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The eastern spotted skunk (Spilogale putorius) was once common throughout the midwestern and southeastern United States, with consistent annual range-wide harvests of »100 000 animals. In the 1940s, however, populations seemingly crashed and the species is currently listed by various state agencies as endangered, threatened, or 'of concern' across much of its range. We examined long-term harvest records from 10 states to better understand the 20th century population dynamics of eastern spotted skunks, to discern whether the putative decline was biologically real or an artifact of altered harvest pressures and to identify the timing of the decline. Analyses reveal unequivocally that the species was indeed once common in the Great Plains. Beginning in about 1940, harvests dramatically declined, although the onset of declines differed between states. By the early 1950s total harvests in all states were < 10% of pre-crash harvest. Thereafter, rates of decline slowed, but nevertheless continued, such that by the 1980s harvests were <1% of those during pre-decline years. Analyses show that these declines are real and not an artifact of harvest effort. Although the causes of the decline remain unclear, the analyses suggest a need for immediate attention to address the long-term persistence of this species. [ABSTRACT FROM AUTHOR]

Survival and cause-specific mortality of eastern spotted skunks (Spilogale putorius) was assessed for a radio-monitored population in the Ouachita Mountains of westcentral Arkansas, USA. We monitored 33 eastern spotted skunks over a 23 mo period. Mean annual survival was 0.354 (0.339-0.368, 95% CI), and survival estimates were similar across age and sex categories. Survival increased for males as measures of body condition index increased. This pattern was reversed tot females, although interpretation of the patterns is potentially confounded by female reproductive status. Of 19 mortality events, 63% (12) were caused by avian predators, most likely great horned owls (Bubo virginianus), 26% (5) were caused by mammalian predators, and 11% (2) were due to unknown causes. Although eastern spotted skunks are known to avoid open areas and forested areas where die understory is less dense and the canopy more open, 11 of 12 avian-caused deaths occurred in mature shortleaf pine stands with an open canopy and herbaceous understory. [ABSTRACT FROM AUTHOR]

Small carnivores are of increasing conservation concern globally, including those formerly thought to be widespread and abundant. Three weasel species (Mustela nivalis, M. frenata, and M. erminea) are distributed across most of North America, yet several recent studies have reported difficulty detecting weasels within their historical range and several states have revised the status of weasels to that of species of conservation concern. To investigate the status and trends of weasels across the United States (US) and Canada, we analyzed four separate datasets: historical harvests, museum collections, citizen scientist observations (iNaturalist), and a recent US-wide trail camera survey. We observed 87-94% declines in weasel harvest across North America over the past 60 years. Declining trapper numbers and shifts in trapping practices likely partially explain the decline in harvest. Nonetheless, after accounting for trapper effort and pelt price, we still detected a significant decline in weasel harvest for 15 of 22 evaluated states and provinces. Comparisons of recent and historical museum and observational records suggest relatively consistent distributions for M. erminea, but a current range gap of >1000 km between two distinct populations of M. nivalis. We observed a dramatic drop-off in M. frenata records since 2000 in portions of its central, Great Lakes, and southern distribution, despite extensive sampling effort. In 2019, systematic trail camera surveys at 1509 sites in 50 US states detected weasels at 14 sites, all of which were above 40o latitude. While none of these datasets are individually conclusive, they collectively support the hypothesis that weasel populations have declined in North America and highlight the need for improved methods for detecting and monitoring weasels. By identifying population declines for small carnivores that were formerly abundant across North America, our findings echo recent calls to expand investigations into the conservation need of small carnivores globally., Competing Interests: The authors have declared that no competing interests exist.

With the accelerating pace of global change, it is imperative that we obtain rapid inventories of the status and distribution of wildlife for ecological inferences and conservation planning. To address this challenge, we launched the SNAPSHOT USA project, a collaborative survey of terrestrial wildlife populations using camera traps across the United States. For our first annual survey, we compiled data across all 50 states during a 14-week period (17 August-24 November of 2019). We sampled wildlife at 1,509 camera trap sites from 110 camera trap arrays covering 12 different ecoregions across four development zones. This effort resulted in 166,036 unique detections of 83 species of mammals and 17 species of birds. All images were processed through the Smithsonian's eMammal camera trap data repository and included an expert review phase to ensure taxonomic accuracy of data, resulting in each picture being reviewed at least twice. The results represent a timely and standardized camera trap survey of the United States. All of the 2019 survey data are made available herein. We are currently repeating surveys in fall 2020, opening up the opportunity to other institutions and cooperators to expand coverage of all the urban-wild gradients and ecophysiographic regions of the country. Future data will be available as the database is updated at eMammal.si.edu/snapshot-usa, as will future data paper submissions. These data will be useful for local and macroecological research including the examination of community assembly, effects of environmental and anthropogenic landscape variables, effects of fragmentation and extinction debt dynamics, as well as species-specific population dynamics and conservation action plans. There are no copyright restrictions; please cite this paper when using the data for publication., (© 2021 The Authors. Ecology © 2021 The Ecological Society of America.)

Eastern and western spotted skunks ( Spilogale putorius and Spilogale gracilis ) serve as definitive hosts for skunk cranial worm ( Skrjabingylus chitwoodorum ), a metastrongylid nematode that spends its adult stage inhabiting the frontal sinuses of the host cranium. Skunk cranial worm can cause severe damage to the skull of spotted skunks, and this damage is identifiable in preserved specimens. We visited six mammal collections between 2016 and 2018 and used 578 spotted skunk skull specimens to identify patterns in prevalence and severity of skunk cranial worm damage in spotted skunks. Specimens were collected between 1895 and 1981 from across the US. We assessed effects of host genetic clade, collection year, precipitation, and sex on prevalence and severity rates. We hypothesized that the midwestern genetic clade (plains spotted skunk, Spilogale putorius interrupta ), which experienced a range-wide population decline in the mid-1900s, would experience the highest infection and severity rates. We expected precipitation, but not sex to influence infection and severity. Our top models indicated that host genetic clade, precipitation in the year prior to specimen collection, and the year prior to specimen collection best predicted prevalence and severity of skunk cranial worm. We suggest the positive association with precipitation is a result of local availability of gastropods, the intermediate host for skunk cranial worm. There was a negative association between prior year and prevalence, but the severity of damage increased over time for all clades. Given concerns over population declines of spotted skunks as well as observations of increasing damage over the past century, there is a need for further research on the impacts of cranial worm infection on individual-scale behavior, reproduction and survival, and on population-scale demographics.

Baylisascaris procyonis is a nematode of significant concern to public and domestic animal health as well as wildlife management. The population genetics of B. procyonis is poorly understood. To gain insights into patterns of genetic diversity within (infrapopulation level) and among (component population level) raccoon (Procyon lotor) hosts, and specifically to assess the relative importance of indirect and direct transmission of the parasite for explaining observed population structure, we collected 69 B. procyonis from 17 wild raccoons inhabiting five counties in Missouri and Arkansas, USA. Informative regions of mitochondrial (CO1, CO2) and nuclear (28S, ITS2) genes were amplified and the distribution and genetic variability of these genes were assessed within and across raccoons. Concatenation of the CO1 and CO2 mtDNA sequences resulted in 5 unique haplotypes, with haplotype diversity 0.456 ± 0.068. The most common haplotype occurred in 94% of raccoons and 72.5% of B. procyonis. Sequences for 28S rDNA revealed four unique nuclear genotypes, the most common found in 100% of raccoons and 82.6% of B. procyonis. ITS2 genotypes were assessed using fragment analysis, and there was a 1:1 correspondence between 28S and ITS-2 genotypes. Infrapopulation variation in haplotypes and genotypes was high and virtually all hosts infected with multiple sequenced nematodes also harbored multiple haplotypes and genotypes. There was a positive relationship between the size of the analyzed infrapopulation (i.e., the number of nematodes analyzed) and the number of haplotypes identified in an individual. Collectively this work emphasizes the importance of indirect transmission in the lifecycle to this parasite., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Trypanosoma cruzi, the causative agent of Chagas' disease, is a substantial public health concern in Latin America. Although rare in humans and domestic animals in the United States, T. cruzi is commonly detected in some wildlife species, most commonly raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana). To increase our understanding of the reservoir host species range and geographic distribution, 11 species of mammals from six states spanning the known range of T. cruzi (Arizona, California, Florida, Georgia, Missouri, and Virginia) were tested for antibodies to T. cruzi using indirect immunofluorescent antibody testing. In addition, culture isolation attempts were conducted on a limited number of animals from Georgia and Florida. Evidence of T. cruzi was found in every state except California; however, low numbers of known reservoirs were tested in California. In general, the highest seroprevalence rates were found in raccoons (0-68%) and opossums (17-52%), but antibodies to T. cruzi were also detected in small numbers of striped skunks (Mephitis mephitis) from Arizona and Georgia, bobcats (Lynx rufus) from Georgia, two coyotes (Canis latrans) from Georgia and Virginia, and a ringtail (Bassariscus astutus) from Arizona. Culture-based prevalence rates for raccoons were significantly greater than those for opossums; however, seroprevalences of raccoons and opossums from several geographic locations in Georgia and Florida were not different, indicating that exposure rates of these two species are similar within these areas. For both raccoons and opossums, seroprevalence was significantly higher in females than in males. No difference was detected in seroprevalence between adults and juveniles and between animals caught in urban and rural locations. Our results indicate that T. cruzi prevalence varies by host species, host characteristics, and geographic region and provides data to guide future studies on the natural history of T. cruzi in the United States.