Tesi sul tema "Betar (Poland)"

Polar bears spend the majority of their lives on the sea ice, where they gain access to seals and mates. In western Hudson Bay, the sea ice melts for three to four months in the summer, and polar bears there are forced onto land. These bears live on their fat reserves for the duration of the iceless period, until temperatures get colder in the fall and freeze up begins. The aggregation of polar bears near Churchill, Manitoba during the ice free period has led to a thriving tourist industry, with a large influx of tourists visiting Churchill in the fall in a six to eight week period, yet little is known about the impacts of this industry on the biology of the bears. This study investigated the effect of tourist vehicles and human presence on the behavior of polar bears over the fall of 2003 and 2004. Overall time budgets were estimated for bears, and the behavior of males and females was compared. Females spent significantly less time lying and more time in locomotion than males. Time budgets were also estimated for bears in the presence and absence of tourist vehicles. Bears spent less time lying and more time in a sit/stand position in the presence of vehicles. Air temperature had no significant effect on the time budgets of polar bears. Tundra vehicle approaches were manipulated to determine effects on polar bear behavior, and to investigate any variables that significantly affected response, including habituation. A response was defined as any sudden whole body movement or change in position or behavior at the time of approach. A total of 25% of all bears responded to the experimental vehicle approach. For bears that responded to approach, the average distance at response was 43 m. The average speed of the vehicle was 0.66 ± 0.02 m/s (range 0.23 to 1.15 m/s). Approach variables that significantly influenced the likelihood of response of a bear to an approaching vehicle included angle of approach and vehicle speed. Direct approaches, in which the bear was in the path of the moving vehicle, had a higher probability of eliciting a response than indirect approaches, in which the vehicle stayed to one side of the bear at all times. Higher speeds of the vehicle increased the probability of a response by a bear. Behaviors of the bear that significantly predicted a response were shifting of the body and smacking of the lips. A playback study was conducted to determine the effects of human induced sound on polar bears. There was no significant effect of human sound on polar bears. Results presented here provide the first experimental evidence of variables in the tourist industry that affect polar bear behavior, and the first evidence of behavioral cues predicting a response to vehicle approach.
M.S.
Department of Biology
Arts and Sciences
Biology

The purpose of this thesis research was to examine the dynamic relationship between climate change and tourism, with a direct focus on Churchill, Manitoba’s polar bear viewing industry. This unique tourism industry and the polar bears it depends on, are experiencing the negative effects of climate change due to warmer temperatures and melting sea ice, which significantly impacts the health, appearance, and prevalence of polar bears on display for tourists. Not only is this tourism industry affected by climate change, it also contributes to the ongoing changes of climatic conditions. This is due to the dependence of fossil fuel energy used for transportation, accommodation, and activities which directly contributes to the release of greenhouse gas emissions and thus to global climate change. Emissions from tourism has increased by 3% over the last 10 years, largely as a result of the accessibility and affordability of air travel, the most energy intensive form of transportation (Lenzen et al., 2018; UNWTO-UNEP-WMO, 2008). It has been suggested that in response to the increase in the demand to travel, the tourism industry should take a leadership role to reduce their total greenhouse gas emissions in an effort to decrease the impact of climate change. In this study, a visitor survey was conducted during four weeks of Churchill’s 2018 polar bear viewing season (October 16 to November 16). The aim of the survey was to: 1) estimate greenhouse gas emissions from polar bear viewing tourists and the polar bear viewing industry; 2) identify tourists’ awareness of the impacts of climate change (to and from tourism activities); 3) understand tourist’s climate-related travel motivations, and 4) identify tourists’ opinions on climate change mitigation strategies. Visitor surveys were hand- distributed at the Churchill Northern Studies Centre and at the Churchill Airport to tourists who had participated on a polar bear viewing tour. Surveys were analyzed and compared with the results from similar studies (Dawson et al., 2010 and Groulx, 2015) to identify the changing trends in greenhouse gas emissions, travel motivations, tourists’ knowledge of climate change, and acceptance of climate change mitigation strategies. Similar to trends observed 10 years ago, emissions from polar bear viewing tourists are 3-34 times higher than the average global tourist experience. Tourists’ awareness about climate change has stayed relatively consistent, despite the topic of climate change having received increased attention globally. Tourists recognize that climate change is happening and that it is human induced however, there is still a lack of understanding of how air travel is a contributor to climatic change. Although briefly mentioned in some participant’s responses, the main motivation was not to see a polar bear before it disappeared from the wild. The majority of tourists identified they were traveling to Churchill simply for the opportunity to see a polar bear. Additional motivators were photography, the Northern Lights, and for the opportunity to see other Arctic animals. The climate change mitigation strategies that tourists believed to be the most effective to reduce emissions were educational programs and transportation alternatives (such as taking the train- which was not an option at the time of study due to a rail line shutdown). This research contributes to the existing knowledge about tourism and climate change and provides a current analysis of Churchill’s polar bear viewing industry, enabling a comparison between findings from another study conducted over ten years ago. This research also makes conclusions about climate change mitigation strategies that might be effective for Churchill’s tourism industry to reduce their impact on the environment.

One of the main attractions for tourists visiting Svalbard, Norway, are polar bears. The polar bear is a vulnerable species, dependent on sea ice to survive as this is where they hunt, wander and raise their cubs. Ship-based tourism poses a number of threats mainly due to the disturbances caused by the presence of ships, damage of critical habitats and the increasing interactions and deadly conflicts between humans and polar bears. Appropriate and effective legislation based on scientific knowledge of the impacts of ship-based tourism on polar bears is necessary to ensure sustainable tourism and environmental protection. Species protection and habitat conservation is not an issue isolated to Svalbard or the polar bears but rather just one part of the pressing global issue concerning loss of biodiversity, which is one of the greatest threats to humankind. The Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention) aims to ensure the conservation of wild flora and fauna species and their habitats. At the time of signing, the Norwegian Government excluded Svalbard from the application of the Bern Convention, ensuring that national conservation policies for Svalbard would be promoted. The Svalbard Environmental Protection Act is the main act regulating environmental protection on Svalbard, including both general principles and specific provisions regarding species and habitat protection. This paper explores the various needs of the polar bear population in Svalbard and the impacts caused by ship-based tourism. The Bern Convention’s provisions relating to the identified threats posed by ship-based tourism are examined and compared with the corresponding provisions in the Svalbard Environmental Protection Act. Moreover, this paper analyses the potential benefits that could arise from the application of the Bern Convention to the Svalbard territory. This paper concludes that the protection of the polar bears could, de jure, be strengthened by the Bern Convention, mainly due to the extensive interpretation of the types of activities that should be prohibited by signatory states. However, the Bern Convention can only be enforced by non-binding mechanisms and it is therefore unlikely that the application of the convention would lead to stronger protection of the polar bears than that which is provided by national legislation. The protection of the polar bear from threats caused by ship-based tourism would therefore, de facto, most likely not be strengthened by the application of the Bern Convention.

Loss of sea ice due to global warming may affect the phenology and distribution of polar bear (Ursus maritimus) denning by altering access to denning habitats. We examined trends in the selection of maternal denning substrate (land versus sea-ice denning) in the southern Beaufort Sea (SB), addressing the potential influence of summer land-use and fall sea-ice conditions on substrate selection. We developed an algorithm based on statistical process control methods to remotely identify denning bears and estimate denning phenology from temperature sensor data collected on collars deployed 1985–2013 in the SB and Chukchi Sea (CS). We evaluated cub survival relative to den entrance, emergence, and duration, and examined differences in the phenology of land and sea-ice dens. Land denning in the SB was more common during years when ice retreated farther from the coast and off of the continental shelf in September. All SB bears that occupied land prior to denning subsequently denned on land; however, only 29% of denning bears that summered on sea ice denned on land. Den entrance and duration in the SB and CS were similar, although CS bears emerged later. Land dens were occupied longer than those on ice. Bears later observed with cubs remained in dens 23 days longer and emerged from denning 17 days later on average than bears that denned but were subsequently observed without cubs, suggesting that den exit dates are related to cub survival. The increase in land-based denning in the SB when sea ice retreated farther from shore, along with the positive correlation between fall land-use and land denning, suggest that further sea-ice declines may result in continued increases of onshore denning. Growing numbers of denning females along the coast may increase the potential for human-bear interactions.

Human-bear interactions are an important consideration of bear biology, as interactions can lead to destruction of property as well as injury or death for both human and bear. Successful analysis of why these interactions occur can lead to appropriate preventative measures and mitigation of further conflict. Bryce Canyon National Park (BRCA) is comprised of relatively poor bear habitat, but a black bear population exists on the Paunsaugunt Plateau, on which the park occupies the eastern edge. Park managers expressed interest in learning more about bear movements and, specifically, bear use of anthropogenic features following a number of human-bear incidents located at backcountry campsites within park boundaries. By analyzing data from GPS radio-collared bears, trail cameras, existing literature, park incident reports and in-depth campsite assessments, we were able to show how bears are using both natural and anthropogenic features on the Bryce landscape. Campsites were assessed for bear habitat, displacement and encounter potential in order to establish an overall human-bear conflict potential. AIC model selection and resource selection functions using GPS collar data showed that bears selected for some anthropogenic features (campsites, springs), while actively avoiding others (trails, roads). Trail camera data, existing literature and park incident reports all pointed toward use of trails. We then considered all data sources used in the analysis and compiled rankings of human-bear conflict potential for each of the backcountry campsites within BRCA, and submitted a detailed report of findings, conclusions and recommendations to NPS personnel. Second, we investigated human-bear interactions at polar bear dens sites on Alaska's North Slope. As parturient female polar bears in the Southern Beaufort Sea subpopulation increasingly construct maternal dens on coastal land features rather than sea ice, they become more likely to interact with industry and other human activity. We wanted to understand what levels of human interaction could lead to disturbance of denning polar bears, and what types of responses were being exhibited by bears following those interactions. We subdivided potential disturbance stimuli into groups based on their size, motion and sound and the used AIC model selection techniques and multinomial logistic regression to analyze records of human-bear interactions at den sites ranging from 1975 through the present day. We found significant probabilities of varying levels of bear disturbance response among a number of stimuli and intensities. However, denning bear families were overall more tolerant of human activity near den sites than expected. Den abandonments were rare, and we documented no cases of reproductive failure following a disturbance event. We hope that our results from the analysis can be used to further enhance management of industry when operating in polar bear denning habitat.

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.

In this thesis, a critical analysis is proposed of the relationships between Inuit participation, science and policy in wildlife governance in the Nunavut Territory, Canada. This analysis situates the emergence of a participatory regime for the governance of wildlife in Nunavut, explores its performance and examines the relations between the ways in which wildlife governance arrangements are currently represented in policy and how they are played out in practice across the territory. To pursue these objectives, this research draws upon a number of theoretical perspectives and methodological strategies poised at a crossroads between environmental geography, science and technology studies, political ecology and ecological anthropology. It combines participant observation, semi-directed interviews and literature-based searches with approaches to the study of actor-networks, hybrid forums and scientific practices associated with Latour and Callon, as well as with Foucauldian and post-Foucauldian analyses of power, governmentality and subjectivity. This analysis suggests that the overall rationale within which wildlife governance operates in Nunavut remains largely based on a scientific and bureaucratic framework of resource management that poses significant barriers to the meaningful inclusion of Inuit views. In spite of their participation in wildlife governance through a range of institutional arrangements, consultation practices and research initiatives, the Inuit of Nunavut remain critical of the power relations embedded within existing schemes, where significant decision-making authority remains under the control of the territorial (or federal) government, and where asymmetries persist with regard to the capacity of various actors to produce and mediate their claims. In addition, while the use of Inuit knowledge, or Inuit Qaujimajatuqangit, in wildlife governance in Nunavut has produced some collaborative research and management endeavours, it has also crystallised a divide between ‘Inuit’ and ‘scientific’ knowledge, generated unresolved conflicts, fuelled mistrust among wildlife co-management partners and led to an overall limited inclusion of Inuit observations, values and beliefs in decision-making.

Accumulation of dynamic and thermodynamic forces in the Arctic are decreasing the extent of thin annual sea ice which polar bear rely on for survival. It is imperative that we identify the preferred habitat of polar bears to fully understand their future requirements. In this thesis, surveys of polar bear tracks and the surrounding sea ice variables, at various scales, were recorded. Sea ice roughness was measured through surveys of the sample area in situ, with an electromagnetic induction (EM) system (IcePIC) mounted to a helicopter, and analyzed through advanced synthetic aperture radar (ASAR) images of the study area. In situ Polar bear tracks provided a limited association with the EM sea ice roughness and a negative association to ASAR sea ice roughness. Results indicate a significant association between EM mean values and ASAR brightness means. In addition, EM statistics and ASAR texture statistics were correlated through a best fit regression model. These associations display a remote method to identify preferred polar bear habitat and provide a potential linkage between the regional (EM) and remotely sensed (ASAR) assessment of sea ice roughness.
October 2008

Recent research indicates climate change will be amplified in Polar Regions, which will cause decreases to sea ice thickness and extent throughout the Arctic. Polar bears (Ursus maritimus) will be directly affected by changes to Arctic sea ice conditions because they rely on the ice substrate for numerous aspects of their life history. Perhaps of most importance, polar bears use the sea ice platform to access their main prey, pagophilic seals. Determining specific effects of climate-induced environmental change on polar bears will require monitoring at numerous spatiotemporal scales and across various levels of biological organization. In this dissertation I used and refined a variety of ecological monitoring tools that evaluated the effects of seasonal and longer-term unidirectional sea ice changes to various aspects of polar bear ecology. At a molecular level, I used urea to creatinine ratios in polar bear blood to show that an increased number of polar bears were in a physiological fasting state during spring captures in 2005-2006 compared to the mid-1980s. These changes corresponded to broad-scale changes in Arctic sea ice composition, which may have altered prey availability. I also used measurements of naturally occurring stable isotopes (δ13C, δ15N) in polar bear tissues to examine their diet, which included both lipid-rich blubber and the proteinaceous tissues of their marine mammal prey. Because the proportion of proteins and lipids consumed likely depended on prey type and size, it was necessary to consider metabolic routing of these macromolecules separately when using isotope mixing models to determine and monitor polar bear diet. I also monitored polar bear movement and migration behaviour at the population level. Specific landscape sea ice metrics corresponded to seasonal population migration patterns and fidelity to particular geographic regions. Trends in the timing of these seasonal population migration patterns were likely associated with climate-induced changes to sea ice dynamics. Finally, I examined migration behaviour in relation to local sea ice dynamics in individual polar bears and demonstrated a mechanistic understanding of the relationship between sea ice and polar bear migration patterns.
Ecology

Inuit estimates of polar bear characteristics from tracks could complement ongoing capture-mark-recapture methods to frequently monitor polar bear populations in response to climate-induced habitat changes. Before the inclusion of these Inuit track estimates, they need to be evaluated for reliability and accuracy. Building on previous work, which showed increased reliability among active Inuit hunters, this thesis research reports i) reliability in estimates of sex, age, size, and age of track of a larger number of tracks by a larger number of Inuit hunters; ii) preliminary accuracy assessments of sex and size estimates; iii) semi-structured interviews with Inuit hunters regarding their polar bear tracking experience and techniques; and iv) potential relations between Inuit hunting experience and reliability and accuracy in diagnosing tracks. The Inuit hunters were reliable and consistent as a group in making estimates of sex (α=0.74 and mean corrected item-total correlation=0.45), age (α=0.81 and mean corrected item-total correlation=0.63), and size (α=0.91 and mean corrected item-total correlation=0.73), as well as age of track estimates with the exclusion of a single participant (α=0.85 and mean corrected item-total correlation=0.63). Preliminary accuracy assessments suggest Inuit hunters are generally accurate in their estimates of sex (mean 65.28% agreement with genetic sex estimates) and potentially size from tracks, warranting further efforts to determine accuracy in these estimates as well as age and age of track. Semi-structured, open-ended interviews with each hunter revealed they use similar tracking techniques, which may explain their high agreement in making estimates. In addition, Inuit tracking experience and the use of particular tracking methods may correlate with individual reliability and accuracy in track diagnoses. These results suggest the information that Inuit hunters provide may inform any tracking-based polar bear survey.
Thesis (Master, Biology) -- Queen's University, 2010-08-15 13:06:07.948

This dissertation attempts to improve the understanding of spatial distribution and evolution of snow-covered sea ice as related to polar bear habitat. This will be accomplished at both the local (i.e. 1m spatial resolution) and regional scales (i.e. 100 km spatial resolution) for various types of first-year sea ice (FYI) through four primary objectives. The first primary objective (i.e. Chapter 3) examines the observed and modeled temporal evolution of snow over smooth FYI, as well as the estimation of on-ice meteorological conditions. Results suggest that increases in observed snowdrifts and changes to the orientation of the drifts are related to snowfall and drifting events. Modeling these changes over time using a spatially distributed snow model is not able to accurately estimate the snow distribution. As well, only the on-ice temperature and humidity can be estimated from land-based station data, limiting the modeling of snow over sea ice. The second primary objective (i.e. Chapter 4) extends this research to rough FYI types, more relevant to polar bear habitat. More specifically this objective studies the spatial pattern of snow distribution over rough ice and ridges and the relationship between ice roughness and meteorological conditions. Results suggest that ice roughness influences the magnitude of snow depth, while the wind direction during periods of snow deposition and/or blowing snow events will impact the spatial pattern. The third primary objective (i.e. Chapter 5) focuses on developing a more feasible method of deriving surface roughness. This objective attempts to use satellite imagery and texture analysis to derive surface roughness for snow-covered sea ice. Results suggest that a Gamma speckle reduction filter, coupled with a grey-level co-occurrence matrix texture measure (Entropy or Angular Second Moment) is able to account for more than 88% of the variability in the surface roughness. The final primary objective (i.e. Chapter 6) examines the temporal evolution and factors controlling the changes in sea ice characteristics over regional scale for a period from 1978 to 2002. Observed anomalies in sea ice characteristics within some of the polar bear subpopulations may be explained by thermodynamic and/or dynamic factors. Results suggest that published reduction in polar bear population and condition within the subpopulations co-occur with these observed changes in sea ice characteristics.

The intent of this practicum is to improve pedestrian access in and around Churchill. Challenges and causes for rational fear in the landscape were identified and paths and mechanisms were designed to mitigate these concerns. The purpose is to make the landscape a more welcoming place that can be enjoyed and celebrated by a wider range of users.

Human-caused ecological change negatively affects the sustainability of many wildlife populations but may be especially challenging for large carnivores and ungulates. Long-term physiological stress may be an important mechanism linking ecological change with impaired health and reduced population performance in these groups. The determination of hair cortisol concentration (HCC) has recently demonstrated potential as a biomarker of long-term stress in humans and domestic animals, and may also represent a practical technique for use in free-ranging wildlife. The objectives of this research program were to: 1) develop and apply an accurate and reliable method for measuring cortisol levels in hair collected opportunistically or remotely from free-ranging grizzly bears (Ursus arctos), polar bears (Ursus maritimus), and caribou (Rangifer tarandus sp.), and 2) to evaluate the utility of HCC as a biomarker of long-term stress (and thus potentially useful conservation tool) in these threatened species. An enzyme-immunoassay (EIA) based technique for measuring HCC in non-human primates was successfully modified for use with small quantities (5-100 mg) of hair representative of samples which may be obtained through opportunistic (e.g. hunting, research captures, archives) or remote (e.g. barb wire snagging) methods in each species. HCC was determined in 151 free-ranging grizzly bears from Alberta, Canada (mean 2.84 pg/mg, range 0.62-43.33 pg/mg); 185 free-ranging polar bears from southern Hudson Bay, Canada (mean 0.48 pg/mg range, 0.16-2.26 pg/mg); in 12 captive Alaskan caribou (R. t. granti) (mean 2.31 pg/mg, range, 1.57-3.86 pg/mg) and 12 captive reindeer (R .t. tarandus) (mean 2.88 pg/mg, range 2.21-3.40 pg/mg) injected either with adrenocorticotropic hormone (ACTH) or saline; and in 94 free-ranging caribou (R. t. groenlandicus) from West Greenland (mean 2.21 pg/mg, range 0.60-6.90 pg/mg). Factors influencing HCC in each species were then explored including: 1) technical considerations for the prudent use of HCC analysis and 2) potential relationships between HCC, biological traits, health, and prevailing environmental conditions. Evidence revealed in this study suggests that, with further research, this technique may show potential as a practical conservation tool for use in free-ranging grizzly bear, polar bear, and caribou populations.

Selected Methodical Approaches to Regional Population Forecast: A case study in the South Bohemian Region Abstract The aim of this thesis is to introduce selected methodological approaches to population forecasts, focusing on the regional level and considering different lengths of time series. Specific procedures are applied to create a population forecast for the South Bohemian Region. In the theoretical part of this thesis, the stages of population forecasts processing are determined. The Cohort Component method with migration, which can be used to create population forecast, is characterized. Another part describes selected analytical models and functions for partial mortality, fertility and migration forecasts, including Indirect estimation of net migration. To extrapolate parameters, selected trending functions and the Box-Jenkins methodology are characterized in the part of the time series analysis. The analytical part of this thesis focuses on the creation of the South Bohemian Region forecast from short initial time series and long initial time series. From short initial time series, the partial forecast of mortality is analyzed by the Heligman-Pollard model, the partial forecast of fertility is analyzed by the Beta function and the partial forecast of migration is analyzed by 25%, 50% and 75%...