Eastern Spotted Skunk Spilogale Putorius Research Articles

First tracking of an eastern spotted skunk litter from birth to independence

Abstract We tracked a female eastern spotted skunk Spilogale putorius in North Carolina, USA, that gave birth to a litter of three kits in summer 2020. Using camera traps and radio-collars, we were able to monitor the movement and behaviors of the female and litter. We observed behaviors including food provisioning, play-fighting, and interspecific interactions. We tracked the movements of the kits past independence from their mother and documented dispersal events for two kits. This is the first known successful attempt to track eastern spotted skunk kits from birth to independence, providing new insights into the ecology of this cryptic species.

Efficacy of attractants for detecting eastern spotted skunks: an experimental approach

Estimates of abundance and occupancy are essential for wildlife management, particularly for species of conservation concern such as eastern spotted skunks Spilogale putorius. Most studies of eastern spotted skunks rely on limited evidence for best monitoring practices, and while many studies use attractants to increase detections, previous studies have not tested attractants against a control of no attractant to determine their effectiveness. We tested two common attractants (sardines and fatty acid tablets) and one uncommon attractant (wild boar carcasses) against a control of no attractant to determine if any attractant increased detections of eastern spotted skunks or changed their temporal activity. Based on our model, sardines and wild boar carcasses improved detections by three and eight times that of the control, respectively. Further, for every 100 trap nights, we detected eastern spotted skunks 10.67 times with wild boar carcasses, 1.02 times with sardines, 0.53 times with fatty acid tablets and 0.44 times with no attractant. Wild boar carcasses also substantially decreased latency to detection, with skunks detected two times faster than at other attractants and almost three times faster than at the control. Eastern spotted skunks were most active in the early morning before sunrise, and their temporal activity did not vary significantly by attractant. This study is the first to use an experimental framework to test attractants for eastern spotted skunks, and our results showed that choice of attractant matters. Large animal carcasses, although rarely used, may be most effective for detecting eastern spotted skunks, while fatty acid tablets were no different than the control, and we recommend against their use in future studies. Monitoring plans should incorporate our results as increasing detections is essential to understanding the abundance, range and demographics of eastern spotted skunks.

Mating behavior of Eastern Spotted Skunk Spilogale putorius Linnaeus, 1758 (Mammalia: Carnivora: Mephitidae) revealed by camera trap in Texas, USA

Eastern Spotted Skunks Spilogale putorius are an understudied Vulnerable small carnivore. Here we report a novel capture of Eastern Spotted Skunks mating via a camera trap in central Texas. This detection adds to the minimal natural history knowledge of the species and highlights the utility of camera traps for documenting rarely observed behaviors.

Quantifying temporal variation in dietary niche to reveal drivers of past population declines

Abstract Given the long and dynamic history of anthropogenic disturbances to ecosystems, it is difficult to determine the drivers of past population declines. These uncertainties dilute the efficacy of conservation efforts and might hinder species and ecosystem recovery. Niche quantification can be a useful tool for understanding drivers of past population declines. Niche parameters reflect key resources used, providing insight into the conditions needed to achieve population stability. By reconstructing a population's niche position and space over a period of decline and comparing to historic baselines, shifts in the realized niche of a species can be assessed. Comparing shifts to historic information on resource availability and timing of declines can allow practitioners to identify probable drivers of species decline. We demonstrated the utility of this technique by reconstructing parameters of isotopic dietary niche over a 130‐year period and comparing isotopic niche reconstructions to land use and crop harvests during this same period via regression and Bayesian standard ellipsoid (SIBER) analyses. We use a formerly widespread but now endangered species, the eastern spotted skunk Spilogale putorius, addressing the hypothesis that land use change and agricultural intensification led to a historical collapse of key dietary resources which correlates with population declines in this species. To help control for isotopic variability unrelated to population decline, we compare trends to those of a secure, but ecologically similar generalist mesocarnivore, the striped skunk Mephitis mephitis, across the same spatiotemporal scale. We present evidence that historic dietary changes occurred in spotted skunks in the early 1900s but not to the same degree in striped skunks. Changes in isotopic composition correspond with the temporal period of decline and are explained by concurrent changes in land use. These results support the hypothesis that loss of key dietary resources as a result of land use change and agricultural intensification played a significant role in population declines of spotted skunks in this region. A free Plain Language Summary can be found within the Supporting Information of this article.

Increasing Detection by Reducing Disturbance and Excluding Nontarget Small Mammal Species: An Occupancy Study Approach

Abstract Track tubes are a noninvasive, efficient method to monitor populations of small mammals that can be implemented on a large landscape scale and are a cost-effective approach for certain sampling situations. As with all field sampling tools, modifications are made depending on research objectives, habitat being sampled, and target species. We conducted two experiments with the objective to increase efficiency and decrease labor while retaining high detection probabilities as part of an Annual Multi-Agency Regional Southeastern Beach Mouse Peromyscus polionotus niveiventris Habitat Occupancy Survey. We conducted studies along a contiguous 72-km coastline of the Cape Canaveral Barrier Island Complex in east-central Florida, USA, that includes the Kennedy Space Center, Cape Canaveral Air Force Station, and Canaveral National Seashore. We conducted the experiments to address several issues that had regularly compromised our survey data. One experiment assessed the ideal length of deployment times for track tubes in various habitat types with multiple species where southeastern beach mice were previously detected. Another experiment, determined how to restrict certain meso-mammal species (raccoons Procyon lotor, and eastern spotted skunks Spilogale putorius) from knocking over the tubes or reaching into the tubes, thus reducing disturbance that results in missing data; or from entering the tubes (cotton rats Sigmodon hispidus), thereby obscuring any potential or actual footprints of the southeastern beach mouse or other targeted species. We observed an increase in the detection rate of southeastern beach mice in track tubes with increased nights of deployment (likelihood ratio test χ2 = 18.71, df = 3, P < 0.001) with the greatest increase between 3 nights and 6 nights and apparent leveling off between nights 9 and 12 and a large decrease in the detection rate of southeastern beach mice in track tubes with 0.5-in. (1.3-cm) excluders compared with the other-size excluders (likelihood ratio test χ2 = 167.89, df = 5, P < 0.001). We also found that 1-in. (2.5-cm) excluders prevented access by meso-mammals or entry by cotton rats and did not adversely affect the detection of either beach mice or cotton mice Peromyscus gossypinus, but did reduce disturbance and resulted in fewer missing data. These statistically significant process improvements have application for others involved with small mammal monitoring and species management.

Conservation Status of the Eastern Spotted Skunk Spilogale putorius in the Appalachian Mountains of Tennessee

Abstract The conservation status of the eastern spotted skunk (Spilogale putorius) was assessed in the Appalachian Mountains of Tennessee from November 1995 through June 1997. Population status and seasonal abundance were examined using live-trapping on an 8 × 8 grid in Monroe County. Relative abundance was assessed at selected sites in Blount, Greene, Monroe, Unicoi and Washington counties employing additional live-trapping methods. In 5723 trap-nights only four S. putorius were captured (trap-success rate = 0.07%). The most common mammals captured were the opossum (Didelphis virginiana) and the raccoon (Procyon lotor). All eastern spotted skunks were captured in rhododendron (Rhododendron spp.) thickets near streams. A program to monitor the status of the species in the Appalachians is recommended as a management measure.

ISOSPORA SPILOGALES N. SP. AND I. SENGERI N. SP. (PROTOZOA: EIMERIIDAE) FROM THE SPOTTED SKUNK, SPILOGALE PUTORIUS AMBARVALIS.

SYNOPSIS. Two new species of Isospora are described from the feces of an eastern spotted skunk Spilogale putorius ambarvalis imported into Montana from Florida. The oocysts of I. spilogales n. sp. are 29 to 38 by 22 to 28 μ and contain 2 sporocysts measuring 17 to 22 by 13 to 16 μ; a few Caryospora‐like oocysts containing a single sporocyst were considered abnormal I. spilogales oocysts. The oocysts of I. sengeri n. sp. are 16 to 23 by 12 to 18 μ and contain 2 sporocysts measuring 10 to 14 by 8 to 12 μ.