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

Evaluation of Bird Response to Propane Exploders in an Airport Environment

Bird-aircraft collisions (bird-strikes) cause serious safety hazards to aircraft, costing civilian aviation at least $496 million annually in the U.S. Non-lethal bird-frightening devices, such as propane exploders, are commonly used to deter birds from airport environments. We conducted a study during August - October 2004 to determine the efficacy of propane exploders utilized with and without concurrent lethal reinforcement activities for altering bird behavior at John F. Kennedy International Airport in Queens, New York. Two groups of 8 propane exploders each were deployed on the airfield. One group of propane exploders was set to “off” (control), whereas the other group was programmed to activate at 15-minute intervals (treatment). This pattern was reversed each week for a 12-week period. In addition, lethal control activities to reduce gull-aircraft collisions were conducted during August and September 2004. We conducted bird observations associated with propane exploders during the lethal control program (8-week period) and following the end of the program (4-week period). The number of bird flocks (≥1 birds) that were within 150 m of treatment (n = 432) and control (n = 442) propane exploders was similar. Simultaneous lethal control activities at the airport did not alter the effectiveness of the propane exploders. Birds responded (e.g., altered flight path) on 3 of 21 (14.3%) occasions when a bird flock was within 150 m of a treatment propane exploder that activated. Our findings suggest propane exploders used in this manner in this airport environment do not significantly alter birds behavior or reduce the threat of bird-strikes. Future research is needed to evaluate techniques such as motion-activated propane exploders to enhance the effectiveness of this tool to reduce wildlife hazards at airports

Modeling raccoon (Procyon lotor) habitat connectivity to identify potential corridors for rabies spread

The United States Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Wildlife Services National Rabies Management Program has conducted cooperative oral rabies vaccination (ORV) programs since 1997. Understanding the eco-epidemiology of raccoon (Procyon lotor) variant rabies (raccoon rabies) is critical to successful management. Pine (Pinus spp.)-dominated landscapes generally support low relative raccoon densities that may inhibit rabies spread. However, confounding landscape features, such as wetlands and human development, represent potentially elevated risk corridors for rabies spread, possibly imperiling enhanced rabies surveillance and ORV planning. Raccoon habitat suitability in pine-dominated landscapes in Massachusetts, Florida, and Alabama was modeled by the maximum entropy (Maxent) procedure using raccoon presence, and landscape and environmental data. Replicated (n = 100/state) bootstrapped Maxent models based on raccoon sampling locations from 2012–2014 indicated that soil type was the most influential variable in Alabama (permutation importance PI = 38.3), which, based on its relation to landcover type and resource distribution and abundance, was unsurprising. Precipitation (PI = 46.9) and temperature (PI = 52.1) were the most important variables in Massachusetts and Florida, but these possibly spurious results require further investigation. The Alabama Maxent probability surface map was ingested into Circuitscape for conductance visualizations of potential areas of habitat connectivity. Incorporating these and future results into raccoon rabies containment and elimination strategies could result in significant cost-savings for rabies management here and elsewhere

APPLE PRODUCTION, VOLE CONTROL, AND WILD TURKEYS: FINDING A BALANCE IN VERMONT

Meadow voles (Crotus pennsylvanicus) and pine voles (Crotus inetorum) cause extensive damage to apple trees by gnawing and girdling trunk and root systems. In 1991, approximately 70% of Vermont\u27s 90 commercial apple producers were using zinc phosphide (ZP) treated cracked corn to manage vole damage. From November 1991 throughout January 1992, 36 confirmed wild turkey deaths were attributed to the broadcast application of ZP treated cracked coin in Vermont orchards. As a result of public concern regarding impacts to nontarget wild turkeys, a working group was formed with representation of various state and federal agencies as well as the apple industry to address this issue and review current vole damage management strategies. Since 1992, statewide voluntary compliance with working group recommendations that included shifting to ZP treated rolled oats have reduced the risk of wild turkey exposure to ZP. In this paper we discuss the effectiveness of the working group recommendations as measured by a mail survey of apple producers as well as a preliminary 4-year analysis of statewide rodenticide sales

Rabies Surveillance Identifies Potential Risk Corridors and Enables Management Evaluation

Intensive efforts are being made to eliminate the raccoon variant of rabies virus (RABV) from the eastern United States and Canada. The United States Department of Agriculture (USDA) Wildlife Services National Rabies Management Program has implemented enhanced rabies surveillance (ERS) to improve case detection across the extent of the raccoon oral rabies vaccination (ORV) management area. We evaluated ERS and public health surveillance data from 2006 to 2017 in three northeastern USA states using a dynamic occupancy modeling approach. Our objectives were to examine potential risk corridors for RABV incursion from the U.S. into Canada, evaluate the effectiveness of ORV management strategies, and identify surveillance gaps. ORV management has resulted in a decrease in RABV cases over time within vaccination zones (from occupancy (ψ) of 0.60 standard error (SE) = 0.03 in the spring of 2006 to ψ of 0.33 SE = 0.10 in the spring 2017). RABV cases also reduced in the enzootic area (from ψ of 0.60 SE = 0.03 in the spring of 2006 to ψ of 0.45 SE = 0.05 in the spring 2017). Although RABV occurrence was related to habitat type, greater impacts were associated with ORV and trap–vaccinate–release (TVR) campaigns, in addition to seasonal and yearly trends. Reductions in RABV occupancy were more pronounced in areas treated with Ontario Rabies Vaccine Bait (ONRAB) compared to RABORAL V-RG®. Our approach tracked changes in RABV occurrence across space and time, identified risk corridors for potential incursions into Canada, and highlighted surveillance gaps, while evaluating the impacts of management actions. Using this approach, we are able to provide guidance for future RABV management

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

The Path to Eliminating Raccoon Rabies in the Eastern US-Obstacles and Opportunities in Urban-Suburban Landscapes

Rabies in terrestrial wildlife poses a significant public and animal health threat. Oral rabies vaccination (ORV) targeting specific vector species has proven effective in eliminating certain rabies variants in Europe and Canada. The goal of eliminating the raccoon rabies variant (RRV) in the US is achievable through an integrated ORV program at the landscape scale. Current wildlife rabies management in the US includes extensive air and ground ORV programs in 16 eastern states coordinated by Wildlife Services (WS)’ National Rabies Management Program. More than 10 million vaccine-baits are distributed annually targeting raccoons (Procyon lotor) and striped skunks (Mephitis mephitis) with the long-term goal of eliminating RRV. Achieving vaccine-induced herd immunity in target species in developed landscapes has proven challenging due to abundant anthropogenic food sources, higher wildlife densities, decreased home ranges, habitat fragmentation, and non-target bait competition. Effectively managing RRV in the urban-suburban landscape requires greater understanding of meso-carnivore ecology in these landscapes and critical analyses of current baiting strategies. Preliminary results from urban-suburban studies demonstrate fewer potential ORV bait encounters for target species than expected, lower seroconversion rates compared to rural habitats and patchy bait distribution patterns. New technologies including the use of Point of Interest GPS units to document ground bait distribution in combination with research conducted by WS including ORV field trials, urban density studies, and raccoon, skunk, and opossum (Didelphis virginiana) ecology have provided valuable insight to overcome the obstacles of urban rabies management and make eliminating RRV a reality

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