1,354 research outputs found
Effect of Goose Removals on a Suburban Canada Goose Population
Local-nesting or resident Canada geese (Branta canadensis) are coming into conflict with people and human activities in urban-suburban areas throughout North America. Capture and removal of molting geese, followed by translocation or euthanasia, is a simple way to reduce the number of geese in an area, but some critics of lethal goose control methods claim that other geese will quickly fill the void left when geese are removed from a problem area. To better understand the effectiveness of urban-suburban goose removal programs, we captured 591 resident geese (mostly adult birds) in suburban Rockland County, New York, during the summer molt, 2004 and 2005. The birds were transported, marked with neck and leg bands and released in a rural area approximately 320 km to the northwest. Band returns indicated that at least 46% of translocated geese were eventually harvested by hunters, most of those (52%) during the first September hunting season after release, and most (72%) were taken within 50 km of the release site. Neckband observations indicated that \u3c10% of translocated birds returned to Rockland County, and few (\u3c1%) moved to suburban areas near the release site. Annual molting period goose surveys throughout Rockland County from 2004- 2008 indicated that removal of geese from selected sites in Clarkstown resulted in nearly 60% fewer geese town wide for three subsequent years, and other geese did not quickly move in to replace birds that we removed. This study demonstrated that goose removal can be an effective way to reduce local goose populations in some areas for at least three years
Classification of newborn EEG maturity with Bayesian averaging over decision trees
EEG experts can assess a newborn’s brain maturity by visual analysis of age-related patterns in sleep EEG. It is highly desirable to make the results of assessment most accurate and reliable. However, the expert analysis is limited in capability to provide the estimate of uncertainty in assessments. Bayesian inference has been shown providing the most accurate estimates of uncertainty by using Markov Chain Monte Carlo (MCMC) integration over the posterior distribution. The use of MCMC enables to approximate the desired distribution by sampling the areas of interests in which the density of distribution is high. In practice, the posterior distribution can be multimodal, and so that the existing MCMC techniques cannot provide the proportional sampling from the areas of interest. The lack of prior information makes MCMC integration more difficult when a model parameter space is large and cannot be explored in detail within a reasonable time. In particular, the lack of information about EEG feature importance can affect the results of Bayesian assessment of EEG maturity. In this paper we explore how the posterior information about EEG feature importance can be used to reduce a negative influence of disproportional sampling on the results of Bayesian assessment. We found that the MCMC integration tends to oversample the areas in which a model parameter space includes one or more features, the importance of which counted in terms of their posterior use is low. Using this finding, we proposed to cure the results of MCMC integration and then described the results of testing the proposed method on a set of sleep EEG recordings
Optical properties monitor: Experiment definition phase
The stability of materials used in the space environment will continue to be a limiting technology for space missions. The Optical Properties Monitor (OPM) Experiment provides a comprehensive space research program to study the effects of the space environment-both natural and induced-on optical, thermal and space power materials. The OPM Experiment was selected for definition under the NASA/OAST In-Space Technology Experiment Program. The results of the OPM Definition Phase are presented. The OPM Experiment will expose selected materials to the space environment and measure the effects with in-space optical measurements. In-space measurements include total hemispherical reflectance total integrated scatter and VUV reflectance/transmittance. The in-space measurements will be augmented with extensive pre- and post-flight sample measurements to determine other optical, mechanical, electrical, chemical or surface effects of space exposure. Environmental monitors will provide the amount and time history of the sample exposure to solar irradiation, atomic oxygen and molecular contamination
A Ten-Year Record of Supraglacial Lake Evolution and Rapid Drainage in West Greenland Using an Automated Processing Algorithm for Multispectral Imagery
The rapid drainage of supraglacial lakes introduces large pulses of meltwater to the subglacial environment and creates moulins, surface-to-bed conduits for future melt. Introduction of water to the subglacial system has been shown to affect ice flow, and modeling suggests that variability in water supply and delivery to the subsurface play an important role in the development of the subglacial hydrologic system and its ability to enhance or mitigate ice flow. We developed a fully automated method for tracking meltwater and rapid drainages in large (\u3e 0.125 km2) perennial lakes and applied it to a 10 yr time series of ETM+ and MODIS imagery of an outlet glacier flow band in West Greenland. Results indicate interannual variability in maximum coverage and spatial evolution of total lake area. We identify 238 rapid drainage events, occurring most often at low (\u3c 900 m) and middle (900–1200 m) elevations during periods of net filling or peak lake coverage. We observe a general progression of both lake filling and draining from lower to higher elevations but note that the timing of filling onset, peak coverage, and dissipation are also variable. Lake coverage is sensitive to air temperature, and warm years exhibit greater variability in both coverage evolution and rapid drainage. Mid-elevation drainages in 2011 coincide with large surface velocity increases at nearby GPS sites, though the relationships between ice-shed-scale dynamics and meltwater input are still unclear
Quantifying suspended sediment concentration in subglacial sediment plumes discharging from two Svalbard tidewater glaciers using Landsat-8 and in situ measurements
This work was supported by National Science Foundation IGERT award: [Grant Number DGE-0801490]; National Science Foundation GK-12 award: [Grant Number DGE-0947790]; NASA supplement award: [Grant Number NNX10AG22G]; American Alpine Club under their Research Grant; Geological Society of America under their Research Grant; the ConocoPhillips-Ludin Northern Area Program under the CRIOS project (Calving Rates and Impact on Sea Level); and Dartmouth Earth Sciences Department.Marine-terminating outlet glaciers discharge mass through iceberg calving, submarine melting, and meltwater run-off. While calving can be quantified by in situ and remote-sensing observations, meltwater run-off, the subglacial transport of meltwater, and submarine melting are not well constrained due to inherent difficulties observing the subglacial and proglacial environments at tidewater glaciers. Remote-sensing and in situ measurements of surface sediment plumes, and their suspended sediment concentration (SSC), have been used as a proxy for glacier meltwater run-off. However, this relationship between satellite reflectance and SSC has predominantly been established using land-terminating glaciers. Here, we use two Svalbard tidewater glaciers to establish a well-constrained relationship between Landsat-8 surface reflecance and SSC and argue that it can be used to measure relative meltwater run-off at tidewater glaciers throughout a summer melt season. We find the highest correlation between SSCs and Landsat-8 surface reflectance by using the red + NIR band combination (r2 = 0.76). The highest correlation between SSCs and in situ field spectrometer measurements is in the 740-800 nm wavelength range (r2 = 0.85), a spectral range not currently measured by Landsat. Additionally, we find that in situ and Landsat-8 measurements for surface reflectance of SSCs are not interchangeable and therefore establish a relationship for each detection method. We then use the Landsat-8 relationship to calculate total surface sediment load, finding a strong correlation between total surface sediment load and a proxy for meltwater run-off (r2 ≥ 0.89). Our results establish a new metric to calculate SSCs from Landsat-8 surface reflectance and demonstrate how the SSC of subglacial sediment plumes can be used to monitor relative seasonal meltwater discharge at tidewater glaciers.Publisher PDFPeer reviewe
A Comparison of Lethal and Non-Lethal Management Approaches to Reduce Damage Associated with Urban Crow Roosts in New York and Virginia
Crow populations have steadily increased in many parts of the country since 1966. Although large winter congregations of crows in urban environments are not a new phenomenon, the number of complaints regarding damage associated with these large (2,000-20,000 individuals) roosts appears to be increasing. In an effort to assist the public in reducing impacts of urban crow roosts, USDA, APHIS, Wildlife Services in Virginia and New York implemented large-scale roost dispersal programs in the winter of 2001-2002. The goal of the programs were to manage local crow populations to minimize associated noise, accumulations of crow fecal droppings on and around residences, strong ammonia odors from fecal droppings, property damage, clean-up costs and threats to human health and safety. Multiple meetings involving the public and key stakeholders were convened where a variety of options and consequences of each option were discussed. Options considered were no action, habitat alteration, cultural methods, roost dispersal, and roost depopulation. Wildlife Services in each state took different approaches to managing crow roosting sites based on state regulations, available tools, scope of the problem, consequences of each management action, effectiveness of methods, and public input. In Virginia, a lethal control program was initiated targeting one roost site (2,000-6 ,000 crows/roost) using the avicide DRC-1339. The goals were to remove a significant percentage of the local crow population and disperse the remaining crows. This project resulted in an estimated 73% reduction in crow numbers at the primary roost site and altered roost dynamics at another roost. The cooperators satisfaction level was an immediate 75% reduction in damage based on a polling of affected property owners. This satisfaction level was based on a reduction in fecal droppings, maintenance costs to clean up fecal droppings, noise, and abundance of crows. In upstate New York, two roost sites (16,000-20,000 crows/roost) were successfully dispersed using a non-lethal hazing program (pyrotechnics, recorded crow distress calls and hand-held lasers). In New York, no avicides were registered at the time of this project and the Cities of Troy and Albany requested that WS try a non-lethal program prior to implementing a lethal control program. The number of crows in the primary roost in the cities of Albany and Troy were reduced by more than 95% over the course of an eight-day program. Significant reduction in crow numbers and damage remained more than eight weeks later. In this paper we will provide a comparison of crow management projects in Virginia and New York and discuss implications of different approaches for managing urban crows
Double-crested Cormorants
The history of conflict between double-crested cormorants (Figure 1) and human interest in fisheries is long and convoluted. Following a low point in the 1970s, populations of cormorants expanded in North America, as did concerns about impacts on fisheries. By the late 1990s, natural resource agencies in 27 states reported losses of free-ranging fish stocks to cormorants. Agencies in 10 states, ranging from the Southwest to the Northeast, considered cormorant predation to be of moderate to major concern to fishery management.
Overall, double-crested cormorants are not major consumers of commercial and sportfish species. However, exceptions have been recorded at specific sites with documented impacts on local fisheries (see Damage to Fisheries section). Cormorants often congregate and can have significant local impacts where high concentrations of fish occur, such as stocking release sites, private fishing ponds, aquaculture ponds, reservoirs, spawning sites, and other areas.
Cormorants may be managed whenever their damage justi-fies the granting of the permits necessary to control them. Adult cormorants eat approximately 19 ounces of food per day, so local impacts of large flocks on fisheries can be substantial. Although cormorants frequently are blamed for reductions in fish harvests, this is not always substantiat-ed. Sometimes other factors, such as pollution, invasive species, and habitat loss may be the primary factor or con-tributing factors in the decline of fisheries
Mitigation of Double-crested Cormorant Impacts on Lake Ontario: From Planning and Practice to Product Delivery
The New York State Department of Environmental Conservation initiated a Double-crested Cormorant (Phalacrocorax auritus) control program in the eastern basin of Lake Ontario to mitigate cormorant impacts in 1999. Key objectives included improving the quality of Smallmouth Bass (Micropterus dolomieu) and other fisheries, restoring the structure and function of the warmwater fish community and reducing cormorant impacts to nesting habitats of other colonial waterbird species. In eight years of intensive control, cormorant numbers declined, with a corresponding reduction in estimated fish consumption. Diversity and numbers of co-occurring waterbirds either increased or have not been shown to be negatively impacted by management. Woody vegetation favorable to Black-crowned Night-Herons (Nycticorax nycticorax) has been maintained. A ca. 2.5-fold increase in the abundance of Smallmouth Bass abundance in assessment nets over the last seven years is a sign of improved recruitment to the fishery. Since the target population level of 4,500 to 6,000 cormorants has essentially been achieved, the eastern Lake Ontario cormorant program is expected to shift in 2007 from a population reduction focus towards a less intensive program intended to prevent population resurgence
Mitigation of Double-crested Cormorant Impacts on Lake Ontario: From Planning and Practice to Product Delivery
The New York State Department of Environmental Conservation initiated a Double-crested Cormorant (Phalacrocorax auritus) control program in the eastern basin of Lake Ontario to mitigate cormorant impacts in 1999. Key objectives included improving the quality of Smallmouth Bass (Micropterus dolomieu) and other fisheries, restoring the structure and function of the warmwater fish community and reducing cormorant impacts to nesting habitats of other colonial waterbird species. In eight years of intensive control, cormorant numbers declined, with a corresponding reduction in estimated fish consumption. Diversity and numbers of co-occurring waterbirds either increased or have not been shown to be negatively impacted by management. Woody vegetation favorable to Black-crowned Night-Herons (Nycticorax nycticorax) has been maintained. A ca. 2.5-fold increase in the abundance of Smallmouth Bass abundance in assessment nets over the last seven years is a sign of improved recruitment to the fishery. Since the target population level of 4,500 to 6,000 cormorants has essentially been achieved, the eastern Lake Ontario cormorant program is expected to shift in 2007 from a population reduction focus towards a less intensive program intended to prevent population resurgence
Use of a Direct, Rapid Immunohistochemical Test for Diagnosis of Rabies Virus in Bats
Rabies, a zoonotic encephalitis due to transmission of a lyssavirus, such as rabies virus (RABV), has the highest case fatality of any infectious disease. A global program for the elimination of human rabies caused by dogs is proposed for realization by 2030. Sensitive, specific, and inexpensive diagnostic tests are necessary for enhanced surveillance to detect infection, inform public health and veterinary professionals during risk assessments of exposure, and support overall programmatic goals. Multiple laboratory techniques are used to confirm a suspect case of rabies. One method for the detection of lyssavirus antigens within the brain is the direct rapid immunohistochemical test (dRIT), using light microscopy, and suitable for use under field conditions. Besides dogs, other major RABV reservoirs reside among mammalian mesocarnivores and bats. To date, use of the dRIT has been applied primarily for the diagnosis of RABV in suspect mesocarnivores. The purpose of this study was to assess the usefulness of the dRIT to the diagnosis of rabies in bats, compared to the gold-standard, the direct fluorescent antibody test (DFAT). Brains of 264 suspect bats, consisting of 21 species from Arizona and Texas, were used in the evaluation of the dRIT. The overall sensitivity of the dRIT was 100% (0.969–1.0, 95% CI) and the specificity was 94.6% (0.896–0.976, 95% CI), comparable to the DFAT. This preliminary study demonstrated the utility of the dRIT in the confirmation of RABV infection in bats. Future studies should include additional geographic, lyssavirus, and mammalian species representations for broader application during enhanced rabies surveillance, with incorporation of any potential adjustments to standard protocols, as needed
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