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The number of ground‐nesting ducks in the marshes of Great Salt Lake (GSL), Utah has drastically decreased in the past few decades. One potential cause for this decline is the increase in climate extremes caused by global warming. From 2019 through 2023, GSL marshes experienced 1 year of historic spring rainfall (2019), 2 years of historic droughts (2021 and 2022), and 1 year of record snowfall (2023). We used this time period to test the hypothesis that climate extremes impact both the number of duck nests and their fate (i.e., successful, depredated, or abandoned). We counted 563 nests of cinnamon teal (Spatula cyanoptera), 168 mallards (Anas platyrhynchos), and 220 gadwalls (Mareca strepera). Nest numbers varied among years and were positively correlated with the amount of spring rainfall (April and May). Clutch sizes differed among years and were lowest during the drought years. Raccoons (Procyon lotor) and striped skunks (Mephitis mephitis) were the major predators of nests. The percentage of all duck nests that were depredated varied among years and increased from 40% and 46% during the 2 wet years to 75% and 90% during the 2 drought years. The percentage of nests that were successful varied among years and were highest during the wet years. The yearly percentage of successful nests was negatively correlated with the abundance of all predators and positively correlated with snowfall because few skunks and raccoons survived the winter of 2023 with its heavy snowfall. Daily survival rates (x¯$$ \overline{x} $$ = 0.93), were similar among duck species, but varied among years; DSRs were lowest during the drought years (0.86 and 0.92) and highest during the wet years (0.96 for both years). Our results suggest that climate extremes will have an adverse impact on both the number of duck nests and the percentage of them that are successful. [ABSTRACT FROM AUTHOR]

Disease caused by the archetypical amdoparvovirus (APV), Aleutian mink disease virus (AMDV), has been well studied, but APV infections in other carnivores are poorly understood. Skunk amdoparvovirus (SKAV), one of a handful of newly discovered APVs, is apparently species-specific in striped skunks (Mephitis mephitis) and has a high prevalence across North America. We have evaluated the infection status and viral tissue distribution in a cohort of 26 free-ranging California skunks from a single rehabilitation facility who were euthanized due to poor prognosis for recovery from neurologic disease. SKAV was detected in the majority of this cohort, and virus was associated with a spectrum of lesions including tubulointerstitial nephritis, meningoencephalitis, myocarditis, and arteritis. Affected tissue and patterns of inflammation were partially overlapping with those of AMDV infection but were notably distinct in the kidney.

Skunk amdoparvovirus (Carnivore amdoparvovirus 4, SKAV) is closely related to Aleutian mink disease virus (AMDV) and circulates primarily in striped skunks (Mephitis mephitis) in North America. SKAV poses a threat to mustelid species due to reported isolated infections of captive American mink (Neovison vison) in British Columbia, Canada. We detected SKAV in a captive striped skunk in a German zoo by metagenomic sequencing. The pathological findings are dominated by lymphoplasmacellular inflammation and reveal similarities to its relative Carnivore amdoparvovirus 1, the causative agent of Aleutian mink disease. Phylogenetic analysis of the whole genome demonstrated 94.80% nucleotide sequence identity to a sequence from Ontario, Canada. This study is the first case description of a SKAV infection outside of North America. [ABSTRACT FROM AUTHOR]

Urban coyotes are commonly exposed to rodenticides used to control non-native commensal rodents, but these rodents are rare in published accounts of their diets. An alternative source of rodenticide exposure is through the consumption of mesocarnivores that have themselves eaten either toxic bait directly or poisoned rodents or invertebrates. Carcasses of 311 nuisance and road-killed coyotes from suburban and urban areas of southern California were collected from 2016-2018. Stomachs were dissected and prey items were identified visually. Stomach contents containing tissue from suspected mammalian prey (N = 178) were homogenized and DNA was extracted. Genus-specific primers (123-366 bp) were designed for Virginia opossums, raccoons, and striped skunks, regionally common species that are known to be consumed by coyotes. PCR was performed for each primer pair, and presence of PCR products of particular amplicon lengths were determined by gel electrophoresis. Coyote stomachs containing a PCR product of the appropriate size were considered to contain that prey item. Land use data were used to assess landscape factors that are associated with the consumption of mesocarnivores. Combining both techniques, mesocarnivores were detected at low frequencies: opossums (8%) were more common than raccoons (2%) and skunks (2%). Some 72% of meso-carnivores present in stomachs were detected by molecular methods, while 66% were identified by morphological methods. Opossums were associated with increased development and anthropogenic land use, while skunks were associated with large natural areas, and raccoons used all habitat types. The extent to which mesocarnivores themselves eat poisoned prey remains unknown, although they may be a potential source of exposure for coyotes. Additionally, landscape factors do not appear to be related to raccoon consumption but may influence presence, and therefore consumption, of skunks and opossums.

Babesia species are intraerythrocytic protozoan parasites that infect a variety of hosts. The goal of this study was to evaluate the piroplasm species present in skunks in various states in the United States and determine whether there was any geographic variation. Spleen, whole blood, or blood on filter paper were received from Pennsylvania, Kentucky, North Carolina, South Carolina, Georgia, Missouri, Louisiana, Texas, Kansas, and California, and were tested for Babesia sp. We tested four species of skunks including striped skunk (Mephitis mephitis, n = 72), eastern spotted skunk (Spilogale putorius, n = 28), western spotted skunk (Spilogale gracilis, n = 15), and hog-nosed skunk (Conepatus leuconotus, n = 11). A PCR assay targeting the 18S rRNA region and cox1 region were used to determine if skunks were infected with piroplasms and for phylogenetic analyses. A total of 48.4% (61/126) of skunks tested positive for a Babesia species. Both the 18S and cox1 analysis supported a skunk-specific Babesia microti-like sp. of carnivores as well as a species in the B. microti complex that is phylogenetically unique from both B. microti of humans and the B. microti-like sp. of carnivores. In the 18S analysis, there was a third species of Babesia in hog-nosed skunks in the western piroplasm group. This study shows that at least three species of piroplasms occur in skunk species in the United States and further highlights the importance of phylogenetic analyses and the use of multiple gene targets when studying piroplasms.

The effectiveness of tiletamine-zolazepam (1.7 mg/kg) plus medetomidine (0.07 mg/kg; TZM) as an immobilizing combination in raccoons (Procyon lotor; n=43) and striped skunks (Mephitis mephitis; n=7) was evaluated during October 2019. Mean (±SD) induction time for raccoons was 15.0±6.6 min. First signs of recovery (head up) occurred 12.9±6.0 min after receiving atipamezole reversal (0.35 mg/kg) and animals were standing in 30.3±16.1 min. Mean induction time for skunks was 11.7±5.8 min. Following reversal, skunks first raised their heads in 6.7±4.3 min and stood in 17.1±12.9 min. Recovery in skunks and female raccoons was not related to length of time immobilized, but male raccoons that were immobilized for longer periods of time stood faster after reversal. Raccoon heart rate (HR) remained steady during immobilization, but respiration rate (RR) and rectal temperature (RT) declined. The HR and RR were similar among males and females, but RT of male raccoons were, on average, 0.5 C higher than those of females, and rate of temperature decline was slower for males. The HR, RR, and RT of skunks declined during immobilization. Although induction times for both raccoons and skunks were longer than expected, induction and recovery were smooth, side effects were few, analgesia was adequate for nonsurgical procedures, and reversal reduced time in captivity. [ABSTRACT FROM AUTHOR]

The oil produced by the anal glands of the striped skunk is known to be a strong deterrent to potential predators. However, it is also a common ingredient in many trap lures, especially those for carnivores such as the coyote. This paradoxical nature of skunk oil being both attractive and aversive has yet to be investigated, leaving a gap in the understanding of how predators of skunks respond to visual and olfactory information. In this project, camera traps with baited skunk models with either black-andwhite or brown pelage were deployed in natural areas around Southern California in order to study the effects of skunk oil and pelt coloration on predator behavior. Our study found scented models were less likely to be visited, indicating an avoidance of the oil and its scent.

Wild animals have been implicated as the origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but it is largely unknown how the virus affects most wildlife species and if wildlife could ultimately serve as a reservoir for maintaining the virus outside the human population. We show that several common peridomestic species, including deer mice, bushy-tailed woodrats, and striped skunks, are susceptible to infection and can shed the virus in respiratory secretions. In contrast, we demonstrate that cottontail rabbits, fox squirrels, Wyoming ground squirrels, black-tailed prairie dogs, house mice, and racoons are not susceptible to SARS-CoV-2 infection. Our results expand the knowledge base of susceptible species and provide evidence that human-wildlife interactions could result in continued transmission of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Rabies is a fatal viral zoonosis that is transmitted by bite contact with saliva of an infected animal. In the U.S., human deaths are rare, but each year over 5,000 rabid animals are reported and over 90% of cases are from wildlife. Multiple species of carnivores and bats are the primary sylvatic reservoirs in the U.S., and several variants circulate independently among these two taxonomic orders. Rabies prevention efforts led by USDA APHIS Wildlife Services using live recombinant vaccine baiting began in 1995 and currently target raccoons and canids, but the territory of the south-central skunk rabies virus variant has been expanding in recent years, leading to incursions into areas previously free of carnivore rabies. Colorado has been one such area, where multiple species of bats were the main rabies reservoir prior to 2007. By 2012, the number of rabid striped skunks exceeded rabid bats in Colorado. Larimer County and Weld County, in Northern Colorado, both witnessed skunk rabies epizootics starting in 2012 that have continued through 2013. Despite spillover events into raccoons, red foxes, companion animals, and livestock during 2012 and 2013, no other host species appears to support independent circulation of the south-central skunk variant in Northern Colorado. Virus isolation from salivary glands of rabid animals will help to quantify the likelihood for secondary transmission from spillover hosts and guide intervention strategies targeting wildlife. We describe the spatiotemporal pattern of the epizootic and predict likely areas of spread along the Front Range of Northern Colorado.

Targeted surveillance for raccoon rabies virus was conducted between February and May 2017, near Waweig, New Brunswick, Canada, in response to detection of a rabid striped skunk (Mephitis mephitis) on 8 February 2017. A total of six skunks, 11 raccoons (Procyon lotor), and two porcupines (Erethizon dorsatum) were live-trapped, euthanized, and tested for rabies virus antigens using the direct rapid immunohistochemical test. Of these, only two skunks tested positive for rabies. All three rabid skunks came from the same location, an abandoned barn used as a denning site. Four of five skunks removed from this barn were males. Feeding, aggression, extreme response to noise and light stimuli, and exposure to porcupine quills were observed in two rabid skunks. No additional cases of rabies in wildlife were detected in the area since 8 March 2017. A targeted surveillance approach that removed potentially infected wildlife followed by localized oral rabies vaccine distribution was implemented in this locality. [ABSTRACT FROM AUTHOR]

The most important reservoir of wildlife rabies on the American Great Plains is the striped skunk. A rabid striped skunk taken in August 1988 near Deaver, WY became the index case for a subsequent epizootic in a previously skunk rabies free area. In 1989, more rabid skunks occurred and the epizootic was moving throughout Sage Creek and in later years (1990-1993) through the entire Shoshone River basin. Federal, state, and local officials cooperated in a rabies program with the goal of addressing the health and safety of the region’s citizens, domestic animals, and livestock. Three areas of focus in the program were: 1) immunization of pets and livestock, 2) public education, and 3) skunk population monitoring and control. Rabies immunizations were re-emphasized by the local veterinarians and public health officials for pets to decrease potential rabies spillover to other species. Public education emphasized the dangers of rabies and the behavior of rabid animals using local news media and assemblies at area schools. This paper provides a synoptic overview of the third component – skunk population monitoring and control provided by USDA/APHIS’s Wyoming Wildlife Services (WS). WS provided trapping expertise starting in 1990 with rabid specimens identified by the Wyoming State Veterinary Laboratory. Starting in 1990, WS’s National Wildlife Research Center provided data analysis of rabid locations for the entire epizootic (i.e., 1988-1993). These analyses demonstrated the epizootic’s movements through the novel first use of a Geographic Information System that merged a wildlife disease (i.e., rabies) case/capture locations and dates with additional GIS data layers including hydrology, human population density, and land use. The epizootic ended in 1994 with striped skunks, bats, cats, and one horse affected. Studying this epizootic should benefit officials in planning future surveillance and/or depopulation programs. This study demonstrated the need for a skunk rabies vaccine and effective delivery system, and if the latter had been available maybe this epizootic would have been more limited in its scope and duration.

A Live Trap Loaning Program has evolved to address urban wildlife problems in Reno, Nevada. The program, operated by USDA Wildlife Services, has responded to the public’s need to address urban wildlife problems in the absence of an active Wildlife Services specialist in this urban area. The species for which most of the live traps (cage or enclosed) have been requested, since the program’s initiation in FY 1992, are California ground squirrels, raccoons, and striped skunks. We discuss information transfer and educational components of this program, which convey to the public information on the biology of target species, proper handling of non-target catches, handouts, and options available for resolving their wildlife problems.

ABSTRACT We tested whether striped skunks (Mephitis mephitis) in Flagstaff, Arizona, USA, could be recognized based on variation in pelage patterns and whether camera position influenced that outcome. We presented 11 volunteers with 2 sets of 24 photographs taken between 1 January and 15 February 2015, one with animals photographed from the side, the other from above. Each set of 24 photographs included 9 pairs, with each pair representing 2 different images of the same animal. Volunteers scored twice as many correct matches and 4‐fold fewer false matches when photographs were taken from above. Regardless of camera position, the total number of unique skunks in each set was underestimated (83% of total from above, 75% from side), likely because some skunks had very similar pelage patterns. Our results indicate that variation in nose stripe, back stripe, dorsal and ventral tail pattern, and shape of tail can be used to recognize individual striped skunks but similarity in those characteristics among some individuals may cause total number of unique individuals to be underestimated regardless of camera orientation. © 2017 The Wildlife Society.

Twenty-five Conservation Reserve Program (CRP) contract holders in Riley County, Kansas were surveyed by telephone to assess their perceptions of wildlife damage relative to CRP plantings. Sixty-four percent experienced wildlife damage on their farm or ranch. Respondents felt that five species causing damage on their farm or ranch had become more common due to enrollment of lands in the CRP. White-tailed deer (Odocoileus virginianus) accounted for 64.3% of these observations, followed by wild turkey (Meleagris gallopavo), eastern cottontail (Sylvilagus floridanus), striped skunk (Mephitis mephitis), and Virginia opossum (Didelphis virginiana), which accounted for 14.3%, 7.1%, 7.1 %, and 7.1% of the damage observations, respectively. Only 12.5% of respondents attempted to control wildlife damage, and none felt that wildlife damage was severe enough to preclude future enrollment in programs such as the CRP. Most respondents allowed hunting or trapping by non-family members on their CRP lands (68.8%), but none felt that increased hunting or trapping would reduce the amount of wildlife damage they experienced. All respondents felt that the benefits of the CRP exceeded costs associated with wildlife damage and that the program was highly beneficial overall.

Small-to-medium sized mammals and large animals are lucrative sources of blood meals for ixodid ticks that transmit life-threatening tick-borne flaviviruses (TBFVs). TBFVs have been isolated from various organs obtained from wild-caught Myodes and Apodemus species in Europe and Asia. Thus, these rodents are well-established reservoirs of TBFVs. Wild-caught Peromyscus species have demonstrated seropositivity against Powassan virus, the only TBFV known to circulate in North America, suggesting that they may play an important role in the biology of the virus in this geographic region. However, virus isolation from Peromyscus species is yet to be demonstrated. Wild-caught medium-sized mammals, such as woodchucks (Marmota monax) and skunks (Mephitis mephitis) have also demonstrated seropositivity against POWV, and virus was isolated from apparently healthy animals. Despite the well-established knowledge that small-to-medium sized animals are TBFV reservoirs, specific molecular biology addressing host-pathogen interactions remains poorly understood. Elucidating these interactions will be critical for gaining insight into the mechanism(s) of viral pathogenesis and/or resistance. [ABSTRACT FROM AUTHOR]

Background: Prevention and control of wildlife disease invasions relies on the ability to predict spatio-temporal dynamics and understand the role of factors driving spread rates, such as seasonality and transmission distance. Passive disease surveillance (i.e., case reports by public) is a common method of monitoring emergence of wildlife diseases, but can be challenging to interpret due to spatial biases and limitations in data quantity and quality. Methodology/Principal findings: We obtained passive rabies surveillance data from dead striped skunks (Mephitis mephitis) in an epizootic in northern Colorado, USA. We developed a dynamic patch-occupancy model which predicts spatio-temporal spreading while accounting for heterogeneous sampling. We estimated the distance travelled per transmission event, direction of invasion, rate of spatial spread, and effects of infection density and season. We also estimated mean transmission distance and rates of spatial spread using a phylogeographic approach on a subsample of viral sequences from the same epizootic. Both the occupancy and phylogeographic approaches predicted similar rates of spatio-temporal spread. Estimated mean transmission distances were 2.3 km (95% Highest Posterior Density (HPD95): 0.02, 11.9; phylogeographic) and 3.9 km (95% credible intervals (CI95): 1.4, 11.3; occupancy). Estimated rates of spatial spread in km/year were: 29.8 (HPD95: 20.8, 39.8; phylogeographic, branch velocity, homogenous model), 22.6 (HPD95: 15.3, 29.7; phylogeographic, diffusion rate, homogenous model) and 21.1 (CI95: 16.7, 25.5; occupancy). Initial colonization probability was twice as high in spring relative to fall. Conclusions/Significance: Skunk-to-skunk transmission was primarily local (< 4 km) suggesting that if interventions were needed, they could be applied at the wave front. Slower viral invasions of skunk rabies in western USA compared to a similar epizootic in raccoons in the eastern USA implies host species or landscape factors underlie the dynamics of rabies invasions. Our framework provides a straightforward method for estimating rates of spatial spread of wildlife diseases. [ABSTRACT FROM AUTHOR]

Aleutian disease virus (ADV, Amdovirus, Parvoviridae) primarily infects farmed mustelids (mink and ferrets) but also other fur-bearing animals and humans. Three Aleutian disease (AD) cases have been described in captive striped skunks; however, little is known about the relevance of AD in free-ranging carnivores. This work describes the pathological findings and temporospatial distribution in 7 cases of AD in free-ranging striped skunks. All cases showed neurologic disease and were found in a 46-month period (2010–2013) within a localized geographical region in California. Lesions included multisystemic plasmacytic and lymphocytic inflammation (ie, interstitial nephritis, myocarditis, hepatitis, meningoencephalitis, pneumonia, and splenitis), glomerulonephritis, arteritis with or without fibrinoid necrosis in several organs (ie, kidney, heart, brain, and spleen), splenomegaly, ascites/hydrothorax, and/or encephalomalacia with cerebral microangiopathy. ADV infection was confirmed in all cases by specific polymerase chain reaction and/or in situ hybridization. The results suggest that AD is an emerging disease in free-ranging striped skunks in California. [ABSTRACT FROM AUTHOR]

We provide information on recent records of the 2 subspecies of striped skunk occurring in the northeastern (Mephitis mephitis estor) and northwestern (M. m. holzneri) region of Baja California, Mexico. Most of the recent records for these subspecies come from valleys and suburban zones. [ABSTRACT FROM AUTHOR]

Predicting the geographic spread of wildlife epidemics requires knowledge about the movement patterns of disease hosts or vectors. The field of landscape genetics provides valuable approaches to study dispersal indirectly, which in turn may be used to understand patterns of disease spread. Here, we applied landscape genetic analyses and spatially explicit models to identify the potential path of raccoon rabies spread in a mesocarnivore community. We used relatedness estimates derived from microsatellite genotypes of raccoons and striped skunks to investigate their dispersal patterns in a heterogeneous landscape composed predominantly of agricultural, forested and residential areas. Samples were collected in an area covering 22 000 km2 in southern Québec, where the raccoon rabies variant ( RRV) was first detected in 2006. Multiple regressions on distance matrices revealed that genetic distance among male raccoons was strictly a function of geographic distance, while dispersal in female raccoons was significantly reduced by the presence of agricultural fields. In skunks, our results suggested that dispersal is increased in edge habitats between fields and forest fragments in both males and females. Resistance modelling allowed us to identify likely dispersal corridors used by these two rabies hosts, which may prove especially helpful for surveillance and control (e.g. oral vaccination) activities. [ABSTRACT FROM AUTHOR]

Background: Striped skunks (Mephitis mephitis) are susceptible to infection with some influenza A viruses. However, the viral shedding capability of this peri-domestic mammal and its potential role in influenza A virus ecology are largely undetermined. Methodology/Principal Findings: Striped skunks were experimentally infected with a low pathogenic (LP) H4N6 avian influenza virus (AIV) and monitored for 20 days post infection (DPI). All of the skunks exposed to H4N6 AIV shed large quantities of viral RNA, as detected by real-time RT-PCR and confirmed for live virus with virus isolation, from nasal washes and oral swabs (maximum ≤106.02 PCR EID50 equivalent/mL and ≤105.19 PCR EID50 equivalent/mL, respectively). Some evidence of potential fecal shedding was also noted. Following necropsy on 20 DPI, viral RNA was detected in the nasal turbinates of one individual. All treatment animals yielded evidence of a serological response by 20 DPI. Conclusions/Significance: These results indicate that striped skunks have the potential to shed large quantities of viral RNA through the oral and nasal routes following exposure to a LP AIV. Considering the peri-domestic nature of these animals, along with the duration of shedding observed in this species, their presence on poultry and waterfowl operations could influence influenza A virus epidemiology. For example, this species could introduce a virus to a naive poultry flock or act as a trafficking mechanism of AIV to and from an infected poultry flock to naive flocks or wild bird populations. [ABSTRACT FROM AUTHOR]

Background: Striped skunks (Mephitis mephitis) are susceptible to infection with some influenza A viruses. However, the viral shedding capability of this peri-domestic mammal and its potential role in influenza A virus ecology are largely undetermined. Methodology/Principal Findings: Striped skunks were experimentally infected with a low pathogenic (LP) H4N6 avian influenza virus (AIV) and monitored for 20 days post infection (DPI). All of the skunks exposed to H4N6 AIV shed large quantities of viral RNA, as detected by real-time RT-PCR and confirmed for live virus with virus isolation, from nasal washes and oral swabs (maximum ≤106.02 PCR EID50 equivalent/mL and ≤105.19 PCR EID50 equivalent/mL, respectively). Some evidence of potential fecal shedding was also noted. Following necropsy on 20 DPI, viral RNA was detected in the nasal turbinates of one individual. All treatment animals yielded evidence of a serological response by 20 DPI. Conclusions/Significance: These results indicate that striped skunks have the potential to shed large quantities of viral RNA through the oral and nasal routes following exposure to a LP AIV. Considering the peri-domestic nature of these animals, along with the duration of shedding observed in this species, their presence on poultry and waterfowl operations could influence influenza A virus epidemiology. For example, this species could introduce a virus to a naive poultry flock or act as a trafficking mechanism of AIV to and from an infected poultry flock to naive flocks or wild bird populations. [ABSTRACT FROM AUTHOR]

Powassan virus, a member of the tick-borne encephalitis group of flaviviruses, encompasses 2 lineages with separate enzootic cycles. The prototype lineage of Powassan virus (POWV) is principally maintained between Ixodes cookei ticks and the groundhog (Marmota momax) or striped skunk (Mephitis mephitis), whereas the deer tick virus (DTV) lineage is believed to be maintained between Ixodes scapularis ticks and the white-footed mouse (Peromyscus leucopus). We report 14 cases of Powassan encephalitis from New York during 2004-2012. Ten (72%) of the patients were residents of the Lower Hudson Valley, a Lyme disease-endemic area in which I. scapularis ticks account for most human tick bites. This finding suggests that many of these cases were caused by DTV rather than POWV. In 2 patients, DTV infection was confirmed by genetic sequencing. As molecular testing becomes increasingly available, more cases of Powassan encephalitis may be determined to be attributable to the DTV lineage. [ABSTRACT FROM AUTHOR]

A striped skunk ( Mephitis mephitis) rabies epizootic in northwestern Wyoming was studied from the Index Case in 1988 to the last case in 1993, and possibly is the first rabies epizootic in a previously rabies-free zone monitored from beginning to end. The 843 km 2 study area comprised skunk habitat along 90 km of Shoshone River’s floodplain from Bighorn Lake upstream to Cody. Of 1,015 skunks tested, 215 were rabies-positive. Integrating spatial and temporal data from positive cases, we analyzed the epizootic’s movements and dynamics at 6-month intervals using multivariate movement maps, a new multivariate descriptive methodology presented here to demonstrate the epizootic’s directional flow, while illustrating areas with higher case densities (i.e., wave crests). This approach should help epidemiologists and public health officials to better understand future rabies epizootics. [ABSTRACT FROM AUTHOR]

Six Virginia opossums (Didelphis virginiana), nine raccoons (Procyon lotor) and one striped skunk (Mephitis mephitis) collected from Keith County Nebraska were examined for ectoparasites. All three host species were parasitized by adults of the American dog tick, Dermacentor variabilis. Opossums were also parasitized by the flea Pulex simulans and the tiny fur mite Didelphilichus serrifer; the latter species represents a new state record for Nebraska. Raccoons were also parasitized by P. simulans and by the lagomorph- associated flea Euhoplopsyllus glacialis affinis, whereas the skunk was also parasitized by the chewing louse Neotrichodectes mephiditis. [ABSTRACT FROM AUTHOR]

The article offers information on a study conducted by researchers Julien Mainguy from Ministere des ressources naturelles et de la Faune, Christine Fehlner-Gardiner from Centre of Expertise for Rabies and Dennis Slate from the U.S. Department of Agriculture to compare the performance of oral vaccine baits (OCBs) against rabies for raccoons from Quebec and Vermont. It examines the use of raccoon sera in the comparison of the OCBs Raboral V-RG and Onrab.

Understanding plant community responses to combinations of biotic and abiotic factors is critical for predicting ecosystem response to environmental change. However, studies of plant community regulation have seldom considered how responses to such factors vary with the different phases of the plant growth cycle. To address this deficit we studied an aquatic plant community in an ecosystem subject to gradients in mute swan (Cygnus olor) herbivory, riparian shading, water temperature and distance downstream of the river source. We quantified abundance, species richness, evenness, flowering and dominance in relation to biotic and abiotic factors during the growth-, peak-, and recession-phases of the plant growth cycle. We show that the relative importance of biotic and abiotic factors varied between plant community properties and between different phases of the plant growth cycle. Herbivory became more important during the later phases of peak abundance and recession due to an influx of swans from adjacent pasture fields. Shading by riparian vegetation also had a greater depressing effect on biomass in later seasons, probably due to increased leaf abundance reducing light intensity reaching the aquatic plants. The effect of temperature on community diversity varied between upstream and downstream sites by altering the relative competitiveness of species at these sites. These results highlight the importance of seasonal patterns in the regulation of plant community structure and function by multiple factors. [ABSTRACT FROM AUTHOR]

The article explores rabies antibody prevalence in wild-caught raccoons and striped skunks, Mephitis mephitis, and pinpoint factors influencing the probability of being antibody positive at the individual level in these species. Oral rabies vaccination campaigns have been conducted in which ONRAB vaccination baits were distributed in 2007-2009 in Quebec. The yearly percentages of antibody-positive raccoons and skunks varied between 35% and 56% and 11% and 17%, respectively.

Pleistocene climate fluctuations rearranged ecosystems, and influenced the contemporary distribution of modern species. Although specialist species were often restricted to isolated refugia by Pleistocene climate change, generalist species may have been less constrained in their distribution and movements. We used a combination of genetic data and previously published fossil data to investigate the phylogeography and contemporary population structure of a generalist species, the striped skunk (Mephitis mephitis). We sequenced a portion of the mitochondrial cytochrome-b gene (601 base pairs) and amplified 8 microsatellite loci from 314 striped skunk specimens. Phylogenetic analysis of the cytochrome-b gene revealed the presence of 4 distinct phylogroups, and examination of microsatellite data indicated a pattern of secondary contact among these clades. We infer from these data that during the Rancholabrean stage prior to the Illinoian glaciation, striped skunks emerged from a southern refugium in the Texas-Mexico region and colonized the southeastern United States, forming a 2nd, later refugium in the east. This colonization was followed by a 2nd dispersal event from the southern source population to west of the Rocky Mountains during the Illinoian glacial period. During the Sangamonian interglacial stage, 2 distinct subclades formed on either side of the Sierra Nevada. During the Holocene, the subclade that colonized the Great Basin then expanded east across the northern Rockies and recolonized the Great Plains to create an area of secondary contact with the southern phylogroup. Secondary contact occurred to a lesser extent with individuals from the eastern phylogroup east of the Mississippi River. It appears that periodic Pleistocene glacial expansions and retreats caused a series of range expansions and secondary contact events in this native North American species to create a complex pattern of population structure today. [ABSTRACT FROM AUTHOR]

The article compares the field performance of Onrab and Raboral V-RG oral rabies vaccine in raccoons and striped skunks in New Brunswick and Maine. Results of analyses by rabies virus serum neutralization assays and competitive enzyme-linked immunosorbent assay showed no significant difference between the two vaccines in the proportion of antibody-positive striped skunks. A significant difference in vaccine performance was observed among raccoons.

Data from wildlife disease surveillance programs are used to inform implementation of disease control (e.g., vaccination, population reduction) in space and time. We developed an approach to increase detection of raccoon rabies in raccoons (Procyon lotor) and skunks (Mephitis mephitis) of Québec, Canada, and we examined the implications of using this approach for targeted surveillance. First we modeled the probability of sampling a rabid animal relative to environmental characteristics of sampling locations. Rabid animals were more likely to be found in low-lying flat landscapes that had higher proportions of corn-forest edge habitat and hay agriculture, and that were within 20 km of one or more known rabies cases. From the model, we created 2 complementary risk maps to identify areas where rabid animals were most likely to be sampled. One map accounted for habitat and known rabies case locations, and can be used to define an infection zone from which surveillance can be targeted along the periphery to determine if disease is continuing to spread. The other map only accounted for habitat and can be used to locate areas most likely to contain rabid animals when the disease is present. In a further analysis we compared the 2 most successful methods for detecting raccoon rabies in Québec, given the disease was present. Government trapping operations (active surveillance) detected more cases in the short-term, but citizen notification (passive and enhanced) was more effective after 12 trapping days from which the initial rabies case was found. Our approach can benefit wildlife and public health agencies wanting to assess the disease status of regions by targeting surveillance to habitats most likely to contain infected animals and by defining the duration over which sampling methods are effective. [ABSTRACT FROM AUTHOR]

The article presents research on aerial distribution of oral vaccine baits to immunize raccoons or Procyon lotor and striped skunks or Mephitis mephitis in the wildlife against rabies. It references a study by Jean-Philippe Boyer and colleagues published in the same issue of the journal. It examines the effects of habitat and the timing of the bait distribution on the contact rate between the animals and the ONRAB&nreg vaccine bait.

Macroscopic sarcocysts are often observed in ducks, but at present their taxonomic status remains uncertain because ducks serve as intermediate hosts for several such parasites in the genus Sarcocystis. One such species, Sarcocystis rileyi, was long ago established to involve the northern shoveler duck (Anas clypeata) and the striped skunk (Mephitis mephitis) as its intermediate and definitive hosts, respectively. Here, we employed light microscopy, electron microscopy, and DNA sequencing to more precisely describe diagnostic attributes of parasites presumed to represent S. rileyi occurring in a naturally-infected mallard duck (Anas platyrhynchos). By light and transmission electron microscopy, sarcocysts from the mallard duck resembled the S. rileyi described from A. clypeata. We document 18S, ITS-1, and 28S rDNA sequences from the mallard duck, the first for S. rileyi from any host. Sequences of conserved and variable portions of nuclear ribosomal DNA indicated that S. rileyi is related to, but distinct from, parasites employing opossums as their definitive host (including Sarcocystis neurona and Sarcocystis falcatula). Diagnostic ultrastructural features and nucleotide sequences should aid in future studies and communications regarding this parasitic taxon, which lends itself to experimentation because its sarcocysts are macroscopic and easily excised from infected birds. [ABSTRACT FROM AUTHOR]

We used radiotelemetry to document and compare activity and movement between the western spotted skunk Spilogale gracilis, and the striped skunk Mephitis mephitis in Texas. Mephitis mephitis had a higher rate of movement than S. gracilis. Both species had highest rates of movement during autumn, coinciding with dispersal of young. With the exception of summer, M. mephitis was significantly more active than S. gracilis and generally took shorter breaks during nightly activity. We documented statistical differences in activity between species for all seasons. Highest activity of one species occurred during lowest activity of the other species, which may indicate avoidance of the larger more-dominant species, M. mephitis, by S. gracilis. [ABSTRACT FROM AUTHOR]

Multicomponent aposematic warning signals are generally accepted to function as a deterrent to predatory attacks; however, the relative importance of specific visual cues used by wild predators to recognize defended animals is poorly understood. Here, I use naturally and reciprocally colored taxidermy models of striped skunks (Mephitis mephitis) and gray foxes (Urocyon cinereoargenteus) to explore the impact of aposematic coloration and body shape on the behavior of wild mammalian predators. Models were baited, and all visiting species were recorded with remote video cameras at 10 wilderness sites in California, USA. I found that mammalian predators not only approached black-and-white models more hesitantly than gray-colored models but also reacted negatively to skunk-shaped models, suggesting that predators may generalize noxious qualities to both skunk coloration and skunk shape. This study also found an effect of skunk abundance on animal behavior with predators less likely to visit black-and-white models and more hesitant in their approach to skunk-shaped models at sites with greater skunk abundance. These findings suggest that prior experience and the frequency with which aposematic prey are encountered in a landscape are important predictors of predator avoidance of defended prey. [ABSTRACT FROM PUBLISHER]

1. Occupancy estimation and modelling based on detection–nondetection data provide an effective way of exploring change in a species’ distribution across time and space in cases where the species is not always detected with certainty. Today, many monitoring programmes target multiple species, or life stages within a species, requiring the use of multiple detection methods. When multiple methods or devices are used at the same sample sites, animals can be detected by more than one method. 2. We develop occupancy models for multiple detection methods that permit simultaneous use of data from all methods for inference about method-specific detection probabilities. Moreover, the approach permits estimation of occupancy at two spatial scales: the larger scale corresponds to species’ use of a sample unit, whereas the smaller scale corresponds to presence of the species at the local sample station or site. 3. We apply the models to data collected on two different vertebrate species: striped skunks Mephitis mephitis and red salamanders Pseudotriton ruber. For striped skunks, large-scale occupancy estimates were consistent between two sampling seasons. Small-scale occupancy probabilities were slightly lower in the late winter/spring when skunks tend to conserve energy, and movements are limited to males in search of females for breeding. There was strong evidence of method-specific detection probabilities for skunks. As anticipated, large- and small-scale occupancy areas completely overlapped for red salamanders. The analyses provided weak evidence of method-specific detection probabilities for this species. 4. Synthesis and applications. Increasingly, many studies are utilizing multiple detection methods at sampling locations. The modelling approach presented here makes efficient use of detections from multiple methods to estimate occupancy probabilities at two spatial scales and to compare detection probabilities associated with different detection methods. The models can be viewed as another variation of Pollock's robust design and may be applicable to a wide variety of scenarios where species occur in an area but are not always near the sampled locations. The estimation approach is likely to be especially useful in multispecies conservation programmes by providing efficient estimates using multiple detection devices and by providing device-specific detection probability estimates for use in survey design. [ABSTRACT FROM AUTHOR]

Thousands of mammals are killed annually from vehicle collisions, making the issue an important one for conservation biologists and environmental managers. We recorded all readily identifiable kills on or immediately adjacent to roads in the southern Great Plains from March 2004–March 2007. We also recorded distance traveled, whether a road was paved or divided, the number of lanes, and prevailing habitat. Surveys were opportunistic and were conducted by car during conditions of good visibility. Over our 239 surveys and >16,500 km traveled, we recorded 1412 roadkills from 18 different mammal species (size ranged from Sciurus squirrels to the white-tailed deer, Odocolieus virginianus). The overall kill rate was 8.50 / 100 km. Four species were prone to collisions: the Virginia opossum ( Didelphis virginiana), nine-banded armadillo ( Dasypus novemcinctus), striped skunk ( Mephitis mephitis), and northern raccoon ( Procyon lotor). Together they accounted for approximately 85% (1198) of all roadkills. Mortality rate differed significantly between 2- and 4-lane roads (8.39 versus 7.79 / 100 km). Kill rates were significantly higher on paved versus unpaved roads (8.60 versus 3.65 / 100 km), but did not depend on whether a road was divided. Roadkills were higher in spring than in fall (1.5×), winter (1.4×), or summer (1.3×). The spring peak (in kills / 100 km) was driven chiefly by the armadillo (2.76 in spring/summer versus 0.73 in autumn/winter) and opossum (2.65 versus 1.47). By contrast, seasonality was dampened by a late winter/early spring peak in skunk mortalities, for which 41% occurred in the 6-week period of mid-February through March. The raccoon did not exhibit a strong seasonal pattern. Our data are consistent with dispersal patterns of these species. Our results underscore the high rate of highway mortality in the southern plains, as well as differences in seasonality and road type that contribute to mortality. Conservation and management efforts should focus on creating underpasses or using other means to reduce roadkill rates. [ABSTRACT FROM AUTHOR]

Case Description—A 5-month-old captive female striped skunk (Mephitis mephitis) was evaluated because of lethargy, signs of depression, azotemia, and erythema of the skin around the eyes. Clinical Findings—Antemortem diagnostic tests revealed renal disease but failed to identify an etiologic agent. A diagnosis of severe nonsuppurative interstitial nephritis was made on the basis of results of histologic examination of renal biopsy specimens. Treatment and Outcome—The skunk was administered isotonic fluids SC daily and later every other day because of the handling-related stress. Because of the skunk's deteriorating condition, it was euthanized after 24 days of supportive care. Aleutian disease was diagnosed on the basis of positive results of a PCR assay that targeted the DNA from Aleutian disease virus (ADV); positive results for ADV were also obtained by use of plasma counterimmunoelectrophoresis and an ELISA. Genetic sequencing of the 365-base pair PCR product revealed 90% sequence identity with mink ADV Clinical Relevance—In the skunk of this report, infection with a skunk-specific parvovirus resulted in clinical signs and pathologic changes similar to those associated with ADV infection in mink. For skunks with signs of renal failure, differential diagnoses should include parvovirus infection. In confirmed cases of infection with this ADV-like virus, appropriate quarantine and biosecurity measures should be in place to prevent spread to other susceptible animals within a zoological collection. [ABSTRACT FROM AUTHOR]

Viable Toxoplasma gondii was isolated by bioassay in mice from tissues of 2 feral cats (Felis domesticus), 2 raccoons (Procyon lotor), a skunk (Mephitis mephitis) trapped in remote locations in Manitoba, Canada, and a black bear (Ursus americanus) from Kuujjuaq, northern Quebec, Canada. Genotyping of these T. gondii isolates using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast marker Apico revealed 4 genotypes. None of the isolates was clonal archetypal Types I, II, and III found in the United States. These results are in contrast with the Type II genotype that is widespread in domestic animals and humans throughout the United States and Europe. This is the first genotyping of T. gondii isolates from this part of North America. [ABSTRACT FROM AUTHOR]

During 2005-2006, sera and tissues from raccoons (Procyon lotor), coyotes (Canis latrans), and skunks (Mephitis mephitis) from the state of Wisconsin were tested for Toxoplasma gondii infection. Antibodies to T. gondii were found in 32 of 54 (59.2%) raccoons, 18 of 35 (51.4%) coyotes, and 5 of 7 (71.4%) skunks using the modified agglutination test and a cut-off titer of 1:20. Pooled tissues (brains, hearts, and tongues) from 30 raccoons, 15 coyotes, and 1 skunk were bioassayed for T. gondii infection in mice or cats. Viable T. gondii was isolated from 5 of 30 (16.7%) raccoons, 6 of 15 (40.0%) coyotes, and the skunk. Genetic characterization of the 12 parasite isolates by multilocus PCR-RFLP markers revealed 6 different genotypes including 5 atypical and 1 archetypal II lineages. The results indicate the prevalence of T. gondii in wildlife mammals is high and that these animals may serve as an important reservoir for transmission of T. gondii. [ABSTRACT FROM AUTHOR]