The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Matthew E. Gompper - One of the best experts on this subject based on the ideXlab platform.
-
PREVALENCE AND SEVERITY OF Skunk CRANIAL WORM (SKRJABINGYLUS CHITWOODORUM) DAMAGE INCREASE WITH PRECIPITATION IN Spotted SkunkS (SPILOGALE SPP.).
Journal of wildlife diseases, 2020Co-Authors: Summer D. Higdon, Matthew E. GompperAbstract: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.
-
rest site use and the apparent rarity of an ozark population of plains Spotted Skunk spilogale putorius interrupta
Southeastern Naturalist, 2020Co-Authors: Summer D. Higdon, Matthew E. GompperAbstract:Spilogale putorius interrupta (Plains Spotted Skunk) experienced range-wide declines beginning in the 1940s, and knowledge of population persistence and basic habitat requirements of the taxon remains limited. We surveyed for a population of the subspecies in the forested Ozark region of Arkansas. We deployed a dense camera-trap grid (>8000 trap-nights across a 24,611-ha study area) and recorded individuals on 6 occasions at 4 sites; their detection rate was amongst the lowest of all detected species. There were no observed differences between occupied and unoccupied sites. We captured and deployed radio-collars on 2 individuals that were tracked to 12 rest sites. Groundcover was sparse at rest sites, perhaps due to use of rocky outcrops by both individuals.
-
landscape ecology of eastern Spotted Skunks in habitats restored for red cockaded woodpeckers
Restoration Ecology, 2013Co-Authors: Joshua J Millspaugh, Damon B Lesmeister, Rachel S Crowhurst, Matthew E. GompperAbstract:Although examples are rare, conflicts between species of conservation concern can result from habitat restoration that modifies habitat to benefit a single taxon. A forest restoration program designed to enhance habitat for endangered red-cockaded woodpeckers (Picoides borealis) may be reducing available habitat for the eastern Spotted Skunk (Spilogale putorius), a forest-adapted sympatric species of conservation concern that occurs in the Ouachita National Forest, Arkansas, U.S.A. At small scales, eastern Spotted Skunks select early successional forest with structural diversity, whereas red-cockaded woodpeckers prefer mature pine (Pinus spp.) habitat. We surveyed for eastern Spotted Skunks at 50 managed forest stands, modeled occupancy as a function of landscape-level habitat factors to examine how features of restoration practices influenced occurrence, and compared known occupied forest stands to those where active red-cockaded woodpecker nesting clusters were located. The most-supported occupancy models contained forest stand age (negatively associated) and size (positively associated); suggesting eastern Spotted Skunks primarily occupy large patches of habitat with dense understory and overhead cover. Red-cockaded woodpecker nesting clusters were located in smaller and older forest stands. These results suggest that increased overhead cover, which can reduce risk of avian predation, enhances occupancy by small forest carnivores such as eastern Spotted Skunks. Management activities that increase forest stand rotation length reduce the availability of young dense forest. The practice may enhance the value of habitat for red-cockaded woodpeckers, but may reduce the occurrence of eastern Spotted Skunks. Implementing plans that consider critical habitat and extinction risks for multiple species may reduce such conservation conflict.
-
eastern Spotted Skunk spilogale putorius survival and cause specific mortality in the ouachita mountains arkansas
American Midland Naturalist, 2010Co-Authors: Damon B Lesmeister, Matthew E. Gompper, Joshua J Millspaugh, Tony W MongAbstract:Abstract 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 for 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 the 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 ...
-
a survey of parasites identified in the feces of eastern Spotted Skunks spilogale putorius in western arkansas
Journal of Wildlife Diseases, 2008Co-Authors: Damon B Lesmeister, Joshua J Millspaugh, Susan E Wade, Matthew E. GompperAbstract:The endoparasite community of the eastern Spotted Skunk (Spilogale putorius) is poorly known. We surveyed parasites found in the feces of 29 eastern Spotted Skunks captured between March 2005 and January 2007 from a population in west-central Arkansas as part of a broader study of the ecology of the species. We identified 13 species (nine nematodes, four protozoa) from 82 fecal samples. Mean (±SD) number of species per individual Skunk was 4.1±2.1, although this is likely an underestimate because some individuals were sampled more intensively than others. Most of the identified parasite species were also found in other Skunk species or in other small carnivore species.
Rodney A. Mead - One of the best experts on this subject based on the ideXlab platform.
-
Effects of Hysterectomy on Luteal Function in the Western Spotted Skunk (Spilogale putorius latifrons)
2016Co-Authors: Rodney A. Mead, Ann SwannackAbstract:Fifteen pregnant Spotted Skunks were randomly assigned to 1 of 3 groups: (Group I) intact controls; (Group II) hysterectomized during the prolonged preimplantation period and (Group Ill) hysterectomized within 1-4 days after nidation. Blood samples were obtained at various intervals after hysterectomy and assayed for progesterone by radioimmunoassay to determine the effects of hysterectomy on luteal function. Hysterectomy had no significant effect on luteal function and presumably luteal maintenance, as indicated by changes in plasma progesterone levels. These results indicate that neither embryos nor placentae were an essential source of luteotropin and that the uterus played no significant role in regulating the life span of the corpora lutea of pregnancy in the Spotted Skunk
-
Role of Protactin and Luteinizing Hormone in Regulating Timing of Implantation in the Spotted Skunk’
2016Co-Authors: Matthew Berria, M. M. Joseph, Rodney A. MeadAbstract:The western Spotted Skunk exhibits an obligate delay of implantation lasting 200-220 days. The pituitary is essential for luteal activation, The corpora lutea, in turn, secrete the hormones necessary for blastocyst im-plantation. Two experiments were designed to determine which pituitary hormones are responsible for in-creasing luteal activity and induction of implantation, Forty-two pregnant Skunks with delayed implanting blastocysts were treated as follows: 13 served as untreated controls, 6 received 0,5 mg prolactin (PRL) daily, and 5 received diluent beginning in January. Four received 1.5 mg bromocriptine (CB-154) daily, 3 received both CB-154 and PRL, 3 received diluent, 5 received a gonadotropin-releasing hormone agonist (GnRHa) dispensed from osmotic minipumps, and 3 received diluent dispensed from osmotic minipumps starting in April. The Skunks were subjected to a natural photoperiod. Duration of preimplantation and blood levels of progester-one and luteinizing hormone were measured. PRL significantly (p<0.05) shortened and CB-154 significantly (p<0.05) prolonged the duration of preimplantation when compared to controls (148 ± 33.6 vs. 251 ± 3.2 vs. 199 ± 5.1 days, respectively). PRL was able to reverse the inhibitory effect of CB-154 when both were admin-istered simultaneously (195 ± 4.0 vs. 251 ± 3.2 days). GnRHa had no significant (p>O.O5) effect on duration of preimplantation (199 ± 5.1 days) when compared to controls (203 ± 3.2 days). These results indicate that PRL is the primary pituitary hormone responsible for increased luteal activity and subsequent blastocyst implanta-tion in the Spotted Skunk
-
occurrence of amitotic division of trophoblast cell nuclei in blastocysts of the western Spotted Skunk spilogale putorius latifrons
Hereditas, 2004Co-Authors: Galina K Isakova, Rodney A. MeadAbstract:A cytogenetic examination of spreaded cells of diapausing and early activated blastocysts obtained from 7 female western Spotted Skunks was performed. Mitosis was not observed in 1626 cells obtained from 9 diapausing blastocysts; however, 12 (1.5%) figures of diploid mitosis were seen in 851 cells from 5 early activated embryos. Diameter of the cell nuclei varied from 4 to 29 μm during diapause, and from 5 to 40 μm in activated blastocyst, and the heterogeneity in nuclear size was significantly different between diapausing and activated embryos (P<0.01). About 80% of nuclei from diapausing blastocysts measured 9 to16 μm, whereas a similar percentage of nuclei from activated blastocysts ranged from 15 to 27 μm. Many enlarged nuclei exhibited morphological features characteristic of mammalian polytene (i.e. endopolyploid with polytenic organization of chromosomes) trophoblast cells. The number of silver stained nucleoli in all the nuclei did not exceed 2, which corresponds to the number of nucleolus organizers in the diploid karyotype in this species of Skunk and suggests the polytene organization of chromosomes in enlarged nuclei. About 10% of large interphase nuclei were observed to undergo amitosis, i.e. direct division by constriction. The resulting nuclear fragments in diapausing blastocysts usually had normal morphology and active nucleoli. In activated embryos, nearly 15% of amitotically divided nuclei appeared to be dividing into fragments of unequal size, one of which had normal cell nuclear morphology and extremely large silver positive nucleoli, and the other fragment exibited signs of cell death. We interpret these data as indicating that 1) amitotic division of trophoblast endopolyploid cell nuclei in the Skunk blastocysts may generate new trophoblast cells which contribute to increased cell number during both diapause and activation stages, and 2) activation of blastocysts after diapause is related to the production of trophoblast cells with enhanced synthetic capabilities.
-
spatiotemporal expression of cyclooxygenase 1 and cyclooxygenase 2 during delayed implantation and the periimplantation period in the western Spotted Skunk
Biology of Reproduction, 1999Co-Authors: Sanjoy K Das, S K Dey, J Wang, Rodney A. MeadAbstract:Embryonic development in the western Spotted Skunk is arrested after blastocyst formation for about 200 days. This developmental arrest is believed to be due to insufficiency of uterine conditions to support continuous development. Implantation and decidualization are defective in cyclooxygenase 2 (Cox2)-, but not Cox1-, deficient mice. We therefore used Northern and in situ hybridization to investigate changes in uterine expression of Cox1 and Cox2 genes during various stages of pregnancy in the Spotted Skunk. Cox1 was constitutively expressed at all stages of pregnancy examined, but it did exhibit localized up-regulation in the trophoblast and necks of uterine glands at early implantation sites. Cox2 expression was highly regulated with little or no expression during delayed implantation. Cox2 expression was first detected in the uterus and trophoblast prior to blastocyst attachment and remained detectable for 5-6 days after blastocyst attachment. Cox2 expression was also localized in the luminal and glandular epithelia of uterine segments located between implantation chambers. Changes in Cox expression were not correlated with the abrupt increase in uterine weight that occurs simultaneously with renewed embryonic development but was correlated with an influx of serum proteins into the uterus observed in a previous study.
-
changes in uterine expression of leukemia inhibitory factor during pregnancy in the western Spotted Skunk
Biology of Reproduction, 1999Co-Authors: Douglas J Hirzel, S K Dey, Sanjoy K Das, J Wang, Rodney A. MeadAbstract:Mutation of the leukemia inhibitory factor (LIF) gene results in reproductive failure in LIF mice due to an inability to implant their blastocysts. This condition is reversed by infusion of LIF or by transferral of embryos to pseudopregnant, wild-type mice. This led us to hypothesize that embryonic diapause in the Spotted Skunk is due to insufficient uterine expression of LIF whereas resumption of development and implantation are associated with increased LIF expression. We also investigated the hormonal control of LIF expression. Uterine concentrations of LIF mRNA were determined by quantitative reverse transcription-polymerase chain reaction. Changes in cell-specific localization of LIF mRNA and protein were determined by in situ hybridization and immunocytochemistry. LIF mRNA was detected but was not abundant during embryonic diapause; it then increased when blastocysts resumed development and remained elevated prior to implantation. LIF mRNA and protein could not be localized in the uterus during embryonic diapause but were quite apparent in luminal and glandular epithelium during blastocyst activation. Prolactin, progesterone, and estradiol failed to increase uterine concentrations of LIF mRNA above those in ovariectomized controls. These data are consistent with the initial hypothesis and suggest that LIF may somehow be involved in preparing the uterus for implantation in the Spotted Skunk.
Robert C. Dowler - One of the best experts on this subject based on the ideXlab platform.
-
genetic variation within a species of parasitic nematode skrjabingylus chitwoodorum in Skunks
Journal of Nematology, 2021Co-Authors: Allie N Denham, Robert C. Dowler, Malorri R Hughes, Nicholas J Negovetich, Loren K. AmmermanAbstract: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.
-
Genetic variation in the eastern Spotted Skunk (Spilogale putorius) with emphasis on the plains Spotted Skunk (S. p. interrupta)
Journal of Mammalogy, 2018Co-Authors: Alexandra A. Shaffer, Robert C. Dowler, J. Clint Perkins, Adam W. Ferguson, Molly M. Mcdonough, Loren K. AmmermanAbstract: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 (FST = 0.178; Cytb sequence divergence = 1.2%) than between these subspecies and the plains Spotted Skunk (average FST = 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.
-
phylogeography of a widespread small carnivore the western Spotted Skunk spilogale gracilis reveals temporally variable signatures of isolation across western north america
Ecology and Evolution, 2017Co-Authors: Adam W. Ferguson, Jerry W. Dragoo, Molly M. Mcdonough, Loren K. Ammerman, Gema I Guerra, Margaret Rheude, Robert C. DowlerAbstract:We analyzed phylogeographic patterns in the western Spotted Skunk, Spilogale gracilis Merriam, 1890 (Carnivora: Mephitidae) in relation to historical events associated with Pre-Pleistocene Divergence (PPD) and Quaternary climate change (QCC) using mitochondrial DNA from 97 individuals distributed across Western North America. Divergence times were generated using BEAST to estimate when isolation in putative refugia occurred. Patterns and timing of demographic expansion was performed using Bayesian skyline plot. Putative climatic refugia resulting from Quaternary climate change were identified using paleoecological niche modeling and divergence dates compared to major vicariant events associated with Pre-Pleistocene conditions. We recovered three major mitochondrial clades corresponding to western North America (California, Baja, and across the Great Basin), east-central North America (Texas, central Mexico, New Mexico), and southwestern Arizona/northwestern Mexico. Time to most recent common ancestor for S. gracilis occurred ~1.36 Ma. Divergence times for each major clade occurred between 0.25 and 0.12 Ma, with signature of population expansion occurring 0.15 and 0.10 Ma. Ecological niche models identified three potential climatic refugia during the Last Interglacial, (1) west coast of California and Oregon, (2) northwestern Mexico, and (3) southern Texas/northeastern Mexico as well as two refugia during the Last Glacial Maximum, (1) western USA and (2) southern Texas/northeastern Mexico. This study supports PPD in shaping species-level diversity compared to QCC-driven changes at the intraspecific level for Spilogale, similar to the patterns reported for other small mammals (e.g., rodents and bats). Phylogeographic patterns also appear to have been shaped by both habitat and river vicariance, especially across the desert southwest. Further, continuing climate change during the Holocene coupled with anthropogenic modifications during the Anthropocene appears to be removing both of these barriers to current dispersal of western Spotted Skunks.
-
activity patterns of two sympatric species of Skunks mephitis mephitis and spilogale gracilis in texas
Southwestern Naturalist, 2010Co-Authors: Sean A. Neiswenter, Robert C. Dowler, John H YoungAbstract:Abstract We used radiotelemetry to document and compare activity and movement between the western Spotted Skunk Spilogale gracilis, and the striped Skunk Mephitis mephitis in Texas. Mephitis mephitis had a higher rate of movement than S. gracilis. Both species had highest rates of movement during autumn, coinciding with dispersal of young. With the exception of summer, M. mephitis was significantly more active than S. gracilis and generally took shorter breaks during nightly activity. We documented statistical differences in activity between species for all seasons. Highest activity of one species occurred during lowest activity of the other species, which may indicate avoidance of the larger more-dominant species, M. mephitis, by S. gracilis.
Kevin R. Crooks - One of the best experts on this subject based on the ideXlab platform.
-
spatial and genetic organization of the island Spotted Skunk spilogale gracilis amphiala
Southwestern Naturalist, 2013Co-Authors: Krista L Jones, Jerry W. Dragoo, Dirk H. Van Vuren, Kevin R. Crooks, Mary Brooke Mceachern, Bernie MayAbstract:We assessed the spatial and genetic organization of the island Spotted Skunk (Spilogale gracilis amphiala) on Santa Cruz Island, California. Home ranges of adults were largely non-overlapping, consistent with expectations for a solitary species. Contrary to expectations, we found no evidence of a matrilineal spatial structure. Relatedness of adult females was not negatively correlated with geographic distance, nor was it positively correlated with overlap of home ranges, possibly because of excessive dispersal caused by exceptionally high densities. We did find evidence of a patrilineal structure at one study site, where relatedness among males was negatively correlated with distance. The explanation for differences between males and females in genetic structure is uncertain, but it may reflect the differential influence of high density on dispersal of males and females.
-
genetic differentiation of island Spotted Skunks spilogale gracilis amphiala
Journal of Mammalogy, 2011Co-Authors: Chris H Floyd, Dirk H. Van Vuren, Kevin R. Crooks, David K. Garcelon, Krista L Jones, Natalia M Belfiore, Bernie MayAbstract:The island Spotted Skunk (Spilogale gracilis amphiala) is endemic to the 2 largest California Channel Islands, Santa Cruz and Santa Rosa. Unlike the island fox (Urocyon littoralis) and island subspecies of the deer mouse (Peromyscus maniculatus), the island Spotted Skunk shows no morphological differentiation between islands and is differentiated only weakly from mainland subspecies, suggesting recent colonization. However, the islands have been isolated from each other and the mainland throughout the Quaternary Period. We used 8 microsatellite loci to investigate the distribution of genetic variation within and among populations of Spotted Skunks from 8 localities (the 2 islands and 6 mainland localities), representing 4 subspecies. Tissue samples were obtained from 66 fresh specimens collected from 2000 to 2002 and 142 museum specimens collected from 1906 to 1994. Allelic richness and heterozygosity in island Spotted Skunk populations was approximately 30% lower than that found in mainland localities or subspecies. All localities or subspecies were significantly differentiated (mean FST was 0.17 and 0.13 for localities and subspecies, respectively). Contrary to comparisons based on morphological data, genetic differentiation was especially strong between islands and between island and mainland localities or subspecies. Patterns of differentiation suggest that Skunks colonized the Channel Islands shortly before rising sea levels separated Santa Cruz and Santa Rosa islands (11,500 years ago). Our results indicate that the taxonomic status of the island Spotted Skunk should be reconsidered and that both island populations might constitute evolutionarily significant units worthy of conservation.
-
sudden increase in a rare endemic carnivore ecology of the island Spotted Skunk
Journal of Mammalogy, 2008Co-Authors: Krista L Jones, Dirk H. Van Vuren, Kevin R. CrooksAbstract:The island Spotted Skunk (Spilogale gracilis amphiala), an insular endemic carnivore, recently increased unexpectedly from rarity to abundance on Santa Cruz Island, California. Two explanations have been proposed for this striking increase: competitive release due to decline of the island fox (Urocyon littoralis santacruzae) and vegetative recovery due to removal of feral livestock. To examine the causes and consequences of the increase, we assessed abundance, body mass, home-range size, spatial resource use (den sites and habitat use), temporal resource use, and diet of island Spotted Skunks during abundance in 2003–2004 and compared it with similar measures during rarity in 1992. Capture success of Skunks increased exponentially from 1992 to 2004 (r ¼ 0.38), leading to extraordinarily high densities (9–19 individuals/km 2 ). Both body mass and home-range size remained unchanged, suggesting that per capita resource abundance was not higher in 2003–2004 compared to 1992. We found modest shifts in habitat use, diet, and possibly diurnal activity, providing some support for release from exploitative competition as an explanation for the increase. However, there was a marked shift in den selection, toward unprotected dens and away from multiple use, that is not likely attributable to either release from exploitative competition or to island recovery. Thus, our results suggest that, although both of these processes have likely played a role, release from interference competition also may be a factor behind the dramatic increase in number of Skunks. Skunks on Santa Cruz Island may be nearing or even exceeding carrying capacity, and the future of the population and its effects on the endangered island fox remain unclear.
-
hematology and serum chemistry of the island Spotted Skunk on santa cruz island
Journal of Wildlife Diseases, 2003Co-Authors: Kevin R. Crooks, David K. Garcelon, Cheryl A Scott, Jeffery T Wilcox, Steven F Timm, Dirk H. Van VurenAbstract:We determined serum biochemistry and hematologic values for island Spotted Skunks (Spilogale gracilis amphiala) on Santa Cruz Island (California, USA). Samples were collected from island Spotted Skunks chemically restrained with ketamine hydrochloride and acepromazine in August 1999 (dry season) and from Skunks manually restrained in August 2000 (dry season) and January 2001 (wet season). One parameter, glucose, significantly differed with season, with higher levels during the wet season. Serum chemistry and hematologic profiles suggest that method of restraint (manual or chemical), as well as other methodologic details, may influence blood characteristics in the island Spotted Skunk.
-
Resource utilization by two insular endemic mammalian carnivores, the island fox and island Spotted Skunk
Oecologia, 1995Co-Authors: Kevin R. Crooks, Dirk VurenAbstract:We compared resource utilization of two insular endemic mammalian carnivores, the island Spotted Skunk and island fox, along niche dimensions of space, food, and time on Santa Cruz Island. We predicted that resource use by foxes and Skunks would differ along one or more niche dimensions, and that both species would have broader niches or higher densities compared with mainland relatives. Island foxes and island Spotted Skunks differed to some extent in habitat use, diets, and circadian activity, which may account for their long-term coexistence. Nonetheless, substantial overlap between Skunks and foxes in spatial, dietary, and temporal dimensions suggests that competition between the two species does occur. Moreover, competition may be asymmetric, affecting Skunks more than foxes. Compared with mainland foxes, island foxes have smaller body size, smaller home range, increased population density, increased diurnal activity, and behavior that is more highly inquisitive and less flightprone all common features of insular faunas. Island Skunks, however, apparently have not developed these changes, perhaps due to asymmetric competition with foxes in conjunction with severe ecosystem disturbances caused by feral sheep.
Mundy H Hackett - One of the best experts on this subject based on the ideXlab platform.
-
detection rates of eastern Spotted Skunks spilogale putorius in missouri and arkansas using live capture and non invasive techniques
American Midland Naturalist, 2007Co-Authors: Mundy H Hackett, Damon B Lesmeister, Joshua J Millspaugh, Jacqueline Desantycombes, Warren G Montague, Matthew E. GompperAbstract:The eastern Spotted Skunk (Spilogale putorius) is a rare species of conservation concern throughout much of its range, but effective management is hampered by a lack of information on appropriate survey strategies. We validated three commonly used techniques to identify the presence of eastern Spotted Skunks at four sites in Missouri and Arkansas where the species was known to occur. Live-capture with box-traps revealed a strong seasonal pattern in capture success in both states, with virtually all captures occurring between late Sept. and early May. This pattern of detection also occurred when surveys were conducted using non-invasive camera-traps and enclosed track-plates in Missouri. Track-plates were more efficient than camera-traps at detecting eastern Spotted Skunks, with a lower latency to initial detection (LTD) and higher probability of detection (POD). Our results indicate that the use of enclosed track-plates is a powerful non-invasive technique for detecting eastern Spotted Skunks when surveys are conducted between late Sept. and early May. Surveys conducted during late spring and summers are inappropriate given the high likelihood of not detecting the species despite its presence.
-
the long term range wide decline of a once common carnivore the eastern Spotted Skunk spilogale putorius
Animal Conservation, 2005Co-Authors: Matthew E. Gompper, Mundy H HackettAbstract: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.
-
The long-term, range-wide decline of a once common carnivore: the eastern Spotted Skunk (Spilogale putorius
2005Co-Authors: Mundy H HackettAbstract: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. ‘On a round trip of 595 miles between Stockport and Sioux City, Iowa, during the last week of April, 1942, 19 dead Spotted Skunks were seen on the road for an average of about one every 26 miles. The route was retraced only 100 miles. Five of the Skunks were encountered on an 11-mile stretch [...] in the center of the state.’ (Crabb, 1948
