Understanding the density‐dependent processes that drive population demography in a changing world is critical in ecology, yet measuring performance–density relationships in long‐lived mammalian ...species demands long‐term data, limiting scientists' ability to observe such mechanisms. We tested performance–density relationships for an opportunistic omnivore, grizzly bears (Ursus arctos, Linnaeus, 1758) in the Greater Yellowstone Ecosystem, with estimates of body composition (lean body mass and percent body fat) serving as indicators of individual performance over two decades (2000–2020) during which time pronounced environmental changes have occurred. Several high‐calorie foods for grizzly bears have mostly declined in recent decades (e.g., whitebark pine Pinus albicaulis, Engelm, 1863), while increasing human impacts from recreation, development, and long‐term shifts in temperatures and precipitation are altering the ecosystem. We hypothesized that individual lean body mass declines as population density increases (H1), and that this effect would be more pronounced among growing individuals (H2). We also hypothesized that omnivory helps grizzly bears buffer energy intake from changing foods, with body fat levels being independent from population density and environmental changes (H3). Our analyses showed that individual lean body mass was negatively related to population density, particularly among growing‐age females, supporting H1 and partially H2. In contrast, population density or sex had little effect on body fat levels and rate of accumulation, indicating that sufficient food resources were available on the landscape to accommodate successful use of shifting food sources, supporting H3. Our results offer important insights into ecological feedback mechanisms driving individual performances within a population undergoing demographic and ecosystem‐level changes. However, synergistic effects of continued climate change and increased human impacts could lead to more extreme changes in food availability and affect observed population resilience mechanisms. Our findings underscore the importance of long‐term studies in protected areas when investigating complex ecological relationships in an increasingly anthropogenic world.
Revealing mechanisms underlying demography of long‐lived omnivores is of critical in a changing world. Using long‐term data on grizzly bears from the Greater Yellowstone Ecosystem, we show that variation in individual performance (measured as lean body mass) is primarily a density‐dependent process, particularly among younger females. Conversely, large omnivores exhibit plastic tactics in the face of current landscape‐level perturbations maintaining seasonal threshold of body fat required for hibernation and reproduction. However, synergistic effects of continued climate change and other forms of human impact could in the future affect food availability, and consequently, the observed population resilience mechanisms.
The negative impacts on bears (Ursus spp.) from human activities associated with roads and developments are well documented. These impacts include displacement of bears from high-quality foods and ...habitats, diminished habitat effectiveness, and reduced survival rates. Additionally, increased public visitations to national parks accompanied with benign encounters with bears along park roads have caused more bears to habituate to the presence of people. In some contexts, habituation can predispose bears to being exposed to and rewarded by anthropogenic foods, which can also lower survival rates. The managers and staff of Yellowstone National Park located in Wyoming, Montana, and Idaho, USA, and Grand Teton National Park in northwestern Wyoming, USA have implemented several proactive strategies to mitigate the negative aspects of bear habituation. These strategies include providing park visitors with educational information on bear viewing etiquette, managing roadside viewing opportunities, installing bear-resistant infrastructure, hazing bears from developments, enforcing food and garbage storage regulations, and making human activities as predictable as possible to bears. Under the current management strategies, thousands of visitors are still able to view, photograph, and appreciate bears while visiting these parks each year. The opportunity to view bears provides a positive visitor experience and contributes millions of dollars to the local economies of park gateway communities. Positive bear viewing experiences also help build an important appreciation and conservation ethic for bears in people that visit national parks. For many years, managers were concerned about decreasing and threatened bear populations. Now more jurisdictions are facing new challenges caused by increasing bear populations. This paper highlights a successful attempt to address these issues.
Autumn ungulate hunting in the Greater Yellowstone Ecosystem carries the risk of hunter–grizzly bear (Ursus arctos) conflict and creates a substantial challenge for managers. For Grand Teton National ...Park, Wyoming, USA, a key information need is whether increased availability of elk (Cervus canadensis) carcasses during a late autumn (Nov–Dec) harvest within the national park attracts grizzly bears and increases the potential for conflict with hunters. Using a robust design analysis with 6 primary sampling periods during 2014–2015, we tested the hypothesis that the elk harvest resulted in temporary movements of grizzly bears into the hunt areas, thus increasing bear numbers. We detected 31 unique individuals (6 F, 25 M) through genetic sampling and retained 26 encounter histories for analysis. Markovian movement models had more support than a null model of no temporary movement. Contrary to our research hypothesis, temporary movements into the study area occurred between the July–August (no hunt; N̄2014–2015 = 5) and September–October (no hunt; N̄2014–2015 = 24) primary periods each year, rather than during the transition from September–October (no hunt) to November–December (hunt; N̄2014–2015 = 15). A post hoc analysis indicated that September–October population estimates were biased high by detections of transient bears. Grizzly bear presence during the elk hunt was limited to approximately 15 resident bears that specialized in accessing elk carcasses. The late timing of the elk hunt likely moderated the effect of carcasses as a food attractant because it coincides with the onset of hibernation. From a population response perspective, the current timing of the elk harvest likely represents a scenario of low relative risk of hunter–bear conflicts. The risk of hunter–grizzly bear encounters remains, but may be more a function of factors that operate at the level of individual bears and hunters, such as hunter movements and bear responses to olfactory cues.
In the Greater Yellowstone Ecosystem, counts of female grizzly bears (Ursus arctos) with cubs-of-the-year (females with cubs) from systematic aerial surveys and opportunistic ground sightings are ...combined with demographic data to derive annual population estimates. We addressed 2 limitations to the monitoring approach. As part of a rule set, a conservative distance of >30 km currently is used as a threshold to assign sightings to unique females with cubs, resulting in underestimation bias. Using telemetry locations of females with cubs collected during 1997–2019, we created 1,000 data sets for each of 5 levels of simulated number of females with cubs, simulated sightings by selecting among these locations, and evaluated the classification performance of alternative distance criteria (12–30 km). Under all scenarios, 12–16-km criteria maximized classification performance and minimized estimation bias; the 16-km criterion was optimal for current conditions and sampling efforts. Our second objective was to test generalized additive models (GAMs) as a flexible trend analysis technique. We simulated 1,000 time series for each of 10 scenarios (10, 15, and 20% decline over periods of 5, 10, and 15 yrs, plus stability), applied GAMs, and assessed metrics associated with the posterior distribution of the instantaneous rate of change. We detected declines among >99.6% of replicates under the 15 and 20% decline scenarios and in 84.7–94.7% of replicates under the 10% decline scenario. From decline onset to first detection, periods ranged from 3.7 (20% decline over 5 yrs) to 11.1 (10% decline over 15 yrs), with 3.9–8.8 years mean duration of detection events. The GAM approach allows detection of directional changes in population trend, including early warning metrics, and stabilization after such changes. Retrospective application of the 16-km distance criterion and GAMs resulted in higher population estimates and growth rates than are reported using current methods.
Case Study Gunther, Kerry A.; Wilmot, Katharine R.; Cain, Steven L. ...
Human-wildlife interactions,
12/2018, Letnik:
12, Številka:
3
Journal Article
Recenzirano
The negative impacts on bears (Ursus spp.) from human activities associated with roads and developments are well documented. These impacts include displacement of bears from high-quality foods and ...habitats, diminished habitat effectiveness, and reduced survival rates. Additionally, increased public visitations to national parks accompanied with benign encounters with bears along park roads have caused more bears to habituate to the presence of people. In some contexts, habituation can predispose bears to being exposed to and rewarded by anthropogenic foods, which can also lower survival rates. The managers and staff of Yellowstone National Park located in Wyoming, Montana, and Idaho, USA, and Grand Teton National Park in northwestern Wyoming, USA have implemented several proactive strategies to mitigate the negative aspects of bear habituation. These strategies include providing park visitors with educational information on bear viewing etiquette, managing roadside viewing opportunities, installing bear-resistant infrastructure, hazing bears from developments, enforcing food and garbage storage regulations, and making human activities as predictable as possible to bears. Under the current management strategies, thousands of visitors are still able to view, photograph, and appreciate bears while visiting these parks each year. The opportunity to view bears provides a positive visitor experience and contributes millions of dollars to the local economies of park gateway communities. Positive bear viewing experiences also help build an important appreciation and conservation ethic for bears in people that visit national parks. For many years, managers were concerned about decreasing and threatened bear populations. Now more jurisdictions are facing new challenges caused by increasing bear populations. This paper highlights a successful attempt to address these issues.
Language matters: a UK perspective Lloyd, C. E.; Wilson, A.; Holt, R. I. G. ...
Diabetic medicine,
December 2018, 2018-12-00, 20181201, Letnik:
35, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Aim
To review the existing evidence regarding the use of language in clinical encounters.
Background
Awareness of the importance of language in clinical encounters is mostly lacking or located within ...broader discussions on communication.
Methods
A scoping study was conducted to review existing research that could increase our understanding of the role language plays as well as identify gaps in knowledge and inform the development of a position statement on language in diabetes care.
Results
Evidence shows that, although carefully chosen language can have a positive effect, there is a potential negative impact of language on people's experiences of diabetes care. The use of stigmatizing and discriminatory words during communication between healthcare practitioners and people with diabetes can lead to disengagement with health services as well as sub‐optimal diabetes self‐management. Clinical encounters can be compromised where language barriers exist or where there is limited understanding of cultural differences that may have an impact on diabetes self‐management. What little empirical evidence there is shows that training can improve language and communication skills.
Conclusion
This review raises a number of questions that are being addressed by the NHS England Language Matters Group, which has developed a set of recommendations to support the use of appropriate language in clinical encounters.
What's new?
This paper reviews existing evidence regarding the use of language in clinical encounters.
Poor language practices can lead to stigma, lack of engagement with self‐management, low satisfaction with care and poor clinical outcomes.
Research has demonstrated the importance of good communication skills and that appropriate use of language can benefit psychosocial well‐being and support optimal diabetes self‐management.
Our review has directly informed the publication of a UK Position Statement on Language Matters.
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