scholarly journals Resource partitioning between kit foxes (Vulpes macrotis) and coyotes (Canis latrans): a comparison of historical and contemporary dietary overlap

2018 ◽  
Vol 96 (5) ◽  
pp. 497-504 ◽  
Author(s):  
P.A. Byerly ◽  
R.C. Lonsinger ◽  
E.M. Gese ◽  
A.J. Kozlowski ◽  
L.P. Waits
Keyword(s):  
Great Basin ◽  
Native Species ◽  
Dietary Diversity ◽  
Canis Latrans ◽  
Population Level ◽  
Relative Importance ◽  
Dietary Overlap ◽  
Kit Fox ◽  
Prey Diversity ◽  
Vulpes Macrotis

Range expansions by generalists can alter communities and introduce competitive pressures on native species. In the Great Basin Desert, USA, coyotes (Canis latrans Say, 1823) have colonized and are now sympatric with native kit foxes (Vulpes macrotis Merriam, 1888). Since both species have similar diets, dietary partitioning may facilitate coexistence. We analyzed coyote and kit fox diets, then compared our results to an earlier study. Because populations are dynamic, we expected that decreases in prey or increases in predator abundance could alter dietary patterns. We found no significant changes in population-level prey diversity for kit foxes or coyotes, but found high levels of dietary overlap between species. We did detect a significant decrease in the relative importance of leporids (family Leporidae) in the diets of both canids, but they remained important for coyotes. The relative importance of small mammals was greater for kit foxes than coyotes, but their importance had not changed significantly over time. We detected significant declines in prey diversity per sample (scat-level dietary diversity) for both canids, suggesting that during a foraging event, individuals may encounter less diverse prey now than historically. These findings suggested that kit foxes and coyotes were not limited by prey, despite high dietary overlap.

scholarly journals Estimating densities for sympatric kit foxes (Vulpes macrotis) and coyotes (Canis latrans) using noninvasive genetic sampling

2018 ◽  
Vol 96 (10) ◽  
pp. 1080-1089 ◽  
Author(s):  
R.C. Lonsinger ◽  
P.M. Lukacs ◽  
E.M. Gese ◽  
R.N. Knight ◽  
L.P. Waits
Keyword(s):  
Great Basin ◽  
Canis Latrans ◽  
Density Estimates ◽  
Intraguild Interactions ◽  
Noninvasive Genetic Sampling ◽  
Kit Fox ◽  
Genetic Sampling ◽  
Vulpes Macrotis ◽  
Capture Recapture ◽  
Precipitous Decline

Kit fox (Vulpes macrotis Merriam, 1888) populations in the Great Basin Desert have declined and are of increasing concern for managers. Increasing coyote (Canis latrans Say, 1823) abundance and subsequent intraguild interactions may be one cause for this decline. Concurrent monitoring of carnivores is challenging and therefore rarely conducted. One possible solution for monitoring elusive carnivores is using noninvasive genetic sampling. We used noninvasive genetic sampling to collect fecal DNA from kit foxes and coyotes and estimate their densities from 2013–2014 in Utah, USA. We identified individuals based on microsatellite genotypes and estimated density with multisession spatially explicit capture–recapture models. Mean kit fox density was 0.02 foxes·km−2, while coyote densities were up to four times greater (0.07–0.08 coyotes·km−2). Kit fox densities were significantly lower than densities in the 1950s but were comparable with estimates from the late 1990s, suggesting that populations may be stabilizing after a precipitous decline. Our kit fox density estimates were among the lowest documented for the species. Our coyote density estimate was the first reported in our region and revealed that despite seemingly high abundance, densities are low compared with other regions. Our results suggested that kit foxes may be able to coexist with coyotes.

scholarly journals Molecular epidemiology of a fatal sarcoptic mange epidemic in endangered San Joaquin kit foxes (Vulpes macrotis mutica)

2020 ◽  
Author(s):  
Jaime L. Rudd ◽  
Deana L. Clifford ◽  
Brian L. Cypher ◽  
Joshua M. Hull ◽  
A. Jane Riner ◽  
...  
Keyword(s):  
Large Scale ◽  
Genetic Difference ◽  
Population Level ◽  
Sarcoptes Scabiei ◽  
Sarcoptic Mange ◽  
Canis Lupus Familiaris ◽  
Red Foxes ◽  
Kit Fox ◽  
Vulpes Macrotis ◽  
Vulpes Macrotis Mutica

Abstract Background: In 2013, sarcoptic mange, caused by Sarcoptes scabiei mites, precipitated a catastrophic decline of the formerly stable urban population of endangered San Joaquin kit foxes ( Vulpes macrotis mutica ) in Bakersfield, California, USA. In 2019, a smaller sarcoptic mange outbreak affected kit foxes 58 km southwest of Bakersfield in the town of Taft, California. To determine whether the Taft outbreak could have occurred as spillover from the Bakersfield outbreak and whether epidemic control efforts must involve not only kit foxes but also sympatric dogs ( Canis lupus familiaris ), coyotes ( Canis latrans ), and red foxes ( Vulpes vulpes ), we evaluated genotypes and gene flow among mites collected from each host species.Methods: We used 10 Sarcoptes microsatellite markers (SARM) to perform molecular typing of 445 S. scabiei mites collected from skin scrapings from twenty-two infested kit foxes, two dogs, five coyotes, and five red foxes from Bakersfield, Taft, and other nearby cities.Results: We identified 60 alleles across all SARM loci; kit fox- and red fox-derived mites were relatively monomorphic, while genetic variability was greatest in Bakersfield coyote- and dog-derived mites. AMOVA analysis documented distinct mite populations unique to hosts, with an overall F ST of 0.467. The lowest F ST (i.e. closest genetic relationship, F ST = 0.038) was between Bakersfield and Taft kit fox-derived mites while the largest genetic difference was between Ventura coyote- and Taft kit fox-derived mites (F ST = 0.843).Conclusion: These results confirm the close relationship between the Taft and Bakersfield outbreaks. The Sarcoptes host specificity suggests that, although an inter-species spillover event likely initiated the kit fox mange outbreak, mite transmission is now primarily intraspecific. Therefore, any large-scale population level intervention should focus on treating kit foxes within the city.

scholarly journals Molecular epidemiology of a fatal sarcoptic mange epidemic in endangered San Joaquin kit foxes (Vulpes macrotis mutica)

2020 ◽  
Author(s):  
Jaime L. Rudd ◽  
Deana L. Clifford ◽  
Brian L. Cypher ◽  
Joshua M. Hull ◽  
A. Jane Riner ◽  
...  
Keyword(s):  
Large Scale ◽  
Genetic Difference ◽  
Population Level ◽  
Sarcoptes Scabiei ◽  
Sarcoptic Mange ◽  
Canis Lupus Familiaris ◽  
Red Foxes ◽  
Kit Fox ◽  
Vulpes Macrotis ◽  
Vulpes Macrotis Mutica

Abstract Background: In 2013, sarcoptic mange, caused by Sarcoptes scabiei mites, precipitated a catastrophic decline of the formerly stable urban population of endangered San Joaquin kit foxes (Vulpes macrotis mutica) in Bakersfield, California, USA. In 2019, a smaller sarcoptic mange outbreak affected kit foxes 58 km southwest of Bakersfield in the town of Taft, California. To determine whether the Taft outbreak could have occurred as spillover from the Bakersfield outbreak and whether epidemic control efforts must involve not only kit foxes but also sympatric dogs (Canis lupus familiaris), coyotes (Canis latrans), and red foxes (Vulpes vulpes), we evaluated genotypes and gene flow among mites collected from each host species.Methods: We used 10 Sarcoptes microsatellite markers (SARM) to perform molecular typing of 445 S. scabiei mites collected from skin scrapings from twenty-two infested kit foxes, two dogs, five coyotes, and five red foxes from Bakersfield, Taft, and other nearby cities.Results: We identified 60 alleles across all SARM loci; kit fox- and red fox-derived mites were relatively monomorphic, while genetic variability was greatest in Bakersfield coyote- and dog-derived mites. AMOVA analysis documented distinct mite populations unique to hosts, with an overall FST of 0.467. The lowest FST (i.e. closest genetic relationship, FST = 0.038) was between Bakersfield and Taft kit fox-derived mites while the largest genetic difference was between Ventura coyote- and Taft kit fox-derived mites (FST = 0.843).Conclusion: These results confirm the close relationship between the Taft and Bakersfield outbreaks. Although a spillover event likely initiated the kit fox mange outbreak, mite transmission is now primarily kit fox-to-kit fox. Therefore, any large-scale population level intervention should focus on treating kit foxes within the city.

scholarly journals Characteristics of current and historical kit fox (Vulpes macrotis) dens in the Great Basin Desert

2003 ◽  
Vol 81 (1) ◽  
pp. 96-102 ◽  
Author(s):  
Wendy M Arjo ◽  
Tim J Bennett ◽  
Adam J Kozlowski
Keyword(s):  
Home Range ◽  
Great Basin ◽  
Geographical Area ◽  
Home Range Size ◽  
Physical Characteristics ◽  
Range Size ◽  
Multiple Use ◽  
Mountainous Areas ◽  
Kit Fox ◽  
Vulpes Macrotis

We examined the ecological and physical characteristics of den sites for 13 adult kit fox (Vulpes macrotis) in western Utah from December 1998 to February 2001. We also compared current and historical den distribution among habitat types. The number of den sites used was not influenced by home-range size (P = 0.11) or season (P = 0.40), but was influenced by geographical area. Home-range size was smallest (P = 0.007) and the number of dens used was greatest (P = 0.009) in mountainous areas. Ecological and physical characteristics of single-use dens (n = 30) were compared with those of multiple-use (n = 53) and natal dens (n = 8). Characteristics that differed between den types included number of entrances (P = 0.0001), diameter of entrances (P = 0.003), and height of vegetation along transects (P = 0.0001). Natal den entrance azimuths were weighted towards a northwesterly aspect (P = 0.0022); however, single- and multiple-use den exits appeared to be randomly distributed. Historical changes in kit fox den site selection have occurred since 1959 (P < 0.0001). We characterized more dens in invasive grasslands and fewer in greasewood (Sarcobatus vermiculatus) habitats than previously described. The conversion of native habitat to grassland and the increase in coyote population may have altered kit fox distribution to include mountainous areas not previously described.

scholarly journals Molecular epidemiology of a fatal sarcoptic mange epidemic in endangered San Joaquin kit foxes (Vulpes macrotis mutica)

2020 ◽  
Author(s):  
Jaime L. Rudd ◽  
Deana L. Clifford ◽  
Brian L. Cypher ◽  
Joshua M. Hull ◽  
A. Jane Riner ◽  
...  
Keyword(s):  
Large Scale ◽  
Genetic Difference ◽  
Population Level ◽  
Sarcoptes Scabiei ◽  
Sarcoptic Mange ◽  
Canis Lupus Familiaris ◽  
Red Foxes ◽  
Kit Fox ◽  
Vulpes Macrotis ◽  
Vulpes Macrotis Mutica

Abstract Background: In 2013, sarcoptic mange, caused by Sarcoptes scabiei mites, precipitated a catastrophic decline of the formerly stable urban population of endangered San Joaquin kit foxes (Vulpes macrotis mutica) in Bakersfield, California, USA. In 2019, a smaller sarcoptic mange outbreak affected kit foxes 58 km southwest of Bakersfield in the town of Taft, California. To determine whether the Taft outbreak could have occurred as spillover from the Bakersfield outbreak and whether epidemic control efforts must involve not only kit foxes but also sympatric dogs (Canis lupus familiaris), coyotes (Canis latrans), and red foxes (Vulpes vulpes), we evaluated genotypes and gene flow among mites collected from each host species. Methods: We used 10 Sarcoptes microsatellite markers (SARM) to perform molecular typing of 445 S. scabiei mites collected from skin scrapings from twenty-two infested kit foxes, two dogs, five coyotes, and five red foxes from Bakersfield, Taft, and other nearby cities. Results: We identified 60 alleles across all SARM loci; kit fox- and red fox-derived mites were relatively monomorphic, while genetic variability was greatest in Bakersfield coyote- and dog-derived mites. AMOVA analysis documented distinct mite populations unique to hosts, with an overall FST of 0.467. The lowest FST (i.e. closest genetic relationship, FST = 0.038) was between Bakersfield and Taft kit fox-derived mites while the largest genetic difference was between Ventura coyote- and Taft kit fox-derived mites (FST = 0.843). Conclusions: These results confirm the close relationship between the Taft and Bakersfield outbreaks. Although a spillover event likely initiated the kit fox mange outbreak, mite transmission is now primarily kit fox-to-kit fox. Therefore, any large-scale population level intervention should focus on treating kit foxes within the city.

scholarly journals Carnivora atnd their larger mammalian prey species invenory and abundance in the Janos-Nuevo Casas Grandes praire dog complex, Chihuahua.

2014 ◽  
Vol 3 (1) ◽  
pp. 95 ◽  
Author(s):  
Rurik H. List Sánchez ◽  
David W. Macdonald
Keyword(s):  
Canis Latrans ◽  
Prairie Dog ◽  
Casas Grandes ◽  
Kangaroo Rats ◽  
Taxidea Taxus ◽  
Kit Fox ◽  
Carnivore Species ◽  
Vulpes Macrotis ◽  
Lepus Californicus ◽  
North Western

Abstract. This study examined the carnivore species composition and abundance in the Janos-Nuevo Casas Grandes prairie dog complex of north-western Chihuahua, Mexico. Thirteen species of carnivores were recorded in habitats including prairie dog towns, grassland, mesquite scrub and riparian vegetation. From artificial scent-stations and spotlight transects the most abundant carnivore species appeared to be the kit fox Vulpes macrotis and the coyote Canis latrans. Striped/hooded skunks (Mephitis spp) and American badgers (Taxidea taxus) were also common. No significant differences were found between the abundance of kit foxes or coyotes on prairie dog towns or grassland; but skunks were more abundant on grasslands. The abundance of hares (Lepus californicus), rabbit (Sylvilagus audubonii), and kangaroo rat (Dipodomys spp) was also estimated; hares and kangaroo rats were more abundant in the grassland, whilst rabbits were more abundant in prairie dog towns.Resumen. Se estudió la composición de espeices de carnívoros en el complejo de perros llaneros Janos-Nuevo Casas Grandes, en el noroeste de Chihuahua, México. Se registraron 13 especies de carnívoros en los siguientes hábitats; colonias de perros lIaneros, pastizal, matorral de mezquite y vegetación riparia. Por medio de estaciones olfativas y transectos de lampareo se determinó que la zorra norteña Vulpes macrotis y el coyote Canis latrans fueron los más abundantes. Los zorrillos (Mephitis spp) y tejones (Taxidea taxus) también fueron comunes. No se encontraron diferencias significativas en la abundancia de zorras norteñas o coyotes entre colonias de perros llaneros o pastizal. Los zorrillos fueron más abundantes en el pastizal. También se estimó la abundancia de liebres (Lepus californicus), conejos (Sylvilagus audubonii), y ratas canguro (Dipodomys spp); las liebres y ratas canguro son más abundantes en el pastizal, mientras los conejos son mas abundantes en las colonias de perros lIaneros.Key words: Carnivore abundance, Chihuahua, Mexico, prairie dog, scent-station, spotlighting.

scholarly journals Molecular epidemiology of a fatal sarcoptic mange epidemic in endangered San Joaquin kit foxes (Vulpes macrotis mutica)

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jaime L. Rudd ◽  
Deana L. Clifford ◽  
Brian L. Cypher ◽  
Joshua M. Hull ◽  
A. Jane Riner ◽  
...  
Keyword(s):  
Large Scale ◽  
Genetic Difference ◽  
Population Level ◽  
Sarcoptes Scabiei ◽  
Sarcoptic Mange ◽  
Canis Lupus Familiaris ◽  
Red Foxes ◽  
Kit Fox ◽  
Vulpes Macrotis ◽  
Vulpes Macrotis Mutica

Abstract Background In 2013, sarcoptic mange, caused by Sarcoptes scabiei mites, precipitated a catastrophic decline of the formerly stable urban population of endangered San Joaquin kit foxes (Vulpes macrotis mutica) in Bakersfield, California, USA. In 2019, a smaller sarcoptic mange outbreak affected kit foxes 58 km southwest of Bakersfield in the town of Taft, California. To determine whether the Taft outbreak could have occurred as spillover from the Bakersfield outbreak and whether epidemic control efforts must involve not only kit foxes but also sympatric dogs (Canis lupus familiaris), coyotes (Canis latrans), and red foxes (Vulpes vulpes), we evaluated genotypes and gene flow among mites collected from each host species. Methods We used 10 Sarcoptes microsatellite markers (SARM) to perform molecular typing of 445 S. scabiei mites collected from skin scrapings from twenty-two infested kit foxes, two dogs, five coyotes, and five red foxes from Bakersfield, Taft, and other nearby cities. Results We identified 60 alleles across all SARM loci; kit fox- and red fox-derived mites were relatively monomorphic, while genetic variability was greatest in Bakersfield coyote- and dog-derived mites. AMOVA analysis documented distinct mite populations unique to hosts, with an overall FST of 0.467. The lowest FST (i.e. closest genetic relationship, FST = 0.038) was between Bakersfield and Taft kit fox-derived mites while the largest genetic difference was between Ventura coyote- and Taft kit fox-derived mites (FST = 0.843). Conclusions These results confirm the close relationship between the Taft and Bakersfield outbreaks. Although a spillover event likely initiated the kit fox mange outbreak, mite transmission is now primarily kit fox-to-kit fox. Therefore, any large-scale population level intervention should focus on treating kit foxes within the city.

The interactive effects of stream temperature, stream size, and non-native species on Yellowstone cutthroat trout

2021 ◽  
Author(s):  
Robert Al-Chokhachy ◽  
Mike Lien ◽  
Bradley B. Shepard ◽  
Brett High
Keyword(s):  
Native Species ◽  
Cutthroat Trout ◽  
Population Level ◽  
Stream Temperature ◽  
Interactive Effects ◽  
Oncorhynchus Clarkii ◽  
Wide Range ◽  
Yellowstone Cutthroat Trout ◽  
Stream Size ◽  
Native Salmonids

Climate change and non-native species are considered two of the biggest threats to native salmonids in North America. We evaluated how non-native salmonids and stream temperature and discharge were associated with Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) distribution, abundance, and body size, to gain a more complete understanding of the existing threats to native populations. Allopatric Yellowstone cutthroat trout were distributed across a wide range of average August temperatures (3.2 to 17.7ºC), but occurrence significantly declined at colder temperatures (<10 ºC) with increasing numbers of non-natives. At warmer temperatures occurrence remained high, despite sympatry with non-natives. Yellowstone cutthroat trout relative abundance was significantly reduced with increasing abundance of non-natives, with the greatest impacts at colder temperatures. Body sizes of large Yellowstone cutthroat trout (90th percentile) significantly increased with warming temperatures and larger stream size, highlighting the importance of access to these more productive stream segments. Considering multiple population-level attributes demonstrates the complexities of how native salmonids (such as Yellowstone cutthroat trout) are likely to be affected by shifting climates.

Production at the Cohort and Population Levels

2020 ◽  
pp. 149-168
Author(s):  
Michael J. Fogarty ◽  
Jeremy S. Collie
Keyword(s):  
Population Ecology ◽  
Life Stage ◽  
Population Level ◽  
Fish Population ◽  
Individual Growth ◽  
Relative Importance ◽  
Compensatory Mechanisms ◽  
Fisheries Science ◽  
Dominant Component ◽  
Time Period

The dominant focus on production processes in fisheries science sets it apart from other areas of population ecology in which population numbers are the principal currency for analysis. This chapter extends consideration of individual growth and mortality rates provided in earlier chapters to broaden the context for understanding cohort and population processes. A cohort is a group of organisms born within a given time period (e.g. year). How a fish population will respond to harvesting requires not only accurate accounting of its effective reproductive output but an understanding of the relative importance of compensatory mechanisms operating at different points in the life cycle. Recruitment (the number in a cohort surviving to a specified life stage or age) emerges as a dominant component of production at the population level. A dominant theme in this chapter concerns population regulation as embodied in the recruitment process and the high variability in this process.

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