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At least 1,243 records · Page 69Linked to original sources

Spawning and hatching of endangered Gila Chub in captivity

Information on reproductive characteristics of the endangered Gila Chub Gila intermedia is largely limited and qualitative, and culture techniques and requirements are virtually unknown. Here we provide the first published data on spawning and selected reproductive and developmental characteristics of Gila Chub. Fish were brought to the laboratory in March 2003 from Sabino Creek, Arizona (12.3°C). Fish were then warmed slowly and spawned at 14.9°C, 10 d after collection. Following this initial spawning, Gila Chub spawned consistently in the laboratory without hormonal, chemical, photoperiod, temperature, or substrate manipulation during all times of the year. Spawns were noted at temperatures ranging from about 15°C to 26°C; however, we noted that Gila Chub spawned less frequently at temperatures above 24°C. Multiple spawning attempts per year per individual are probable. There was a strong, inverse relationship between time to hatch and incubation temperature. The hatch rate of eggs was high (mean = 99.43%), and larval Gila Chub accepted a variety of natural and formulated diets at first feeding. The future of Gila Chub may someday depend in part on hatchery propagation to provide specimens for restocking formerly occupied habitats and establishing refuge populations. Information from our study can aid future efforts to successfully spawn and rear Gila Chub and related species.

North American Journal of Aquaculture↗

Recharge from a subsidence crater at the Nevada test site

Current recharge through the alluvial fans of the Nevada Test Site (NTS) is considered to be negligible, but the impact of more than 400 nuclear subsidence craters on recharge is uncertain. Many of the craters contain a playa region, but the impact of these playas has not been addressed. It was hypothesized that a crater playa would focus infiltration through the surrounding coarser-grained material, thereby increasing recharge. Crater U5a was selected because it represented a worst case for runoff into craters. A borehole was instrumented for neutron logging beneath the playa center and immediately outside the crater. Physical and hydraulic properties were measured along a transect in the crater and outside the crater. Particle-size analysis of the 14.6 m of sediment in the crater and morphological features of the crater suggest that a large ponding event of ≈63000 m 3 had occurred since crater formation. Water flow simulations with HYDRUS-2D, which were corroborated by the measured water contents, suggest that the wetting front advanced initially by as much as 30 m yr −1 with a recharge rate 32 yr after the event of 2.5 m yr −1 Simulations based on the measured properties of the sediments suggest that infiltration will occur preferentially around the playa perimeter. However, these sediments were shown to effectively restrict future recharge by storing water until removal by evapotranspiration (ET). This work demonstrated that subsidence craters may be self-healing.

Soil Science Society of America Journal↗

Host selection and lethality of attacks by sea lampreys (Petromyzon marinus) in laboratory studies

Parasitic-phase sea lampreys (Petromyzon marinus) are difficult to study in the wild. A series of laboratory studies (1984-1995) of single attacks on lake trout (Salvelinus namaycush), rainbow trout (Oncorhynchus mykiss), and burbot (Lota lota) examined host size selection; determined the effects of host size, host species, host strain, and temperature on host mortality; and estimated the weight of hosts killed per lamprey. Rainbow trout were more able and burbot less able to survive attacks than lake trout. Small sea lampreys actively selected the larger of two small hosts; larger sea lampreys attacked larger hosts in proportion to the hosts' body sizes, but actively avoided shorter hosts (a?? 600 mm) when larger were available. Host mortality was significantly less for larger (43-44%) than for smaller hosts (64%). However, the yearly loss of hosts per sea lamprey was less for small hosts (range, 6.8-14.2 kg per sea lamprey) than larger hosts (range, 11.4-19.3 kg per sea lamprey). Attacks at the lower of two temperature ranges (6.1-11.8A?C and 11.1-15.0A?C) did not significantly reduce the percentage of hosts killed (54% vs. 69%, p > 0.21), but longer attachment times at lower temperatures reduced the number of hosts attacked (33 vs. 45), and produced the lowest loss of hosts (6.6 kg per sea lamprey). Low temperature appeared to offset other factors that increase host mortality. Reanalysis of 789 attacks pooled from these studies, using forward stepwise logistic regression, also identified mean daily temperature as the dominant factor affecting host mortality. Observations in Lakes Superior, Huron, and Ontario support most laboratory results.

Journal of Great Lakes Research↗

Avoidance behavior of ruffe exposed to selected formulations of piscicides

Ruffe were introduced into Duluth Harbor, Minnesota in the early 1980s, probably by release of ballast water from sea-going freighters. Since then, it has become the most abundant species in the fish community. The sensitivity of ruffe to a number of piscicides has been demonstrated, however, the feasibility of using piscicides to control populations depends on whether ruffe can detect piscicides and move to untreated water. We used a two-choice preference testing system to evaluate avoidance or attraction reactions of ruffe during exposures to the lampricides TFM and bayluscide and the general fish toxicants rotenone and antimycin. We used a second testing system to evaluate the potential for benthic ruffe to move vertically in the water column to avoid piscicides dissolving from experimental bottom-release formulations of bayluscide and antimycin. Near-lethal concentrations of TFM and rotenone tended to repel ruffe. Antimycin and bayluscide did not seem to repel ruffe in the avoidance chamber, but bottom-release formulations (antimycin granules—0.25% a.i. and bayluscide granules—3.2% a.i.) did cause increased swimming and surfacing activity among ruffe in column tests. We conclude that TFM and rotenone could be used to treat entire bodies of water, while bottom-release formulations of antimycin and bayluscide may have more application for treating localized concentrations of ruffe.

Journal of Great Lakes Research↗

The joint effect of changes in urbanization and climate on trends in floods: A comparison of panel and single-station quantile regression approaches

Estimates of annual maximum (peak) flow quantiles are needed for basins undergoing changes in both urbanization and climate. Most previous work on the effect of urbanization on peak flows has considered urbanization alone and only the spatial variation in flood quantiles or its mean temporal effect, and most work on the effect of nonstationarity in climate has focused on single-station analyses, which give uncertain results for extreme quantiles. To address these gaps, three approaches to the statistical estimation of the joint effects of changes in impervious cover and climate on the estimation of peak-flow quantiles were compared: single-station quantile regression; a fixed effect panel-quantile regression (pQR) method using a location (mean) shift to homogenize the panel; and a location-scale panel regression model (pQRmom), which accounts for both scale (variance) and location effects. The different approaches were applied to a dataset consisting of instantaneous annual peak flows from 127 minimally nested basins in the midwestern United States with at least 4 % change in imperviousness. The annual maximum daily discharge from a water-balance model was selected as the primary climate predictor; in addition, to provide a comparison of climate predictors, precipitation was also considered. The coefficients from single-station regressions were usually sufficiently certain to determine the effects of climate variation but usually too uncertain to estimate the effects of urbanization. The panel-quantile regression approaches give much more certain results, but their estimates of quantile dependence differ: although both indicate urbanization effects decreasing with decreasing annual exceedance probability (AEP), the pQRmom urbanization coefficients are insignificantly different from zero for AEPs less than 0.10, whereas the pQR coefficients remain positive and are significant except for AEP = 0.01, the smallest AEP value considered. Although the location-scale structure of the pQRmom approach has less flexible quantile dependence than the pQR approach, the pQRmom approach has somewhat lower overall error, and it is found that by subsetting the dataset to homogenize the scale effects, the pQR and pQRmom results become similar, indicating the insignificant urbanization coefficients for small AEPs of the pQRmom results are likely correct for the study dataset.

Arkansas, Illinois, Indiana, Iowa, Michigan, Minne↗

Developmental instability in Rhus copallinum L.: multiple stressors, years, and responses

Developmental instability, as assessed by leaf fluctuating asymmetry and stem internode allometry, was examined at nine sites, representing three levels of disturbance, over multiple years. Site selection was based on land‐use disturbance classes related to training of mechanized infantry and other land management activities at Fort Benning, Georgia. Developmental instability varied among sites and years, and there was a strong site‐by‐year interaction for many traits. Indeed, depending on the year, the same site could be ranked as having the greatest and least amount of leaf fluctuating asymmetry. Burning a site the year prior to collecting the leaves profoundly influenced measures of leaf fluctuating asymmetry. In the absence of recent burning, leaf fluctuating asymmetry declined with increasing disturbance, but burning the year prior to collecting the leaves reversed this trend. Total plant cover, proportion of bare ground, and amount of plant litter influenced the amount of leaf asymmetry in a site‐dependent manner. Overall, burning influenced the levels of developmental instability more than either disturbance or microhabitat variables such as total plant cover, which should reflect competition in a plant’s immediate neighborhood.

International Journal of Plant Sciences↗

High-resolution remote sensing and multistate occupancy estimation identify drivers of spawning site selection in fall chum salmon (Oncorhynchus keta) across a sub-Arctic riverscape

Groundwater upwellings provide warmer, stable overwinter temperatures for developing salmon embryos, which may be particularly important in cold, braided, gravel-bed sub-Arctic rivers. We used a three-year time series of aerial counts and remote sensing to estimate the distribution of low and high aggregations of spawning fall chum salmon ( Oncorhynchus keta ), classify approximately 0.5 km long river segments by geomorphic channel type, and map thermal variability along a 25.4 km stretch of the Teedriinjik River, Alaska. We used a dynamic multistate occupancy model to estimate detectability, occupancy, and the dynamics of spawning aggregations among river segments. Detectability was higher for large (>150) relative to smaller aggregations. Unoccupied segments were likely to remain so from year to year; low abundance spawning segments were dynamic and rarely remained in that state for multiple years, while ∼20%–35% of high abundance segments remained stable, indicating the presence of high-quality spawning habitat. Spawning habitat use was associated with warmer water temperatures likely caused by groundwater upwellings. We identified spawning habitat characteristics and trends in usage by fall chum salmon, which will inform land management decisions and assist in evaluating impacts of shifting climate conditions and resource management on Arctic salmon populations.

Alaska↗

Sea lamprey ( Petromyzon marinus ) parasite-host interactions in the Great Lakes

Prediction of how host mortality responds to efforts to control sea lampreys ( Petromyzon marinus ) is central to the integrated management strategy for sea lamprey (IMSL) in the Great Lakes. A parasite-host submodel is used as part of this strategy, and this includes a type-2 multi-species functional response, a developmental response, but no numerical response. General patterns of host species and size selection are consistent with the model assumptions, but some observations appear to diverge. For example, some patterns in sea lamprey marking on hosts suggest increases in selectivity for less preferred hosts and lower host survival when preferred hosts are scarce. Nevertheless, many of the IMSL assumptions may be adequate under conditions targeted by fish community objectives. Of great concern is the possibility that the survival of young parasites (parasitic-phase sea lampreys) varies substantially among lakes or over time. Joint analysis of abundance estimates for parasites being produced in streams and returning spawners could address this. Data on sea lamprey marks is a critical source of information on sea lamprey activity and potential effects. Theory connecting observed marks to sea lamprey feeding activity and host mortality is reviewed. Uncertainties regarding healing and attachment times, the probability of hosts surviving attacks, and problems in consistent classification of marks have led to widely divergent estimates of damages caused by sea lamprey. Laboratory and field studies are recommended to provide a firmer linkage between host blood loss, host mortality, and observed marks on surviving hosts, so as to improve estimates of damage.

Journal of Great Lakes Research↗

Nomad Rover field experiment, Atacama Desert, Chile 1. Science results overview

Nomad was deployed for a 45 day traverse in the Atacama Desert, Chile, during the summer of 1997. During this traverse, 1 week was devoted to science experiments. The goal of the science experiments was to test different planetary surface exploration strategies that included (1) a Mars mission simulation, (2) a science on the fly experiment, where the rover was kept moving 75% of the operation time. (The goal of this operation was to determine whether or not successful interpretation of the environment is related to the time spent on a target. The role of mobility in helping the interpretation was also assessed.) (3) a meteorite search using visual and instrumental methods to remotely identify meteorites in extreme environments, and (4) a time-delay experiment with and without using the panospheric camera. The results were as follow: the remote science team positively identified the main characteristics of the test site geological environment. The science on the fly experiment showed that the selection of appropriate targets might be even more critical than the time spent on a study area to reconstruct the history of a site. During the same operation the science team members identified and sampled a rock from a Jurassic outcrop that they proposed to be a fossil. The presence of paleolife indicators in this rock was confirmed later by laboratory analysis. Both visual and instrumental modes demonstrated the feasibility, in at least some conditions, of carrying out a field search for meteorites by using remote-controlled vehicles. Finally, metrics collected from the observation of the science team operations, and the use team members made of mission data, provided critical information on what operation sequences could be automated on board rovers in future planetary surface explorations.

Atacama Desert↗

Development of a SWAT+ model to improve conservation practice efficacy for protecting stream health in karst pasturelands

Placing appropriate conservation practices in critical source areas of pollutants can benefit stream health in karst environments susceptible to agricultural pollution. Watershed models, such as the Soil and Water Assessment Tool+ (SWAT+), can optimize both practice selection and placement across the landscape, but to our knowledge no studies have tested this model in karst pasturelands. Our goal was to understand pollutant dynamics in pasturelands with karst topography in southwest Virginia, United States. We built a SWAT+ model to predict streamflow and pollutant loads for four watersheds. SWAT+ predicted that streamflow estimates were most affected by setting the available water capacity to zero and increasing the hydraulic conductivity of the soil, revealing that water, and associated pollutants, move primarily through subsurface pathways. Predicted sediment yield was negatively associated with agricultural land cover and was strongly influenced by channel erodibility—indicating that the predominant sediment source may be streambanks. Therefore, practices that stabilize stream banks (e.g., fencing cattle out of streams) may be most effective at reducing sediment loads. The model unsatisfactorily predicted total nitrogen and total phosphorus loads. The utility of SWAT+ for cattle grazing operations in karst regions could be improved by more accurately representing the effects of cattle grazing on streambank erosion and the dynamic subsurface movement of pollutants.

Virginia↗

Fine-scale habitat preference of green sturgeon (Acipenser medirostris) within three spawning locations in the Sacramento River, California

Vast sections of the Sacramento River have been listed as critical habitat by the National Marine Fisheries Service for green sturgeon spawning ( Acipenser medirostris ), yet spawning is known to occur at only a few specific locations. This study reveals the range of physical habitat variables selected by adult green sturgeon during their spawning period. We integrated fine-scale fish positions, physical habitat characteristics, discharge, bathymetry, and simulated velocity and depth using a 2-dimensional hydraulic model (FaSTMECH). The objective was to create habitat suitability curves for depth, velocity, and substrate type within three known spawning locations over two years. An overall cumulative habitat suitability score was calculated that averaged the depth, velocity, and substrate scores over all fish, sites, and years. A weighted usable area (WUA) index was calculated throughout the sampling periods for each of the three sites. Cumulative results indicate that the microhabitat characteristics most preferred by green sturgeon in these three spawning locations were velocities between 1.0-1.1 m/s, depths of 8-9 m, and gravel and sand substrate. This study provides guidance for those who may in the future want to increase spawning habitat for green sturgeon within the Sacramento River.

California↗

Spawning habitat selection and egg deposition by reintroduced Lake Sturgeon in a tributary to Cayuga Lake, NY

In June 2017, we documented the first observed spawning event by a reintroduced population of Lake Sturgeon ( Acipenser fulvescens ) in Fall Creek, a tributary to Cayuga Lake, New York, USA. This is the first observed spawning encounter of adult Lake Sturgeon since the beginning of the multi-agency Lake Sturgeon restoration effort in Cayuga Lake initiated in 1995 by the New York State Department of Environmental Conservation. Lake Sturgeon egg deposition was found specifically on substrate mainly composed of gravel sized rocks with depths and flows that made up a unique microhabitat combination within the creek which is not typical of habitat identified in other Lake Sturgeon spawning habitat studies across the Great Lakes. An estimated 810,052 ± 24,386 eggs were deposited in the sampled area of Fall Creek. The identified, potentially productive spawning microhabitat type in Fall Creek is likely to be widespread in similar tributaries around Cayuga Lake as well as small tributaries to other Finger Lakes and Lake Ontario. Ongoing research is focused on the evaluation of the extent of Finger Lakes habitat similar to that identified in Fall Creek. This microhabitat evaluation of sturgeon spawning and the broad scale landscape knowledge of tributary habitats, should support subsequent management to restore Lake Sturgeon.

New York↗

Geochemistry and petrology of selected coal samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

Indonesia has become the world's largest exporter of thermal coal and is a major supplier to the Asian coal market, particularly as the People's Republic of China is now (2007) and perhaps may remain a net importer of coal. Indonesia has had a long history of coal production, mainly in Sumatra and Kalimantan, but only in the last two decades have government and commercial forces resulted in a remarkable coal boom. A recent assessment of Indonesian coal-bed methane (CBM) potential has motivated active CBM exploration. Most of the coal is Paleogene and Neogene, low to moderate rank and has low ash yield and sulfur (generally < 10 and < 1??wt.%, respectively). Active tectonic and igneous activity has resulted in significant rank increase in some coal basins. Eight coal samples are described that represent the major export and/or resource potential of Sumatra, Kalimantan, Sulawesi, and Papua. Detailed geochemistry, including proximate and ultimate analysis, sulfur forms, and major, minor, and trace element determinations are presented. Organic petrology and vitrinite reflectance data reflect various precursor flora assemblages and rank variations, including sample composites from active igneous and tectonic areas. A comparison of Hazardous Air Pollutants (HAPs) elements abundance with world and US averages show that the Indonesian coals have low combustion pollution potential.

International Journal of Coal Geology↗

Insights on the characteristics and sources of gas from an underground coal mine using compositional data analysis

Coal mine gas originates from the gas emission zone (GEZ) of the mine, as well as the longwall face and pillars. Gas emissions are controlled directly at the sources using horizontal or vertical boreholes drilled from surface or from the entries in advance of mining, or it is captured from the fractured and caved zones (gob) using ventholes during mining. The rest of the gas, especially that gas that originates from the longwall face and caved zone, mixes with the ventilation air and travels through bleeder and return entries before being exhausted to atmosphere from air shafts. Although the gas associated with mining mostly focuses on methane, the gas is not pure methane but is a mixture (where both the components and their quantities vary depending on the sampling location). Understanding the evolution of the composition of the gas from source to different sampling and evaluation points in mines using proper statistical analysis and interpretation methods can lead to better designed degasification and ventilation systems and the selection of the most adequate utilization method for generating energy from the gas. In this work, we present the results of compositional data analysis (CoDa) of gases sampled at different locations in a longwall mine operating in Pennsylvanian coal-bearing strata in the Northern Appalachian coal basin. Sampling locations were from accessible parts of the bleeder entries, returns, bleeder evaluation points and shafts within the mine, and also from gob gas ventholes (GGV) and coal degasification boreholes drilled in the panel areas. In addition, desorbed gas samples from seams that are important for the mine were included in the analyses for comparison. The compositional data analysis showed that the gas composition shifts based on the sampling location, putting in-mine and pure coalbed gases on the opposite ends. Removal of air from the samples did not change this observation suggesting that oxygen is depleted especially for in-mine samples, which is due to oxidation. Results also suggested that desorbed gas samples may not represent the composition of the coal seam gas.

International Journal of Coal Geology↗

Regression models of discharge and mean velocity associated with near-median streamflow conditions in Texas: utility of the U.S. Geological Survey discharge measurement database

A database containing more than 16,300 discharge values and ancillary hydraulic attributes was assembled from summaries of discharge measurement records for 391 USGS streamflow-gauging stations (streamgauges) in Texas. Each discharge is between the 40th- and 60th-percentile daily mean streamflow as determined by period-of-record, streamgauge-specific, flow-duration curves. Each discharge therefore is assumed to represent a discharge measurement made for near-median streamflow conditions, and such conditions are conceptualized as representative of midrange to baseflow conditions in much of the state. The hydraulic attributes of each discharge measurement included concomitant cross-section flow area, water-surface top width, and reported mean velocity. Two regression equations are presented: (1) an expression for discharge and (2) an expression for mean velocity, both as functions of selected hydraulic attributes and watershed characteristics. Specifically, the discharge equation uses cross-sectional area, water-surface top width, contributing drainage area of the watershed, and mean annual precipitation of the location; the equation has an adjusted R-squared of approximately 0.95 and residual standard error of approximately 0.23 base-10 logarithm (cubic meters per second). The mean velocity equation uses discharge, water-surface top width, contributing drainage area, and mean annual precipitation; the equation has an adjusted R-squared of approximately 0.50 and residual standard error of approximately 0.087 third root (meters per second). Residual plots from both equations indicate that reliable estimates of discharge and mean velocity at ungauged stream sites are possible. Further, the relation between contributing drainage area and main-channel slope (a measure of whole-watershed slope) is depicted to aid analyst judgment of equation applicability for ungauged sites. Example applications and computations are provided and discussed within a real-world, discharge-measurement scenario, and an illustration of the development of a preliminary stage-discharge relation using the discharge equation is given.

Texas↗

An automated imagery orthorectification pilot

Automated orthorectification of raw image products is now possible based on the comprehensive metadata collected by Global Positioning Systems and Inertial Measurement Unit technology aboard aircraft and satellite digital imaging systems, and based on emerging pattern-matching and automated image-to-image and control point selection capabilities in many advanced image processing systems. Automated orthorectification of standard aerial photography is also possible if a camera calibration report and sufficient metadata is available. Orthorectification of historical imagery, for which only limited metadata was available, was also attempted and found to require some user input, creating a semi-automated process that still has significant potential to reduce processing time and expense for the conversion of archival historical imagery into geospatially enabled, digital formats, facilitating preservation and utilization of a vast archive of historical imagery. Over 90 percent of the frames of historical aerial photos used in this experiment were successfully orthorectified to the accuracy of the USGS 100K base map series utilized for the geospatial reference of the archive. The accuracy standard for the 100K series maps is approximately 167 feet (51 meters). The main problems associated with orthorectification failure were cloud cover, shadow and historical landscape change which confused automated image-to-image matching processes. Further research is recommended to optimize automated orthorectification methods and enable broad operational use, especially as related to historical imagery archives.

Journal of Remote Sensing↗

Atlas of microscopic images of biochar using reflected light microscopy in biochar characterization

Derived through the thermochemical conversion of biomass, biochar is a carbon-rich substance recognized for its significance in environmental applications and sustainable agriculture. As interest in its utilization continues to rise, it becomes crucial to comprehend how the source material and pyrolysis parameters influence the properties of biochar and, consequently, to research the suitability of various analytical methods for characterizing it. Despite the current utilization of numerous physical and chemical methods, the untapped potential of reflected light microscopy warrants further exploration. While a few recent studies suggest a correlation between certain microscopic characteristics and selected physical and chemical properties of biochar, the data are limited and difficult to compare. This is primarily due to variations in the types of original biomass used and lack of information about pyrolysis conditions. Moreover, because only a limited number of photographs taken under a reflected light microscope are publicly available to-date, it is difficult to evaluate morphological differences between various biochars and other organic materials such as inertinites from coal, charcoal, etc. To address limited availability of publicly available data, this “Atlas of Microscopic Images of Biochar” presents a collection of more than 300 images contributed by researchers from Poland, the United States, Canada, Australia, Brazil, and Denmark. These photomicrographs capture optical characteristics of a diverse array of biochar, demonstrating its unique morphological and structural features. This visual documentation can serve as a valuable resource for researchers, industry professionals, educators, and enthusiasts interested in investigating the complexities of biochar forms.

Indiana Journal of Earth Sciences↗

Modeling movement and fidelity of American black ducks

Spatial relationships among stocks of breeding waterfowl can be an important component of harvest management. Prediction and optimal harvest management under adaptive harvest management (AHM) requires information on the spatial relationships among breeding populations (fidelity and inter-year exchange), as well as rates of movements from breeding to harvest regions. We used band-recovery data to develop a model to estimate probabilities of movement for American black ducks (Anas rubripes) among 3 Canadian breeding strata and 6 harvest regions (3 in Canada, and 3 in the United States) over the period 1965-1998. Model selection criteria suggested that models containing area-, year-, and age-specific recovery rates with area- and sex-specific movement rates were the best for modeling movement. Movement by males to southern harvest areas was variable depending on the originating area. Males from the western breeding area predominantly moved to the Mississippi Flyway or southern Atlantic Flyway (??ij = 0.353, SE = 0.0187 and ??ij = 0.473, SE = 0.037, respectively), whereas males that originated in the eastern and central breeding strata moved to the northern Atlantic flyway (??ij = 0.842, SE = 0.010 and ??ij = 0.578, SE = 0.0222, respectively). We used combined recoveries and recaptures in Program MARK to estimate fidelity to the 3 Canadian breeding strata. Information criteria identified a model containing sex- and age-specific fidelity for black ducks. Estimates of fidelity were 0.9695 (SE = 0.0249) and 0.9554 (SE = 0.0434) for adult males and females, respectively. Estimates of fidelity for juveniles were slightly lower at 0.9210 (SE = 0.0931) and 0.8870 (SE = 0.0475) for males and females, respectively. These models have application to the development of spatially stratified black duck harvest management models for use in AHM.

Journal of Wildlife Management↗