suitability index for the wetland-breeding Black Tern based on remotely sensed land cover to choose habitat to enhance or restore. We tested the validity of this index and compared it to an alternative index we constructed from results of field surveys. Over 2 breeding seasons, we surveyed for presence of Black Tern breeding colonies in 158 wetlands across the Great Lakes region and compared our findings with predictions of the existing index. We used our first season of surveys, nu...

Endocrine disrupting alkylphenolic chemicals and other contaminants in wastewater treatment plant effluents, urban streams, and fish in the Great Lakes and Upper Mississippi River Regions

Urban streams are an integral part of the municipal water cycle and provide a point of discharge for wastewater treatment plant (WWTP) effluents, allowing additional attenuation through dilution and transformation processes, as well as a conduit for transporting contaminants to downstream water supplies. Domestic and commercial activities dispose of wastes down-the-drain, resulting in wastewater containing complex chemical mixtures that are only partially removed during treatment. A key issue associated with WWTP effluent discharge into streams is the potential to cause endocrine disruption in fish. This study provides a long-term (1999–2009) evaluation of the occurrence of alkylphenolic endocrine disrupting chemicals (EDCs) and other contaminants discharged from WWTPs into streams in the Great Lakes and Upper Mississippi River Regions (Indiana, Illinois, Michigan, Minnesota, and Ohio). The Greater Metropolitan Chicago Area Waterways, Illinois, were evaluated to determine contaminant concentrations in the major WWTP effluents and receiving streams, and assess the behavior of EDCs from their sources within the sewer collection system, through the major treatment unit processes at a WWTP, to their persistence and transport in the receiving stream. Water samples were analyzed for alkylphenolic EDCs and other contaminants, including 4-nonylphenol (NP), 4-nonylphenolpolyethoxylates (NPEO), 4-nonylphenolethoxycarboxylic acids (NPEC), 4-tert-octylphenol (OP), 4-tert-octylphenolpolyethoxylates (OPEO), bisphenol A, triclosan, ethylenediaminetetraacetic acid (EDTA), and trace elements. All of the compounds were detected in all of the WWTP effluents, with EDTA and NPEC having the greatest concentrations. The compounds also were detected in the WWTP effluent dominated rivers. Multiple fish species were collected from river and lake sites and analyzed for NP, NPEO, NPEC, OP, and OPEO. Whole-body fish tissue analysis indicated widespread occurrence of alkylphenolic compounds, with the highest concentrations occurring in streams with the greatest WWTP effluent content. Biomarkers of endocrine disruption in the fish indicated long-term exposure to estrogenic chemicals in the wastewater impacted urban waterways.

Stopover duration of mallards during autumn in the Illinois River valley

ABSTRACTEstimates of time spent at migratory stopovers are often used to develop habitat conservation objectives for a variety of avian species, namely waterfowl. Because of limited previous research and a need for accurate conservation planning objectives, we estimated stopover duration and factors influencing stay of mallards (Anas platyrhynchos) in Illinois using radio telemetry during autumns 2009 and 2010. Total stopover duration of migrating mallards was approximately 68 days and was approximately twice that of previous studies which could have significant implications on habitat needs used for conservation planning purposes. Duration of stay post‐capture did not vary by sex, body condition, year, or age but was inversely related to capture date. Our results suggest that wetland conservation objectives could increase 16.2% if our contemporary estimates were included in current planning models of the Upper Mississippi River and Great Lakes Region Joint Venture. © 2014 The Wildlife Society.

Regional, Very Heavy Daily Precipitation in NARCCAP Simulations

Abstract The authors analyze the ability of the North American Regional Climate Change Assessment Program's ensemble of climate models to simulate very heavy daily precipitation and its supporting processes, comparing simulations that used observation-based boundary conditions with observations. The analysis includes regional climate models and a time-slice global climate model that all used approximately half-degree resolution. Analysis focuses on an upper Mississippi River region for winter (December–February), when it is assumed that resolved synoptic circulation governs precipitation. All models generally reproduce the precipitation-versus-intensity spectrum seen in observations well, with a small tendency toward producing overly strong precipitation at high-intensity thresholds, such as the 95th, 99th, and 99.5th percentiles. Further analysis focuses on precipitation events exceeding the 99.5th percentile that occur simultaneously at several points in the region, yielding so-called “widespread events.” Examination of additional fields shows that the models produce very heavy precipitation events for the same physical conditions seen in the observations.

Archaeology of Minnesota: The Prehistory of the Upper Mississippi River Region

Review of: Archaeology of Minnesota: The Prehistory of the Upper Mississippi River Region, by Guy Gibbon.

Archaeology of Minnesota: the prehistory of the Upper Mississippi River region

Contents Preface and Acknowledgments Introduction: The Tools of the Trade 1.Environments of Minnesota Paleoindian and Archaic Period, ca. 11,200 to 500 BC 2First People: Paleoindian and Early Archaic Adaptations 3Prairie Everywhere: Middle and Late Archaic Adaptations Initial Woodland Period, ca. 1000-500 BC to AD 500-700 4Southern Deer Hunters, Gardeners, and Bison Hunters: Initial Woodland Adaptations in Southern Minnesota 5Northern Hunters, Fishers, and Wild Rice Harvesters: Initial Woodland Adaptations in Central and Northern Minnesota Terminal Woodland and Mississippian Period, ca. AD 500-700 to 1650 6Terminal Woodland Effigy Mound Builders and Bison Hunters: Terminal Woodland Adaptations in Southern Minnesota 7First Tribes in Southern Minnesota: Mississippian and Plains Village Adaptation 8.First Tribes in Central and Northern Minnesota: Terminal Woodland Adaptations Conclusion: Long-Term Pattern in the Past Notes Bibliography Index

Population Status and Habitat Associations of the King Rail in the Midwestern United States

The migratory population of the King Rail (Rallus elegans) has declined dramatically during the past 50 years, emphasizing the need to document the distribution and status of this species to help guide conservation efforts. In an effort to guide King Rail breeding habitat protection and restoration, a landscape suitability index (LSI) model was developed for the Upper Mississippi River and Great Lakes Region Joint Venture (JV). To validate this model, 264 sites were surveyed across the JV region in 2008 and 2009 using the National Marshbird Monitoring protocol. Two other similarly collected data sets from Wisconsin (250 sites) and Ohio (259 sites) as well as data from the Cornell Laboratory of Ornithology's eBird database were added to our data set. Sampling effort was not uniform across the study area. King Rails were detected at 29 sites with the greatest concentration in southeastern Wisconsin and northeastern Illinois. Too few detections were made to validate the LSI model. King Rail detection sites tended to have microtopographic heterogeneity, more emergent herbaceous wetland vegetation and less woody vegetation. The migrant population of the King Rail is rare and warrants additional conservation efforts to achieve stated conservation population targets.

Wetland food resources for spring‐migrating ducks in the Upper Mississippi River and Great Lakes Region

AbstractWetlands in the Upper Mississippi River and Great Lakes Region (UMRGLR) must annually sustain populations of migrating waterfowl from the mid‐continent of North America. We used multi‐stage sampling to estimate plant and invertebrate food biomasses (kg/ha) for ducks in 3 wetland habitat types at 6 stop‐over locations in the UMRGLR during 2006 and 2007. Total biomass was greatest in palustrine emergent (PEM; ${\bar {x}}$ = 208 kg/ha, SE = 23, median = 120), followed by palustrine forested (PF; ${\bar {x}}$ = 87 kg/ha, SE = 7; median = 43), and lacustrine–riverine (LR; ${\bar {x}}$ = 52 kg/ha, SE = 7; median = 27) wetlands. Ducks that foraged in forested and LR wetlands encountered the least food abundance during spring in the UMRGLR. Our estimates of food abundance were the lowest reported among other landscape scale surveys from mid‐continent North America. About 1 in every 5 PEM wetlands and over half of our PF and LR wetlands that we sampled contained &lt;50 kg/ha of food, suggesting many had little or no forage value to ducks during spring. Biomass of plant foods generally exceeded invertebrate biomass in all habitat types, although invertebrate biomass estimates exceeded plant biomass in 8 of 29 sites when considered by wetland type and year. Total food biomass estimates varied widely (${\bar {x}}$ = 6–425 kg/ha) between years and among habitats; thus, using global arithmetic means to estimate food abundance for conservation planning obscures fine scale temporal and spatial variation that may be necessary for management on local and sub‐regional levels. Distributions of food biomass estimates were right‐skewed, causing us to question whether arithmetic means realistically represent levels of food abundance that all ducks encounter during spring migration. Alternative measures of central tendency (e.g., median) may be more biologically realistic, particularly if spring‐migrating ducks are not distributed in an ideal‐free manner with respect to food abundance. Future research should determine how ducks distribute themselves in relation to variation in food abundance in space and time during spring migration to strengthen the biological approach to conservation planning in non‐breeding Joint Venture areas of the North American Waterfowl Management Plan. © 2011 The Wildlife Society.