Coyotes in the Eastern US: Status and Implications --Damage Problems and Economic Losses from Coyotes in the Northeastern U.S.--

Losses of livestock to coyotes (Canis latrans) have historically been a matter of concern to ranchers and Animal Damage Control personnel in the western US. With range expansion of the coyote into the eastern US, coyote depredations on domestic stock and fowl appears to be emerging as an issue that will deserve to be more fully addressed by researchers, policy makers and management personnel in this region of the US. This portion of the panel presentation will review and discuss damage problems and losses from coyotes in the northern states of the Eastern Animal Damage Control (ADC) Region

Research Needs in Wildlife Damage Control: Research Needs as Perceived by State Directors in the Eastern ADC Region

This presentation provides a brief overview of wildlife damage-related research needs as they are perceived by Animal and Plant Health Inspection Service (APHIS), Animal Damage Control (ADC) State Directors in the Eastern ADC Region. There are 23 State Directors in the Eastern ADC Region who are responsible for managing operational and technical assistance animal damage programs in 31 states. Because of their collective experience with a variety of species and control techniques under various environmental circumstances, their imput and insight should be valuable in helping those in the research community more clearly define wildlife damage-related research needs

Double-Crested Cormorant and Ring-Billed Gull Damage Management on Lake Champlain: Are Basin-Wide Objectives Achievable?

Ring-billed gulls (Larus delewarensis) and double-crested cormorants (Phalacrocorx auritus) have nested on Lake Champlain since 1949 and 1982, respectively. Recent increases in cormorant nesting populations and pioneering activities of both species to previously uncolonized islands have resulted in impacts related to accumulation of bird guano and interspecific competition with less common species. Of primary concern are: decreases in wildlife and plant diversity on islands; reduced aesthetics and property values of island associated with the loss of trees; and predation or competition for nesting space with other species such as the state-endangered common tern (Sterna hirundo). In addition, public concerns have been raised over potential impacts to fish species by cormorants, as well as urban-suburban gull activity impacting human health and safety and property. Nine stakeholder meetings have been held since 1990, to consider prospective management strategies for gulls and cormorants on Lake Champlain, Vermont. Since 1994, limited site-specific control efforts have been conducted by USDA-APHIS-ADC (ADC) at the request of the Vermont Fish and Wildlife Department (VFWD) and private landowners who recently experienced damage from these species. A technique for the removal of cormorant nests in trees has been developed and tested by ADC using portable pumps to deliver pressurized water to remove the nests. This technique has proven successful in tree nests up to approximately 15 m. Also, an alternative method is being tested to selectively remove nesting cormorants from a great blue heron (Ardea herodius) rookery. Currently, a draft environmental assessment is being prepared cooperatively by VFWD and ADC that explores alternatives for future management over 5 years beginning in 1998. Extensive public involvement using a variety of approaches will occur during the summer of 1997. VFWD, in cooperation with ADC, will continue to approach damage management on Lake Champlain for these species on a site-specific basis while working toward a more comprehensive interstate and international agreement on goals for basin-wide population and ecosystem management

ORAL RABIES VACCINATION—A PROGRESS REPORT

Oral rabies vaccination (ORV) targeting specific wild Carnivora species has emerged as an integral adjunct to conventional rabies control strategies to protect humans and domestic animals. ORV has been applied with progress toward eliminating rabies in red foxes (Vulpes vulpes) in western Europe and southern Ontario, Canada. Beginning in the 1990’s, coordinated ORV was implemented in Texas to contain and eliminate variants of rabies virus in the gray fox (Urocyon cinereoargenteus ) and coyote (Canis latrans ) and in several eastern U.S. States with the goal of preventing spread of raccoon (Procyon lotor ) rabies. The primary components of the control strategy include: enhanced rabies surveillance, coordinated ORV, use of natural barriers to bolster ORV, and contingency actions to treat emerging foci. The National Rabies Management Program, which is a cooperative program that began in 1997, has progressively grown to meet rabies control needs and currently includes ORV in 16 eastern states and Texas and Arizona. Annually, approximately 11 million baits are distributed over about 200,000 km2 in strategic locations to contain and eliminate variants of the rabies virus in coyotes, gray foxes and raccoons. Canine rabies in coyotes has been eliminated from Texas and a maintenance ORV barrier created along the Rio Grande in Texas has been challenged in 2001 and 2004, underscoring its importance in preventing re-infection with canine strain of rabies from Mexico. Hotspots in or near ORV zones targeting gray fox rabies, as well as breaches in ORV zones focused on raccoon rabies in Ohio and Massachusetts (Cape Cod) continue to be treated to restore the integrity of original ORV efforts. Development of new or improved oral rabies vaccines and baits that are also effective in vaccinating striped skunks (Mephitis mephitis) are among several key challenges facing the program. Skunks appear to help maintain the raccoon variant and serve to re-infect areas (Guerra et al. 2003), potentially confounding our ability to achieve long-term rabies management goals with currently available tools. A more comprehensive discussion of the current status of ORV in the U.S., including advances in enhanced rabies surveillance, application of contingency action plans, and research and management initiatives to address challenges facing rabies control in terrestrial wildlife nationally is provided by Slate et al. (2005)

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

ORAL RABIES VACCINATION: REDUCING ECONOMIC UNCERTAINTY VIA RESPONSE SURFACE ANALYSIS

Economic uncertainty surrounds the distribution of Raboral V-RG7 as an oral rabies vaccine (ORV) bait for the containment or elimination of raccoon-variant rabies in the United States. This paper describes a costs-savings model of ORV. It also describes Excel XP7 code that was prepared to compute potential net savings (NS) and benefit-cost ratios (BCRs) associated with Raboral V-RG7 bait distributions. Currently, baits and bait distributions are relatively expensive; individual baits are produced at a cost of $1.27 for federal use and typically dispensed at \u3e75 baits/km2. Distribution is estimated at$8.62/km2, $15.80/km2, and$33.30/km2 for fixed-winged (FW), ground (Gnd), and rotary-winged (RW) applications, respectively. Although many assumptions are required, iterative runs of the code allow plotting NS and BCR response surfaces for diverse scenarios based on 6 ORV variables: area (km2), bait-price (US/vaccine bait), bait-density (#/km2), application frequency (n), mode-of-delivery [US for % fixed-winged (FW), % rotarywinged (RW), and % ground-dispensed (Gnd)], and effectiveness (% seropositive titer conversion). Using a raccoon-rabies-epizootic-containment scenario for parts of Pennsylvania and a modest epizootic cost estimate of $40 million, the greatest NS ($6.4 to 38.4 million) and BCR (2.85 to 25.76) indices occurred for a one-time bait distribution involving FW aircraft over a fourth of the state with a $0.90/bait price. As expected, greater reliance on the more expensive RW and Gnd modes of bait distribution compared to FW aircraft, coupled with higher bait prices and higher bait densities, decreased NS and BCR indices. The utility of the approach to economic forecasting and decision making of ORV effects are discussed

Tactics and Economics of Wildlife Oral Rabies Vaccination, Canada and the United States

Progressive elimination of rabies in wildlife has been a general strategy in Canada and the United States; common campaign tactics are trap–vaccinate–release (TVR), point infection control (PIC), and oral rabies vaccination (ORV). TVR and PIC are labor intensive and the most expensive tactics per unit area (≈$616/km2 [in 2008 Can$, converted from the reported $450/km2 in 1991 Can$] and ≈$612/km2 [$500/km2 in 1999 Can$], respectively), but these tactics have proven crucial to elimination of raccoon rabies in Canada and to maintenance of ORV zones for preventing the spread of raccoon rabies in the United States. Economic assessments have shown that during rabies epizootics, costs of human post-exposure prophylaxis, pet vaccination, public health, and animal control spike. Modeling studies, involving diverse assumptions, have shown that ORV programs can be cost-efficient and yield benefit:cost ratios \u3e1.0

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

Potential effect of prior raccoonpox virus infection in raccoons on vaccinia-based rabies immunization

<p>Abstract</p> <p>Background</p> <p>The USDA, Wildlife Services cooperative oral rabies vaccination (ORV) program uses a live vaccinia virus-vectored (genus <it>Orthopoxvirus</it>) vaccine, Raboral V-RG^®(V-RG), to vaccinate specific wildlife species against rabies virus in several regions of the U.S. Several naturally occurring orthopoxviruses have been found in North America, including one isolated from asymptomatic raccoons (<it>Procyon lotor</it>). The effect of naturally occurring antibodies to orthopoxviruses on successful V-RG vaccination in raccoons is the focus of this study.</p> <p>Results</p> <p>Overall, raccoons pre-immunized (n = 10) with a recombinant raccoonpox virus vaccine (RCN-F1) responded to vaccination with V-RG with lower rabies virus neutralizing antibody (VNA) titers than those which were not pre-immunized (n = 10) and some failed to seroconvert for rabies VNA to detectable levels.</p> <p>Conclusion</p> <p>These results suggest that the success of some ORV campaigns may be hindered where raccoonpox virus or possibly other orthopoxvirus antibodies are common in wildlife species targeted for ORV. If these areas are identified, different vaccination strategies may be warranted.</p

Rabies in North America: A Model of the One Health Approach

The One Health concept merges environmental, wildlife, domestic animal, and human health into a global, interconnected context. Though recently a popular catchphrase due to the emergence and reemergence of diseases such as foot-and-mouth disease (FMD), bluetongue, bovine spongiform encephalopathy (BSE), Q Fever, Rift Valley fever, Nipah virus, West Nile virus (WNV), severe acute respiratory syndrome (SARS), highly pathogenic H5N1 avian influenza, and plague, the One Health concept is not new. The One Health approach to managing infectious diseases aims to promote and implement meaningful collaboration and communication between multiple allied disciplines working locally, nationally, and internationally to attain optimal health for people, domestic animals, wildlife, and our environment. Rabies is an ancient disease that results in more than 55,000 human deaths worldwide each year. Historic and current emphasis on interdisciplinary approaches to rabies control provides a prime example of a zoonotic disease that is being managed more effectively via the One Health approach. In North America, a few meso-carnivores and bats serve as reservoirs of rabies, perpetuating continual infection of humans, pets, and livestock. Increased emphasis on surveillance and control of rabies in wildlife is the key to local, regional, and continental elimination strategies