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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 ( x ¯ = 34. 4 s) and investigating ( 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. [ABSTRACT FROM AUTHOR]

Few studies have investigated the ecology of urban striped skunks (Mephitis mephitis) despite their role as a primary rabies vector species paired with an ability to thrive in these landscapes. Information on home range, nightly movements, and habitat selection, is important for rabies management planning regarding the placement of oral rabies vaccine (ORV) baits and for management of skunk populations more generally. Our aim was to obtain baseline ecological information with an emphasis on spatial ecology of urban striped skunks in the Northern Great Plains region that is lacking in the literature. We used radio telemetry to track 22 (4 M, 18 F) skunks during September 2016 to November 2016 and March 2017 to November 2017. Size of home range using kernel density estimation with smoothing by least squares cross validation identified that male skunks ( x ¯ = 4.36 km2, SE ± 0.79) had larger home ranges than females ( x ¯ = 1.79 km2, SE ± 0.24). Female skunk home ranges varied by season with the largest home ranges detected during summer 2017. We found no evidence that use-availability was associated with habitat type or season among female skunks. Female skunks were more likely to be found closer to water; however, we found no association of use with road characteristics and geographic location within the study area. Targeting ORV efforts in areas near water may be warranted, but considering differences in habitat selection for skunk studies in urban areas, we caution that ORV baiting programs may not be one-size-fits-all, and a framework for effective bait placement would benefit from studies specific to the management area of interest. [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]

Variation within major histocompatibility complex (MHC) genes is important in recognizing pathogens and initiating an immune response. These genes are relevant in enhancing our understanding of how species cope with rapid environmental changes and concomitant fluctuations in selective pressures such as invasive, infectious diseases. Disease-based models suggest that diversity at MHC is maintained through balancing selection arising from the coevolution of hosts and pathogens. Despite intensive balancing selection, sequence motifs or even identical MHC alleles can be shared across multiple species; three potential mechanisms have been put forth to explain this phenomenon: common ancestry, convergent evolution, and random chance. To understand the processes that maintain MHC similarity across divergent species, we examined the variation at two orthologous MHC-DRB genes in widespread North American Musteloid species, striped skunks ( Mephitis mephitis), and raccoons ( Procyon lotor). These species are often sympatric and exposed to a similar suite of diseases (e.g., rabies, canine distemper, and parvovirus). Given their exposure to similar selective pressures from pathogens, we postulated that similar DRB alleles may be present in both species. Our results indicated that similar motifs are present within both species, at functionally relevant polymorphic sites. However, based on phylogenetic analyses that included previously published MHC sequences of several closely related carnivores, the respective MHC-DRB alleles do not appear to have been maintained through common ancestry and unlikely through random chance. Instead, the similarities observed between the two mesocarnivore species may rather be due to evolutionary convergence. [ABSTRACT FROM AUTHOR]

n urban population of Endangered San Joaquin kit foxes ( Vulpes macrotis mutica) has persisted in the city of Bakersfield, (Kern County, California), for several decades. Urban kit foxes may play an important role in future range wide recovery efforts for the species. As such, a comprehensive understanding of the issues that can influence the long-term survival of this population is essential for the development of effective management strategies. Although urban kit foxes have been studied extensively in Bakersfield, interactions between kit foxes and other urban carnivore species are poorly understood. Urban environments can provide a number of opportunities for species to interact in ways not usually observed in natural habitats. Interactions between urban populations of striped skunks ( Mephitis mephitis) and kit foxes were investigated at denning locations and cat feeding stations on the California State University-Bakersfield campus, California, USA. A total of 130 individual denning sites were identified, of which 39 (30%) were used by both species. Simultaneous den use by foxes and skunks was recorded on four occasions. Inter and intra-specific aggression was recorded at cat feeding stations on ten separate occasions including three incidences of aggression towards kit foxes by skunks and feral cats ( Felis catus). Telemetry data and cat feeding station observations clearly show that interspecific contact does occur in urban environments. [ABSTRACT FROM AUTHOR]

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. [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]

The article presents a study which investigates the acute toxicity of sodium monofluoroacetate to striped skunk. It says that the striped skunks were live trapped and provided with a maintenance diet of 0.5 kilogram (kg) commercial dry bone meal and dogfood once a day. Results show that all skunks reacted to the toxicant and displayed a latent period during the onset of sodium monofluoroacetate.

The potential role of wild mammals in avian influenza A virus (IAV) transmission cycles has received some attention in recent years and cases where birds have transmitted IAV to mammals have been documented. However, the contrasting cycle, wherein a mammal could transmit an avian IAV to birds, has been largely overlooked. We experimentally tested the abilities of two mammalian species to transmit avian IAV to mallards (Anas platyrhynchos) in simulated natural environments. Results suggested that striped skunks (Mephitis mephitis) can successfully transmit avian IAV to mallards through indirect contact with shared resources, as transmission was noted in 1 of 4 of the mallards tested. Cottontail rabbits (Sylvilagus sp.) exhibited a similar pattern, as one of five cottontail rabbits successfully transmitted IAV to a mallard, likely through environmental contamination. For each mammalian species tested, the mallards that became infected were those paired with the individual mammals with the lowest shedding levels but were anecdotally observed to be the most active animals. Mammals associated with and around poultry rearing facilities should be taken into consideration in biosecurity plans. [ABSTRACT FROM AUTHOR]