Antipredator strategies of Alaskan moose: are maternal trade-offs influenced by offspring activity?

2001 ◽  
Vol 79 (11) ◽  
pp. 2055-2062 ◽  
Author(s):  
Kevin S White ◽  
Joel Berger
Keyword(s):  
Ursus Arctos ◽  
Grizzly Bear ◽  
Vegetative Cover ◽  
South Central ◽  
Trade Offs ◽  
Intermediate Distance ◽  
Lactating Females ◽  
Protective Cover ◽  
Natural Predation ◽  
A Site

To maximize fitness, mothers must both provision and protect neonates, demands that may be in conflict, particularly in systems that still experience high levels of natural predation. Whether variation in offspring behaviour alters this putative conflict is not known. The objective of this study was to test hypotheses about the extent to which neonatal activity and ecological variables mediate trade-offs between maternal vigilance and foraging. To address these questions we contrasted data from behavioural observations on female moose (Alces alces) that differed in parity, calf activity, and habitat use at a site in south-central Alaska where they are subject to high levels of grizzly bear (Ursus arctos) and wolf (Canis lupus) predation. Our analyses revealed that females with active juveniles were more vigilant (and as a consequence spent less time feeding) than those with inactive young; vigilance of females without attendant young was intermediate. Distance to apparent protective refugia (e.g., vegetative cover) was positively related to vigilance for all calf-status categories, but lactating females spent more time closer to thick vegetation than did nonlactating females. These results suggest that (i) mothers adjust vigilance when young are inactive to compensate for the loss of foraging opportunities during periods of neonate activity, thereby reducing juvenile vulnerability and increasing the overall feeding rate, and (ii) females with young reduce foraging compromises and, presumably, predation risk by spending more time close to protective cover than do nonlactating females. We conclude that maternal trade-offs can be highly labile and that mothers are able to adjust rapidly to environment-specific situations.

A tes

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
IJE Manager
Keyword(s):  
Energy Supply ◽  
Fossil Fuels ◽  
Geographical Location ◽  
Weather Conditions ◽  
Past Century ◽  
Solar Pv ◽  
Pv Systems ◽  
Trade Offs ◽  
A Site ◽  
Selection Methodology

In the past century, fossil fuels have dominated energy supply in Indonesia. However, concerns over emissions are likely to change the future energy supply. As people become more conscious of environmental issues, alternatives for energy are sought to reduce the environmental impacts. These include renewable energy (RE) sources such as solar photovoltaic (PV) systems. However, most RE sources like solar PV are not available continuously since they depend on weather conditions, in addition to geographical location. Bali has a stable and long sunny day with 12 hours of daylight throughout the year and an average insolation of 5.3 kWh/m2 per day. This study looks at the potential for on-grid solar PV to decarbonize energy in Bali. A site selection methodology using GIS is applied to measure solar PV potential. Firstly, the study investigates the boundaries related to environmental acceptability and economic objectives for land use in Bali. Secondly, the potential of solar energy is estimated by defining the suitable areas, given the technical assumptions of solar PV. Finally, the study extends the analysis to calculate the reduction in emissions when the calculated potential is installed. Some technical factors, such as tilting solar, and intermittency throughout the day, are outside the scope of this study. Based on this model, Bali has an annual electricity potential for 32-53 TWh from solar PV using amorphous thin-film silicon as the cheapest option. This potential amount to three times the electricity supply for the island in 2024 which is estimated at 10 TWh. Bali has an excessive potential to support its own electricity demand with renewables, however, some limitations exist with some trade-offs to realize the idea. These results aim to build a developmental vision of solar PV systems in Bali based on available land and the region’s irradiation.

A grizzly bear from the Middle Wisconsin of Woodbridge, Ontario

1976 ◽  
Vol 13 (2) ◽  
pp. 341-347 ◽  
Author(s):  
Charles S. Churcher ◽  
Alan V. Morgan
Keyword(s):  
Ursus Arctos ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Bone Fragment ◽  
Mammuthus Primigenius ◽  
Ursus Arctos Horribilis ◽  
Before And After ◽  
Lake Simcoe ◽  
Left Humerus ◽  
Woolly Mammoth

The distal end of the left humerus of a grizzly bear, Ursus arctos, has been recovered from above the Early Wisconsin Sunnybrook Till at Woodbridge, Ontario, from the same horizon that previously has yielded remains of the woolly mammoth, Mammuthus primigenius. The age of these specimens is estimated at 40 000–50 000 years BP, within the mid-Wisconsin, Port Talbot Interstadial. The only other recognized Canadian record of a grizzly bear east of Manitoba is from a gravel sequence at Barrie, near Lake Simcoe, Ontario, dated from a bone fragment to 11 700 ± 250 years BP. A specimen recovered in Toronto in 1913 from an Early Wisconsin horizon is also considered to represent the grizzly. Bears of the grizzly type, Ursus arctos-horribilis were present in Ontario before and after the Early and Late Wisconsin ice advances.

scholarly journals Gray Wolves, Canis lupus, Killed by Cougars, Puma concolor, and a Grizzly Bear, Ursus arctos, in Montana, Alberta, and Wyoming

2008 ◽  
Vol 122 (1) ◽  
pp. 76 ◽  
Author(s):  
Michael D. Jimenez ◽  
Valpa J. Asher ◽  
Carita Bergman ◽  
Edward E. Bangs ◽  
Susannah P. Woodruff
Keyword(s):  
United States ◽  
Canis Lupus ◽  
Ursus Arctos ◽  
Puma Concolor ◽  
Western United States ◽  
Grizzly Bear ◽  
Grey Wolf ◽  
Gray Wolves ◽  
Large Predators

Four cases where large predators caused Grey Wolf (Canis lupus) mortality are recorded. We describe two incidents of Cougars (Puma concolar) killing Wolves in Montana and one incident of a Cougar killing a Wolf in Alberta. We report the first recorded incident of a Grizzly Bear (Ursus arctos) killing a Wolf in the western United States.

scholarly journals Evaluation of Various Perimeter Barrier Products

2021 ◽  
Author(s):  
Rabin Bhattarai ◽  
◽  
Yufan Zhang ◽  
Jacob Wood ◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Sediment Concentration ◽  
Department Of Transportation ◽  
Vegetative Cover ◽  
Buffer Strip ◽  
Erosion Rates ◽  
Sediment Removal ◽  
Loam Soil ◽  
A Site ◽  
Large Scale Tests

Construction activities entail substantial disturbance of topsoil and vegetative cover. As a result, stormwater runoff and erosion rates are increased significantly. If the soil erosion and subsequently generated sediment are not contained within the site, they would have a negative off-site impact as well as a detrimental influence on the receiving water body. In this study, replicable large-scale tests were used to analyze the ability of products to prevent sediment from exiting the perimeter of a site via sheet flow. The goal of these tests was to compare products to examine how well they retain sediment and how much ponding occurs upstream, as well as other criteria of interest to the Illinois Department of Transportation. The products analyzed were silt fence, woven monofilament geotextile, Filtrexx Siltsoxx, ERTEC ProWattle, triangular silt dike, sediment log, coconut coir log, Siltworm, GeoRidge, straw wattles, and Terra-Tube. Joint tests and vegetated buffer strip tests were also conducted. The duration of each test was 30 minutes, and 116 pounds of clay-loam soil were mixed with water in a 300 gallon tank. The solution was continuously mixed throughout the test. The sediment-water slurry was uniformly discharged over an 8 ft by 20 ft impervious 3:1 slope. The bottom of the slope had a permeable zone (8 ft by 8 ft) constructed from the same soil used in the mixing. The product was installed near the center of this zone. Water samples were collected at 5 minute intervals upstream and downstream of the product. These samples were analyzed for total sediment concentration to determine the effectiveness of each product. The performance of each product was evaluated in terms of sediment removal, ponding, ease of installation, and sustainability.

Spatially explicit carrying capacity estimates to inform species specific recovery objectives: Grizzly bear (Ursus arctos) recovery in the North Cascades

2018 ◽  
Vol 222 ◽  
pp. 21-32 ◽  
Author(s):  
Andrea L. Lyons ◽  
William L. Gaines ◽  
Peter H. Singleton ◽  
Wayne F. Kasworm ◽  
Michael F. Proctor ◽  
...  
Keyword(s):  
Carrying Capacity ◽  
Ursus Arctos ◽  
Spatially Explicit ◽  
Grizzly Bear ◽  
North Cascades ◽  
The North ◽  
Species Specific ◽  
Capacity Estimates

scholarly journals Novel range overlap of three ursids in the Canadian subarctic

2019 ◽  
Vol 5 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Douglas Andrew Clark ◽  
Ryan Brook ◽  
Chelsea Oliphant-Reskanski ◽  
Michel P. Laforge ◽  
Kiva Olson ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Black Bear ◽  
Grizzly Bear ◽  
American Black Bear ◽  
Remote Cameras ◽  
American Black ◽  
Range Overlap ◽  
Conservation Concern ◽  
Response To Environmental Change ◽  
First Time

We describe for the first time in the peer-reviewed literature observations of American black bear (Ursus americanus Pallas, 1780), grizzly bear (Ursus arctos Linnaeus, 1758), and polar bear (Ursus maritimus Phipps, 1774) at the same locations. Using remote cameras we documented 401 bear-visits of all three species at three camps in Wapusk National Park, Canada, from 2011–2017. These observations add to a growing body of evidence that grizzlies are undergoing a substantial range increase in northern Canada and the timing of our observations suggests denning locally. Polar and grizzly bears are of conservation concern regionally and internationally, so from the literature we assessed the potential effects on conservation efforts from interactions between these three species. In aggregate, those effects are likely to be positive for grizzlies and weakly negative for black and polar bears; further research is needed. Range overlap of these three species in this dynamic ecotonal region should not be viewed as a threat to any of them, but rather as an ecological response to environmental change that needs to be better understood.

Predation on moose and caribou by radio-collared grizzly bears in east central Alaska

1988 ◽  
Vol 66 (11) ◽  
pp. 2492-2499 ◽  
Author(s):  
R. D. Boertje ◽  
W. C. Gasaway ◽  
D. V. Grangaard ◽  
D. G. Kelleyhouse
Keyword(s):  
Important Implication ◽  
Rangifer Tarandus ◽  
Ursus Arctos ◽  
Prey Availability ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
East Central ◽  
Specific Factors ◽  
Low Levels ◽  
Predation Rates

Radio-collared grizzly bears (Ursus arctos) were sighted daily for approximately 1-month periods during spring, summer, and fall to estimate predation rates. Predation rates on adult moose (Alces alces) were highest in spring, lowest in summer, and intermediate in fall. The highest kill rates were by male grizzlies killing cow moose during the calving period. We estimated that each adult male grizzly killed 3.3–3.9 adult moose annually, each female without cub(s) killed 0.6–0.8 adult moose and 0.9–1.0 adult caribou (Rangifer tarandus) annually, and each adult bear killed at least 5.4 moose calves annually. Grizzly predation rates on calves and grizzly density were independent of moose density and are probably more related to area-specific factors, e.g., availability of alternative foods. An important implication of our results is that managers should not allow moose densities to decline to low levels, because grizzlies can have a greater relative impact on low- than on high-density moose populations and because grizzly predation can be difficult to reduce. Grizzly bears were primarily predators, rather than scavengers, in this area of low prey availability (11 moose/grizzly bear); bears killed four times more animal biomass than they scavenged.

scholarly journals Site-Specific Nutrient Management for Irrigated Rice in South Central Region of Bangladesh

2018 ◽  
Vol 20 (2) ◽  
pp. 1-9
Author(s):  
MAA Mamun ◽  
SA Islam ◽  
MS Islam ◽  
AJ Mridha ◽  
MA Saleque
Keyword(s):  
Grain Yield ◽  
Central Region ◽  
Field Trial ◽  
Nutrient Management ◽  
Rice Yield ◽  
Substantial Variation ◽  
Irrigated Rice ◽  
Site Specific ◽  
South Central ◽  
A Site

A site-specific nutrient management (SSNM) field trial was conducted for irrigated rice using five fertilizer treatments: i) omission of N, ii) omission of P, iii) omission of K, iv) NPK and v) farmers’ practice (FP). Substantial variation in the native N, P, and K supply was found among farmers’ fields. The indigenous soil K produced 4.5 to 5.0 t ha-1 but native P and N gave only rice yield of 3.5 to 4.0 t ha-1. The highest grain yield (6.0 to 7.5 t ha-1) was obtained from balanced fertilization, followed by FP (4.0 to 5.0 t ha-1).The optimal grain yield at Faridpur was obtained by using N, P and K at 135, 8 and 49 kg ha-1; 139, 9 and 42 kg ha-1; and 140, 10 and 43 kg ha-1 for high, medium and low land rice, respectively. However, for Gopalgonj district fertilizer doses of N, P and K were 140, 11 and 38 kg ha-1; 142, 10 and 42 kg ha-1; and 138, 10 and 49 kg ha-1; and for Madaripur district, 126, 8 and 46 kg ha-1; 120, 7 and 38 kg ha-1; and 99, 6 and 27 kg ha-1 for high, medium and low land rice, respectively. These predicted fertilizer doses increase farmers’ income and protect environment from pollution.Bangladesh Agron. J. 2017, 20(2): 1-9

Application of an Integrated Assessment Model (IAM) to for strategic scale delta assessment of socio-ecological risk: Supporting Policy in Coastal Bangladesh

2020 ◽  
Author(s):  
Craig Hutton ◽  
Robert Nicholls ◽  
Alex Chapman ◽  
Charlotte Marcinko ◽  
Munsur Rahman ◽  
...  
Keyword(s):  
Integrated Assessment ◽  
Policy Decision ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
The Sustainable Development ◽  
Coastal Bangladesh ◽  
Strategic Risk ◽  
South Central ◽  
Trade Offs ◽  
The Government

<p>There is growing recognition that new approaches, underpinned by more system-oriented decision support tools, will be required to facilitate development compatible with the Sustainable Development Goals (SDGs) and to prevent the risk of dangerous socio-environmental breakdown. We demonstrate the potential of Integrated Assessment Models (IAMs) to inform strategic policy decision making at a regional level, helping to understand key trade-offs as well as indirect or unintended impacts. The stakeholder co-produced Delta Dynamic Emulator Model (ΔDIEM) model is applied to the southwest coastal zone (pop. 14m) where high rates of extreme poverty prevail. The model integrates biophysical drivers, ecosystem services and community level household wellbeing, and in this work is applied an behalf of the Planning Commission of the Government of Bangladesh in order to assess strategic risk in coastal Bangladesh (2050) and particularly to support the Bangladesh Delta Plan 2100. The intervention we investigated included i) A proposed extensive polder network in the south-central region of coastal Bangladesh ii) Strategic development of a chronically waterlogged area of the delta. In both areas we highlight insights on implications of biophysical drivers on poverty, livelihoods and inequality as well as on risk transfer between regions and populations associated with implementation. In doing so we critically assess IAMs’ growing potential to ask and explore key questions and scenarios about the functioning of integrated biophysical and socioeconomic systems. Finally, we point to ongoing applications of the model in West Bengal</p>

A study of predominant aerobic microflora of black bears (Ursus americanus) and grizzly bears (Ursus arctos) in northwestern Alberta

1987 ◽  
Vol 33 (11) ◽  
pp. 949-954 ◽  
Author(s):  
L. J. Goatcher ◽  
M. W. Barrett ◽  
R. N. Coleman ◽  
A. W. L. Hawley ◽  
A. A. Qureshi
Keyword(s):  
Soil Bacteria ◽  
Ursus Arctos ◽  
Random Distribution ◽  
Ursus Americanus ◽  
Black Bear ◽  
Black Bears ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Streptococcus Species ◽  
Generic Composition

Swab specimens were obtained from nasal, rectal, and preputial or vaginal areas of 37 grizzly and 17 black bears, captured during May to June of 1981 to 1983, to determine the types and frequency of predominant aerobic microflora. Bacterial genera most frequently isolated from bears were Escherichia, Citrobacter, Hafnia, Proteus, Staphylococcus, and Streptococcus species, comprising about 65% of the isolates. Erwinia, Xanthomonas, Agrobacterium, Rhizobium, and Gluconobacter/Acetobacter were also isolated but at lower frequencies (< 5%). Comparison of bacterial generic composition using similarity quotient values showed no appreciable differences between grizzly and black bear flora. Also, no outstanding differences in bacterial generic composition were observed among grizzly bear samples; however, differences were noted among black bear samples. Fungal genera most commonly encountered included Cryptococcus, Rhodotorula, Cladosporium, Penicillium, Sporobolomyces, and Candida. In general, the microflora of both bear types were marked by generic diversity and random distribution. The majority of microorganisms isolated from the plant samples in the study area were also found in bear samples. This observation and the presence of certain water and soil bacteria in samples from bears suggest that the predominant microflora of both grizzly and black bears were transient and probably influenced by their foraging habits and surrounding environments.

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