20 research outputs found

    American Bison Ecology and Bison-Cattle Interactions in an Isolated Montane Environment

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    As bison are considered to be ecologically extinct, and negative interactions between bison and cattle are perceived to limit bison restoration and cattle production, I designed a series of studies to test for potential competition between bison (Bison bison) and cattle (Bos taurus) for forage on the Henry Mountains in southern Utah. These studies provide insight into key information gaps previously identified by the Utah Division of Wildlife Resources (UDWR), Bureau of Land Management, and the local grazing association. The results indicate that bison and cattle are not strong competitors for forage on the Henry Mountains. Jackrabbits (Lepus californicus) emerged as the strongest competitive threat to cattle, consuming more than twice the amount of forage consumed by bison. Further, bison habitat preferences did not match with cattle habitat needs as reported by a survey of the local ranching community. This suggests that negative impacts on cattle due to bison have been overstated. Still, any potential negative impacts of bison will be felt by a small group of local individuals. This prompted me to design a new management scheme, which has the potential to increase the number of bison on the Henry Mountains while also compensating local ranchers for reducing the number of cattle they graze in the area. This system should be mutually beneficial for the local ranching community and the UDWR, and easily implemented by taking advantage of the currently exiting conservation license program

    Comparison of Nest Defense Behaviors of Goshawks (Accipiter gentilis) from Finland and Montana

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    As human impacts on wildlife have become a topic of increasing interest, studies have focused on issues such as overexploitation and habitat loss. However, little research has examined potential anthropogenic impacts on animal behavior. Understanding the degree to which human interaction may alter natural animal behavior has become increasingly important in developing effective conservation strategies. We examined two populations of northern goshawks (Accipiter gentilis) in Montana and Finland. Goshawks in Finland were not protected until the late 1980s, and prior to this protection were routinely shot, as it was believed that shooting goshawks would keep grouse populations high. In the United States, Goshawk were not managed as predator control. Though aggressive nest defense has been characterized throughout North America, goshawks in Finland do not show this same behavior. To quantify aggression, we presented nesting goshawks with an owl decoy, a human mannequin, and a live human and recorded their responses to each of the trial conditions. We evaluated the recordings for time of response, duration of response, whether or not an active stimulus was present to elicit the response (i.e., movement or sound), and the sex of the bird making the response. We used t-Test with unequal variance to compare mean number of responses and response duration. Our results suggested that goshawks in Montana exhibit more aggressive nest defense behaviors than those in Finland. While this could be due to some biotic or abiotic factor that we were not able to control for in a study on such a small scale, it is also possible that the results from this study suggest another underlying cause, such as an artificial selection pressure created by shooting goshawks

    Effects of environmental and anthropogenic landscape features on mule deer harvest in Nebraska

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    Understanding the habitat use of wildlife species is important for effective management. Nebraska has a variety of habitat types, with the majority being covered by rangeland and cropland. These habitat types likely influence the harvest of mule deer (MD; Odocoileus hemionus) in Nebraska, but their specific effects are unknown, and moreover, harvest may also be influenced by the accessibility of deer habitats for hunters. We modeled which environmental and anthropogenic landscape features influenced harvest densities. Spatial analysis in a Geographic Information System was used to determine the mean values of environmental and anthropogenic landscape features at the county level. We then used a generalized linear model to determine which of those factors influenced MD harvest from 2014–2016. We found that NDVI amplitude, hunter effort, road density, terrain roughness, and canopy cover influence MD harvest in Nebraska. According to our model, MD harvest densities are significantly greater areas with NDVI amplitude ∼38, increasing hunter effort, road densities near 1,750 m/km2, increasing terrain roughness, and decreasing canopy cover. Understanding increased harvest densities of MD can be beneficial for wildlife managers, allowing for more efficient allocation of efforts and expenses by managers for population management

    Phenology of Antler Casting and Occurrence of Late-Breeding in Nebraska White-Tailed Deer

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    White-tailed deer (Odocoileus virginianus) in Nebraska primarily breed in November (stimulated by photoperiod), but this season extends into December and January for unfertilized females and healthy fawns reaching the appropriate breeding weight by winter. Variation in the typical mating period can be attributed to geographic region, skewed sex ratios, and fawns reaching sexual maturity during their first year of birth. During April of 2019, we observed late season breeding by a male white-tailed deer in the central Platte River valley and documented late antler casting for this same late-copulating male. An additional male was observed in April of 2020 still retaining antlers within the region. To understand the irregularity of these observations relative to the central Platte River valley, we documented observations of early and late antler casting utilizing long-term cast antler collection and camera trap data. We were able to establish a baseline for antler casting phenology within this region to denote a shift in average casting timeframe (more than one month later than previously recorded in this region) and document early and the latest known antler casting within the literature. Herein, we detail the variation in antler casting phenology for white-tailed deer in this region, and the latest known occurrence of natural breeding in the state. Our findings help us better understand the life history of the Nebraska white-tailed deer population and can assist state wildlife biologists and property managers as they assess seasonal harvest regulations and adaptively manage the changing resource

    Genetic Analysis of the Henry Mountains Bison Herd

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    Wild American plains bison (Bison bison) populations virtually disappeared in the late 1800s, with some remnant animals retained in what would become Yellowstone National Park and on private ranches. Some of these private bison were intentionally crossbred with cattle for commercial purposes. This forced hybridization resulted in both mitochondrial and nuclear introgression of cattle genes into some of the extant bison genome. As the private populations grew, excess animals, along with their history of cattle genetics, provided founders for newly established public bison populations. Of the US public bison herds, only those in Yellowstone and Wind Cave National Parks (YNP and WCNP) appear to be free of detectable levels of cattle introgression. However, a small free-ranging population (~350 animals) exists on public land, along with domestic cattle, in the Henry Mountains (HM) of southern Utah. This isolated bison herd originated from a founder group translocated from YNP in the 1940s. Using genetic samples from 129 individuals, we examined the genetic status of the HM population and found no evidence of mitochondrial or nuclear introgression of cattle genes. This new information confirms it is highly unlikely for free-living bison to crossbreed with cattle, and this disease-free HM bison herd is valuable for the long-term conservation of the species. This bison herd is a subpopulation of the YNP/WCNP/HM metapopulation, within which it can contribute significantly to national efforts to restore the American plains bison to more of its native range

    Evaluating Elk Summer Resource Selection and Applications to Summer Range Habitat Management

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    In much of the west, National Forest lands are managed in part to provide and protect elk (Cervus elaphus) habitat needs, and summer elk habitat is managed with consideration to motorized routes. We evaluated the relative importance of nutritional resources, access routes and other landscape attributes on elk summer resource selection at multiple spatial scales.  Resource selection models for 9 different western Montana elk populations, as well are regional models using data from all 9 herds, were compared to determine the applicability of resource selection models for informing habitat management recommendations. We found thatin all populations nutritional resources, best represented using NDVI metrics, were the most important factors associated with elk summer resource selection. Access route disturbances, best represented by the density of all routes (i.e., routes open and closed to motorized use), affected resource selection in all populations, however, the influence of access routes was relatively small as compared to nutritional resources. Regional models of resource selection predicted resource selection across populations better than population-specific models, thus we recommend these types of models be used to inform regional habitat management. Our results suggest that managers should expand the current management paradigm for elk summer habitat to also consider nutritional resources as an important component of elk summer habitat. Time-integrated NDVI, an easily accessible and free data source, may be useful as an assessment tool to identify areas of optimal elk nutrition

    Testing a global standard for quantifying species recovery and assessing conservation impact.

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    Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard

    Challenges to Professional Accreditation of Forestry Degree Programs with Low Enrollments: The Utah State University Experience

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    As a result of its setting in the semi‐arid Intermountain West where forests are confined largely to montane environments, Utah State University (USU) has historically had relatively low undergraduate enrollments in forestry compared to other natural resource disciplines and compared to other institutions in the U.S. also offering a broad range of natural resource degrees. As a result of this history, coupled to the national trend over the past two decades of proportionally lower enrollments in forestry compared to other natural resource disciplines, undergraduate enrollment in forestry at USU currently constitutes less than 4% of total enrollments in natural resources. This situation makes it difficult to justify the offering of forestry courses and the hiring of faculty with forestry degrees, which in turn is a challenge to the maintenance of professional accreditation in forestry. Our response to this challenge has been to create a solid professional core of courses that is basic to the science and management of terrestrial ecosystems and is taught by faculty from a wide array of natural resource disciplines, coupled to a modest component of specialization in forestry in the third and fourth years of study. This approach, while perhaps disadvantageous from the standpoint of professional accreditation under current standards, provides our forestry majors with a broad background in the science and management of terrestrial ecosystems and in some ways anticipates current discussions at the national level regarding the accreditation of broader programs in natural resources

    Comparing Social Media Observations of Animals During a Solar Eclipse to Published Research

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    A wide variety of environmental stimuli can influence the behavior of animals including temperature, weather, light, lunar and seasonal cycles, seismic activity, as well as other perturbations to their circadian rhythm. Solar eclipses offer a unique opportunity to evaluate the relative influence of unexpected darkness on behavior of animals due to their sudden interference with local light levels and meteorology. Though occasionally bizarre, modern studies have lent support to the idea that at least some individuals of certain species display altered behavior during these events. A comparison of informal observations of animal behavior during solar eclipse from social media (i.e., March for Science Facebook discussion) to those conducted scientifically (published literature) can elucidate how well this topic is being covered. Describing which species and behaviors are covered in each source can reveal gaps in the literature which can emphasize areas for future research. We enumerated a total of 685 observations of approximately 48 different types of animals reacting to the 2017 Great American Solar Eclipse from over 800 posts on the discussion. The animals most frequently reported on social media as reacting to the eclipse were invertebrates (40% of social media observations) and birds (35% of social media observations). A total of 26 published studies recorded 169 behavior observations of approximately 131 different animal species. The group with the highest number of observations in the literature were birds with 62 records (37% of literature observations). Most observations reported decreases in activity (38.7% of bird observations) followed by increases in vocalization (24.2% of bird observations). There were approximately 30 different species of invertebrate observed (24% of literature observations), most frequently reported of which were zooplankton (14.6% of invertebrate observations)

    Black Bear Activity and Visitation Patterns at Human Food Sources in Utah

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    ABSTRACT Bear activity and behaviors in areas of human use or proximity require research because of significant and potentially dangerous conflicts between humans and bears. Previous studies in areas of the country outside of Utah determined that black bears (Ursus americanus) tend to exhibit diurnal or crepuscular activity patterns. Activity patterns, however, may be influenced by humans, especially in urbanized landscapes or in areas such as campgrounds where anthropogenic food resources are available. Our study objectives were to determine bear activity schedules and changes in visitation patterns to regularly supplied anthropogenic food sites in the La Sal Mountains of southeastern Utah. Using remote camera stations, we determined that bear visitation was primarily crepuscular and nocturnal (76.3% of visits), and bears did not visit freshly provisioned sites more quickly or more frequently through time. Although bear activity is different by region, provisioning food may not alter bear activity at supplemental feeding sites
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