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Background: Throughout the Americas, Lyssavirus rabies (RV) perpetuates as multiple variants among bat and mesocarnivore species. Interspecific RV spillover occurs on occasion, but clusters and viral host shifts are rare. The spillover and host shift of a big brown bat (Eptesicus fuscus) RV variant Ef-W1 into mesocarnivores was reported previously on several occasions during 2001–2009 in Flagstaff, Arizona, USA, and controlled through rabies vaccination of target wildlife. During autumn 2021, a new cluster of Ef-W1 RV cases infecting striped skunks (Mephitis mephitis) was detected from United States Department of Agriculture enhanced rabies surveillance in Flagstaff. The number of Ef-W1 RV spillover cases within a short timeframe suggested the potential for transmission between skunks and an emerging host shift. Materials and Methods: Whole and partial RV genomic sequencing was performed to evaluate the phylogenetic relationships of the 2021–2023 Ef-W1 cases infecting striped skunks with earlier outbreaks. Additionally, real-time reverse-transcriptase PCR (rtRT-PCR) was used to opportunistically compare viral RNA loads in brain and salivary gland tissues of naturally infected skunks. Results: Genomic RV sequencing revealed that the origin of the 2021–2023 epizootic of Ef-W1 RV was distinct from the multiple outbreaks detected from 2001–2009. Naturally infected skunks with the Ef-W1 RV showed greater viral RNA loads in the brain, but equivalent viral RNA loads in the mandibular salivary glands, compared to an opportunistic sample of skunks naturally infected with a South-Central skunk RV from northern Colorado, USA. Conclusion: Considering a high risk for onward transmission and spread of the Ef-W1 RV in Flagstaff, public outreach, enhanced rabies surveillance, and control efforts, focused on education, sample characterization, and vaccination, have been ongoing since 2021 to mitigate and prevent the spread and establishment of Ef-W1 RV in mesocarnivores. [ABSTRACT FROM AUTHOR]

Wildlife translocation and cross-species transmission can impede control and elimination of emerging zoonotic diseases. Tracking the geographic origin of both host and virus (i.e., translocation versus local infection) may help determine the most effective response when high-risk cases of emerging pathogens are identified in wildlife. In May 2022, a coyote (Canis latrans) infected with the raccoon (Procyon lotor) rabies virus variant (RRV) was collected in Lewis County, West Virginia, USA, an area free from RRV. We applied host population genomics and RRV phylogenetic analyses to determine the most likely geographic origin of the rabid coyote. Coyote genomic analyses included animals from multiple eastern states bordering West Virginia, with the probable origin of the rabid coyote being the county of collection. The RRV phylogenetic analyses included cases detected from West Virginia and neighboring states, with most similar RRV sequences collected in a county 80 km to the northeast, within the oral rabies vaccination zone. The combined results suggest that the coyote was infected in an RRV management area and carried the RRV to Lewis County, a pattern consistent with coyote local movement ecology. Distant cross-species transmission and subsequent host movement presents a low risk for onward transmission in raccoon populations. This information helped with emergency response decision-making, thereby saving time and resources. [ABSTRACT FROM AUTHOR]

USDA APHIS Wildlife Services plans for and responds to a variety of exigencies such as wildlife hazards to aircraft, disease emergence from wildlife translocations, oral rabies vaccine barrier compromises, and extreme weather events. These are often collaborative efforts with state and federal agencies and others. Climate change based in part on fossil fuel use and methane gas emissions has predictable as well as unknown consequences. As a federal leader in wildlife disease research and management, it is incumbent upon Wildlife Services to be current with the scientific literature; assess potential impacts and wildlife disease management intervention needs from predicted climate change scenarios; and outline a plan of preparedness to meet a variety of potential exigencies.

Understanding pathogen emergence in new host species is fundamental for developing prevention and response plans for human and animal health. We leveraged a large-scale surveillance dataset coordinated by United States Department of Agriculture, Animal and Plant Health Inspection Service and State Natural Resources Agencies to quantify the outbreak dynamics of SARS-CoV-2 in North American white-tailed deer (Odocoileus virginianus; WTD) throughout its range in the United States. Local epidemics in WTD were well approximated by a single-outbreak peak followed by fade out. Outbreaks peaked early in the northeast and mid-Atlantic. Local effective reproduction ratios of SARS-CoV-2 were between 1 and 2.5. Ten percent of variability in peak prevalence was explained by human infection pressure. This, together with the similar peak infection prevalence times across many counties and single-peak outbreak dynamics followed by fade out, suggest that widespread transmission via human-to-deer spillover may have been an important driver of the patterns and persistence. We provide a framework for inferring population-level epidemiological processes through joint analysis of many sparsely observed local outbreaks (landscape-scale surveillance data) and linking epidemiological parameters to ecological risk factors. The framework combines mechanistic and statistical models that can identify and track local outbreaks in long-term infection surveillance monitoring data. [ABSTRACT FROM AUTHOR]

American crow populations have increased steadily since 1966 in many parts of the U.S. Large winter congregations of crows in urban environments have resulted in an increased number of requests for assistance in managing nocturnal roosts in New York. In 2002, the USDA APHIS Wildlife Services program initiated a large-scale non-lethal winter roost dispersal program in Troy, New York. Since that time, similar programs have been implemented in 4 other cities in New York to manage crow roosts ranging in size from 8,000 - 63,000 individuals. The goals of the programs were to minimize noise, accumulations of crow feces around residences, strong odors associated with droppings, property damage, clean-up costs, and potential threats to human health and safety. The primary management strategy relied on dispersing concentrated crow populations from high-impact high-conflict areas, to low-impact low-conflict areas. An integrated management program using pyrotechnics, amplified recorded crow distress calls, and hand-held lasers was implemented to successfully disperse local crow roosts, reducing populations at the majority of core roost sites each year by more than 98%. In some instances, significant reductions in crow numbers and associated damage persisted >8 weeks after management without additional interventions, although most sites required multiple additional “spot treatments.” High-profile urban wildlife management projects of this type require multiple meetings with key stakeholders and the public and often attract intense media interest, adding complexity to these programs. We provide summary information from 5 cities in New York documenting crow management techniques, intensity of effort, number of interventions required to relocate crow populations, and key lessons learned regarding sciencebased project documentation, project transparency, communication, and the need for long-term adaptive management strategies to meet project goals.

New York State has an estimated population of 249,702 resident Canada geese. Human-goose conflicts are increasing, including unacceptable accumulation of goose feces in public parks, overgrazing of landscaped lawns, noise, and aggressive behavior of individual geese. An integrated Canada goose management program was conducted and evaluated at 8 sites in Orange County, New York from 2004 to 2006. The program, conducted from March through November each year, consisted of egg oiling (300-470 eggs oiled a year), hazing to reduce local goose populations using multiple techniques, public outreach/education, and program monitoring. The monitoring component included goose movement and population surveys using neck-collared geese and standardized fecal counts, at both managed and unmanaged sites. We monitored 3 unmanaged (“control”) sites to provide a comparison. We conducted fecal surveys, as an indirect method for potentially estimating site-specific goose populations and associated reduction in damage. The number of droppings counted, when standardized to droppings per foot per day, decreased at treated sites (2004, 0.16; 2005, 0.12; 2006, 0.05) but did not differ at unmanaged sites, indicating a sustained population reduction on site during the project. In addition, the mean number of geese observed at treated sites decreased each year (2004, 77; 2005, 19; 2006, 11) while the mean number at unmanaged sites did not differ. The alternate location of the majority of dispersed geese is unknown, although monitoring of marked birds indicates that many birds moved only short distances (

USDA APHIS Wildlife Services has been a primary cooperator in the Cape Cod Oral Rabies Vaccination Program (CCORVP) in southeastern Massachusetts since 2001. The CCORVP (1994 - present) was originally designed to reduce the incidence of terrestrial rabies adjacent to the Cape Cod Canal in order to prevent its spread on to peninsular Cape Cod. However, since the barrier breach in 2004, CCORVP is now focused on rabies control in this coastal resort area southeast of Boston, MA. An integral component of wildlife rabies management is oral vaccination with vaccine-laden baits. Consequently, maximizing bait uptake rates is critical to achieving sufficient population immunity to reduce rabies prevalence and achieve control. To that end, knowledge of raccoon food habits, especially at ORV bait delivery times (spring and fall on Cape Cod) is crucial. We undertook a study of raccoon food selection in southeastern Massachusetts to assess the presence of and interest in competing food resources. We collected intact stomachs from raccoons found dead or euthanized for rabies testing within the CCORVP zone during 2006 (n = 33) and 2007 (n = 109) for analysis. Stomach contents were dominated by vegetation (80%), followed by invertebrates (43%), non-food items (41%), vertebrates (35%), and hair (primarily raccoon based on appearance) (15%). Food item occurrence appears to be related to age. We present findings, potential management implications, and suggestions for assessing food use related to rabies control in other locations.

Management of the raccoon rabies virus variant in North America is conducted primarily using oral rabies vaccination (ORV). When a sufficient proportion of the population is vaccinated ((60%), rabies transmission can be eliminated. To date, ORV programs have successfully controlled and eliminated raccoon rabies in rural areas, but there has been less success in urban areas. We studied the proportions of rabies virus neutralizing antibodies (RVNA) in a raccoon (Procyon lotor) population during a 3-yr ORV trial in developed areas of Burlington, Vermont, US. We used a modified N-mixture model to estimate raccoon abundance, RVNA seroprevalence, and capture rates jointly to examine factors that relate to ORV success to better inform management. We found that raccoon abundance was lower in less-developed areas compared to urban centers. Raccoon RVNA seroprevalence decreased as population abundance increased; it increased as the average age of the population increased. Nontarget opossum (Didelphis virginiana) captures correlated with a decrease in raccoon RVNA seroprevalence in low-development areas, suggesting that they may be competing for baits. The target bait density across the entire study area was 150 baits/km2, but a hand baiting strategy was heavily concentrated on roads, resulting in uneven bait densities within sampling sites (0–484 baits/km2 ). Uneven bait distribution across the study area may explain low RVNA seroprevalence in some locations. Our results suggest that increases in bait density across the study area may improve RVNA seroprevalence and support annual ORV to account for raccoon population turnover. [ABSTRACT FROM AUTHOR]

Raccoon rabies virus (RRV) has been managed using multiple vaccination strategies, including oral rabies vaccination and trap-vaccinate-release (TVR). Identifying a rabies vaccination strategy for an area is a nontrivial task. Vaccination strategies differ in the amount of effort and monetary costs required to achieve a particular level of vaccine seroprevalence (efficiency). Simulating host movement relative to different vaccination strategies in silico can provide a useful tool for exploring the efficiency of different vaccination strategies. We refined a previously developed individual-based model of raccoon movement to evaluate vaccination strategies for urban Hamilton, Ontario, Canada. We combined different oral rabies vaccination baiting (hand baiting, helicopter, and bait stations) with TVR strategies and used GPS data to parameterize and simulate raccoon movement in Hamilton. We developed a total of 560 vaccination strategies, in consultation with the Ontario Ministry of Natural Resources and Forestry, for RRV control in Hamilton. We documented the monetary costs of each vaccination strategy and estimated the population seroprevalence. Intervention costs and seroprevalence estimates were used to calculate the efficiency of each strategy to meet targets set for the purpose of RRV control. Estimated seroprevalence across different strategies varied widely, ranging from less than 5% to more than 70%. Increasing bait densities (distributed using by hand or helicopter) led to negligible increase in seroprevalence. Helicopter baiting was the most efficient and TVR was the least efficient, but helicopter-based strategies led to lower levels of seroprevalence (6–12%) than did TVR-based strategies (17–70%). Our simulations indicated that a mixed strategy including at least some TVR may be the most efficient strategy for a local urban RRV control program when seroprevalence levels >30% may be required. Our simulations provide information regarding the efficiency of different vaccination strategies for raccoon populations, to guide local RRV control in urban settings. [ABSTRACT FROM AUTHOR]

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.

Knowledge of wildlife population abundance and activity patterns is integral to sound management decisions. Traditional methods of determining population abundance include mark-recapture, catch/unit effort, aerial and ground counts, and harvest-based or removal efforts. Capture methods are labor intensive and expensive. Census methods are potentially expensive and are often impractical for many wildlife species. Harvest-derived population estimates are not useful where harvest is limited. Tracking or scent stations have been used to index wildlife activity and abundance, but the use of traditional scented-tracking stations may lead to biased population activity or abundance estimates. We built on previous evaluations of passive and scented tracking stations to determine their potential utility for providing raccoon and other carnivore population information to support decisions for wildlife rabies control in coastal pine-oak communities. Methods were evaluated through several small-scale studies conducted in southeastern Massachusetts. Passive tracking stations appear more sensitive to raccoon activity than scented tracking stations (1.38% of scented stations visited vs. 3.38% of passive stations) under apparently low raccoon population densities. Despite concerns over the utility of track-based indices, we recommend the use of passive tracking stations to index raccoon activity over scented tracking stations.

At the request of the New York City Police Department, the Port Authority of New York and New Jersey, and the New York State Department of Environmental Conservation, a team of USDA APHIS Wildlife Services (WS) biologists mobilized in less than 24 hours to assist federal, state and local law enforcement officials in managing birds and rodents impacting the recovery of evidence as a result of the September 11, 2001 terrorist attacks on the World Trade Center. During the 10-month recovery effort from September 2001 to June 2002, more than 1.7 million tons of debris was shipped from “Ground Zero” in Manhattan to a high-security crime scene at the Fresh Kills Landfill (FKL), Staten Island, New York. Close to a billion pieces of debris were sorted by law enforcement officials to recover personal effects, human remains, and other evidence to document the crime and identify victims, as part of the largest forensic investigation in U.S. history. Within days of bringing debris to FKL, more than 2,600 gulls were on site, disrupting work of law enforcement officials and creating a concern that evidence would be lost to birds. Historically, FKL has been a feeding and loafing site for over 100,000 gulls. To address this unprecedented wildlife damage management problem, WS implemented an integrated bird and rodent management program that involved 69 biologists from 23 states. The goal was to reduce the impact of gulls, crows, house mice, and Norway rats on law enforcement personnel, equipment, and evidence collection including a zero-tolerance policy for gulls and crows landing on the working face. A combination of population surveys and direct management activities targeting gulls and crows was initiated 12-14 hours a day, 7 days a week using visual and noise deterrents including pyrotechnics, mylar tape, human and dead-bird effigies, lasers, paint ball guns, and lethal removal of a limited number of birds. In addition, commensal rodent surveys with snap traps were conducted twice monthly to document population trends and explore the need for rodent control on site. We deployed over 23,000 pyrotechnics and dispersed over 172,000 gulls and 5,000 crows from the site. We removed 293 house mice and 46 Norway rats in 6,000 trap-nights. The program was highly effective in preventing gulls and crows from feeding on remains and disrupting workers. We discuss other key lessons learned regarding an emergency response program to manage wildlife.

Persistence of unique rabies virus variants in a diverse array of terrestrial carnivores and insectivorous bats makes rabies control in the U.S. a complex task. The public health system in the U.S. is effective in keeping human deaths near zero each year in the face of enzootic wildlife rabies, but the annual cost of coexistence with the disease is high, exceeding $300 million. In addition, each year tens of thousands of people are impacted by anxiety, fear, and trauma associated with potential or actual rabies exposure to themselves and their domestic animals. Exclusion, proper storage and disposal of garbage, and removal of problem animals are often effective alternatives to address wildlife rabies threats at specific sites; however, oral rabies vaccination (ORV) is the only currently available technique that shows promise for wildlife rabies control on a broad geographic and species scale. In this paper, we discuss progress toward using ORV to contain specific terrestrial rabies virus variants in the U.S. and planning towards coordinated national efforts to explore the elimination of terrestrial variants of rabies virus in the U.S.

We evaluated bird and small mammal use of two mowed (15 to 25 cm height) and two unmowed vegetation plots (40 to 88 ha) at John F. Kennedy International Airport (JFKIA), New York, in 1998 to 1999 to determine which management strategy would best reduce wildlife use of the airport. We counted more birds per 5- minute observation period in unmowed plots than mowed plots in both 1998 (9.0 versus 7.9) and 1999 (11.7 versus 8.6). Maximum vegetation height was greater (P

In spite of significant progress toward the application of recycling and other waste minimization processes, active landfills are expected to remain a common feature on the landscape for the foreseeable future. The availability of food and habitat at landfills will continue to act as a catalyst for a variety of human-wildlife conflicts. In this paper, we will focus specifically on on-site and off-site conflicts and management alternatives to resolve conflicts associated with gulls at landfills. Case histories of gull damage management programs conducted by Wildlife Services will be presented to illustrate the effectiveness of control strategies adapted to meet site-specific management objectives at landfills in the northeastern United States.