Sustainable human–wildlife coexistence requires a mechanistic understanding of the many ways that humans affect animals. However, progress is hampered by the lack of accessible data measuring the dynamic presence of people. Here, we leverage mobile-device data to disentangle how human presence and landscape modification differentially influence the use of geographic and environmental space for 37 mammal and bird species across the United States. Human presence affected more than 65% of species, with substantial variation across species. For ~60% of species that responded to human activities, the effects were interdependent—animals tended to react more strongly to human presence in less modified habitats. Our results demonstrate that human presence and landscape modification have complex combined effects on wildlife, which need to be considered for effective management.

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

Spilogale interrupta (Plains Spotted Skunk) and other species within the Spilogale genus have often been documented as using burrows for cover; however, schematics of a Plains Spotted Skunk burrow have only been documented once in the literature. While recovering 2 GPS radio transmitters in the Katy Prairie region of Southeast Texas, we excavated 2 active Plains Spotted Skunk burrows. Herein, we describe the schematics of 1 system that likely was excavated initially by a Geomys breviceps (Baird's Pocket Gopher) and the general schematics of a second burrow system frequently used by a different radio-collared individual. Both systems contained an obstructed entrance and a detritus-filled central cavity and were in locations higher in elevation than the surrounding matrix. Our observations further confirm the 3 requirements for Plains Spotted Skunk diurnal rest-location usage-protection from predation, thermoregulatory benefits, and protection from inclement weather-while providing additional insight into the intricacies of the burrow system itself. Further research into the structure of Spilogale burrows is needed to improve future conservation and management efforts of the genus.

Background: Chagas disease is one of the world's most neglected tropical diseases, infecting over six million people across the Americas. The hemoparasite Trypanosoma cruzi is the etiological agent for the disease, circulating in domestic, peridomestic, and sylvatic transmission cycles that are maintained by triatomine vectors and a diversity of wild and synanthropic hosts. Public health and wildlife management interventions targeting the interruption of T. cruzi transmission rely on an understanding of the dynamics driving the ecology of this zoonotic pathogen. One wildlife host that purportedly plays a role in the transmission of Chagas disease within the southern United States is the striped skunk (Mephitis mephitis), although infection prevalence in this species is poorly understood. Materials and Methods: To this end, we conducted a PCR-based surveillance of T. cruzi in 235 wild skunks, representing 4 species, across 76 counties and 10 ecoregions in Texas, United States, along with an evaluation of risk factors associated with the infection. Results: We recovered an overall T. cruzi prevalence of 17.9% for all mephitid taxa aggregated, ranging between 6.7% for plains spotted skunks (Spilogale putorius interrupta) and 42.9% for western spotted skunks (Spilogale gracilis). We report the first cases of T. cruzi infection in plains spotted and American hog-nosed skunks (Conepatus leuconotus), of important note for conservation medicine since populations of both species are declining within Texas. Although not statistically significant, we also detected trends for juveniles to exhibit greater infection risk than adults and for differential sex biases in T. cruzi prevalence between taxa, which align with variations in species-specific seasonal activity patterns. No geographic or taxonomic risk factors were identified. Conclusion: Our study contributed key data for population viability analyses and epidemiologic models in addition to providing a baseline for future T. cruzi surveillance among skunks and other wildlife species.

The Amazonian marsh rat, Holochilus sciureus, is a member of the subfamily Sigmodontinae, the second-largest subfamily of muroid rodents, with 410 species and ca. 84 genera in 12 tribes. This semiaquatic rodent is distributed in South America and is of great economic and epidemiological importance. In this study, we obtained the first mitochondrial genome of the genus Holochilus obtained from a tissue sample associated with a museum voucher specimen. The generated mitogenome sequence of H. sciureus is 16,358 bp length. It comprises a control region and a conserved set of 37 genes encoding for 2 rRNA genes, 22 tRNA genes and 13 protein-coding genes. We conducted a phylogenetic analysis that included H. sciureus and the only five other published mitochondrial genomes of this poorly studied subfamily of rodents.

Four species of spotted skunks (Carnivora, Mephitidae, Spilogale) are currently recognized: Spilogale angustifrons, S. gracilis, S. putorius, and S. pygmaea. Understanding species boundaries within this group is critical for effective conservation given that regional populations or subspecies (e.g., S. p. interrupta) have experienced significant population declines. Further, there may be currently unrecognized diversity within this genus as some taxa (e.g., S. angustifrons) and geographic regions (e.g., Central America) never have been assessed using DNA sequence data. We analyzed species limits and diversification patterns in spotted skunks using multilocus nuclear (ultraconserved elements) and mitochondrial (whole mitogenomes and single gene analysis) data sets from broad geographic sampling representing all currently recognized species and subspecies. We found a high degree of genetic divergence among Spilogale that reflects seven distinct species and eight unique mitochondrial lineages. Initial divergence between S. pygmaea and all other Spilogale occurred in the Early Pliocene (~ 5.0 million years ago). Subsequent diversification of the remaining Spilogale into an "eastern" and a "western" lineage occurred during the Early Pleistocene (~1.5 million years ago). These two lineages experienced temporally coincident patterns of diversification at ~0.66 and ~0.35 million years ago into two and ultimately three distinct evolutionary units, respectively. Diversification was confined almost entirely within the Pleistocene during a timeframe characterized by alternating glacial-interglacial cycles, with the origin of this diversity occurring in northeastern Mexico and the southwestern United States of America. Mitochondrial-nuclear discordance was recovered across three lineages in geographic regions consistent with secondary contact, including a distinct mitochondrial lineage confined to the Sonoran Desert. Our results have direct consequences for conservation of threatened populations, or species, as well as for our understanding of the evolution of delayed implantation in this enigmatic group of small carnivores.

While museum voucher specimens continue to be the standard for species identifications, biodiversity data are increasingly represented by photographic records from camera traps and amateur naturalists. Some species are easily recognized in these pictures, others are impossible to distinguish. Here we quantify the extent to which 335 terrestrial nonvolant North American mammals can be identified in typical photographs, with and without considering species range maps. We evaluated all pairwise comparisons of species and judged, based on professional opinion, whether they are visually distinguishable in typical pictures from camera traps or the iNaturalist crowdsourced platform on a 4-point scale: (1) always, (2) usually, (3) rarely, or (4) never. Most (96.5%) of the 55,944 pairwise comparisons were ranked as always or usually distinguishable in a photograph, leaving exactly 2,000 pairs of species that can rarely or never be distinguished from typical pictures, primarily within clades such as shrews and small-bodied rodents. Accounting for a species geographic range eliminates many problematic comparisons, such that the average number of difficult or impossible-to-distinguish species pairs from any location was 7.3 when considering all species, or 0.37 when considering only those typically surveyed with camera traps. The greatest diversity of difficult-to-distinguish species was in Arizona and New Mexico, with 57 difficult pairs of species, suggesting the problem scales with overall species diversity. Our results show which species are most readily differentiated by photographic data and which taxa should be identified only to higher taxonomic levels (e.g., genus). Our results are relevant to ecologists, as well as those using artificial intelligence to identify species in photographs, but also serve as a reminder that continued study of mammals through museum vouchers is critical since it is the only way to accurately identify many smaller species, provides a wealth of data unattainable from photographs, and constrains photographic records via accurate range maps. Ongoing specimen voucher collection, in addition to photographs, will become even more important as species ranges change, and photographic evidence alone will not be sufficient to document these dynamics for many species.

Research on rare or understudied species often benefits from employing multiple survey techniques to ensure highest efficacy in detecting individuals. The plains spotted skunk (Spilogale putorius interrupta) is an uncommon mephitid historically distributed throughout much of Texas, USA. To inform the current distribution of plains spotted skunks in Texas, we integrated occurrence data from natural history collections and field surveys with data from academic, wildlife, and citizen scientist groups, resulting in 286 verified occurrence records from 1892 through 2018. We modeled historic species distribution using 64 records from natural history collections to direct surveying efforts in 13 counties using live traps, camera traps, and track plates. Field surveys and citizen science camera trap surveys resulted in 16 records while crowdsourcing resulted in 23 verified reports detailing 78 unique plains spotted skunk records. Our efforts resulted in a 49% increase in occurrence records from 1892 to 2018 (186-286) and a 1,000% increase in records since 2000 (10-110). Using our methods, researchers and managers can optimize collection of plains spotted skunk occurrence data to better understand the species, produce more robust datasets for future management, and help ensure the best science is used when drafting conservation plans for plains spotted skunks.

The diversity, clinical manifestations, and impact on overall health of pathogenic fungi in Spilogale putorius (Eastern Spotted Skunk [ESS]) have been poorly investigated. Herein, we describe the first reported cases of fungal dermatitis in ESS from a population in southeastern Texas. In 2016, two of 3 ESS live-trapped in Harris County, TX, exhibited symptoms consistent with dermatophytosis. We isolated fungus from 1 of 2 cultures grown from scraped samples of infected ESS skin and morphologically identified it as Microsporum canis. Reviewing local wildlife rehabilitation records, we were able to confirm the prevalence of dermatophytosis within local mephitid populations. We examine the implications of the discovery of a zoonotic fungal pathogen in ESS in light of its importance in wildlife medicine as well as its ramifications for the health of domestic animals and humans.

Although the Galápagos Islands are recognized for their contribution to our understanding of evolutionary theory and have received the attention of scientists for over 185 years, our understanding of the native rodents there has been minimal relative to many other groups of organisms.  Much of what we knew through most of the 20th century was based solely on species descriptions.  Chromosome data has been limited to only Nesoryzomys narboroughi (2n = 32, FN (number of autosomal arms) = 50) and Aegialomys galapagoensis (2n = 56; FN = 58).  We present the karyotypes of the only remaining extant species in the genus, N. swarthi (2n = 56; FN = 54) and N. fernandinae (2n = 44; FN = 54).  Chromosomal banding reveals that extensive rearrangement has occurred within Nesoryzomys, including Robertsonian fusion and tandem fusion events but these alone cannot account for the diverse diploid numbers found within the genus.  We propose that 1) N. swarthi represents the ancestral karyotype for the genus, similar to A. galapagoensis, 2) N. swarthi and N. fernandinae share the same fundamental number, suggesting divergence by Robertsonian fusions, and 3) N. narboroughi has the most derived karyotype, based on banding morphology and low diploid number.

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.

Improper or inefficient survey designs are commonly cited as underlying issues contributing to failure to detect rare or understudied species. Researchers primarily rely on information obtained when species were widely distributed and abundant to inform research design. Recently, interest in Spilogale putorius (Eastern Spotted Skunk) has piqued due to declining populations and an uncertain conservation status. To address knowledge gaps on the effects of seasonality, bait choice, and survey design on capture efficacy and sex ratio, we surveyed Spilogale putorius interrupta (Plains Spotted Skunk) in the Katy Prairie region of Texas with 2 survey designs. Our systematic survey design provided 2 bait types, a 5-day survey length, and a grid array of traps, while our casual live-trapping surveys had 1 bait type with varied survey length and trap array. From February 2019 through August 2020, we captured 29 unique Plains Spotted Skunks 49 times. Analysis of systematic survey data indicates that seasonality and bait type did not affect capture success. Additionally, surveys conducted in the summer resulted in similar overall capture rates but higher female capture rates when compared to other seasons. Our finding of similar capture rates among seasons is in contrast to previous reports that suggest reduced capture efficacy of spotted skunks during the summer. These results improve the current knowledge of techniques for capturing spotted skunks and offer more efficient means for researchers to assess populations.

Evolutionary radiations stemming from colonization of archipelagos provide valuable insights into mechanisms and modes of speciation.  For this reason, the fauna inhabiting the Galapagos Islands has been the focus of numerous emblematic ecological and evolutionary studies.  However, studies focused on rodents have been scarce.  Rice rats radiated in situ into at least seven endemic species: Aegialomys galapagoensis, Nesoryzomys narboroughi, N. swarthi, N. fernandinae, N. indefessus, N. darwini and Megaoryzomys curioi.  Only the first four species remain extant on the archipelago.  These species are considered vulnerable, mainly due to human activities and invasive species.  Despite their interesting evolutionary history, questions surrounding phylogenetic relationships, colonization events, genetic diversity and demography of populations remain unresolved.  We used the D-loop region of mtDNA to infer phylogenetic relationships, colonization events, date divergences, and conduct population genetic analyses of the four extant endemic species inhabiting the Galapagos Islands.  We found that all species were monophyletic. A. galapagoensis is sister to A. xanthaeolus from the continent, and both of them are the sister clade of the genus Nesoryzomys.  Our results also showed that there were two colonization events to the islands.  The first event was the arrival of the ancestor of Nesoryzomys during the Pliocene, when divergences between genera occurred.  The second was Aegialomys during middle Pleistocene, when species diversification began.  Populations on each island show high genetic diversity and most show signals of recent expansion.  However, future studies are needed to accurately assess the conservation status of these populations.  We suggest ongoing monitoring of these vulnerable endemic species, including ecological and population genetic studies.  In addition, future studies using genome-wide molecular markers and additional species from the continent, as well as sampling extinct species from the islands, will improve our knowledge about the origin and relationships of the endemic rodents of the Galapagos Islands.

The Systematic Collections Committee of the American Society of Mammalogists advises curators and other personnel affiliated with natural history collections in matters relating to administration, curation, and accreditation of mammal specimens and their associated data. The Systematic Collections Committee also maintains a list of curatorial standards for managing a collection-accreditation program under the auspices of the American Society of Mammalogists. To date, the Systematic Collections Committee has provided guidance for the more traditional specimen collections (skin, skeletal, fluid, etc.) and specimen data management. Given the rapidly expanding role of genetic resources in biological research, the Systematic Collections Committee herein presents a series of formal guidelines and standards designed to assist collections professionals in the current best practices for curation and maintenance of collections of genetic resources, to ensure long-term integrity of the archived material, and to address personnel safety and guidelines for researchers and curatorial staff. These guidelines and standards are intended to provide constructive guidance and a mechanism of accreditation for collections that vary in scale and infrastructure.

We assessed the genetic variability of the eastern spotted skunk (Spilogale putorius) throughout the range of the species, with an emphasis on the potentially endangered plains spotted skunk subspecies (S. p. interrupta). Tissue samples from a variety of sources including field surveys, state agencies, and museum tissue collections allowed a detailed assessment of the genetic variability in S. putorius using both microsatellite markers and cytochrome b (Cytb) gene sequences. Our analysis of 118 specimens established that genetic patterns were consistent with the currently accepted taxonomy of the 3 recognized subspecies: S. p. putorius, S. p. ambarvalis, and S. p. interrupta. The differentiation between S. p. putorius and S. p. ambarvalis was less pronounced (F-ST = 0.178; Cytb sequence divergence = 1.2%) than between these subspecies and the plains spotted skunk (average F-ST = 0.278; Cytb sequence divergence = 2.9%). Overall, genetic variability in the plains spotted skunk was lower than that seen in common carnivores (e.g., striped skunks, Mephitis mephitis, and raccoons, Procyon lotor), but slightly higher than in the endangered black-footed ferret (Mustela nigripes). The heterozygosity levels more closely resemble those found within the island spotted skunk (S. gracilis amphiala) from the Channel Islands of California and other vertebrates that have a "threatened" conservation status.

Estimates of the distribution and prevalence of the sinus roundworm (Skrjabingylus chitwoodorum) have been based largely on the inspection of skunk (Mephitidae) skulls showing damage from infections. We examined 595 striped skunks (Mephitis mephitis) and nine hog-nosed skunks (Conepatus leuconotus) that had tested negative for rabies by the Texas Department of State Health Services (US) between November 2010 and April 2015 to determine species of Skrjabingylus, prevalence and intensity of infection, and distribution of infection in Texas by county. We expected ecoregions with more precipitation to have higher rates of infection than more-arid ecoregions. Prevalence of S. chitwoodorum in striped skunks was 48.7%, with a mean intensity of 19.4 (SD=24.44, range=1-181) nematodes. There was a bias for the left sinus. The prevalence of infection varied among ecoregions of Texas, but it was not correlated with precipitation. Infection intensity did not vary among ecoregions. The prevalence of sinus roundworms in rabies-negative skunks suggested that behavioral changes because of skrjabingylosis might have been responsible for the submission by the public of some skunks for rabies testing.