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The family Mephitidae is almost exclusively restricted to the Americas, 9 of 11 species belonging to 3 genera are distributed from southern Canada to Chile. Despite the high diversity and continental distribution of this taxon, there is no quantitative review that evaluates the state of research to determine current advances and knowledge gaps, as well as the research efforts necessary to develop effective conservation programs and reduce potential threats to species. Our goal was to analyze the scientific literature on the family Mephitidae in the Americas published from 1900 to 2021 to identify the patterns and potential causes of bias based on species, research topics, in addition to regions and countries, and to define research priorities to guide future efforts. We recorded a total of 926 studies related to the American mephitids. The number of publications by species, research topic, and the geographic area was distributed heterogeneously, but we observed significantly marked biases. The most studied species was Mephitis mephitis, most of the studies focused on diseases and pathologies, and most of the research was conducted in North America, mainly in the United States. Overall, there was an accumulated and gradual increase in the number of publications over time, with greater scientific production between 2010 and 2021. Our review shows that the research allocation to mephitids, except for Spilogale putorius, is driven by economic or human interest rather than conservation reasons. We prioritize future research towards mephitid species, research topics, and geographic areas in the Americas that need it the most to reduce the scientific gap and to increase the availability of relevant information. [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]

Recent research suggests that raccoons (Procyon lotor) can transmit several important pathogens affecting humans, including protozoans. In Japan, the number of wild raccoons has increased since they were first introduced more than 50 years ago. Here, we report the first survey of Cryptosporidium infection using fecal swabs of raccoons captured in Osaka, Japan. Of 116 raccoons examined by PCR targeting of the Cryptosporidium 18S rRNA gene, 7 (6.03%; 2 adults and 5 young animals) were positive, and the isolates were identified as Cryptosporidium skunk genotype (subtype XVIa) and C. parvum based on sequence and phylogenetic analyses. Both species and the genotype are zoonotic; thus, our results suggest that raccoons could transmit Cryptosporidium infections to humans in Japan. [ABSTRACT FROM AUTHOR]

Large-scale distribution models are effective predictors of habitat suitability and connectivity across broad landscapes and are useful management tools, though few large-scale species distribution models exist for medium-sized predators in urban landscapes. We modeled the potential distribution of 4 medium-sized predators in a 17,361-km2 portion of the Chicago Metropolitan Area. We applied a maximum entropy algorithm model (MaxEnt) using presence-only data collected via remote cameras from 54 Lake County, Illinois, forest preserves during August-October 2008-2012. Environmental data layers used to model distributions were distances to forest, grassland, barren land, crops, wetlands, developed open space, developed low intensity, developed high intensity, water, primary roads, secondary roads, and tertiary roads. Coyotes (Canis latrans) had the greatest area of potential distribution followed by opossums (Didelphis virginiana), striped skunks (Mephitis mephitis), and raccoons (Procyon lotor). Models for all species had high AUC values (0.90-0.94) indicating strong predictive performance. More than 50% of the study area was predicted to be within the distributional limit for each focal species. Distance to forest was the most important contributory predictor for all species modeled (82% - 96%) and higher probability of presence for all 4 species was indicated closer to forest and further from tertiary roads. However, coyotes and raccoons were predicted to prefer habitat closer to highly-developed areas. Our research indicates medium-sized predators are highly synanthropic and able to persist within the Chicago Metropolitan Area given adequate availability of non-urban land cover, particularly forest, and ample green space linking forest patches within highly-developed areas. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Remarkable adaptations in the Carnivora have evolved as a way of dealing with feeding competition, accentuating hypocarnivorous or hypercarnivorous morphotypes. The Carnivora is a highly successful order with 47 living species in South America. Their history in South America is recent, and includes few lineages that arrived before the Panamanian bridge was completed (procyonids), and others that arrived later (felids, mephitids). Here, we evaluated the trophic segregation of small carnivorans ( Conepatus chinga, Galictus cuja, Lontra provocax, Lyncodon patagonicus, and the introduced Neovison vison) from southern South America, using a geometric morphometric approach, i.e., Principal Component and Canonical Variate Analysis, to study shape variations and t-tests to study size variation. We also performed Canonical Phylogenetic Ordination to study the association between shape, size, diet, and phylogeny. We identified C. chinga as the most hypocarnivorous member of the guild, G. cuja, L. patagonicus, and N. vison as hypercarnivores, with L. provocax in an intermediate position. Semiaquatic habits segregate Lontra provocax, and partially N. vison, from other species. Significant differences in size were observed between all species pairs, except C. chinga and N. vison. Phylogeny accounts for a very important part of morphological variance, with cladogenetic events between mustelids and mephitids responsible for almost 55 % of it. The small carnivoran guild of southern South America is represented by species adapted to different feeding strategies, with C. chinga and L. provocax preying mainly on invertebrates, G. cuja and L. patagonicus specifically on small vertebrates, and the non-native N. vison with a highly diverse diet. [ABSTRACT FROM AUTHOR]

Intraguild predation (IGP) and interspecific killing (IK) have been recently acknowledged as important ecological forces that could influence community structure. Not only can carnivores influence prey community composition, they might also impact the populations of other carnivores. The goal of the current study was to assess the role of IGP and IK as significant forces influencing carnivoran assemblages in South America. To this end, we compiled the available records on 35 species of terrestrial carnivorans in the subcontinent, to investigate the potential and actual extent of IGP/IK as widespread ecological forces. We considered potential intraguild predators those having >20 % range overlap and body mass 2-5.4 times greater than that of other guild members and likely-potential intraguild predators those that, in addition, were also hypercarnivorous. The potential number of intraguild predators for those species evaluated ranged from zero to 18 (mean = 5.35 ± SE 0.74). IGP/IK events ( n = 116) included 52 pairs of Neotropical carnivorans, 13 of which were killers and 25 were victims. Confirmed intraguild predator species ( n = 13) accounted for 37.1 % of the assemblage, nearly the same value predicted to be likely potential predators ( n = 14). IGP and IK were highly associated with the hypercarnivorous felids, whereas victim species were most often the omnivorous procyonids and skunks. The results indicate jaguars, pumas, and ocelots as the species most likely to have significant impact on the guild. IGP and IK are not random and reflect widespread interactions that influence carnivoran community structure in South America. [ABSTRACT FROM AUTHOR]

Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in studies of evolutionary innovation and functional diversification. It has been believed that the RNASE1 gene duplications are correlated with the plant-feeding adaptation of foregut-fermenting herbivores. Here, we characterized RNASE1 genes from Caniformia, which has a simple digestive system and lacks microbial digestion typical of herbivores, in an unprecedented scope based on both gene sequence and tissue expression analyses. Remarkably, the results yielded new hypotheses regarding the evolution and the function of Caniformia RNASE1 genes. Four independent gene duplication events in the families of superfamily Musteloidea, including Procyonidae, Ailuridae, Mephitidae and Mustelidae, were recovered, rejecting previous Mustelidae-specific duplication hypothesis, but supporting Musteloidea duplication hypothesis. Moreover, our analyses revealed pronounced differences among the RNASE1 gene copies regarding their selection pressures, pI values and tissue expression patterns, suggesting the differences in their physiological functions. Notably, the expression analyses detected the transcription of a RNASE1 pseudogene in several tissues, raising the possibility that pseudogenes are also a potential source during the RNase functional diversification. In sum, the present work demonstrated a far more complex and intriguing evolutionary pattern and functional diversity of mammalian ribonuclease than previously thought. [ABSTRACT FROM AUTHOR]

Abstract: Studies on the spatial ecology of Molina''s hog-nosed skunk were conducted in southern Brazil. Between April 2008 and April 2009, 18 individuals were tagged with radio collars and monitored by radio-telemetry (VHF). The average home-range estimated for 12 skunks was 1.63km2 ±1.17km2. Males had home-ranges 2.5 times larger than females, and also showed significantly larger patterns of displacement. These differences in space probably were related not only to sexual size dimorphism, but also to differential behavior between sexes. We identified six basic types of resting sites, among which holes in the ground were the most common and comprised more than 50% of the total. Reuse of resting sites was high (32%), especially for females, which had a significantly higher rate than males. Although they showed a large proportion of home-range overlap even in the core areas, skunks exhibited a solitary life style, rarely sharing resting sites and maintaining relatively long distances from each other, equivalent to twice the distance of daily movements. The almost strictly nocturnal activity pattern observed in this study is a common characteristic of the family. Among practically all of the ecological features analyzed, males and females showed significant differences, denoting the importance of a sex-specific approach in ecological studies regarding this species. [Copyright &y& Elsevier]

The formation of search images can create density-dependent predation. Predators have been shown to form search images when searching for many small prey items in one feeding session. This paper reports experiments that test whether striped skunks can form olfactory search images in other situations: when prey are found over several days, when prey are large, and when prey are found in certain habitats. Striped skunks were raised in captivity, and their reaction distance to food was measured outside in a natural grassy area. In experiment 1 skunks were offered many small food items for several days in a row. From one day to the next, skunks initially detected food from further away, they increased detection distance faster and their maximum detection distance increased – i.e., they formed olfactory search images faster and stronger from one day to the next. In experiment 2 skunks formed search images over several days when finding only one large food item per day. In experiment 3 skunks lost olfactory search images when they entered habitats in which they had previously searched for another type of food. These long-term search images magnify the effects of short-term search images, extend the effects of short- term search image to longer time spans, and affect different species from short-term search images. [ABSTRACT FROM AUTHOR]