No description available.

No description available.

No description available.

Gray wolves (Canis lupus) are frequently captured with leg-hold traps for reintroduction, relocation to reduce depredations on livestock, or as subjects for research projects. Wolves captured with leg-hold traps often sustain injuries to their feet, legs, and teeth during struggles to escape. Other studies have shown that the use of tranquilizer devices on leg-hold traps reduces such injuries to coyotes. This study (1) assessed whether use of tranquilizer trap devices (TTDs) on leg-hold traps reduced the severity of injuries sustained by captured wolves, and (2) examined the effects TTDs have on nontarget species caught during wolf capture operations. Data were collected from 112 wolves (21 pups and 91 adults), as well as 114 nontarget animals from 9 species captured during 1996 in Minnesota. Laboratory evaluations, including radiographs and necropsies of foot and leg injuries of 37 adult wolves captured in Livestock Protection Company (LPC) drag traps equipped with TTDs containing propiopromazine hydrochloride, indicated a significant reduction in severity of injuries compared to traps without TTDs (n = 23) or equipped with placebo TTDs (n = 15). None of the 42 nontarget individuals captured in traps equipped with TTDs containing propiopromazine hydrochloride succumbed to drug overdoses. Injuries were significantly less severe among nontarget animals caught in traps equipped with TTDs containing the tranquilizer, and fewer non target animals (7%) captured in traps equipped with TTDs loaded with propiopromazine sustained severe injuries and had to be destroyed, compared to nontarget animals captured in traps not equipped with propiopromazine TTDs (42%).

Animal movements and space use are fundamental components of life and play integral roles in organismal fitness, population dynamics, and the ecology and evolution of species. The heterogeneous distribution of resources and the movement required to access them, results in ecology being a fundamentally spatial concept. Thus, elucidating animal-habitat relationships is a central focus of wildlife ecology and conservation. I utilized GPS technology, resource selection functions, and generalized linear mixed models, to investigate the immediate post-release movements, denning chronology, release-site fidelity, and season-delineated movements, home ranges, and resource use for six, orphaned and rehabilitated black bears (Ursus americanus). This study represents the first application of GPS monitoring and resource selection for rehabilitated black bears. Data from this study provide insights into the activity of released rehabilitated black bear cubs, highlight trends among the release cohort, and illustrate the variability of individual behavior. Results indicate species-typical behaviors, with bears denning shortly after their releases, exhibiting elevated movement rates and dispersals during late-summer, preferential selection for certain habitat types based on season, and no utilization of anthropogenic-resources. One primary concern for large carnivores that have been captive-reared or had prolonged exposure to humans during rehabilitation, is whether they will exhibit natural behaviors after release. Behavior testing in other species has revealed that many traits exhibited in captivity often translate to wild behavior, however this had not yet been investigated for black bears. This study presents the first application of captive behavior tests for the investigation into black bear personality, defined by consistency in the individual differences in behavior across time or context. Through open field, novel object, startle object, and focal-animal sampling, we investigate the potential for personality in six black bear cubs. Results indicate consistency in behavior across five metrics for the bold-shy axis, and eight sampling events measuring responses for the activity axis, thus indicating personality. Analysis to identify correlations to wild activity metrics did not yield strong statistical support, however. Information presented here may provide a framework for future research into black bear personality, its relationship to life-history and ecology, and lend support for rehabilitation practices for orphan bear cubs.

A study of bottom invertebrates on the lower Logan River, Logan, Utah was conducted from June 1966 to July 1967. One objective was to evaluate on a qualitative and quantitative basis the invertebrate populations above and below a sewage entry in the river. Another objective was to study the year round fluctuations in the invertebrate population. The greatest variety of invertebrates was found in the summer. Chironomidae and Baetis were the only two groups found in abundance over the entire year. Populations were reduced during autumn when water levels rose, and they declined even more sharply during the spring flood. At the station below the sewage entry a wide variety of Chironomidae genera were present and Oligochaeta numbers were low.

Multiyear drought is expected to increase in occurrence and severity in dry regions across the world, such as the American Southwest, endangering native species and ecosystem health. The effects of multiyear drought are often worsened by human water use for consumption, energy production, and agriculture, which, in lakes and reservoirs, cause reduced lake elevation. Reductions in lake elevation may leave previously submerged habitat stranded along shorelines and make tributaries inaccessible to fishes. Here, we show that decreasing lake elevation, associated with drought and water withdrawal, reduces the availability of shoreline cobble habitat to fishes and increases tributary distance by creating an elevation-specific shoreline habitat map and an elevation-specific tributary channel distance map, respectively. We combined 17-years of fish survey data and lake elevation history with our elevation-specific maps to determine whet her the number of fishes observed and the number of fish hatching are related to drought-driven changes in shoreline habitat and tributary channel distance. We surveyed the shoreline zone of Bear Lake, UT-ID, from full pool to a depth of >18m, totaling 94.86 surveyed km2. As lake elevation decreased >6 m from full pool to the lowest historical elevation, shoreline cobble decreased by >97%, and tributary channel distance increases up to 400% that of full pool. Bear Lake sculpin, a cold-water fish species of concern that relies on cobble for spawning, catch per unit effort decreased by >75% at the minimum cobble area available, and the number of sculpin successfully becoming adults declined by as much as 86%. The number of Bear Lake Bonneville cutthroat trout, a sport fish that relies on connections between tributaries and the lake to complete their life cycle, successfully becoming adults declined by as much as 62%, but annual growth was not related to drought. Our research is an example of the severe consequences of multiyear drought conditions and water withdrawal on lakes and reservoirs, as well as the fishes they support. Indeed, understand the effects of extended drought on aquatic habitats is critical to maintain healthy lakes and reservoirs, to sustain native species, and to maintain the health of popular sport fisheries.

Policies regulating wildlife winter-feeding programs may have long-term impacts on conservation and future management of both target and non-target species. In 2000, the Utah Wildlife Board, upon reviewing input from a series of public regional meetings, adopted a Utah Big Game Winter-Feeding Policy. The Utah Division of Wildlife Resources used this policy to regulate winter-feeding programs for mule deer in northern Utah, 2001-2005. I monitored the program effects on mule deer biology, activity and migration, and winter browse utilization and productivity. While feed rations generally compensated for protein and energy deficiencies, they may overlook mineral deficiencies. To determine if mule deer could select for feeds that contained minerals that may be deficient in native browse, I conducted experimental feeding trials using copper supplements. Feeding program success on increasing mule deer winter survival depends heavily on timely implementation. Therefore, I evaluated the utility of a modified body condition index to use deer-vehicle collision carcasses to monitor herd nutritional status, and applied this information to weather data to assist in determining when to implement winter-feeding programs. Lastly, I surveyed a random sample of Utah stakeholders to determine if the policy developed through the regional meeting process reflected wider public opinion rather than traditional consumptive users. This winter-feeding enhanced body condition, and increased adult female survival. When dynamics of fed and non-fed study groups were modeled over five years, the model predicted both populations were declining, with a lower rate of decline in the fed population. The primary cause of mortality for fed and non-fed groups, deer-vehicle collision, nullified benefits accrued from feeding. Deer may have balanced the effects of sagebrush and bitterbrush toxins with nutrients from feed rations, thus resulting in increased browsing of bitterbrush. Fed deer browsed over less area, and migrated earlier in fall and later in spring. Mule deer also selected a consistent proportion of copper-amended rations, suggesting plain rations are nutritionally inadequate. Although most Utah stakeholders were unaware of Utah's big game winterfeeding policy, most believed winter-feeding was an important mule deer management strategy in Utah. When given a choice between using management funds to support winter-feeding or habitat projects, stakeholders preferred funding habitat restoration.

Ecological communities are complex, the structure of which is composed of interactions between multiple community characteristics and the abiotic and biotic factors shaping them. Because of this complexity, ecological studies are generally limited in scope and size, often dissecting communities into their component parts to examine them piece by piece. While this might be the most practical method to study communities, this approach often neglects other characteristics that, with their inclusion, would provide a more complete picture of community ecology. The studies described in this dissertation were conducted in an effort to synthesize the complexity that is inherent in ecological plant communities growing on a Mojave Desert bajada. Each study addresses a separate component of community structure, which, taken as a whole, provides a more thorough understanding of arid plant community dynamics. Overall, our results reveal the importance of substrate variables and their role in shaping plant community structure in arid environments. In addition, these investigations provide evidence of the strong role that facilitation plays on this bajada and possibly arid plant communities as a whole. The comprehensive approach described in this dissertation will enable ecologists to gain a more complete understanding of community dynamics and apply this knowledge to various climate change and land management scenarios.

Virus diseases of stone fruit orchards have existed in Utah for more than a quarter of a century and are seriously diminishing the peach and cherry fruit production. Western X of peach, rusty mottle of cherry, wilt and decline of cherry, and little cherry constitute the most economically important stone fruit virus diseases in Utah. Many orchards, particularly in Davis County, have 50 to 83 percent of the trees infected with one or more of the yellow-red viroses. Surveys have shown that the diseases are spreading from 3 to 5 percent each year. It is believed that certain insects are responsible for the natural spread of the virus diesases of stone fruits. Some inconclusive evidence points to leafhoppers as the potential vectors since many cicadellidids are capable of transmitting virus to plants during the feeding process. They have maintained a reputation for being efficient vectors of plant viruses for many years, as well as inducing other types of plant injury. Their adaptable, piercing-sucking mouth parts inoculate plants with filterable viruses taken in from infected plants. They inflict other types of damage to the host by injecting toxic substances. The most sever type of damage, however, is that caused through the virus infection which generally is systemic. The purpose of this investigation was to determine the occurrence, seasonla abundance, and host preference of leafhoppers occurring in the stone fruit orchards of northern Utah. Leafhopper occurrence in plant environs adjacent to the stone fruit orchards was also studied. Studies were made to determine if any correlation existed between leafhopper abundance and percentage of diseased trees in the orchards. Trap studies and surveys seemed to be the most appropriate technique in approaching this problem. The trap studies were conducted in fifteen stone fruit orchards in five counties of norhtern Utah. Surveys were undertaken in most stone fruit growing areas in the northern part of the state.