Search

The original description of Pachysentis canicola Meyer, 1931 was based on an unknown number of specimens from an undetermined species of Canis in Brazil from the Berlin Museum. It has since been reported from other carnivores in South and North America. Our specimens from the maned wolf, Chrysocyon brachyurus (Illiger, 1815), in Texas, represent a new host record, and has shed more light on morphometric characteristics missing from the original description, and expanded the range of variations in characters that remained fixed since 1931 and that have been repeated in other taxonomic accounts. We have found additional specimens in striped skunk, Mephitis mephitis Schreber, also in Texas. We have performed metal analysis on hooks using EDXA (energy dispersive X-ray analysis). Sequences for the 18S gene and ITS1-5.8-ITS2 region of rDNA were generated to molecularly characterize the species for the first time. Worms with a massive trunk and a globular proboscis with prominent dome-like apical organ and 12 irregular spiral rows of 4–5 hooks deeply embedded in cuticular folds each, totaling 48–60 hooks. We have included line drawings of the male and female reproductive systems, among other structures, also missing from the original and subsequent descriptions. We describe a new population of P. canicola from Texas and report on the metal analysis of its hooks using EDXA. We also assess the phylogenetic position of P. canicola supporting its independent status in the family Oligacanthorhynchidae, inferred from the two molecular markers. This is the foremost molecular characterization of any species of Pachysentis and will provide significant insights and reference for future molecular study of species of Pachysentis, especially from this newly described Texas population.

Communication behaviors play a critical role in both an individual’s fitness as well as the viability of populations. Solitary animals use chemical communication (i.e., scent marking) to locate mates and defend their territory to increase their own fitness. Previous research has suggested that striped skunks (Mephitis mephitis) do not perform scent-marking behaviors, despite being best known for using odor as chemical defense. We used video camera traps to document behaviors exhibited by striped skunks at a remote site in coastal California between January 2012 and April 2015. Our camera traps captured a total of 71 visits by striped skunks, the majority of which (73%) included a striped skunk exhibiting scent-marking behaviors. Overall, we documented 8 different scent-marking behaviors. The most frequent behaviors we documented were cheek rubbing (45.1%), investigating (40.8%), and claw marking (35.2%). The behaviors exhibited for the longest durations on average were grooming ( $$ \overline{x} $$ = 34. 4 s) and investigating ( $$ \overline{x} $$ = 21.2 s). Although previous research suggested that striped skunks do not scent mark, we documented that at least some populations do and our findings suggest that certain sites are used for communication via scent marking. Our study further highlights how camera traps allow researchers to discover previously undocumented animal behaviors.

Haemaphysalis longicornis, the Asian longhorned tick (ALT), is native to eastern Asia, but it has become invasive in several countries, including Australia, New Zealand and recently in the eastern United States (US). To identify wild mammal and avian host species in the US, we conducted active wildlife surveillance in two states with known ALT infestations (Virginia and New Jersey). In addition, we conducted environmental surveys in both states. These surveillance efforts resulted in detection of 51 ALT-infested individuals from seven wildlife species, including raccoon (Procyon lotor), Virginia opossum (Didelphis virginiana), red fox (Vulpes vulpes), woodchuck (Marmota monax), eastern cottontail (Sylvilagus floridanus), striped skunk (Mephitis mephitis) and white-tailed deer (Odocoileus virginianus). We found ALT in the environment in both states and also collected three native tick species (Amblyomma americanum, Dermacentor variablis and Ixodes scapularis) that are vectors of pathogens of public health and veterinary importance. This study provides important specific information on the wildlife host range of ALT in the US.

Spilogale putorius interrupta (Plains Spotted Skunk) was once common across its range in the United States from the Mississippi River to the Rocky Mountains, but it is now rare and being considered for protection under the federal Endangered Species Act. Disease and introduction of agricultural chemicals have been suggested as potential causes of an ostensible rapid decline of >90% in Plains Spotted Skunk populations in the 1940s. I examined published scientific literature, agency reports, and other historical accounts to determine if such a decline actually took place and if there is any evidence that these factors could have caused such a decline. I found anecdotal information implying that there were declines in some states, but I found no substantiation of a widespread precipitous decline during the 1940s-1950s. Harvest records of Plains Spotted Skunks, Didelphis virginiana (Virginia Opossum), and Mephitis mephitis (Striped Skunk) from the central United States all demonstrate similar rates of decline and this, along with nationwide information suggest that the fall in Plains Spotted Skunk harvests during this period was due to a crash in demand across the entire fur market. There was an extensive rabies epidemic during this period but little data supportive of it causing a population crash. Similarly, usage of chemicals for agricultural pest and weed control was found throughout the species range, but only on such a small percentage of farms it is unlikely to have had significant impact on their population. The Plains Spotted Skunk most likely experienced a long, gradual decline in population density and scientists should undertake research focused on potential causes of decline relevant to this timescale such as changes in agricultural practices or predator guilds so as to develop testable hypotheses that will lead to effective conservation actions that will benefit the species.

The presence of human activity and development affects the distribution and behavior of carnivore species in various ways. It is necessary to examine the effects of urbanization and associated habitat fragmentation on the spatial ecology of predators, in order to develop a comprehensive understanding and formulate a proactive approach towards biodiversity protection in such areas. In this study, we observed patterns of occurrence and activity of carnivores in four preserves in metropolitan the New York and New Jersey region. Over the course of a ten-month trail camera study, 104 randomly positioned camera stations (5642 trap nights) yielded 793 total captures of 7 species: black bear (Ursus americanus), bobcat (Lynx rufus), coyote (Canis latrans), opossum (Didelphis virginiana), raccoon (Procyon lotor), red fox (Vulpes vulpes), and striped skunk (Mephitis mephitis). We found correlations between captures and level of human development, preserve size, and time of day of capture. Further, we found that the relative abundance of carnivores was higher in preserves with a higher level of surrounding development, suggesting the use of these habitat fragments as refuges. Coyotes and raccoons were more likely to be observed in areas with higher development. All carnivores combined were more likely to be observed at night in areas wither higher development, indicating a temporal response of carnivores to human activity. Our results emphasize the value of preserving intact habitat fragments in urban and suburban areas, and strongly suggest that carnivore use of parkland and greenspace should be monitored continuously to measure impacts on these species as conversion of surrounding land persists.

The role of free-ranging wildlife in the epidemiology of enteropathogens causing clinical illness in humans and domestic animals is unclear. Salmonella enterica and anti-microbial resistant bacteria have been detected in the faeces of raccoons (Procyon lotor), but little is known about the carriage of these bacteria in other sympatric meso-mammals. Our objectives were to: (a) report the prevalence of Salmonella and associated anti-microbial resistance, Campylobacter spp, Clostridium difficile, and anti-microbial resistant Escherichia coli in the faeces of striped skunks (Mephitis mephitis) and Virginia opossums (Didelphis virginiana) in southern Ontario; and (b) compare the prevalence of these bacteria in the faeces of these meso-mammal hosts with raccoons from a previously reported study. Faecal swabs were collected from striped skunks and Virginia opossums on five swine farms and five conservation areas from 2011 to 2013. Salmonella was detected in 41% (9/22) and 5% (5/95) of faecal swabs from Virginia opossums and striped skunks, respectively. None of the Salmonella serovars carried resistance to anti-microbials. The prevalence of Campylobacter spp., C. difficile, and anti-microbial resistant E. coli ranged from 6% to 22% in striped skunk and Virginia opossums. Using exact logistic regression, Salmonella was significantly more likely to be detected in faecal swabs of Virginia opossums than skunks and significantly less likely in faecal swabs from skunks than raccoons from a previously reported study. In addition, Campylobacter spp. was significantly more likely to be detected in raccoons than opossums. Salmonella Give was detected in 8/9 (89%) of Salmonella-positive Virginia opossum faecal swabs. Our results suggest that striped skunks and Virginia opossums have the potential to carry pathogenic enteric bacteria in their faeces. The high prevalence of Salmonella Give in Virginia opossum faecal swabs in this study as well as its common occurrence in other Virginia opossum studies throughout North America suggests Virginia opossums may be reservoirs of this serovar.

Bird–window collisions (BWCs) represent a source of mortality for both resident and migratory birds that researchers aim to quantify. Factors that limit carcass detection, including removal of carcasses by scavengers and inherent error in observer detection, can complicate these efforts. We combined 2 studies to examine what proportion of carcasses were scavenged and removed and how successful observers were at detecting bird decoys of multiple types. In fall 2019 and spring 2020, we deployed 40 bird carcasses at Radford University campus buildings and monitored visitation events with game cameras for up to 4 nights/5 days. Scavengers visited 31 of the carcasses and scavenged (disturbed but not removed) 14/31. Scavengers included Felis catus (Domestic Cat, n = 6 events), Mephitis mephitis (Striped Skunk, n = 3), and Procyon lotor (Raccoon, n = 3). All mammalian scavenging events were nocturnal. Cats visited carcasses without disturbing them (n = 22 events), whereas Raccoons (3/3 events) and Striped Skunks (3/4) scavenged carcasses on discovery. Mammals scavenged or removed 3 carcasses in the first night after deployment (e.g., in the first 14 h), suggesting that scavenging can cause daily surveyors to miss ∼7.5% of carcasses. Across spring and fall 2020, we deployed 60 decoys of 4 unique types (varying in color or shape), partially obscuring them under shrubs and along landscaped herbaceous vegetation. We found that observers detected 48% of the decoys on their first attempts (min–max: 8.7–100%). Decoy type did not affect observer detection. By our estimates, 2 observers per day could have collectively missed 27% of carcasses. Although BWC projects typically complete surveys once or twice daily, we suggest twice-daily surveys when monitoring BWC during migratory seasons and once-daily surveys at other times to minimize carcass loss due to scavenging.

Scavenging is a known behavior of striped skunks (Mephitis mephitis), though it is rarely documented. Striped skunks were observed and documented scavenging nine human donors at the Forensic Investigation Research Station (FIRS) in Whitewater, Colorado from October 2017 through September 2019. Human remains are placed on the surface, outdoors, in a fenced area, and monitored daily through notes, photographs, and multiple systems for scoring decomposition. Motion-activated game cameras are strategically positioned to monitor potential scavenger activity within the facility. When scavenging occurred, game camera images were temporally correlated to daily photographs and notes to confirm the source of observed defects. Striped skunks at the FIRS scavenged the soft tissue of the arms, legs, genitals, and torso. Game camera images documented skunks digging, climbing on top of remains, repositioning limbs, and using their paws to manipulate tissue. These activities impacted soft tissue, bone, and the surrounding environment. Scavenging patterns varied seasonally, with higher frequency and lower selectivity in the winter. Striped skunks are common throughout most of North America and are likely to scavenge human remains when available. Understanding patterns and behaviors of specific scavengers can help investigators accurately interpret defects found on and around human remains.

Mesocarnivores fill a vital role in ecosystems through effects on community health and structure. Anthropogenic-altered landscapes can benefit some species and adversely affect others. For some carnivores, prey availability increases with urbanization, but landscape use can be complicated by interactions among carnivores as well as differing human tolerance of some species. We used camera traps to survey along a gradient of urban, rural, and forest cover to quantify how carnivore landscape use varies among guild members and determine if a species was a human exploiter, adapter, or avoider. Our study was conducted in and around Corvallis, Oregon from April 2018 to February 2019 (11,914 trap nights) using 47 camera trap locations on a gradient from urban to rural. Our focal species were bobcat (Lynx rufus), coyote (Canis latrans), gray fox (Urocyon cinereoargenteus), opossum (Didelphis virginiana), raccoon (Procyon lotor), and striped skunk (Mephitis mephitis). Raccoon and opossum were human exploiters with low use of forest cover and positive association with urban and rural developed areas likely due to human-derived resources as well as some refugia from larger predators. Coyote and gray fox were human adapters with high use of natural habitats while the effects of urbanization ranged from weak to indiscernible. Bobcat and striped skunk appeared to be human avoiders with negative relationship with urban cover and higher landscape use of forest cover. We conducted a diel temporal activity analysis and found mostly nocturnal activity within the guild, but more diurnal activity by larger-bodied predators compared to the smaller species. Although these species coexist as a community in human-dominated landscapes throughout much of North America, the effects of urbanization were not equal across species. Our results, especially for gray fox and striped skunk, are counter to research in other regions, suggesting that mesopredator use of urbanized landscapes can vary depending on the environmental conditions of the study area and management actions are likely to be most effective when decisions are based on locally derived data.

Background Human population expansion has increased the contact between domestic animals and wildlife, thereby increasing the transmission of infectious diseases including canine distemper virus (CDV). Here, we investigated the risk factors associated with CDV exposure in domestic and wild carnivores from the Janos Biosphere Reserve (JBR), Mexico. Methods A cross‐sectional household questionnaire study was performed in four rural towns to investigate the risk factors associated with the presence of CDV in domestic and wild carnivores from the JBR, Mexico. In addition, we tested serum samples from 70 dogs and three wild carnivores, including one bobcat (Lynx rufus), one striped skunk (Mephitis mephitis) and one gray fox (Urocyon cinereoargenteus) for CDV antibodies using immunochromatographic and viral neutralization assays. Results Overall, 62% of domestic dogs were seropositive for CDV, and the presence of antibodies was significantly higher in free‐roaming owned dogs than dogs with restricted movement. Among the wild carnivores, only the bobcat was seropositive. The rate of vaccination against CDV in dogs was low (7%), and there was a high rate of direct interactions between domestic dogs and wild carnivores. Conclusion Our serological assays show that CDV is circulating in both domestic dogs and wild carnivores, suggesting cross‐species transmission. Our finding of low vaccination rates, high number of unrestrained owned dogs and direct interactions between wildlife and domestic animals reported in the region may be perpetuating the high prevalence of the virus and increasing the risk of CDV transmission between wild and domestic carnivores. Therefore, long‐term longitudinal studies are recommended in order to monitor infectious diseases at the domestic‐wildlife interface in this highly biodiverse region.

Striped skunks (skunks) are susceptible to respiratory infection by influenza A viruses (IAV). As they are common synanthropes, maintenance of IAV in skunks could provide a source of infection for humans. We previously studied the nasal turbinates, lungs and faeces of 50 free-ranging skunks for the presence of IAV and identified two individuals with influenza A(H1N1)pdm09 infection during the 2009/2010 and 2013/2014 flu seasons. Subsequent to publication of that study, ferrets were shown to preferentially replicate and harbour A(H1N1)pdm09 in the soft palate, a site which had not been investigated in the skunks. From March 2015 to May 2016, we surveyed a convenience sample of 80 free-ranging urban skunks for IAV in soft palate, nasal turbinates and lungs. The newly emergent influenza A(H1N1)pdm09 clade 6B.1 was detected at all three sites in one skunk with acute rhinitis in February 2016. Clade 6B.1 was the dominant clade in circulation during the 2015/2016 flu season. As the skunk was detected at the height of flu season, reverse zoonosis was considered the most probable source of infection.

Human activities affect wildlife in a variety of direct (e.g., hunting, supplemental feeding, and culling) and indirect (e.g., displacement from habitat loss, competition with introduced invasive species, and avoidance of human-dominated landscapes) ways. Even ostensibly benign activities such as hiking or horseback riding in established parks may affect the spatial and temporal activity patterns of wildlife species. Characterization and quantification of effects is essential if parks and other protected areas are to balance the dual needs to nurture an appreciation of wildlands or satisfy a need to encounter nature (sensu the biophilia hypotheses) and to ensure that wild animals can survive and reproduce. We explored how human presence affects wildlife presence in a spatially extensive system of camera traps established in various protected areas in coastal southern California. To characterize and quantify effects we developed a conceptual framework on the basis of joint probabilities of occurrence on a per-camera basis and created a novel statistical approach to assess whether observed probabilities of co-occurrence differed from expected probabilities of co-occurrence. We found that same-day co-occurrence of wildlife and humans was significantly lower than expected at > 90% of the cameras established. This pattern held across sites, across the seven species of large and medium-sized mammals (Bobcat Lynx rufus, Mountain Lion Puma concolor, Gray Fox Urocyon cinereoargenteus, Coyote Canis latrans, Striped Skunk Mephitis mephitis, Northern Raccoon Procyon lotor, and Mule Deer Odocoileis hemionus), and across the five types of human disturbance examined (hikers, bicyclists, domestic dogs, vehicles, and equestrians). Our results demonstrate that human presence acutely affects same-day wildlife detections in protected areas, supporting the hypothesis that avoidance behaviour is a type of “mortality-free predation.” Adaptive and flexible management plans need to be established, evaluated, and updated regularly to facilitate the human nature experience while lessening as much as possible long-term degradation of wildlife habitat. Wildlife in urban-adjacent preserves constitute a major part of the nature experience by humans and require effective management of pressures for use and recreation along aside those for wildlife habitat needs.

The visual acuity of striped skunks (Mephitis mephitis) was tested using a 2 alternative forced-choice task with square wave gratings. Skunks were reinforced with food items for touching a ball in front of a striped stimulus when paired with a ball in front of a solid gray stimulus. Skunks demonstrated a maximum visual acuity of 0.42 cycles per degree when tested with bright outdoor illumination. This poor visual acuity may be due to their nocturnal lifestyle, lack of predation, and is consistent with their preferential use of smell and sound during foraging. (PsycINFO Database Record

Tumors are infrequently reported in skunks, with only a few case reports published in the literature. Chylothorax associated with mediastinal lymphoma was diagnosed in a captive 7-yr-old male striped skunk (Mephitis mephitis). The animal presented with anorexia and apathy. Supportive care and prednisolone improved the animal's clinical status for 2 wk preceding its death. Histopathology supported the clinical findings, and the tumor was classified as a mediastinal non–Hodgkin lymphoma, stage 2b, which has not been documented in the literature.

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.

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.

Bioaccumulation of environmental contaminants in mammalian predators can serve as an indicator of ecosystem health. We examined mercury concentrations of raccoons (Procyon lotor; n = 37 individuals) and striped skunks (Mephitis mephitis; n = 87 individuals) in Suisun Marsh, California, a large brackish marsh that is characterized by contiguous tracts of tidal marsh and seasonally impounded wetlands. Mean (standard error; range) total mercury concentrations in adult hair grown from 2015 to 2018 were 28.50 μg/g dw (3.05 μg/g dw; range: 4.46–81.01 μg/g dw) in raccoons and 4.85 μg/g dw (0.54 μg/g dw; range: 1.53–27.02 μg/g dw) in striped skunks. We reviewed mammalian hair mercury concentrations in the literature and raccoon mercury concentrations in Suisun Marsh were among the highest observed for wild mammals. Although striped skunk hair mercury concentrations were 83% lower than raccoons, they were higher than proposed background levels for mercury in mesopredator hair (1–5 μg/g). Hair mercury concentrations in skunks and raccoons were not related to animal size, but mercury concentrations were higher in skunks in poorer body condition. Large inter-annual differences in hair mercury concentrations suggest that methylmercury exposure to mammalian predators varied among years. Mercury concentrations of raccoon hair grown in 2017 were 2.7 times greater than hair grown in 2015, 1.7 times greater than hair grown in 2016, and 1.6 times greater than hair grown in 2018. Annual mean raccoon and skunk hair mercury concentrations increased with wetland habitat area. Furthermore, during 2017, raccoon hair mercury concentrations increased with the proportion of raccoon home ranges that was wetted habitat, as quantified using global positioning system (GPS) collars. The elevated mercury concentrations we observed in raccoons and skunks suggest that other wildlife at similar or higher trophic positions may also be exposed to elevated methylmercury bioaccumulation in brackish marshes.

Striped skunks (Mephitis mephitis) are urban-adapted, generalist mesocarnivores widely distributed throughout North America. Although striped skunks have been studied extensively at small scales, knowledge of habitat influences on striped skunks at large scales is lacking. We developed a species distribution model (SDM) to examine potential striped skunk presence in a 16,058 km2 portion of southern Illinois, USA. We built models using SDM Toolbox and MaxEnt, and incorporated known presence locations, 1 km2 land cover data, and an index of human modification of the landscape. Land cover and human modification explained 98% and 2% of variation in our model, respectively. The highest presence of striped skunks existed in areas with forest cover and developed open space with moderate human modification. The striped skunk presence was lowest in areas with cultivated crops and woody wetlands with either low or high human modification. Forest cover provides natural food and shelter resources for striped skunks, but resources are likely augmented by human activity in developed open space. Cultivated crops only provide seasonal resources, and inundation limits denning in wooded wetlands. Our model indicated striped skunks are a synanthropic species that regularly inhabits both natural and anthropogenic habitats over a large scale.

Carnivores in the families Mustelidae and Mephitidae are essential hosts for the cranial roundworm genus Skrjabingylus. A high prevalence of Skrjabingylus chitwoodorum has been observed in the striped skunk, Mephitis mephitis. Genetic barcoding studies of other nematodes have successfully used the cytochrome oxidase I (COI) mitochondrial gene to analyze genetic variation and divergence. We tested the hypothesis that low population structuring occurs within S. chitwoodorum because M. mephitis is widespread across much of North America and has high levels of gene flow. We extracted DNA from 38 samples of Skrjabingylus removed from the sinuses of M. mephitis and one from the plains spotted skunk, Spilogale putorius interrupta, for amplification and sequencing of COI. Analysis of 492 base pairs confirmed all samples were S. chitwoodorum and showed low genetic divergence (1.0%) within Texas, but high haplotype diversity. Supporting our hypothesis, no obvious divergent lineages based on geographic location were recovered within the samples based on Maximum Likelihood analysis and median joining haplotype network analysis. In fact, samples of Skrjabingylus from New York and South Dakota showed little difference compared with samples from Texas.

Amdoparvovirus is a newly defined parvoviral genus that contains four species (Carnivore amdoparvovirus 1–4), including the well-known Aleutian mink disease virus (AMDV). Amdoparvoviruses cause an immune-associated and often lethal wasting syndrome in Mustelidae and Caninae hosts. In this study, we molecularly investigated amdoparvoviruses detected in 44 striped skunks (Mephitis mephitis) found dead in and around Vancouver, British Columbia, Canada. Some of the animals exhibited pathological changes compatible with amdoparvovirus-associated disease. The nearly complete genomic sequence was obtained for seven different strains and our analyses show how this virus, which we named skunk amdoparvovirus (SKAV), should be classified as a separate species within the genus (proposed Carnivore amdoparvovirus 5). We detected co-infections, recombinant genomes, at least three separate viral lineages, and preliminary evidence for geographic segregation of lineages. Furthermore, we proved that similar viruses, only partially characterized in previous studies and labeled as AMDV, circulate in skunks from other distant areas of North America (Ontario and California) and found evidence for spillover events in mink (Neovison vison). Although SKAVs are capable of causing disease in infected animals, a high proportion of sub-clinical infections has been observed, suggesting these animals might act as asymptomatic carriers and pose a threat to wild and captive carnivores. Finally, we highlight the need for more specific diagnostic tests and further molecular investigations to clarify the epidemiology and host- and geographical distributions of amdoparvoviruses in terrestrial carnivores, especially because the whole spectrum of viral diversity in this group is likely still unknown.

Wildlife species are critical for both feeding vectors and serving as reservoirs of zoonotic vector-borne pathogens. Transmission pathways leading to disease in humans or other target taxa might be better understood and managed given a complete understanding of the relative importance of different reservoir species in nature. Using the conceptual framework of “reservoir potential,” which considers elements of both reservoir competence and vector-host contact, we review the wildlife reservoirs of Trypanosoma cruzi in the southern United States, where many species of triatomine vectors occur and wildlife maintain enzootic cycles that create a risk of spillover to humans, domestic dogs, and captive nonhuman primates that may develop Chagas disease. We reviewed 77 published reports of T. cruzi infection in at least 26 wildlife species across 15 southern states. Among the most well-studied and highly infected reservoirs are raccoon (Procyon lotor), woodrat (Neotoma spp.), and opossum (Didelphis virginiana), with aggregate overall infection prevalences of 36.4, 34.7, and 22.9%, respectively. Just over 60% of studies utilized methods from which an infectiousness index could be generated and show that raccoons and striped skunk (Mephitis mephitis) are among the most infectious wildlife hosts. Triatomine-host contact has sparsely been quantified in the southern United States, but 18 of the 24 host species previously identified to have been fed upon by triatomines are wildlife. Future studies to parameterize the reservoir potential model, especially to quantify wildlife infectiousness, vector-host contact, and the epidemiological importance of parasite strains maintained by wildlife, could open new doors for managing enzootic cycles and reducing T. cruzi spillover risk.

These data provide additional information relevant to the frequency of fisher detections by camera traps, and single-season occupancy and local persistence of fishers in small patches of forest habitats detailed elsewhere, “Landscape Fuel Reduction, Forest Fire, and Biophysical Linkages to Local Habitat Use and Local Persistence of Fishers (Pekania pennanti) in Sierra Nevada Mixed-conifer Forests” [10]. The data provides insight on camera trap detections of 3 fisher predators (bobcat [Lynx rufus]). Coyote [Canis latrans], mountain lion [Puma concolor], 5 mesocarnivores in the same foraging guild as fishers (gray fox [Urocyon cinereoargenteus]) ringtail [Bassariscus astutus], marten [Martes americana], striped skunk [Mephitis mephitis] spotted skunk [Spilogale gracilis], and 5 Sciuridae rodents that fishers consume as prey (Douglas squirrel [Tamiasciurus douglasii]), gray squirrel [Sciurus griseus], northern flying squirrel [Glaucomys sabrinus], long-eared chipmunk [Neotamias quadrimaculatus], California ground squirrel [Spermophilus beecheyi]. We used these data to identify basic patterns of co-occurrence with fishers, and to evaluate the relative importance of presence of competing mesocarnivores, rodent prey, and predators for fisher occupancy of small, 1 km2 grid cells of forest habitat. Keywords: Carnivores, Competition, Distribution, Foraging guild, Predation, Tree squirrels

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.

There is growing need to develop models of spatial patterns in animal abundance, yet comparatively few examples of such models exist. This is especially true in situations where the abundance of one species may inhibit that of another, such as the intensively-farmed landscape of the Prairie Pothole Region (PPR) of the central United States, where waterfowl production is largely constrained by mesocarnivore nest predation. We used a hierarchical Bayesian approach to relate the distribution of various land-cover types to the relative abundances of four mesocarnivores in the PPR: coyote Canis latrans, raccoon Procyon lotor, red fox Vulpes vulpes, and striped skunk Mephitis mephitis. We developed models for each species at multiple spatial resolutions (41.4 km2, 10.4 km2, and 2.6 km2) to address different ecological and management-related questions. Model results for each species were similar irrespective of resolution. We found that the amount of row-crop agriculture was nearly ubiquitous in our best models, exhibiting a positive relationship with relative abundance for each species. The amount of native grassland land-cover was positively associated with coyote and raccoon relative abundance, but generally absent from models for red fox and skunk. Red fox and skunk were positively associated with each other, suggesting potential niche overlap. We found no evidence that coyote abundance limited that of other mesocarnivore species, as might be expected under a hypothesis of mesopredator release. The relationships between relative abundance and land-cover types were similar across spatial resolutions. Our results indicated that mesocarnivores in the PPR are most likely to occur in portions of the landscape with large amounts of agricultural land-cover. Further, our results indicated that track-survey data can be used in a hierarchical framework to gain inferences regarding spatial patterns in animal relative abundance.

Striped skunks (Mephitis mephitis) act as reservoirs of many zoonotic diseases and are highly adept at persisting in urbanized landscapes in high densities. A better understanding of the interaction between skunks and the urban environment can aid in the development of management approaches to disease outbreaks, as well as provide information on wildlife responses to urbanization-induced habitat fragmentation. We studied the genetic structure of a population of striped skunks in an urban environment, assessing the presence of subpopulation structuring, sex-biased philopatry, and natal habitat—biased dispersal. Analysis of microsatellite data failed to detect any significant population clustering or evidence of natal habitat—biased dispersal, but spatial autocorrelation analyses did reveal patterns of limited dispersal (< 2 km) and suggest female-biased philopatry. Our results suggest that urban habitats provide few barriers to gene flow in striped skunks.

We provide information on recent records of the 2 subspecies of striped skunk occurring in the north- eastern (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.

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.

The Virginia opossum (Didelphis virginiana) and the striped skunk (Mephitis mephitis) are often kept as pets, although they are both wild animals. The opossum and striped skunk are usually docile and sociable when raised from infancy. Many states and municipalities restrict ownership, and veterinarians should familiarize themselves with local laws and regulations pertaining to these animals. The biology, husbandry, diet, and general disease information is available for both species. Vaccination recommendations are included for skunks.

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 km(2) 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.

An important prerequisite for the effective use of stable isotopes in animal ecology is the accurate assessment of isotopic discrimination factors linking animals to their diets for a multitude of tissue types. Surprisingly, these values are poorly known in general and especially for mammalian carnivores and omnivores in particular. Also largely unknown are the factors that influence diet-tissue isotopic discrimination such as nutritional quality and age. We raised adult and juvenile striped skunks (Mephitis mephitis) in captivity on a constant omnivore diet (Mazuri Omnivore A 5635). Adults (n=6) and juveniles (n=3) were kept for 7 months and young (n=7) to the age of 50 days. We then examined individuals for stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope values of hair, nails, lipid, liver, muscle, bone collagen and the plasma, and cellular fractions of blood. Discrimination values differed among age groups and were significantly higher for young compared with their mothers, likely due to the effects of weaning. Δ(15)N isotopic discrimination factors ranged from 3.14 (nails) to 5.6‰ (plasma) in adults and 4.3 (nails) to 5.8‰ (liver) for young. For Δ(13)C, values ranged from-3.3 (fat) to 3.0‰ (collagen) in adults and from-3.3 (fat) to 2.0‰ (collagen) in young. Our data provide an important tool for predicting diets and source of feeding for medium-sized mammalian omnivorous adults integrated over short (e.g. liver, plasma) through long (e.g. collagen) periods and underline the potential effects of age on isotopic values in omnivore diets.

Rabies is a fatal zoonotic disease of global importance. Rabies virus is shed in the saliva of infected hosts and is primarily transmitted through bite contact. Canine rabies has been eliminated from the US, but wildlife constitutes more than 90% of the reported cases of animal rabies in the US each year. In the US, several wild carnivore species are reservoirs of distinct variants of rabies virus (RV). After decades of apparent absence, the south-central skunk (SCSK) RV variant was detected in Colorado in 2007 and resulted in a large-scale epizootic in striped skunk ( Mephitis mephitis) populations in northern Colorado starting in 2012. We attempted isolation of RV from salivary gland tissues from confirmed rabid carnivores, comprising 51 striped skunks and seven other wild and domestic carnivores collected during 2013 through 2015 in northern Colorado. We isolated RV from 84.0% (158/188; 95% confidence interval=78.1-88.6%) of striped skunk and 71% (17/24; 95% confidence interval =51-85%) of other carnivore salivary glands. These data suggested that infected reservoir and vector species were equally likely to shed the SCSK RV variant and posed a secondary transmission risk to humans and other animals.

A 10-year-old female striped skunk (Mephitis mephitis) was admitted with severe abdominal distension and lethargy. Cytological examination of the peritoneal fluid revealed activated mesothelial cells. At necropsy, numerous growing together, projecting, 2 to 20 mm in diameter tawny to white masses were scattered throughout the peritoneum including the mesentery, omentum and intestinal serosa. Microscopically, the tumor was composed of prominent papillo-tubular structures, and immunohistochemically, the spindle to polygonal-shaped tumor cells with nuclear polymorphism were strongly reactive for calretinin. Based on those diagnostic features, the neoplasia was diagnosed as malignant mesothelioma. This is the first case report of mesothelioma in the skunk.

Wintertime physiology of captive striped skunks (Mephitis mephitis) in response to cold ambient temperature (Ta) and fasting was investigated with body temperature (Tb) and activity recordings and analyses of hematology, plasma biochemistry and tissue fatty acids (FA). After 105 days of food deprivation, the skunks were in phase II of fasting indicated by the elevated plasma nonesterified FA and glycerol but no accumulation of nitrogen end products. Shorter-chain saturated and monounsaturated FA together with C18-20 n-3 polyunsaturated FA were preferentially mobilized. Individual amino acids responded to fasting in a complex manner, while essential and nonessential amino acid sums remained stable. Increases in hemoglobin and hematocrit suggested dehydration. The activity levels were lower in mid-January-early March, and the activity bouts were mostly displayed between 17:00-23:00 h. Daily torpor was observed in two females with 29 and 46 bouts. The deepest torpor (Tb

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 method- ology 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.

Aposematism and crypticity are viewed as mutually exclusive antipredator defense strategies with skunks being a classic example of the former. Skunks can spray noxious anal secretions and many species (Conepatus and Mephitis spp.) have bold blocks of white fur on black pelage, but spotted skunks (Spilogale sp.) have white spots and lines on a black coat suggesting an additional function. We tested the possibility that spotted skunks are conspicuous at close range but cryptic at a distance. Using quantitative measures of colouration extracted from photographs of taxidermied western spotted skunk, bobcat and striped skunk mounts taken at ≤ 5 m, we found that spotted skunk colouration was significantly more conspicuous than the cryptic bobcat but not than the striped skunk. Differences between mount and background colouration were significantly greater for spotted skunks than for bobcats but not for striped skunks. Both sets of results indicate that spotted skunks match their background poorly when viewed cl...

The biological significance of the tremendous variation in proportions of oligosaccharides and lactose among mammalian milks is poorly understood. We investigated milk oligosaccharides of the striped skunk (Mephitis mephitis) and compared these results to other species of the clade Mustelida. Individual oligosaccharides were identified by proton nuclear magnetic resonance spectroscopy. In the striped skunk, six oligosaccharides were identified: isoglobotriose, 2′-fucosyllactose, A-tetrasaccharide, Galili pentasaccharide, 3′-sialyllactose and monosialyl monogalactosyl lacto-N-neohexaose. Four of these have been found in related Mustelida and the other two in more distantly related carnivorans. The neutral and acidic oligosaccharides derive from three core structures: lactose (Gal(b1‐4)Glc), lacto-N-neotetraose (Gal(b1‐4)GlcNAc(b1‐ 3)Gal(b1‐4)Glc) and lacto-N-neohexaose (Gal(b1‐4)GlcNAc(b1‐3)[Gal(b1‐4)GlcNAc(b1‐6)]Gal(b1‐4)Glc).

Although parvoviruses are commonly described in domestic carnivores, little is known about their biodiversity in nondomestic species. A phylogenetic analysis of VP2 gene sequences from puma, coyote, gray wolf, bobcat, raccoon, and striped skunk revealed two major groups related to either feline panleukopenia virus (“FPV-like”) or canine parvovirus (“CPV-like”). Cross-species transmission was commonplace, with multiple introductions into each host species but, with the exception of raccoons, relatively little evidence for onward transmission in nondomestic species.

Skunks are popular carnivore species kept both in zoological institutions and in households where they are hand raised as exotic pets. These small carnivores are considered the main definitive hosts of the roundworm Baylisascaris columnaris. The purpose of this survey was to investigate the occurrence of Baylisascaris spp. in striped skunks kept as pets or in private zoo collections in some European areas. Copromicroscopic data from two laboratories, one in Italy and one in Germany, were used. A total of 60 animals were selected. Samples came from Germany (n = 30), Italy (n = 23), United Kingdom (n = 5), Austria (n = 1), and the Netherlands (n = 1). Twenty-eight animals were certainly kept as pets in private households in Italy and the UK. Fifteen out of 60 animals (25%) were positive for Baylisascaris spp. Molecular identification of adult parasites was performed in ten of those animals, revealing B. columnaris in all cases. To the authors’ knowledge, this is the first survey of Baylisascaris spp. in captive skunks in Europe.

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.

The defensive display of a threatened adult striped skunk (Mephitis mephitis) involves visual, auditory, and olfactory signals. Detection of a potential predator leads to either avoidance (run, hide, or den) or confrontational (tail-up, stomp, hiss, scratch, charge, aim, and spray) behaviours. Seventy skunks born in captivity were handled at five-day intervals starting at seven days of age and up to 52 days of age. The development of defensive behaviours (tail-up, stomp, run, aim, hide, spray, hiss, scratch, charge, and bite) and physical attributes (eye opening, external auditory meatus opening, and teeth eruption) were recorded. Tail-up, which signifies alertness and enhances warning colouration, was the most common and earliest defence behaviour observed. Musk was present at seven days of age, though the ability of a skunk to forcefully expel its chemical defence is not developed until 17 days. Initially spray events are not aimed at the threat; directed spray is initiated following eye opening at 32 d...

Urban development can have multiple effects on mammalian carnivore communities. We conducted a meta-analysis of 7,929 photographs from 217 localities in 11 camera-trap studies across coastal southern California to describe habitat use and determine the effects of urban proximity (distance to urban edge) and intensity (percentage of area urbanized) on carnivore occurrence and species richness in natural habitats close to the urban boundary. Coyotes (Canis latrans) and bobcats (Lynx rufus) were distributed widely across the region. Domestic dogs (Canis lupus familiaris), striped skunks (Mephitis mephitis), raccoons (Procyon lotor), gray foxes (Urocyon cinereoargenteus), mountain lions (Puma concolor), and Virginia opossums (Didelphis virginiana) were detected less frequently, and long-tailed weasels (Mustela frenata), American badgers (Taxidea taxus), western spotted skunks (Spilogale gracilis), and domestic cats (Felis catus) were detected rarely. Habitat use generally reflected availability for most species. Coyote and raccoon occurrence increased with both proximity to and intensity of urbanization, whereas bobcat, gray fox, and mountain lion occurrence decreased with urban proximity and intensity. Domestic dogs and Virginia opossums exhibited positive and weak negative relationships, respectively, with urban intensity but were unaffected by urban proximity. Striped skunk occurrence increased with urban proximity but decreased with urban intensity. Native species richness was negatively associated with urban intensity but not urban proximity, probably because of the stronger negative response of individual species to urban intensity.

Mammalian carnivores are the primary hosts for the rabies virus in terrestrial disease cycles. While rabies prevalence in Vulpes spp. and Urocyon spp. (foxes), Mephitis mephitis (Striped Skunk), and Procyon lotor (Raccoon) is well documented in Pennsylvania, the reintroduction of Martes pennanti (Fisher) provides another potential vector of this disease. We used a direct, rapid immunohistochemical test to examine brain material from 46 free-ranging Fishers collected throughout Pennsylvania from 2002–2008. Five Fishers had brain material unsuitable for rabies testing, forty Fishers tested negative for the disease, and one individual tested positive. The individual that tested positive was an adult male that was found to be positive for the Eastern Raccoon strain of rabies. This individual was trapped and radio-collared in July 2006 as part of a research project examining Fisher resource selection. Researchers monitored this individual weekly starting July 2006 until October 2006, when it was found...

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.

Birds can hide from visual predators by locating nests where there is cover and from olfactory predators where habitat features create updrafts, high winds, and atmospheric turbulence, but sites optimal for hiding from visual and olfactory predators often differ. We examined how Greater Sage-Grouse (Centrocercus urophasianus) balance the dual needs of hiding from both visual and olfactory predators on Parker Mountain, Utah, where the Common Raven (Corvus corax) is the main visual predator and the striped skunk (Mephitis mephitis) and American badger (Taxidea taxus) are the main olfactory predators. By comparing nest sites to random sites during 2005 and 2006, we found that sage-grouse nest at sites where their nests were obscured from visual predators but were exposed to olfactory predators. To validate these findings, we replicated the study in southwest Wyoming during 2008. Again, we found that visual obscurity at nest sites was greater than at control sites but olfactory obscurity was less. Our results indicate that Greater Sage-Grouse select nest sites where they will be concealed from visual predators but at the cost of locating nests where they are exposed to olfactory predators. In southwest Wyoming, we found that olfactory predators (mammals) and visual predators (birds) depredated an equal number of nests. By selecting nest sites with visual obscurity, Greater Sage-Grouse have reduced the threat from visual predators to where it was similar to the threat posed by olfactory predators.

From April to August, 1993 to 1995, we studied the aposematic behaviour patterns of striped skunks, Mephitis mephitis, incidentally while ground-tracking radio-marked animals. During 2668 h of tracking, 207 defensive postures were displayed by 34 radio-collared (27 females, 7 males) and 21 unidentified skunks. Skunks most often advertised their noxiousness using Tail-up (69.1 % occurrence) and Stomp (17.4%). Encounters were frequently (42.5 %) terminated by the skunk running away from the source of disturbance. Most warning behaviour was directed at radio-trackers (95.7 %), and the remainder was displayed to a variety of predatory and non-predatory animals or objects. Stomp occurred more frequently in taller vegetation, where visual advertisement was limited. Reaction distance of skunks disturbed by observers (median = 6 m) was not affected by wind, movement or vegetation height. The small awareness circle and high tolerance of skunks to disturbance are consistent with the life history traits of aposematic animals.

A striped skunk with neurological signs was euthanized and examined via necropsy. Histologically, protozoa were found in multiple tissues. Protozoal schizonts measured 15 to 25 μm in diameter and contained 4 to 6 μm crescent-shaped merozoites. Protozoa were associated with necrosis and inflammation in the lung, brain, liver, and nasal epithelium. Immunohistochemistry labeled protozoa strongly positive for Sarcocystis neurona. Polymerase chain reaction–amplified products from the protozoan were 99.6% identical to the corresponding portion of the nuclear small subunit ribosomal RNA gene of S neurona. S neurona origin was further confirmed by amplifying a 451–base pair DNA fragment from the skunk lung, which differed by just 2 or 3 base pairs from the small subunit ribosomal RNA gene of S neurona. Striped skunks act as intermediate and aberrant hosts for S neurona; however, S neurona has rarely been found in extraneural tissues in any species, and systemic sarcocystosis has not been reported in skunks. Additionally, canine distemper virus infection was confirmed with histopathology and immunohistochemistry. Concurrent canine distemper suggests that immunosuppression may have played a role in S neurona infection in this skunk.

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.

Three main hypotheses can explain the origin of the sexual size dimorphism: (1) the birth-size hypothesis, which states that birth size of males is larger than that of females; (2) the growth-rate hypothesis, which states that males grow faster than females; (3) the growth-length hypothesis, which states that males grow for a longer period of time than females. We examined the factors that may contribute to sexual size dimorphism with growth data of striped skunks Mephitis mephitis Schreber, 1776 held in captivity in Manitoba (Canada), from 7 to 72 days of age. At seven days of age, the mass of male skunks (mean = 79.7 g ± 13.9 SE, n = 37) was significantly larger than that of females (mean = 71.2 g ± 15.0 SE, n = 35) but the head and body length was not statistically different between males (mean = 110.3 mm ± 8.0 SE, n = 37) and females (mean = 95.3 mm ± 7.4 SE, n = 35). There was no difference in growth rate for mass or for length between sexes. We were not able to test for a difference in growth length between sexes. Our results suggest that mass dimorphism occurs early in life.