Evaluating the influence of water developments on the demography and spatial ecology of a rare, desert-adapted carnivore: the kit fox (\u3ci\u3eVulpes macrotis\u3c/i\u3e)

Constructing water developments to support anthropogenic activities and particular fauna is pervasive across many arid regions of the globe. Despite their prevalence and a predicted increase as a management and conservation tool, water developments may have complex and unanticipated impacts on wildlife. For example, the addition of water developments to the Great Basin Desert in the western United States may have indirectly contributed to a decrease in distribution and abundance of kit foxes (Vulpes macrotis). From 2010 to 2013, we examined survival, relative abundance, and habitat characteristics of kit foxes in relation to water developments on the U.S. Army Dugway Proving Ground, Utah, using a before-after control-impact design. We collected 2 years of baseline data prior to reducing availability of water and continued data collection for another 2 years after removal of water on one-half of the study area. We found no evidence that removing water influenced survival or abundance of kit foxes. In addition, we found areas associated with the majority of water developments differed from current kit fox territories in elevation, soil type, and dominant cover type; historical use by kit foxes of areas associated with water developments is largely unknown. One explanation for our inability to find support for a water effect is that observed changes in the kit fox population and canid community in the Great Basin are attributable to changes in coyote management practices that temporally coincided with, but were largely unrelated to increases in water availability

Evaluating the influence of water developments on the demography and spatial ecology of a rare, desert-adapted carnivore: the kit fox (\u3ci\u3eVulpes macrotis\u3c/i\u3e)

Constructing water developments to support anthropogenic activities and particular fauna is pervasive across many arid regions of the globe. Despite their prevalence and a predicted increase as a management and conservation tool, water developments may have complex and unanticipated impacts on wildlife. For example, the addition of water developments to the Great Basin Desert in the western United States may have indirectly contributed to a decrease in distribution and abundance of kit foxes (Vulpes macrotis). From 2010 to 2013, we examined survival, relative abundance, and habitat characteristics of kit foxes in relation to water developments on the U.S. Army Dugway Proving Ground, Utah, using a before-after control-impact design. We collected 2 years of baseline data prior to reducing availability of water and continued data collection for another 2 years after removal of water on one-half of the study area. We found no evidence that removing water influenced survival or abundance of kit foxes. In addition, we found areas associated with the majority of water developments differed from current kit fox territories in elevation, soil type, and dominant cover type; historical use by kit foxes of areas associated with water developments is largely unknown. One explanation for our inability to find support for a water effect is that observed changes in the kit fox population and canid community in the Great Basin are attributable to changes in coyote management practices that temporally coincided with, but were largely unrelated to increases in water availability

Cougar Predation Rates and Prey Composition in the Pryor Mountains of Wyoming and Montana

Understanding predator-prey dynamics is a fundamental principle of ecology and an ideal component for management decisions. Across North America, the impact of cougars (Puma concolor) on their prey varies regionally. To document the relationships between cougars, bighorn sheep (Ovis canadensis canadensis), mule deer (Odocoileus hemionus), and feral horses (Equus caballus) on the Bighorn Canyon National Recreation Area and the Pryor Mountains, we deployed GPS collars on 6 cougars (the total number residing on the study area), and visited their clusters to determine predation rates and foraging patterns. We examined the composition of cougar kills by species, mule deer sex-age classes, prey size classes, season, and cougar sex. As a measure of selection, we examined the composition of prey killed relative to the composition of ungulates obtained during an aerial survey. We found mule deer were the primary prey, while bighorn sheep constituted secondary prey. While cougars selected for bighorn sheep, this was attributable to a single cougar. Among mule deer, female cougars killed more does and male cougars killed more bucks. Family groups had the highest predation rates (i.e., the shortest time intervals between kills), while adult males had the lowest rate. During the study, cougars were not depredating any feral horses in the area. Maintaining predator and prey numbers will require agencies to monitor and manage all fauna within this complex ecosystem. Habitat manipulations may be necessary to increase populations of deer and bighorn sheep, while continued management of feral horses will be required to reduce competition with native ungulates

Relaxin as a diagnostic tool for pregnancy in the coyote (\u3ci\u3eCanis latrans\u3c/i\u3e)

The diagnosis of pregnancy in the domestic dog (Canis familiaris) often employs specialized equipment, experienced staff, and the cooperation of the bitch. These procedures can be challenging when the subject is a wild canid, particularly in a field setting. In addition, reproductive hormone assays are unreliable as a diagnostic tool because the estrous profiles of pregnant and pseudopregnant canines are similar. However, research has demonstrated that the hormone relaxin can be detected in maternal blood after embryonic implantation, but remains negligible in non-pregnant females. We investigated the use of relaxin as a diagnostic marker of pregnancy in the coyote (C. latrans). A commercially available canine relaxin enzyme immunoassay (ReproCHEKTM) was used to test plasma collected from 124 female coyotes over four consecutive breeding seasons. Mating activities of the captive females were observed; then peripheral blood samples were collected at intervals throughout pregnancy, as well as after parturition. Results demonstrated that relaxin could be detected in the plasma of pregnant coyotes after 28 days of gestation, and in some cases as early as 23 days, while non-pregnant females and male coyotes consistently tested negative. Relaxin also remained detectable in the plasma of the majority of females tested 10–12 weeks after parturition. This qualitative assay for relaxin proved to be a reliable diagnostic tool for pregnancy in the coyote. In addition, blood sampling was relatively easy, could be accomplished with minimal handling, and did not require sedation or anesthesia

Spatial Ecologyand Social Interactions of Jaguars (\u3ci\u3ePanthera onca\u3c/i\u3e) in the Southern Pantanal, Brazil

The Pantanal of Brazil is an important area for the conservation of jaguars (Panthera onca). As the size of traditional large ranches in the Pantanal decreases, human access to jaguar habitat increases, resulting in human-altered landscapes that may influence patterns of resource selection and space use by jaguars. We used global positioning system radiocollars to study jaguars in the southern Pantanal. We radiocollared 10 jaguars (6 males and 4 females), obtained 11,787 locations, and examined their space use, movement rates, and social interactions between October 2001 and April 2004. Estimates of 90% kernel home ranges varied among animals and seasons (range: 34.1–262.9 km2). Core areas (50% isopleth) of both females and males did not differ in size between seasons, but home ranges (90% isopleth) during the dry season were generally larger than during the wet season. The stability of home ranges varied among seasons and individuals. Some females maintained ≥80% of their home ranges from 1 season to the next, whereas other females used ≤50% of their home ranges from the previous season. Site fidelity within individual home ranges also varied; ≥70% of the core areas of some females were located in different sites within their home ranges during different seasons. Locations of females suggested a pattern of spatial avoidance among females during the wet season. Home-range overlap among males was extensive, both in the wet and dry seasons, suggesting that males did not maintain exclusive ranges. Overlap between males and females occurred both in the wet and dry seasons, and movements by females were not restricted within the ranges of individual males. Jaguars were located \u3c200 m apart more often than expected, suggesting some degree of sociality. The reproductive profiles of females suggested either a low conception rate, a low survival rate of young, or that jaguars may be more social than previously thought. Interactions among males also suggested some degree of sociality

Resource Selection by Cougars: Influence of Behavioral State and Season

An understanding of how a predator uses the landscape can assist in developing management plans. We modeled resource selection by cougars (Puma concolor) during 2 behavioral states (moving and killing) and 2 seasons (summer and winter) with respect to landscape characteristics using locations from global positioning system (GPS)-collared cougars in the Pryor Mountains, Montana and Wyoming, USA. Furthermore, we examined predation-specific resource selection at 2 scales (fine and coarse). When possible, we backtracked from cache sites to kill sites and used a fine-scale analysis to examine landscape characteristics of confirmed kills. At this fine scale, kill sites had less horizontal visibility, were more likely to be in juniper (Juniperus spp.)-mountain mahogany (Cercocarpus ledifolius), and were less likely to be in grassland vegetation. For the coarse-scale analysis of predation risk, we used the entire dataset of kills by buffering each cache site by 94.9 m, which was the 95% upper cut-off point of the known distances dragged from kill sites to cache sites, thereby creating buffered cache sites that had a high probability of containing the kill site. We modeled seasonal cougar predation site selection by constructing resource selection functions for these buffered cache sites. The top model for summer predation risk consisted of vegetation class, distance to water, and slope. The top model for winter predation risk included vegetation class and elevation. These predation risk models were similar to but simpler than the resource selection models developed from the moving locations. Essentially, the behavioral state (i.e., killing vs. moving) of the cougar had little influence on resource selection, indicating that cougars are generally in hunting mode while moving through their landscape. To potentially reduce cougar predation on mule deer (Odocoileus hemionus) and bighorn sheep (Ovis canadensis) in our study area, managers can intersect the cougar predation-risk resource selection functions with deer and sheep habitat to guide habitat modification efforts aimed at increasing horizontal visibility in risky vegetation classes

Resource Selection by Cougars: Influence of Behavioral State and Season

An understanding of how a predator uses the landscape can assist in developing management plans. We modeled resource selection by cougars (Puma concolor) during 2 behavioral states (moving and killing) and 2 seasons (summer and winter) with respect to landscape characteristics using locations from global positioning system (GPS)-collared cougars in the Pryor Mountains, Montana and Wyoming, USA. Furthermore, we examined predation-specific resource selection at 2 scales (fine and coarse). When possible, we backtracked from cache sites to kill sites and used a fine-scale analysis to examine landscape characteristics of confirmed kills. At this fine scale, kill sites had less horizontal visibility, were more likely to be in juniper (Juniperus spp.)-mountain mahogany (Cercocarpus ledifolius), and were less likely to be in grassland vegetation. For the coarse-scale analysis of predation risk, we used the entire dataset of kills by buffering each cache site by 94.9 m, which was the 95% upper cut-off point of the known distances dragged from kill sites to cache sites, thereby creating buffered cache sites that had a high probability of containing the kill site. We modeled seasonal cougar predation site selection by constructing resource selection functions for these buffered cache sites. The top model for summer predation risk consisted of vegetation class, distance to water, and slope. The top model for winter predation risk included vegetation class and elevation. These predation risk models were similar to but simpler than the resource selection models developed from the moving locations. Essentially, the behavioral state (i.e., killing vs. moving) of the cougar had little influence on resource selection, indicating that cougars are generally in hunting mode while moving through their landscape. To potentially reduce cougar predation on mule deer (Odocoileus hemionus) and bighorn sheep (Ovis canadensis) in our study area, managers can intersect the cougar predation-risk resource selection functions with deer and sheep habitat to guide habitat modification efforts aimed at increasing horizontal visibility in risky vegetation classes

COYOTE POPULATION PROCESSES REVISITED

It appears that coyote (Canis latrans) abundance is determined primarily by availability of food (prey) as mediated through social dominance hierarchies and a territorial land tenure system. This is reflected in rates of reproduction, dispersal, and mortality, with survival of juveniles a major factor. Suggestions for a new generation of simulation models to explore coyote population functions are included

Identifying individual cougars (\u3ci\u3ePuma concolor\u3c/i\u3e) in remote camera images – implications for population estimates

Context. Several studies have estimated cougar (Puma concolor) abundance using remote camera trapping in conjunction with capture–mark–recapture (CMR) type analyses. However, this methodology (photo-CMR) requires that photo-captured individuals are individually recognisable (photo identification). Photo identification is generally achieved using naturally occurring marks (e.g. stripes or spots) that are unique to each individual. Cougars, however, are uniformly pelaged, and photo identification must be based on subtler attributes such as scars, ear nicks or body morphology. There is some debate as to whether these types of features are sufficient for photo-CMR, but there is little research directly evaluating its feasibility with cougars. Aim. We aimed to examine researchers’ ability to reliably identify individual cougars in photographs taken from a camera-trapping survey, in order to evaluate the appropriateness of photo-CMR for estimating cougar abundance or CMR-derived parameters. Methods. We collected cougar photo detections using a grid of 55 remote camera traps in north-west Wyoming, USA. The photo detections were distributed to professional biologists working in cougar research, who independently attempted to identify individuals in a pairwise matching process. We assessed the level to which their results agreed, using simple percentage agreement and Fleiss’s kappa. We also generated and compared spatially explicit capture–recapture (SECR) density estimates using their resultant detection histories. Key results. There were no cases where participants were in full agreement on a cougar’s ID. Agreement in photo identification among participants was low (n = 7; simple agreement = 46.7%; Fleiss’s kappa = 0.183). The resultant SECR density estimates ranged from 0.7 to 13.5 cougars per 100 km2 (n = 4; s.d. = 6.11). Conclusion. We were unable to produce reliable estimates of cougar density using photo-CMR, due to our inability to accurately photo-tag detected individuals. Abundance estimators that do not require complete photo-tagging (i.e. mark–resight) were also infeasible, given the lack of agreement on any single cougar’s ID. Implications. This research suggested that there are substantial problems with the application of photo-CMR to estimate the size of cougar populations. Although improvements in camera technology or field methods may resolve these issues, researchers attempting to use this method on cougars should be cautious