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A Bear's Eye View: Insight on American Black Bear (Ursus americanus) Hibernation and Foraging Ecology in Virginia's Central Appalachian MountainsHolcombe, Brogan Elizabeth 07 June 2024 (has links)
Following mass agricultural expansion and deforestation in the late 1800s and early 1900s, American black bear populations (Ursus americanus, hereafter black bear) were low across most of Virginia. The Department of Wildlife Resources (VADWR) and the United States Forest Service worked to rebuild wildlife habitat in the state, leading to recovery of bears. While some aspects of black bear hibernation and foraging ecology have been studied, there remain knowledge gaps on key aspects of black bear biology. Hibernation behavior, for example, is understudied with most knowledge stemming from post-hibernation emergence studies. We used a unique dataset with continuous monitoring of mother bears and their cubs from Virginia Tech's Black Bear Research Center in 2015-2016, to better understand hibernation ecology, mother-cub dynamics, and biological-foster cub dynamics. We found that increased black bear activity levels were driven by both higher temperature and photoperiod, but the onset of hibernation was primarily driven by only temperature. Temperature is projected to rise in VA and rising temperatures regionally could be responsible for increased active behaviors in bears, which could lead to increased human-black bear interactions on the landscape, especially during hibernation onset. We also found that mother bears spend similar amounts of time with biological and foster cubs. Biological cubs did not show more dominance behaviors toward fosters than biological siblings, which we also observed with foster, where they did not continuously display these behaviors towards biological cubs. These results are promising for orphan cub fostering programs in VA and other states and indicate that foster cub litter integration can be successful.
Foraging ecology also is challenging to study in black bears because direct observation is generally not possible due to their cryptic nature, closed habitat, or potential danger in observing. We used a dataset from camera collars deployed on 15 bears (8 males, 7 females) in Bath County Virginia in 2018 and 2019 to better understand diet seasonality and to determine habitat and environmental drivers of black bear foraging patterns, particularly on white-tailed deer (Odocoileus virginianus) and invasive plant species. We identified 178 unique diet items to family, genus, or species in videos, much higher numbers than previously reported in the literature, and we found high diet overlap between sexes. Diet composition was primarily influenced by season with higher levels of consumption of herbaceous soft mast in spring, fruit and seed soft mast in summer, and hard mast in fall. Females exhibited more hunting events on deer fawns in spring than males, but males and females consumed similar numbers (28 vs. 24, respectively) via hunting and scavenging combined. Males consumed anthropogenic foods more often than females, particularly when closer to human settlements and males more commonly consumed invasive plant species in spring while females more often consumed insect in spring invasive species in summer. Our results highlight strong seasonally- and subtle sex-mediated differences in black bear diets. We provide information on drivers of diet choices by bears, as well as identify where foraging hotspots on species of interest occur, providing information useful to VADWR in managing increased human-wildlife interactions (and mitigating potential for negative interactions), predator-prey relations, and invasive species spread across the landscape. / Master of Science / American black bears were almost eliminated from Virginia following mass agricultural expansion and deforestation in the late 1800s and early 1900s. The Department of Wildlife Resources (VADWR) and the United States Forest Service worked to rebuild wildlife habitat in the state, leading to recent recovery of bears in VA. However, there are still gaps in our knowledge of black bear ecology and gaining new knowledge will aid in better management of black bears across the state. We used two unique video data sets to study hibernation and foraging (or feeding) ecology to fill important knowledge gaps. To study hibernation behavior, we used a video data set of continuously monitored, temporarily captive mother bears and their cubs held at Virginia Tech's Black Bear Research Center in 2015-2016. We found that black bear activity was driven by both daily temperature and photoperiod (length of daylight), but onset of hibernation was mostly driven by temperature only. With Virginia projected to experience rising, and more variable, temperatures due to climate change, this may mean that bears will stay longer on the landscape in fall, even past the point where vegetation (food) has gone dormant, potentially leading to increased human-black bear interactions as bears seek human foods. We also examined mother-cub interactions and found mother bears did not spend more time with their biological cubs than their fosters (fosters are orphaned black bear cubs arising due to death of mothers) and biological cubs did not show more dominance behaviors (i.e., biting, chasing, or pinning to ground) toward fosters than biological siblings. These are positive results for VADWR's surrogate sow program across the state.
Foraging ecology is difficult to study in black bears because direct observation is generally not possible due to their secretive nature, dense habitat, or potential danger in observing. Therefore, traditionally, many studies collect and examine scat (fecal) samples or stomach contents from harvested bears, but these methods may not find diet items that are quickly digested. We used a unique dataset from video camera collars placed on 15 bears in Bath County Virginia in 2018 and 2019. We found some important differences from the literature - our spring diets had higher proportions of deer and soft vegetation (leaves), however the unknown diet items in the literature were high, leading to incomplete or incorrect diet profiles. Diet composition was primarily influenced by season with higher levels of consumption of leafy soft mast in spring, fruit and seed soft mast in summer, and hard mast in fall. Males and females had high dietary overlap and we found that females had more hunting events on deer fawns in spring than males, but overall males and females consumed similar numbers (28 vs. 24, respectively) via hunting and scavenging combined. Males more often consumed human foods than females, while females more often consumed insect species than males. Also, males more commonly consumed invasive species in spring, while females did so in summer. Our results highlight differences in diet content caused by season and subtle differences in diets between sexes. We provide information on drivers of feeding choices bears make and we identify foraging hotspots for deer and invasive species, information useful to VADWR in managing potential human-wildlife interactions, predator-prey relations, and invasive species spread across the landscape.
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Using stable isotope analysis to estimate black bear (Ursus americanus) diet in VermontDykstra, Eliese Antona 01 January 2015 (has links)
The black bear (Ursus americanus) is an iconic species with cultural, economic and ecological importance in Vermont, USA. Bears exhibit a highly variable diet, and few studies have described bear diet in the state. Information on diet may provide insight into foraging behavior, thus allowing managers to better assess patterns of human-bear conflict. My objectives were to estimate the relative contribution of food items to bear diet and how factors including sex, habitat, food availability, and nuisance status describe patterns of consumption. I collected samples from bears and major food groups including C3 plants, white-tailed deer (Odocoileus virginianus), corn (Zea mays), and human foods, then quantified diet using stable isotope analysis. Samples were collected from 71 bears, 547 plants, and 38 deer throughout Vermont. I also collected 12 corn samples, and 20 human hair samples to represent anthropogenic foods. I determined δ13C and δ15N isotope values for all samples, then used Bayesian mixing models to estimate the contribution of foods and effect of each factor on proportional contribution estimates. Nuisance status best described patterns of diet over other factors. Median percent contributions for non-nuisance bears were 73.2% C3 plants, 23.8% corn, 1.9% human foods, and 0.5% deer. Median percent contributions for nuisance bears were 64.6% C3 plants, 28.9% corn, 3.2% human foods, and 0.7% deer. Factors such as sex, habitat, and food availability exerted less effect on diet than expected. Proportional contribution of meat was lower than in some other parts of North America, suggesting bears forage differently in Vermont. Results provide the first statewide estimate of bear diet and indicate corn may represent a much larger component of diet than previously thought. In particular, bears labeled as nuisance animals may forage on greater proportions of corn throughout the year.
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Analytical And Decision Tools For Wildlife Population And Habitat ManagementRinehart, Kurt 01 January 2015 (has links)
The long-term success of wildlife conservation depends on maximizing the benefits of limited funds and data in pursuit of population and habitat objectives. The ultimate currency for wildlife management is progress toward long-term preservation of ample, wild, free wildlife populations and to this end, funds must be wisely spent and maximal use made from limited data.
Through simulation-based analyses, I evaluated the efficacy of various models for estimating population abundance from harvest data. Because managers have different estimators to choose from and can also elect to collect additional data, I compared the statistical performance of different estimation strategies (estimator + dataset) relative to the financial cost of data collection. I also performed a value of information analysis to measure the impact that different strategies have on a representative harvest management decision. The latter analysis is not based on the cost of data, but rather on the management benefit derived from basing decisions on different datasets.
Finally, I developed a hybrid modeling framework for mapping habitat quality or suitability. This framework makes efficient use of expert opinion and empirical validation data in a single, updatable statistical structure. I illustrate this method by applying it across an entire state.
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Pojetí druhu u medvědovitých (Ursidae): praktická, historická a teoretická perspektiva / Concept of species in bears (Ursidae): practical, historical, and theoretical viewpointWagner, Jan January 2012 (has links)
The present thesis surveys topic of taxonomic diversity and phylogeny of bears (Mammalia, Ursidae) and aspects of its contextual setting under effects of changing conceptual and methodological viewpoints. This problem is studied from several perspectives. The historical perspective is represented by a critical overview of the history of specific and infraspecific classification of bears with special respect to mutual influences of this classification and theoretical concepts of species accepted in particular periods. The perspective of material approach is exemplified by a material-based study of taxonomical and phyletic status of selected Pliocene to Middle Pleistocene ursine taxa. Along with deconstruction of some traditional hypotheses this produced a model explaining species diversification in ursine bears and its discussion in terms of factual relevance of included background concepts. In the pre-evolutionary period the bear species were usually understood broadly, as incipient immanent entities, yet exhibiting obvious certain infraspecific variability. This was established using definitions of varieties (mostly not identifiable with present subspecies or infraspecific taxa) considered as unstable modes of particular species. Although, in the post-Darwinian period, the concept and taxonomic...
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Camera Trapping Large Mammals In Yenice Forest Habitats: A Feasibility Study For Camera Trapping Large Mammals In Yenice Forests, TurkeyCan, Ozgun Emre 01 September 2008 (has links) (PDF)
Widely applicable, quantitative field methods are needed to gather wildlife data for conservation and management initiatives in Turkey. In order to evaluate the use of camera traps in forest habitats of Turkey, we conducted a 5 phase camera trap survey by using 16 passive infrared-triggered cameras with a total sampling effort of 1200 camera trap days in Yaylacik Research Forest, a 50 km2 forest patch of Yenice Forest in Karabü / k during January-May 2006.
The camera trap survey confirmed the presence of grey wolf (Canis lupus), brown bear (Ursus arctos), wildcat (Felis silvestris), red fox (Vulpes vulpes), badger (Meles meles), pine marten (Martes martes), roe deer (Capreolus capreolus) and wild boar (Sus scrofa) in the study area. The camera trap survey also revealed the presence of jackal (Canis aureus) and brown hare (Lepus europaeus), whose presence were not known by people living and working in the area. Contrary to the local belief, neither camera trapping survey nor ground survey confirmed the presence of lynx (Lynx lynx) in Yaylacik Research Forest.
The wolf was observed to be crepuscular and the wildcat showed a diurnal activity pattern. Wildcat seemed to avoid other carnivores spatially and temporally. Simulation studies suggested that camera trap surveys should last 14 days for wolf, 13 days for wildcat, 10 days for pine marten, and 11 days for roe deer, while it is advisable to conduct longer surveys, probably 15-20 days, for wild boar, red fox and brown bears.
The estimated population size for wildcat was 9 (SE=2.28227) with 95% confidence interval of 9 to 25 in the study area. A minimum of 6 brown bears were present in the study area.
Our study indicated that the local knowledge about the presence of wildlife should be considered by researchers, but it cannot replace scientific surveys conducted by field biologists.
This study was the first attempt to assess the presence, relative abundance, activity patterns and diversity of multiple mammal species by the use of camera trapping methodology in Turkey. The results suggest that camera trap surveys have the potential for gathering wildlife data at larger scales in Turkey, where information gap on large mammals is an obstacle for effective management and conservation of mammals.
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Measuring wildlife response to seismic lines to inform land use planning decisions in northwest CanadaTigner, D Jesse Unknown Date
No description available.
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Foraging ecology of brown bears in the Mackenzie Delta region, NWTBarker, Oliver Unknown Date
No description available.
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Foraging ecology of brown bears in the Mackenzie Delta region, NWTBarker, Oliver 06 1900 (has links)
The Mackenzie Delta region, NWT, has a short growing season and highly seasonal climate, and brown bears (Ursus arctos) there face many challenges obtaining their nutritional requirements. Consumption of meat by brown bears is linked to increases in population density, fecundity, growth and body size. I examined the use of Arctic ground squirrels (Urocitellus parryii), and broad whitefish (Coregonus nasus) as meat sources by Mackenzie Delta brown bears. As a preliminary step, I built an Arctic ground squirrel habitat model, using field-surveyed ground squirrel burrow locations. Using this model, I examined bears selection for Arctic ground squirrel habitat as a population, by sex and as individuals, and linked this to results of stable isotope analysis and site investigations. Bears showed little evidence of Arctic ground squirrel use at the population and sex level, but some individual bears appeared to prey heavily on ground squirrels, particularly during hyperphagia. I also described observations of a brown bear using broad whitefish in autumn, and used telemetry locations to show that other bears may also feed heavily on broad whitefish during hyperphagia. My research provides prey-specific evidence for intrapopulation niche variation among Mackenzie Delta brown bears. / Ecology
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American Black Bears (Ursus americanus) of the Paunsaugunt Plateau: Movements and Habitat UseDungan, Rebekah Adriana Castro 02 December 2019 (has links)
Concerns over human-bear conflict and questions about the ecology of Paunsaugunt Plateau's population of black bears (Ursus americanus) arose due to their visitation to popular recreation sites. Greater insight about bears and their habitat use provides a foundation for conflict mitigation and effective management decisions. Between 2014 and 2017, seventeen black bears (11 female, 6 male) were fitted with global positioning system (GPS) radio-collars so that we could track their locations, daily activity patterns, and ambient temperatures. By analyzing bear locations, we calculated annual and seasonal home ranges for 16 bears, including 25 den sites. Home ranges typically consisted of three dominant vegetation types, Utah juniper, ponderosa pine and Douglas fir. I used mixed effects models to better understand den site selection and found that slope (27.87 ± 2.03) was the most significant factor (p < 0.001). I also used mixed effects models to understand black bear selection of annual and seasonal home ranges. Predictor variables with the greatest effect (p < 0.001) were elevation (2419.99 ± 1.35) and aspect (138.44 ± 0.64), with coefficients of 1.128 and -1.483 respectively. Male annual home ranges (327.20 km2 ± 133.58 km2) were significantly larger (p = 0.035) than female home ranges (175.10 km2 ± 55.37 km2). However, annual home ranges for both sexes were larger than those during hyperphagia (p = 0.003) or mating (p = 0.004) seasonal home ranges, between which there was no difference (p = 0.451). Individual home ranges overlapped for most bears, consistent with their non-territorial nature. I found that bears avoided roads and lower elevations, while showing a preference for sloping terrain throughout the non-denning period. Paunsaugunt black bear home ranges are larger than any other black bear home ranges reported in literature. We determined weekly average distances and directions for all bears. For two bears, one male and one female, we determined daily averages and directions. Nine bears provided daily averages for 12 seasonal units across all four years. Activity patterns indicate the typical crepuscular pattern noted in normal bear populations that lack human habituation. Identifying areas core use areas and potential den sites is helpful to understanding black bear ecology and useful when making decisions about how to plan infrastructure and educate the public. This research indicates that Paunsaugunt black bears avoid human activity; however, we need continued research to help determine specific interactions between bears and anthropomorphic influences.
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Post-Den Emergence Behavior and Den Detection of Polar Bears (<em>Ursus maritimus</em>) in Northern Alaska and the Southern Beaufort SeaRobinson, Rusty Wade 01 March 2014 (has links) (PDF)
Pregnant polar bears (Ursus maritimus) construct maternal dens out of snow in the autumn where they give birth to and raise altricial young. In recent years, there has been a decrease in polar sea ice extent and thickness, which has led to changes in denning behavior. One such change in the southern Beaufort Sea (SBS) is that polar bears are selecting maternal den sites on land, rather than on unstable sea ice. This change, coupled with expanding petroleum exploration along Alaska's North Slope, heightens the likelihood of bear-human interactions at maternal den sites. The purpose of this research was to 1) describe polar bears' post-den emergence behavior, establishing a benchmark for comparison to identify behavioral changes associated with climate change and disturbance, and 2) explore factors influencing the efficacy of a currently used den detection method, forward-looking infrared (FLIR). Maternal den sites were observed along Alaska's North Slope from March to April of 2009 and 2010. The mean length of stay at den sites post-emergence was 11.3 ± 7.5 d. The mean date of den emergence was 14 March; abandonment 26 March. Adult females were generally inactive (58.4% out-of-den time) with standing being the most prevalent activity (49.9%). Cubs were generally active (76.7%), playing more than any other activity (45.3%). Bears spent the majority of their time in the den (97.3% for adult females and 99% for cubs) with short bouts of intermittent activity (× = 7 min 42 s). We documented the death of one member of a triplet polar bear litter at its den site. All three cubs showed low activity levels relative to other cubs observed, and one died within one week of den emergence. Necropsy confirmed that the dead cub had a low body weight and was malnourished. Capture later confirmed that the two surviving cubs were also undersized. Triplet litters are often smaller and suffer higher mortality rates than singletons and twins. This cub was not only a triplet but also born following 2 y of record minimum sea ice extent, both of which may have played a role in this cub's death. Concurrent with the den emergence portion of this work, we conducted a separate study to identify limitations and optimal conditions for locating dens using FLIR. We took handheld FLIR images of three artificial dens under varied conditions. We tested variables hypothesized to influence detectability with linear models using a zero-inflated negative binomial distribution. Solar radiation, wind speed, and den wall thickness reduced the likelihood of detecting dens. The negative effect of wind speed on detectability increased with increasing distance. To maximize the efficacy of hand-held FLIR, den surveys should be conducted when solar radiation is <16 w/m2 (night) and when wind speed is <10 km/h (6 mph). Adherence to these guidelines will maximize the protection FLIR can afford to denning bears.
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