Papers by Richard Chipman
Ecological Applications, Mar 31, 2022
Oral baiting is used to deliver vaccines to wildlife to prevent, control, and eliminate infectiou... more Oral baiting is used to deliver vaccines to wildlife to prevent, control, and eliminate infectious diseases. A central challenge is how to spatially distribute baits to maximize encounters by target animal populations, particularly in urban and suburban areas where wildlife such as raccoons (Procyon lotor) are abundant and baits are delivered along roads. Methods from movement ecology that quantify movement and habitat selection could help to optimize baiting strategies by more effectively targeting wildlife populations across space. We developed a spatially explicit, individual-based model of raccoon movement and oral rabies vaccine seroconversion to examine whether and when baiting strategies that match raccoon movement patterns perform better than currently used baiting strategies in an oral rabies vaccination zone in greater Burlington, Vermont, USA. Habitat selection patterns estimated from locally radio-collared raccoons were used to parameterize movement simulations. We then used our simulations to estimate raccoon population rabies seroprevalence under currently used baiting strategies (actual baiting) relative to habitat selection-based baiting strategies (habitat baiting). We conducted simulations on the Burlington landscape and artificial landscapes that varied in heterogeneity relative to Burlington in the proportion and patch size of preferred habitats. We found that the benefits of habitat baiting strongly depended on the magnitude and variability of raccoon habitat selection and the degree of landscape heterogeneity within the baiting area. Habitat baiting improved seroprevalence over actual baiting for raccoons characterized as habitat specialists but not for raccoons that displayed weak habitat selection similar to radiocollared individuals, except when baits were delivered off roads where preferred habitat coverage and complexity was more pronounced. In contrast, in Katherine M. McClure and Guillaume Bastille-Rousseau contributed equally.
Crow populations have steadily increased in man y parts of the country since 1966. Although large... more Crow populations have steadily increased in man y 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 , effectivene ss 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 cormorant populations have increased over the last 20 years within the continental... more Double-crested cormorant populations have increased over the last 20 years within the continental United States. Problems associated with this increase include impacts to commercial aquaculture, damage to property, vegetation, recreational fisheries, and natural resources, as well as concerns over inter-specific competition. Implementation of the forthcoming Environmental Impact Statement for the management of double-crested cormorants will be a monumental task. Several state and federal agencies, along with private citizens and various interest groups will have parts to play. USDA/APHIS/Wildlife Services is expected to have a large part in the implementation of the plan. We discuss the proposed actions to be taken by USDA/APHIS/Wildlife Services, including population reduction measures as well as monitoring population status and reduction of damages caused by double-crested cormorants.
Morbidity and Mortality Weekly Report, Jun 14, 2019
Introduction: Each year, rabies causes approximately 59,000 deaths worldwide, including approxima... more Introduction: Each year, rabies causes approximately 59,000 deaths worldwide, including approximately two deaths in the United States. Before 1960, dogs were a common reservoir of rabies in the United States; however, increasingly, species of wildlife (e.g., bats, raccoons) are the main reservoirs. This report characterizes human rabies deaths, summarizes trends in rabies mortality, and highlights current rabies risks in the United States. Methods: Rabies trends in the United States during 1938-2018 were analyzed using national rabies surveillance data. Data from the Healthcare Cost and Utilization Project for 2006-2014 were used to estimate the number of postexposure prophylaxis (PEP) visits per 100,000 persons during 2017-2018. The Centers for Medicare & Medicaid Services' average sales price data were used to estimate PEP costs. Results: From 1960 to 2018, a total of 125 human rabies cases were reported in the United States; 36 (28%) were attributed to dog bites during international travel. Among the 89 infections acquired in the United States, 62 (70%) were attributed to bats. In 2018, approximately 55,000 persons sought PEP after contact with a potentially rabid animal. Conclusions and Comments: In the United States, wildlife rabies, especially in bats, continues to pose a risk to humans. Travelers also might be exposed to canine rabies in countries where the disease is still present; increased awareness of rabies while traveling abroad is needed. Vaccinating pets, avoiding contact with wildlife, and seeking medical care if one is bitten or scratched by an animal are the most effective ways to prevent rabies. Understanding the need for timely administration of PEP to prevent death is critical.
Applied Animal Behaviour Science, Apr 1, 2023
The United States Department of Agriculture's National Rabies Management Program (NRMP) has coord... more The United States Department of Agriculture's National Rabies Management Program (NRMP) has coordinated the use of oral rabies vaccination (ORV) to control the spread of raccoon rabies virus variant west of the Appalachian Mountains since 1997. Working with state and local partners, the NRMP deploys ORV baits containing a rabies vaccine, primarily targeting raccoon populations (Procyon lotor). Bait competition between raccoons and non-target species may limit the effectiveness of ORV programs, but the extent of bait competition remains poorly quantified, particularly in the southeastern United States. We placed placebo ORV baits in bottomland hardwood (n = 637 baits) and upland pine (n = 681 baits) habitats in South Carolina, USA during August-December 2019 and used remote cameras to examine bait competition between raccoons and non-target species. The estimated proportion of bait consumed by raccoons was 18.8 ± 2.1% in bottomland hardwood and 11.6 ± 2.1% in upland pine habitats. Vertebrate competition appeared to have a minimal effect on raccoon uptake as estimated consumption did not exceed 5% for any species or 8% of bait uptake events cumulatively. We estimated that raccoons were the primary consumer of baits in bottomland hardwood, whereas invertebrates were the primary consumer in upland pine (26.7 ± 1.3% of baits). Our results indicate a need to closely consider the effects of invertebrates on bait consumption to minimize their potential impact on ORV bait uptake by target species. Uptake probabilities by raccoons were relatively low but not primarily driven by competition with vertebrates. As such, strategies to increase the specificity of raccoon uptake may be needed to enhance the effectiveness of ORV baiting programs.
Viruses, Sep 9, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Wildlife Diseases, Mar 31, 2020
The small Indian mongoose (Herpestes auropunctatus) is a rabies reservoir in areas of the Caribbe... more The small Indian mongoose (Herpestes auropunctatus) is a rabies reservoir in areas of the Caribbean including Puerto Rico, but no rabies vaccination program targeting this host exists. We used two derivatives of iophenoxic acid (IPA) to evaluate placebo oral rabies vaccine bait uptake by mongooses in southwestern Puerto Rico. We hand-distributed baits at an application rate of 200 baits/km 2 at three, 400 ha, sites during autumn 2016 and spring 2017. Each site contained 90-100 cage traps in a 100 ha central trapping area. We used ethyl-IPA as a biological marker during the autumn and methyl-IPA during the spring. We live captured mongooses for 10 consecutive days, beginning 1 wk following bait application. We obtained a serum sample from captured mongooses and analyzed the sera for ethyl-and methyl-IPA by liquid chromatographymass spectrometry. During autumn 2016, 63% (55/87) mongooses sampled were positive for ethyl-IPA. In spring 2017, 69% (85/123) of mongooses were positive for methyl-IPA. Pooling seasons, accounting for recaptures between years, and disregarding marker type, 74% (133/179) unique mongooses were positive for IPA biomarker, indicating bait consumption during either the autumn, spring, or both trials. We conclude that distributing baits at an application rate of 200 baits/km 2 is sufficient to reach over 60% of the target mongoose population in dry forest habitats of Puerto Rico.
Journal of Visualized Experiments, Apr 30, 2019
Laboratory-based surveillance is integral for rabies prevention, control and management efforts. ... more Laboratory-based surveillance is integral for rabies prevention, control and management efforts. While the DFA is the gold standard for rabies diagnosis, there is a need to validate additional diagnostic techniques to improve rabies surveillance, particularly in developing countries. Here, we present a standard protocol for the DRIT as an alternative, laboratory or field-based testing option that uses light microscopy as compared to the DFA. Touch impressions of brain tissue collected from suspect animals are fixed in 10% buffered formalin. The DRIT uses rabies virusspecific monoclonal or polyclonal antibodies (conjugated to biotin), a streptavidin-peroxidase enzyme, and a chromogen reporter (such as acetyl 3-amino-9-ethylcarbazole) to detect viral inclusions within infected tissue. In approximately 1 h, a brain tissue sample can be tested and interpreted by the DRIT. Evaluation of suspect animal brains tested from a variety of species in North America, Asia, Africa, and Europe have illustrated high sensitivity and specificity by the DRIT approaching 100% with results compared to DFA. Since 2005, the United States Department of Agriculture's Wildlife Services (USDA WS) program has conducted large-scale enhanced rabies surveillance efforts using the DRIT to test >94,000 samples collected from wildlife in strategic rabies management areas. The DRIT provides a powerful, economical tool for rabies diagnosis that can be used by laboratorians and field biologists to improve current rabies surveillance, prevention and control programs globally.
Viruses, Oct 31, 2019
Intensive efforts are being made to eliminate the raccoon variant of rabies virus (RABV) from the... more 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.
Proceedings of the Vertebrate Pest Conference, 2008
New York State has an estimated population of 249,702 resident Canada geese. Human-goose conflict... more 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 (<2 km). The implementation of an integrated non-lethal goose damage management program over 3 years reduced the number of Canada geese at specific locations and minimized local conflicts. The widespread adoption of this type of program could reduce human-Canada goose conflicts across a larger landscape but will require extensive coordination of local projects, a public involvement process, and an intensive, long-term commitment of resources.
Proceedings of the Vertebrate Pest Conference, 2000
We evaluated bird and small mammal use of two mowed (15 to 25 cm height) and two unmowed vegetati... more 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 5minute 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 ~<0.05) for unrnowed areas than mowed areas after mowing commenced in 1998 and 1999 for each two-week monitoring period. In 1998 to 1999, vegetation density was also higher ~<0.05) for unrnowed plots for 13 of 14 sampling periods. The species composition of vegetation differed (X2=20.54, df=3, f <0.01) among mowed and unmowed plots. Mowed plots contained a higher percentage of grasses (81%versus68%), and a lower percentage of forbs (16% versus 25%) and woody plants (1%versus4%) than unrnowed plots. Vegetation was generally sparse in both unrnowed and mowed plots, a consequence of the poor, sandy soils on much of the airport. We captured 33 small mammals from three species in unmowed plots and 12 individuals of one species in mowed plots in 1999. Small mammal populations increased seasonally in unmowed plots, but remained constant in mowed plots over the same time period. We recommended JFKIA switch from the unmowed vegetation management regime in place since 1986 to a regime of maintaining vegetation mowed at 15 to 25 cm height. This management strategy should reduce bird and small mammal use of grassland areas at JFKIA. Further research should examine use of alternative vegetation types to improve ground cover and vegetation density at JFKIA while minimizing attraction to wildlife.
Journal of Wildlife Diseases, Apr 9, 2019
The effect of high density oral rabies vaccine baiting on rabies virus neutralizing antibody resp... more The effect of high density oral rabies vaccine baiting on rabies virus neutralizing antibody response in raccoons (Procyon lotor)" (2019).
Research Square (Research Square), Oct 5, 2023
Understanding pathogen emergence in new host species is fundamental for developing prevention and... more 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
The Journal of Wildlife Management
Raccoons (Procyon lotor) are the primary reservoir for rabies virus in eastern North America. Man... more Raccoons (Procyon lotor) are the primary reservoir for rabies virus in eastern North America. Management of rabies in raccoons is achieved primarily with the use of oral rabies vaccination (ORV) and effective ORV bait densities are determined in part by the densities of raccoons. Decisions regarding ORV bait densities, however, are limited by an incomplete understanding of raccoon densities across the spectrum of landscapes they occupy. We carried out a mark‐recapture study of raccoons on the Savannah River Site in South Carolina, USA, from 2017–2019, to develop sex‐ and landscape‐specific raccoon density estimates across 4 rural land cover types in the southeastern United States: bottomland hardwood, riparian forest, isolated wetland, and upland pine (Pinus spp.). We captured 404 unique raccoons 773 times over the 3‐year trapping period. Estimated densities were 5.44 ± 0.37 (SE) animals/km2 in bottomland hardwood forest, 2.62 ± 0.32 animals/km2 in riparian forest, 2.19 ± 0.29 anima...
Revista de Educação Continuada em Medicina Veterinária e Zootecnia do CRMV-SP, 2012
Viruses, Jan 22, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Scientific Reports
Raccoons (Procyon lotor) are routinely translocated both legally and illegally to mitigate confli... more Raccoons (Procyon lotor) are routinely translocated both legally and illegally to mitigate conflicts with humans, which has contributed to the spread of rabies virus across eastern North America. The movement behavior of translocated raccoons has important ramifications for disease transmission yet remains understudied and poorly quantified. To examine the spatial ecology of raccoons following experimental translocation, we performed reciprocal 16 km-distance translocations of 30 raccoons between habitats of high and low raccoon density (bottomland hardwood and upland pine, respectively) across the Savannah River Site (SRS) in Aiken, South Carolina, USA (2018–2019). Translocation influenced patterns of raccoon space use, with translocated animals exhibiting a 13-fold increase in 95% utilization distributions (UDs) post- compared to pre-translocation (mean 95% UD 35.8 ± 36.1 km2 vs 1.96 ± 1.17 km2). Raccoons originating from upland pine habitats consistently had greater space use and...
Research Square (Research Square), Apr 21, 2023
Understanding pathogen emergence in new host species is fundamental for developing prevention and... more 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
Broad-scale data show SARS-CoV-2 occurrence in white-tailed deer throughout much of their range i... more Broad-scale data show SARS-CoV-2 occurrence in white-tailed deer throughout much of their range in the conterminous United States and reinforce findings of considerable SARS-CoV-2 infection and exposure. Results shed light on both current infections and prior exposure, with prevalence decreasing over time and seroprevalence increasing.One-Sentence SummaryWhite-tailed deer are infected with, and have been exposed to, SARS-CoV-2 throughout their range in the conterminous US.
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Papers by Richard Chipman