Figure 4 - uploaded by Kerry Nicholson
Content may be subject to copyright.
Distribution of swift fox locations in relation to prairie dog towns (PDT) on the private ranches during 2003.
Source publication
Biologists have suggested that prairie dog (Cynomys ludovicianus) towns provide important habitat for several prairie species including swift foxes (Vulpes velox). To examine this issue for swift foxes, we radiocollared and monitored 72 swift foxes in areas occupied by prairie dogs on the Rita Blanca National Grasslands and on fragmented private ra...
Similar publications
The Model for Nature Policy (MNP) is being developed for the Netherlands Environmental Assessment Agency
(PBL) with the aim of evaluating Dutch nature policy at levels ranging from regional to national. The model
uses the vegetation as a basis for its predictions, which it produces in the form of a ‘nature target types map’.
Recently, however, area...
Citations
... Trophic effects; Figure 1). We predicted that population responses would be most dramatic and swift for the carnivores in our study system that relied on prairie dogs for a large proportion of their diet (e.g., ferruginous hawks [Buteo regalis], American badger, and swift fox ([Vulpes velox]; Kagel et al., 2020;Nicholson et al., 2006;Seery & Matiatos, 2000), with the magnitude of their declines increasing with their dietary reliance on prairie dogs. We anticipated bird communities, which respond more to vegetation structure, would differ most at 2 years post-plague. ...
... On a landscape scale, badger occupancy in Thunder Basin was most strongly affected by proximity to prairie dog colonies prior to plague and declined to a near-zero level after plague. Across their range, swift fox reliance on prairie dog colonies for prey or denning habitat appears to vary considerably (e.g., Kintigh & Andersen, 2005;Nicholson et al., 2006;Shaughnessy & Cifelli, 2004), but we found that swift fox occurrence was both positively associated with proximity to colonies pre-plague and declined substantially following the plague epizootic. These results highlight the importance of prairie dogs for supporting the swift fox population in this landscape. ...
Habitat loss and changing climate have direct impacts on native species but can also interact with disease pathogens to influence wildlife communities. In the North American Great Plains, black‐tailed prairie dogs (Cynomys ludovicianus) are a keystone species that create important grassland habitat for numerous species and serve as prey for predators, but lethal control driven by agricultural conflict has severely reduced their abundance. Novel disease dynamics caused by epizootic plague (Yersinia pestis) within prairie dog colonies have further reduced prairie dog abundances, in turn destabilizing associated wildlife communities. We capitalized on a natural experiment, collecting data on prairie dog distributions, vegetation structure, avian abundance, and mesocarnivore and ungulate occupancy before (2015–2017) and after (2018–2019) a plague event in northeastern Wyoming, USA. Plague decimated black‐tailed prairie dog populations in what was then the largest extant colony complex, reducing colony cover in the focal area from more than 10,000 ha to less than 50 ha. We documented dramatic declines in mesocarnivore occupancy and raptor abundance post‐plague, with probability of occupancy or abundance approaching zero in species that rely on prairie dogs for a high proportion of their diet (e.g., ferruginous hawk [Buteo regalis], American badger [Taxidea taxus], and swift fox [Vulpes velox]). Following the plague outbreak, abnormally high precipitation in 2018 hastened vegetation recovery from prairie dog disturbance on colonies in which constant herbivory had formerly maintained shortgrass structure necessary for certain colony‐associates. As a result, we observed large shifts in avian communities on former prairie dog colonies, including near‐disappearance of mountain plovers (Charadrius montanus) and increases in mid‐grass associated songbirds (e.g., lark bunting [Calamospiza melanocorys]). Our research highlights how precipitation can interact with disease‐induced loss of a keystone species to induce drastic and rapid shifts in wildlife communities. Although grassland taxa have co‐evolved with high spatiotemporal variation, fragmentation of the remaining North American rangelands paired with higher‐than‐historical variability in climate and disease dynamics are likely to destabilize these systems in the future.
... For example, Kamler et al. (2003) and Finley et al. (2005) found that Swift Fox occurrence was negatively associated with agricultural development, while Sovada et al. (2001), Matlack et al. (2000), and Kilgore (1969) observed frequent use of agricultural fields by Swift Foxes. Similarly, in the Northern Great Plains, Swift Foxes are commonly associated with Prairie Dog colonies (Kotliar et al. 1999), whereas evidence of negative association has been documented in the southern Great Plains (Nicholson et al. 2006) and Swift Foxes are known to persist in areas outside of the historical distribution of Prairie Dogs (e.g., Blackfeet Nation; Ausband and Foresman 2007a). While Swift Foxes are known to occupy sagebrush steppe in Wyoming (Olson and Lindzey 2002a) and Montana (Moehrenschager et al. 2006), the proportion of sagebrush in the landscape is negatively associated with inter-population connectivity (Schwalm 2012). ...
... Conversely, there have been multiple studies confirming a negative relationship between the Swift Foxes and the presence of Prairie Dog colonies, more commonly in the southern Great Plains. For example, a three-year study in Texas found significantly fewer Swift Foxes near Prairie Dog colonies (Nicholson et al. 2006). Also, in Oklahoma, Swift Foxes were detected less frequently in sites near Prairie Dog colonies (Shaughnessy and Cifelli 2004). ...
... Much of the current understanding of Swift Fox habitat is derived from studies in the central and southern portion of the species distribution (e.g., Cutter 1958;Finley et al. 2005;Kamler et al. 2003;Kilgore 1969;Matlack et al. 2000;Nicholson et al. 2006Nicholson et al. , 2007Schauster et al. 2002; but see Moehrenschlager et al. 2006). For Swift Foxes in the Northern Great Plains, there remain several key data needs that could improve understanding of Swift Fox habitat requirements in the region considerably. ...
Grassland-dependent Vulpes velox Say (Swift Foxes) occupy only a portion of their historical range in the North American Great Plains and remaining subpopulations are functionally disconnected due to habitat fragmentation and other barriers. Modeling habitat suitability is critical to identifying sites for habitat conservation and reintroduction and increasing subpopulation con-nectivity. We used mixed-effects modeling to simultaneously evaluate Swift Fox presence against habitat variables and subecoregional location. Our results show that habitat suitability is dependent on geographic location. Individual subecoregional models were each influenced by land cover and soil composition but varied by dominant soil component and correlation with surrounding land uses. These findings prioritize localized data for species management and predict how changing landscape composition may impact Swift Fox distribution.
... 14-16 These declines have also been linked to decreasing populations of swift fox, burrowing owl, and mountain plover, three grassland species of conservation concern with the potential for trophic interactions. [17][18][19][20] Swift Fox ...
Trophic cascades occur when flora and fauna directly and/or indirectly influence co-occurring species populations at different levels of the food chain, and North American temperate grasslands provide an interesting case study to research these relationships. • We briefly define trophic cascades in terrestrial systems and explore the potential for a cascading trophic interaction among grassland-associated swift fox (Vulpes velox), western burrowing owl (Athene cunicularia hypugaea), and mountain plover (Charadrius montanus), three rangeland species of conservation concern, on black-tailed prairie dog (Cynomys ludovicianus) colonies using two US Forest Service data sets. • Historic patterns of occurrence and co-occurrence suggest top-down control governs the spatiotemporal distribution patterns of the three species and may be influenced by habitat fragmentation and management actions. • Managing for interactive, multitrophic communities requires the identification of species interactions and the mechanisms that drive them. • Long-term multispecies occupancy research, combined with hypothesized driving mechanisms and the co-occurrence of associated grassland species, is recommended for addressing these complex interactions moving forward.
... The strong selection for prairie dog colonies by badgers in our study contrasts the association between prairie dog colonies and swift fox (Vulpes velox (Say, 1823)), a short-grass prairie carnivore that is considered a dietary generalist (Sovada et al. 2001;Harrison 2003). Swift foxes often are associated with prairie dog ecosystems (Sharps and Uresk 1990;Lomolino and Smith 2003), but Nicholson et al. (2006) reported that swift foxes used prairie dog colonies less than expected and Sasmal et al. (2011) reported that female foxes used prairie dog colonies in proportion to their availability. If the use of prairie dog colonies by swift foxes is typical of generalist carnivores, then we would expect similar selection patterns by badgers. ...
Differentiating species according to their relative niche breadth is a common approach in community ecology that can enhance understanding about how species relate to the environment. Although a species might exhibit a generalized ecology across its entire range, on a local scale, individuals might function as specialists. American badgers (Taxidea taxus (Schreber, 1777)) are terrestrial carnivores that have been described most often as generalists. We compared patterns of habitat selection by badgers at three scales to test the hypothesis that badgers would exhibit behaviors more closely aligned with specialists than generalists when inhabiting landscapes with black-tailed prairie dogs (Cynomys ludovicianus (Ord, 1815)). At a course scale, badgers selected for prairie dog colonies across the landscape. At an intermediate scale, we documented significantly greater use of prairie dog colonies within the home ranges of badgers. At fine scales within colonies, badgers used areas that had relatively high densities of prairie dog burrows, where prey was presumably abundant. On multiple scales, badgers exhibited a narrow use of resources in comparison with the resources available. Our study provides additional evidence that badgers behave as specialists when burrowing rodents are highly concentrated and predictable over space and time.
... While the direct effects of disturbances on native species are often limited, indirect effects mediated through changes in vegetation structure are thought to have a much greater effect [2]. Since the mid-1970s, extensive research has focused on swift fox distribution and demographics [8,[10][11][12][13][14]. However, much of this has focused on the characteristics of individual populations, leaving a large gap in the understanding of landscape-level influences [14,15]. ...
... However, much of this has focused on the characteristics of individual populations, leaving a large gap in the understanding of landscape-level influences [14,15]. Lately, researchers have investigated the influence of landscape variation on swift fox ecology, or compared spatial ecology and demographics across habitat types [11,13,14,[16][17][18]. Viewed as shortgrass specialists, swift foxes have been shown to be capable of exploiting a variety of habitats and prey [8,19,20]. ...
The relationships between predators, prey, and habitat have long been of interest to applied and basic ecologists. As a native Great Plains mesocarnivore of North America, swift foxes (Vulpes velox) depended on the historic disturbance regime to maintain open grassland habitat. With a decline in native grasslands and subsequent impacts to prairie specialists, notably the swift fox, understanding the influence of habitat on native predators is paramount to future management efforts. From 2001 to 2004, we investigated the influence of vegetation structure on swift fox population ecology (survival and density) on and around the Piñon Canyon Maneuver Site, southeastern Colorado, USA. We monitored 109 foxes on 6 study sites exposed to 3 different disturbance regimes (military training, grazing, unused). On each site we evaluated vegetation structure based on shrub density, basal coverage, vegetation height, and litter. Across all sites, annual fox survival rates ranged from 0.50 to 0.92 for adults and 0.27 to 0.78 for juveniles. Among sites, population estimates ranged from 1 to 7 foxes per 10 km transect. Fox density or survival was not related to the relative abundance of prey. A robust model estimating fox population size and incorporating both shrub density and percent basal cover as explanatory variables far outperformed all other models. Our results supported the idea that, in our region, swift foxes were shortgrass prairie specialists and also indicated a relationship between habitat quality and landscape heterogeneity. We suggest the regulation of swift fox populations may be based on habitat quality through landscape-mediated survival, and managers may effectively use disturbance regimes to create or maintain habitat for this native mesocarnivore.
... Results indicated swift foxes in only Dallam and Sherman counties (Fig. 1). Since surveys by K. Mote et al. (in litt.), researchers have documented a declining presence in these counties (Nicholson et al., 2006 ). Determining current distribution in Texas is necessary to develop an appropriate management strategy for conservation of swift foxes in Texas. ...
... These two factors indicate that the species may be at risk of extirpation in Texas. Lack of expansion of populations (i.e., K. Mote, in litt.) and likely recent extirpation from a site within the current distribution (Nicholson et al., 2006) lend further credence to this concern. We do not know what factor or combination of factors is causing the limited distribution and density of swift foxes in Texas. ...
Swift foxes (Vulpes velox) once occupied ca. 79 counties in Texas, but surveys in 1997—1998 indicated the range of the species was reduced to two counties. We used scat-transects and live-trapping during 2005—2007 to assess current distribution of the species in Texas. Our results indicated that distribution of the swift fox in Texas remains significantly reduced from the historical distribution and that population densities are low where the species currently exists. El zorro del desierto (Vulpes velox) antes ocupaba ca. 79 condados de Texas, pero muestreos en 1997—1998 indicaron que la distribución de la especie se redujo a dos condados. Se utilizaron excrementos a través de transectos y captura de animales vivos durante 2005—2007 para evaluar la distribución actual de la especie en Texas. Nuestros resultados indicaron que la distribución de el zorro del desierto en Texas sigue siendo significativamente reducida de la distribución histórica, y que las densidades poblacionales son bajas donde la especie existe en la actualidad.
... Telemetry was performed 3-4 nights per week with no more then two locations collected in a given 12 h period. Locations >3 h apart were regarded as independent for use in home-range estimation (Swihart and Slade 1985;Nicholson et al. 2006). We evaluated the location error of the telemetry system at the distance over which animals were typically tracked (~100 m) using a beacon test. ...
Space use is a fundamental characteristic that informs our knowledge of social relationships and the degree to which individuals are territorial. Until recently, relatively little was known about the spatial ecology and social organization of swift foxes (Vulpes velox (Say, 1823)). We investigated space use of swift foxes on shortgrass prairie in northeastern Colorado. Our first objective was to evaluate sizes of seasonal and annual home ranges and core areas of 13 radio-collared swift foxes monitored continuously for 2 years. Our second objective was to compare home-range and core-area overlap of breeding pairs to that of neighboring foxes, including male–male, female–female, and nonbreeding female–male dyads. Home-range size in our study population was among the smallest previously reported for swift foxes. Males tended to have slightly larger home ranges and core areas than females, and home-range size was significantly larger in the breeding season than in both the pup-rearing and the dispersal seasons; sizes of core areas did not differ seasonally. Spatial overlap between breeding pairs was substantial, whereas spatial overlap between neighbors, particularly males, was low, suggesting territoriality.
... These results are in accordance with previous research (Russell 2006) that indicated foxes selected locations closer to roads likely due to increased prey availability and decreased coyote predation (Almasi-Klausz and Carbyn 1999). Foxes do not depend on prairie dogs solely for their prey; however, use of prairie dog town habitat equivalent to availability indicate that prairie dogs provide increased access to both live prey and carrion during this critical period in the life history of the species (Nicholson et al. 2006). Russell (2006) documented a frequency of occurrence of 41.2% for prairie dogs in feces of swift foxes during summer 2005 in western South Dakota, which was at least twice the frequency of occurrence documented in spring seasons. ...
The swift fox (Vulpes velox) was historically distributed in western South Dakota including the region surrounding Badlands National Park (BNP). The species declined during the mid-1800s, largely due to habitat loss and poisoning targeted at wolves (Canis lupis) and coyotes (C. latrans). Only a small population of swift foxes near Ardmore, South Dakota persisted. In 2003, an introduction program was initiated at BNP with swift foxes translocated from Colorado and Wyoming. We report on habitat use by female swift foxes during the pup-rearing season (May–July) in 2009. Analyses of location data from 13 radiomarked female foxes indicated disproportional use (P < 0.001) of some habitats relative to their availability within swift fox home ranges. Swift foxes used grassland (ŵ = 1.01), sparse vegetation (ŵ = 1.43) and prairie dog towns (ŵ = 1.18) in proportion to their availability, whereas they were less likely to use woodland (ŵ = 0.00), shrubland (ŵ = 0.14), pasture/agricultural-land (ŵ = 0.25) and development (ŵ = 0.16) relative to availability. Swift foxes typically are located in habitats that provide greater visibility, such as shortgrass prairie and areas with sparse vegetation; which allow detection of approaching coyotes (e.g., primary predator of swift foxes).
... This modification allows for a conversion of a Design I radio-telemetry study (where animals are not uniquely identified and availability is defined at the population level, as Neu et al. 1974 originally proposed) to a Design III radio telemetry study (where both resource use and resource availability are identified for each radiomarked animal) (e.g. Broomhall et al. 2003, D'Eon and Serrouya 2005, Nicholson et al. 2006). This modified methodology allowed me to examine the relationship between habitat use and habitat availability when not all habitat types were present in the home range of each covey (White and Garrott 1990) and has been shown to produce similar results to compositional analysis (Manley et al. 2000). ...
Over the past 40 years, northern bobwhite (Colinus virginianus)
populations have experienced range-wide declines. Population parameters have been
gathered throughout most of the range but Mid-Atlantic populations have been largely
ignored. In my study, I sought not only to gather data on winter habitat, movement,
and selection, but also examine the relationship between these metrics and survival. I
captured and radiotracked bobwhites between October and April, 2006-2007 and
2007-2008 non-breeding seasons on a 125km2 area of Cumberland County, New
Jersey, USA. Chi-square analysis with Bonferroni confidence intervals revealed third
order selection of Grassland and Scrub-Shrub habitat classes more often than expected
while Agriculture and Other habitat classes were used less than in proportion to their
availability. The relationship between coveys and Forest habitat appears to be more
complex. Cox proportional hazard analysis revealed that risk of mortality was
increased by use of Grassland habitat, low movement rates, and increased proximity to
occupied buildings and barns. These results indicate that bobwhite coveys may be
isolated in small fragments of usable habitat without sufficient travel corridors to
maintain large enough winter home ranges to meet their biological needs.
Additionally, my data suggests that predators may be forming a preferred search image
on these fragmented habitats, thereby increasing mortality. It is possible bobwhite
suffer from both low quantity and quality of habitat on the landscape. Increased
interspersion of Woody cover on Grasslands as well as land management that
increases Grassland and Scrub-Shrub habitat on the landscape level could increase
bobwhite winter survival and ultimately aid in stabilizing the population in southern New Jersey. House cat predation and window collisions are possible causative factors
for the correlation between mortality risk and distance to occupied buildings and barns
and their potential impacts on bobwhite populations should be investigated in future
studies.
... This direction was likely influenced by the presence of the town of Stratford located to the northeast and the predominance of cropland to the southeast and southwest (Fig. 1). We believe that the direction of dispersal in this study can be explained by swift fox avoidance of crop lands and areas with tall-structured vegetation such as Conservation Reserve Program (CRP) lands (Kamler 2002, Nicholson 2004. Nicholson et al. (2006) reported that swift foxes use short-structured vegetation more than would be expected. ...
... We believe that the direction of dispersal in this study can be explained by swift fox avoidance of crop lands and areas with tall-structured vegetation such as Conservation Reserve Program (CRP) lands (Kamler 2002, Nicholson 2004. Nicholson et al. (2006) reported that swift foxes use short-structured vegetation more than would be expected. ...
Dispersal plays an important role in the population dynamics of many carnivores, yet little information exists about the dispersal and movement patterns of swift foxes (Vulpes velox). We radio-collared and monitored 68 swift foxes for dispersal at 2 study sites in northwestern Texas from January 2002 to April 2004. Dispersal distance for juveniles (13.1 ±0.3 km, s), adults (10 ±4.7 km) and transients (25.4 ±9.1 km) did not differ by age class (F = 1.49, df = 2, P = 0.24) or sex (F = 0.23, df = 1, P = 0.63) but differed by study site (F = 4.72, df = 1, P = 0.04). Mean dispersal distance from private ranches (PR) was greater than from National Grasslands (NG). Peak dispersal occurred during October–November (13 individuals) and January–February (7 individuals). Dispersal direction was influenced by land-use practices (i.e., toward rangelands and away from anthropogenic features). Direction of dispersal among foxes that occupied the NG was uniform (n = 16, P = 0.08), whereas foxes from PR dispersed in a northwesterly direction (n = 18, P ≤0.001) away from a town and croplands. Three resident adult foxes made extraterritorial movements. Distances of these movements ranged from 0.2 km to 11.4 km. Distance of extraterritorial movements did not differ by sex (F = 0.05, P = 0.83), nor by duration of movement (F = 1.11, P = 0.32). Knowledge of movement distances and patterns is important for conservation and protection of swift foxes and their habitats.
