Montana

Swift foxes are endemic to the Great Plains of North America, but they were extirpated from the northern portion of their range by the mid-1900s. Despite several reintroductions to the Northern Great Plains, there is still a large range gap between the swift fox population along the Montana and Canada border, and the population in northeastern Wyoming and northwestern South Dakota. A better understanding of the resources swift foxes use and demography of the population at the edge of this range gap in northern Montana might help to managers to facilitate connectivity among populations.In Chapter 1, we collected fine-scale locational data from swift foxes fitted with Global Positioning System collars to examine movement and resource use patterns during winter of2016-2017 in northeasternMontana. Our results suggest that swift foxes displayed three distinct movement patterns (i.e., resting, foraging, and travelling) during the winter. Distance to road decreased relative probability of use by 39-46% per kilometer across all movement states and individuals, whereas the influence of topographic roughness and distance to crop field varied among movement states and individuals. Overall, while our findings are based on data from three individuals, our study suggests that across movement states during the critical winter season, swift foxes are likely using topography and areas near roads to increase their ability to detect predators.In Chapter 2, weestimated the home range size and evaluated third order resource selection of 22 swift foxes equipped with Global Positioning System tracking collars in northeastern Montana. Swift fox home ranges in our study were some of the largest ever recorded averaging (+/-SE) 42.0 km2+/-4.7. Our results indicate that both
iiienvironmental and anthropogenic factors influenced resource use. At the population level, relative probability of use increased by 3.3% for every5.0%increase in percent grasslands. Relative probability of usedecreased by 7.9%and7.4% for every kilometer away from nonpaved roads and gas well sites, respectively, and decreased by 2.9% and 11.3% for every one-unit increase in topographic roughness and every 0.05 increase in normalized difference vegetation index (NDVI). Overall, to reestablish connectivity among swift fox populations in Montana, our study suggests that managers should aim to maintain large corridors of contiguous grasslands a landscape-scale, a process that will likely require having to work with multiple property owners.In the Northern Great Plains, a suite of carnivores has experienced a large decline in distribution and abundance since the 1800s. In Chapter 3, our objective was to estimate survival and reproductive rates of swift foxes in Montana and assess population viability. In addition, we evaluated support for nine different hypotheses of how several demographic and environmental factors influence survival. We found that adult and juvenile annual survival rates were 54% and 74%, respectively, and fecundity was 0.85. We found the most support for the hypothesis that the percentage of native grassland at the 1km scale
influenced survival and found that survival increased, on average,2.1% for every 5% increase in grassland. The estimated population growth rate of this population was estimated to be 1.002, indicating that the population was likely to be stable. Our results suggest that this population is currently not likely acting as a source population (i.e. not producing a sufficient number of dispersers), which mightbe contributing to the lack of range expansion. The long-term success of swift fox recovery will likely be dependent on maintaining large tracts of contiguous grassland with abundant prey, which would be benefit not only the swift fox,but a suite of recovering carnivores

We built on the existing capacity of a non-governmental organization called the Blackfoot Challenge to proactively address gray wolf (Canis lupus; wolves) livestock conflicts in the Blackfoot Valley of Montana. Beginning in 2007, wolves started rapidly recolonizing the valley, raising concerns among livestock producers. We built on an existing program to mitigate conflicts associated with an expanding grizzly bear (Ursus arctos) population and worked within the community to build a similar program to reduce wolf conflicts using an integrative, multi-method approach. Efforts to engage the community included one-on-one meetings, workshops, field tours, and regular group meetings as well as opportunities to participate in data collection and projects. Initial projects included permanent electric fencing of calving areas and livestock carcass removal to address the threat of grizzly bears and, later, wolves. Subsequently, we used intensive livestock and wolf monitoring provided by range riders in an attempt to reduce the frequency of encounter rates among wolves and livestock. Although we cannot claim causation from our effort, the results were encouraging. Confirmed livestock losses to wolves from 2006 to 2015 averaged 2.2 depredations per year across nearly 50 ranches on about 3,240 km2 that were annually grazed by 16,000–18,000 head of livestock. Fewer than 3 wolves per year have been removed (2.4 wolves per year) due to these depredations for the same period as the population increased from 1 confirmed pack to approximately 12 packs. Our collaborative approach and prior experience with grizzly bears were key in building a proactive program to mitigate conflicts with wolves in a community that was confronted with adjusting to an increasing large carnivore presence over a short period.

Territoriality in animals is of both theoretical and conservation interest. Animals are territorial when benefits of exclusive access to a limiting resource outweigh costs of maintaining and defending it. The size of territories can be considered a function of ecological factors that affect this benefit-cost ratio. Previous research has shown that territory sizes for wolves (Canis lupus) are largely determined by available biomass of prey, and possibly pack size and density of neighboring wolf packs, but has not been interpreted in a benefit-cost framework. Such a framework is relevant for wolves living in the Northern Rocky Mountains where conflicts with humans increase mortality, thereby potentially increasing costs of being territorial and using prey resources located near humans. We estimated territory sizes for 38 wolf packs in Montana from 2008 to 2009 using 90% adaptive kernels. We then created generalized linear models (GLMs) representing combinations of ecological factors hypothesized to affect the territory sizes of wolf packs. Our top GLM, which had good model fit (R² = 0.68, P < 0.0005), suggested that territory sizes of wolves in Montana were positively related to terrain ruggedness, lethal controls, and human density and negatively related to number of surrounding packs relative to the size of the territory. We found that the top GLM successfully predicted territory sizes (R² = 0.53, P < 0.0005) using a jackknife approach. Our study shows that territory sizes of group-living carnivores are influenced by not only intraspecific competition and availability of limiting resources, but also by anthropogenic threats to the group’s survival, which could have important consequences where these territorial carnivores come into conflict with humans.

Though it is widely argued that antipredator responses carry nutritional costs, or risk effects, these costs are rarely measured in wild populations. To quantify risk effects in elk, a species that strongly responds to the presence of wolves, we noninvasively monitored diet selection and nutrient balance in wintering elk in the Upper Gallatin, Montana, USA, over three winters while quantifying the local presence of wolves at a fine spatiotemporal scale. Standard nutritional indices based on the botanical and chemical composition of 786 fecal samples, 606 snow urine samples, and 224 forage samples showed that elk were generally malnourished throughout winter. Increased selection for dietary nitrogen within forage types (e.g., grasses) led to ∼8% higher fecal nitrogen in the presence of wolves. However, urinary allantoin : creatinine and potassium : creatinine ratios decreased in the presence of wolves, suggesting large declines in energy intake, equal to 27% of maintenance requirements. Urinary nitrogen : creatinine ratios confirmed that deficiencies in nitrogen and/or energy were exacerbated in the presence of wolves, leading to increased endogenous protein catabolism. Overall, the nutritional effects of wolf presence may be of sufficient magnitude to reduce survival and reproduction in wintering elk. Nutritionally mediated risk effects may be important for understanding predator–prey dynamics in wild populations, but such effects could be masked as bottom‐up forces if antipredator responses are not considered.

We evaluated the small intestines of 123 gray wolves (Canis lupus) that were collected from Idaho, USA (n=63), and Montana, USA (n=60), between 2006 and 2008 for the tapeworm Echinococcus granulosus. The tapeworm was detected in 39 of 63 wolves (62%) in Idaho, USA, and 38 of 60 wolves (63%) in Montana, USA. The detection of thousands of tapeworms per wolf was a common finding. In Idaho, USA, hydatid cysts, the intermediate form of E. granulosus, were detected in elk (Cervus elaphus), mule deer (Odocoileus hemionus), and a mountain goat (Oreamnos americanus). In Montana, USA, hydatid cysts were detected in elk. To our knowledge, this is the first report of adult E. granulosus in Idaho, USA, or Montana, USA. It is unknown whether the parasite was introduced into Idaho, USA, and southwestern Montana, USA, with the importation of wolves from Alberta, Canada, or British Columbia, Canada, into Yellowstone National Park, Wyoming, USA, and central Idaho, USA, in 1995 and 1996, or whether the parasite has always been present in other carnivore hosts, and wolves became a new definitive host. Based on our results, the parasite is now well established in wolves in these states and is documented in elk, mule deer, and a mountain goat as intermediate hosts.

Numerous studies have documented how prey may use antipredator strategies to reduce the risk of predation from a single predator. However, when a recolonizing predator enters an already complex predator—prey system, specific antipredator behaviors may conflict and avoidance of one predator may enhance vulnerability to another. We studied the patterns of prey selection by recolonizing wolves (Canis lupus) and cougars (Puma concolor) in response to prey resource selection in the northern Madison Range, Montana, USA. Elk (Cervus elaphus) were the primary prey for wolves, and mule deer (Odocoileus hemionus) were the primary prey for cougars, but elk made up an increasingly greater proportion of cougar kills annually. Although both predators preyed disproportionately on male elk, wolves were most likely to prey on males in poor physical condition. Although we found that the predators partitioned hunting habitats, structural complexity at wolf kill sites increased over time, whereas complexity of cougar kill sites decreased. We concluded that shifts by prey to structurally complex refugia were attempts by formerly naïve prey to lessen predation risk from wolves; nevertheless, shifting to more structurally complex refugia might have made prey more vulnerable to cougars. After a change in predator exposure, use of refugia may represent a compromise to minimize overall risk. As agencies formulate management strategies relative to wolf recolonization, the potential for interactive predation effects (i.e., facilitation or antagonism) should be considered.

We examined prey selection, search distance (measured as km traveled/kill), and spatial use of recolonizing wolves (Canis lupus) in a multi‐prey system in northwestern Montana, USA, and southeastern British Columbia, Canada, from 1986 to 1996. Our objective was to explore factors affecting these parameters to better understand wolf–prey relationships of recolonizing wolves. Within white‐tailed deer (Odocoileus virginianus) winter ranges, wolves selectively killed elk (Cervus elaphus) over deer. Number of wolves (r = 0.67, P = 0.03), year (r = 0.68, P = 0.02), and possibly human hunter‐days/elk harvested (r = 0.55, P = 0.08) were positively correlated with variation in proportion of deer killed by wolves annually. Outside of severe winters, white‐tailed deer, elk, and moose (Alces alces) appeared to be equally vulnerable to wolf predation. Search distance of wolves varied by up to 12 times annually. Snow depth (r = 0.73, P = 0.03) and proportion of total kills by wolves that were deer (r = 0.66, P = 0.06) were negatively correlated with the annual variation in the total search distance of wolves. Search distance per wolf was correlated negatively with year (r = 0.66, P = 0.06) and exponentially with hunter‐days/elk harvested (r = 0.70, P = 0.04). Space use by wolves may have been in response to local changes in deer abundance. Wolves appeared to select the most profitable prey species. Severe winters and wolf selection for deer, coinciding with a decrease in elk numbers, increased wolf hunting efficiency by reducing search distance. Further research is needed to determine whether reduced search distance equates to increased kill rates by wolves in this system. Based on the time, expense, and difficulty of gathering data on wolf search distance in this sytem, however, we recommend against assessing impacts of wolves on prey via measuring kill rate. Rather, we suggest monitoring impacts of recolonizing wolves by directly assessing cause‐specific mortality and recruitment rates of prey species.

Bounty records from Montana (1902–1930) were used to better understand spatial and temporal response of wolves (Canis lupus) and cougars (Puma concolor) to an eradication program. Number of payments for wolves declined from a high of 4116 in 1903 to 0 by 1928. Numbers of cougar pelts fluctuated, but generally declined from 177 in 1908 to 2 in 1930. An inverse spatial relationship existed between density of payments for wolves and cougars. Payments for wolves were greatest in the Prairie ecoregion, while payments for cougars were greatest in the Montane. The ratio of pup to adult wolves also was greatest in the Prairie ecoregion and least in the montane. If distribution and frequency of bounty payments were a reflection of the distribution and abundance of wolves, populations were highest and most productive in areas where they currently do not occur.

We summarized the status of wolves (Canis lupus), elk (Cervis elaphus), and woody browse conditions during the 20th century for the upper Gallatin elk winter range in southwestern Montana, USA. During this period, wolves were present until about the mid-1920s, absent for seven decades, and then returned to the basin in 1996. A chronosequence of photographs, historical reports, and studies indicated willows (Salix spp.) along streams became heavily browsed and eventually suppressed following the removal of wolves, apparently due to unimpeded browsing by elk. However, after wolf establishment in 1996, browsing intensity on willows lessened in some areas and we hypothesized that, at both a landscape and fine scale, browsing pressure reflects terrain configurations influencing predation risk (nonlethal effects), in conjunction with lower elk densities (lethal effects). We measured browsing intensity and heights of Booth willow (S. boothii) along 3000 m reaches of the Gallatin River and a tributary to examine the potential influence of wolf/elk interactions upon willow growth. Where the Gallatin Valley is relatively narrow (high predation risk), willows began releasing in 1999 and by 2002 were relatively tall (150–250 cm). In contrast, willow heights along a wider portion of the Gallatin Valley, along the open landscape of the tributary, and an upland site (all low predation risk) generally remained low (<80 cm). We identified terrain and other features that may contribute to the perceived risk of wolf predation, by elk for a given site. Although alternative mechanisms are discussed, changes in willow communities over time following wolf removal and their subsequent reintroduction were consistent with a top-down trophic cascade model involving nonlethal and possibly lethal effects. If similar top-down effects upon vegetation hold true in other regions of North America and other parts of the world where wolves have been extirpated, wolf recovery may represent a management option for helping to restore riparian plant communities and conserve biodiversity.

We studied effects of recolonizing wolves (Canis lupus) in the North Fork of the Flathead area of northwestern Montana on the diets of coyotes (C. latrans) from 1994 to 1997. Wolf and coyote diets differed in frequency of occurrence of prey species during 3 of the 4 summers and winters (P < 0.001) during the study. Coyote diets contained more murid prey items, and wolf diets contained more deer (Odocoileus virginianus and O. hemionus) in the summer and elk (Cervus elaphus) in the winter. Coyotes and wolves ate prey of different size during both the summer (P < 0.001) and winter (P < 0.001) months in 1994–1996: wolves took a greater proportion (P < 0.001) of large (>45 kg) prey species and coyotes, small (<2 kg) prey (P < 0.001). Wolves selected a larger proportion of adults (P < 0.001), whereas coyotes selected a larger proportion of juveniles (P < 0.001) during summer. We believe that differential use of food resources facilitates coexistence of wolves and coyotes in the North Fork of the Flathead area.

Wolves (Canis lupus) will become an important mortality factor on ungulate populations as they recolonize the western United States. Innovative means of altering the wolf-ungulate dynamic to enhance either prey security or the predator population may be necessary to meet management objectives. From 1990 to 1996, we examined multiscale factors affecting hunting success of wolves during winter in a multi-prey system in northwestern Montana and southeastern British Columbia, Canada. Within their home ranges, wolves concentrated their hunting in wintering areas of white-tailed deer (Odocoileus virginianus). They used areas with features that facili- tated travel (low snow and vegetative cover) and habitats that were favored by deer. Along their travel routes, wolves killed deer in areas with higher densities of deer and lower densities of elk (Cervus elaphus) and moose (Alces alces) than expected, based on occurrence of these prey. They killed deer in areas with greater hiding-stalking cover, less slope, and closer to water than expected, based on occurrence along wolf travel routes. More deer were killed in the main valley bottom and ravines than in other landscape classes located along travel routes. Within deer home ranges, wolves killed more deer at flatter sites and at sites with lower densities of deer.

Gray wolf (Canis lupus) populations were eliminated from Montana, Idaho, and Wyoming, as wellas adjacent southwestern Canada by the 1930s. After human-caused mortality of wolves in south western Canada began to be regulated in the 1960s, populations began expanding southward.Dispersing individuals occasionally reached the northern Rocky Mountains of the UnitedStates, but lacked legal protection there until 1974, after passage of the Endangered Species Act of 1973. In 1986, wolves from Canada successfully raised a litter of pups in Glacier NationalPark, Montana, and a small population was soon established. In 1995 and 1996, wolves from western Canada were reintroduced to remote public lands in central Idaho and Yellowstone National Park. These wolves were designated as nonessential experimental populations to increase management flexibility and address local and state concerns. Wolf restoration is rapidly occurring in Montana, Idaho, and Wyoming, and there were at least 28 breeding pairs in December2000. There are now about 63 adult wolves in northwestern Montana, 192 in central Idaho, and 177 in the Greater Yellowstone area. Dispersal of wolves between Canada, Montana, Idaho, and Wyoming has been documented. Occasional lone wolves may disperse into adjacent states, but population establishment outside of Montana, Idaho, and Wyoming is probably not imminent.The gray wolf population in the northwestern U.S. should be recovered and, depending on the completion of state and tribal wolf conservation plans, could be proposed to be removed from Act protection within three years. Wolf restoration has proceeded more quickly and with more benefits, such as public viewing than predicted. Problems, including confirmed livestock depredations, have been lower than estimated. The Service led interagency recovery program focusesits efforts on achieving wolf recovery while addressing the concerns of people who live near wolves. Wolves have restored an important ecological process to several large wild areas in thenorthern Rocky Mountains of the U.S. The program has been widely publicized and is generally viewed as highly successful.

Expansion by wolf (Canis lupus) populations in the western United States creates new opportunities and challenges for researching and managing large mammal predator-prey systems. Therefore, we compared patterns of prey selection between wolves and cougars (Puma concolor) to ascertain the effects of multiple predators on prey and on each other. Because of differences in hunting techniques, we predicted that wolves would kill more vulnerable classes of prey than cougars. Our results did not support this prediction. White- tailed deer (Odocoileus virginianus) composed the greatest proportion of wolf (0.83) and cougar kills (0.87), but elk (Cervus elaphus) and moose (Alces alces) composed a larger proportion of wolf (0.14, 0.03, respectively) than cougar (0.06, 0.02, respectively) kills. Wolves and cougars selected older and younger deer and elk than did hunters. Cougars killed relatively more bull elk (0.74) than did wolves (0.48). Male deer killed by cougars had shorter diastema lengths than did male deer killed by wolves (P = 0.02). Pack hunting by wolves and dense stalking cover may have partially explained the failure to support predictions of the coursing versus stalking dichotomy. Wolves and cougars may be exhibiting exploitation and interference competition that is affecting each others’ behavior and dynamics, and that of their prey.

We compared patterns of prey selection amongwolves (Canis lupus), cougars (Puma concolor), and humans to ascertain the effects of wolf recolonization and multiple predators on prey and on each other. Characteristics of prey selected by wolves and cougars in the same ecosystem have not been previously reported. White-tailed deer (Odocoileus virqinianus) made up the greatest proportion of both wolf (0.83) and cougar diets (0.87), but elk (Cervus elaphus) and moose (Alces alces) made up a larger proportion of wolf (0.14, 0.03, respectively) than cougar (0.06, 0.02, respectively) diets. Wolves and cougars selected the same age classes in both deer and elk. They both selected older and younger deer and elk than hunters did. They both selected fewer males than hunters did and they both selected more fawns and more males than expected based on availability. Cougars killed relatively more bull elk than wolves. Cougars generally killed animals in poorer condition than wolves did, especially in elk. These data may be used by predator/prey managers to anticipate effects of wolf and cougar presence on populations of prey and may also be used to determine potential impacts of one predator on the other. We suggest possible management alternatives to mitigate effects.1Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.