scholarly journals Quantifying energetic costs and defining energy landscapes experienced by grizzly bears

2021 ◽  
Vol 224 (6) ◽  
Author(s):  
Anthony M. Carnahan ◽  
Frank T. van Manen ◽  
Mark A. Haroldson ◽  
Gordon B. Stenhouse ◽  
Charles T. Robbins
Keyword(s):  
Ursus Arctos ◽  
Slope Angle ◽  
Cost Benefit ◽  
Grizzly Bears ◽  
Unit Distance ◽  
Gps Collars ◽  
Landscape Use ◽  
Mountainous Landscapes ◽  
Greater Yellowstone ◽  
The Cost

ABSTRACT Animal movements are major determinants of energy expenditure and ultimately the cost–benefit of landscape use. Thus, we sought to understand those costs and how grizzly bears (Ursus arctos) move in mountainous landscapes. We trained captive grizzly bears to walk on a horizontal treadmill and up and down 10% and 20% slopes. The cost of moving upslope increased linearly with speed and slope angle, and this was more costly than moving horizontally. The cost of downslope travel at slower speeds was greater than the cost of traveling horizontally but appeared to decrease at higher speeds. The most efficient walking speed that minimized cost per unit distance was 1.19±0.11 m s−1. However, grizzly bears fitted with GPS collars in the Greater Yellowstone Ecosystem moved at an average velocity of 0.61±0.28 m s−1 and preferred to travel on near-horizontal slopes at twice their occurrence. When traveling uphill or downhill, grizzly bears chose paths across all slopes that were ∼54% less steep and costly than the maximum available slope. The net costs (J kg−1 m−1) of moving horizontally and uphill were the same for grizzly bears, humans and digitigrade carnivores, but those costs were 46% higher than movement costs for ungulates. These movement costs and characteristics of landscape use determined using captive and wild grizzly bears were used to understand the strategies that grizzly bears use for preying on large ungulates and the similarities in travel between people and grizzly bears that might affect the risk of encountering each other on shared landscapes.

Use of Whitebark Pine (Pinus albicaulis) seeds by GPS-collared Grizzly Bears (Ursus arctos) in Banff National Park, Alberta

2021 ◽  
Vol 135 (1) ◽  
pp. 61-67
Author(s):  
David Hamer
Keyword(s):  
National Park ◽  
Ursus Arctos ◽  
High Elevation ◽  
Habitat Characteristics ◽  
Grizzly Bears ◽  
Pinus Albicaulis ◽  
Whitebark Pine ◽  
Gps Collars ◽  
Additional Information ◽  
Banff National Park

Seeds of Whitebark Pine (Pinus albicaulis) are a major food for Grizzly Bears (Ursus arctos) in the Yellowstone ecosystem. In Canada, Grizzly Bears are known to eat Whitebark Pine seeds, but little additional information, such as the extent of such use and habitat characteristics of feeding sites, is available. Because Grizzly Bears almost always obtain Whitebark Pine seeds by excavating cones from persistent caching sites (middens) made by Red Squirrels (Tamiasciurus hudsonicus), it is possible to infer Whitebark Pine feeding when bears are located near excavated middens in Whitebark Pine stands. During 2013–2018, I conducted a retrospective study in Banff National Park using data from 23 Grizzly Bears equipped by Parks Canada staff with global positioning system (GPS) collars. My objectives were to use GPS fixes to determine the percentage of these bears that had been located in close proximity to excavated middens containing Whitebark Pine seeds and to describe the habitat at these excavated middens. I linked 15 bears (65%) to excavated middens and, by inference, consumption of Whitebark Pine seeds. Excavated middens occurred on high-elevation (mean 2103 ± 101 [SD] m), steep (mean 26° ± 8°) slopes facing mostly (96%) north through west (0–270°). Use of Whitebark Pine seeds by at least 65% of the 23 studied Grizzly Bears suggests that conservation of Whitebark Pine in Banff National Park would concomitantly benefit the at-risk population of Grizzly Bears.

scholarly journals Home range, movements, and denning chronology of the Grizzly Bear (Ursus arctos) in west-central Alberta

2014 ◽  
Vol 128 (3) ◽  
pp. 223 ◽  
Author(s):  
Karen Graham ◽  
Gordon B. Stenhouse
Keyword(s):  
Home Range ◽  
Ursus Arctos ◽  
Home Range Size ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Adult Males ◽  
Gps Collars ◽  
Recovery Planning ◽  
Adult Females ◽  
West Central

An understanding of the natural history of the Grizzly Bear (Ursus arctos) is important for recovery planning. We present data on home range size, movements and denning chronology collected using Global Positioning System (GPS) collars on Grizzly Bears in west-central Alberta. Mean annual kernel estimates for adult (1034 ± 656 (SD) km2) and subadult (1298 ± 1207 km2) males were larger than those for females with cubs of the year (213 ± 212 km2) and lone adult females (337 ± 176 km2) but not different from sub-adult females, females with yearlings, or females with ≥ 2-yr old cubs (P > 0.05). Mean rates of movement among female age–reproductive classes were different from each other (Z9 < 2.70, P > 0.05) but not different from sub-adult males (Z9 < 2.70, P > 0.05). Rates of movement of adult males were significantly different only from those of females with cubs of the year (Z9 = 3.94, P = 0.001). The greatest amount of movement occurred in June and the least in October. Bears traveled fastest in the morning and evening and slowest at night. Pregnant females had the longest denning period (175 days, ± 16 days SD). No difference was detected in denning duration among the remaining five age–sex–reproductive classes (P > 0.05). GPS collars provided large location datasets from which accurate home range estimates, hourly movement rates, and precise denning dates were determined. Examining similarities and differences in the basic biology of Grizzly Bears from various locations will improve our understanding of the plasticity of this species and the potential impacts of habitat and climate change.

Hostile Takeovers and Anti-takeover Defenses in the Russian Corporate Market

2007 ◽  
pp. 70-84 ◽  
Author(s):  
E. Demidova
Keyword(s):  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Benefit Analysis ◽  
Costs And Benefits ◽  
Hostile Takeovers ◽  
Russian Market ◽  
Takeover Defenses ◽  
The Cost ◽  
European Markets

This article analyzes definitions and the role of hostile takeovers at the Russian and European markets for corporate control. It develops the methodology of assessing the efficiency of anti-takeover defenses adapted to the conditions of the Russian market. The paper uses the cost-benefit analysis, where the costs and benefits of the pre-bid and post-bid defenses are compared.

The Evolutionary Psychology of Scientific Publishing: Cost-Benefit Optimization of Players in the Game

2019 ◽  
Author(s):  
Milind Watve
Keyword(s):  
Peer Review ◽  
Current System ◽  
Critical Mass ◽  
Cost Benefit ◽  
Active Role ◽  
Scientific Publishing ◽  
Collective Goal ◽  
The Cost ◽  
Collective Goals ◽  
Innate Tendency

Peer reviewed scientific publishing is critical for communicating important findings, interpretations and theories in any branch of science. While the value of peer review is rarely doubted, much concern is being raised about the possible biases in the process. I argue here that most of the biases originate in the evolved innate tendency of every player to optimize one’s own cost benefits. Different players in the scientific publishing game have different cost-benefit optima. There are multiple conflicts between individual optima and collective goals. An analysis of the cost-benefit optima of every player in the scientific publishing game shows how and why biases originate. In the current system of publishing, by optimization considerations, the probability of publishing a ‘bad’ manuscript is relatively small but the probability of rejecting a ‘good’ manuscript is very high. By continuing with the current publishing structure, the global distribution of the scientific community would be increasingly clustered. Publication biases by gender, ethnicity, reputation, conformation and conformity will be increasingly common and revolutionary concepts increasingly difficult to publish. Ultimately, I explore the possibility of designing a peer review publishing system in which the conflicts between individual optimization and collective goal can be minimized. In such a system, if everyone behaves with maximum selfishness, biases would be minimized and the progress towards the collective goal would be faster and smoother. Changing towards such a system might prove difficult unless a critical mass of authors take an active role to revolutionize scientific publishing.

What's it Worth? Improving Surface Water Quality

1999 ◽  
Vol 40 (10) ◽  
pp. 153-159 ◽  
Author(s):  
D. H. Newsome ◽  
C. D. Stephen
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Surface Water Quality ◽  
Control Measures ◽  
Benefit Analysis ◽  
The Cost

Many countries are investing in measures to improve surface water quality, but the investment programmes for so doing are increasingly becoming subject to cost-benefit analysis. Whilst the cost of control measures can usually be determined for individual improvement schemes, there are currently no established procedures for valuing the benefits attributable to improved surface water quality. The paper describes a methodology that has been derived that now makes this possible.

The Mismatch between Expectations and Realities of AS4 Audits: A Post-Implementation Research Analysis

2017 ◽  
Vol 37 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Sanaz Aghazadeh ◽  
Marietta Peytcheva
Keyword(s):  
Implementation Research ◽  
Risk Premium ◽  
Cost Benefit ◽  
Multiple Methods ◽  
Material Weakness ◽  
Key Stakeholders ◽  
Auditing Standards ◽  
Equilibrium Market ◽  
The Cost ◽  
Research Analysis

SUMMARY We conduct a post-implementation research analysis of AS4, a standard guiding voluntary audits of material weakness (MW) remediation disclosures, to understand the reasons for the scarcity of AS4 audits in practice. We use multiple methods (experiments, comment letter analysis, and surveys) to understand the perspectives of key stakeholders. We find that regulators' expectations of the use of the standard did not come to fruition because an equilibrium market for active use of the standard could not be achieved; that managers desire to engage in AS4 audits for the riskier MWs but do not expect the associated costs to be high; and that auditors are reluctant to audit riskier MWs and would charge a considerable risk premium. Finally, we find that investors value AS4 audits, especially for riskier MWs, and find value in an AS4 audit for those risky MWs beyond that of the year-end audit. The overall findings of our study indicate that a mismatch in the cost-benefit functions of the key stakeholders led to a lack of AS4 audits. Our findings are important given the high costs associated with auditing standards development and approval.

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