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.

Grizzly bear digging sites for Hedysarum sulphurescens roots in southwestern Alberta

1984 ◽  
Vol 62 (12) ◽  
pp. 2571-2575 ◽  
Author(s):  
Anne C. Holcroft ◽  
Stephen Herrero
Keyword(s):  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Ursus Arctos ◽  
Function Analysis ◽  
Soil Surface ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Rock Fragments ◽  
Ursus Arctos Horribilis ◽  
Steep Slopes

Characteristics of sites where Hedysarum sulphurescens Rydb. roots were extensively, less extensively, or not dug by grizzly bears Ursus arctos horribilis Ord. were analyzed in relation to topographic, vegetative, soil, and geologic features. Discriminant function analysis significantly separated dug and undug sites, but did not separate extensively and less extensively dug sites. Ease of breaking the soil surface, presence of shaly rock fragments, loose cobble and gravel, and steep slopes were characteristic of dug sites. The abundance of H. sulphurescens appeared less important than the loose nature of the substrate indicating that digging time was important in optimizing energetics.

Grizzly bear feeding activity at alpine army cutworm moth aggregation sites in northwest Montana

1998 ◽  
Vol 76 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Don White, Jr. ◽  
Katherine C Kendall ◽  
Harold D Picton
Keyword(s):  
National Park ◽  
Ursus Arctos ◽  
Feeding Activity ◽  
Grizzly Bears ◽  
Glacier National Park ◽  
Grizzly Bear ◽  
Use Patterns ◽  
Ursus Arctos Horribilis ◽  
Early Fall ◽  
Minimum Numbers

Grizzly bears (Ursus arctos horribilis) consume army cutworm moths (Euxoa auxiliaris) from late June through mid-September at alpine moth aggregation sites in Glacier National Park, Montana. To better understand the importance of army cutworm moths to grizzly bears, we determined the sex and age classes and minimum numbers of grizzly bears foraging at known alpine moth aggregation sites, and documented the timing and use patterns of grizzly bears foraging in these areas. A minimum of 36 grizzly bears were observed 106 times feeding at 6 of 9 known moth aggregation sites from late June through mid-September in 1992-1995; no bears were observed on moth sites in 1993. Bears fed on moth aggregations disproportionately more at elevations >2561 m, on slopes between 31° and 45°, and on southwest-facing aspects. Lone adult grizzly bears appeared to be underrepresented and subadults overrepresented at moth sites. Moths are highly digestible; all parts are digested except for the exoskeleton. We propose that army cutworm moths are an important, high-quality, preferred summer and early-fall food for grizzly bears in Glacier National Park. We do not present any data that demonstrate an increase in the importance of moths when other foods fail.

scholarly journals Seasonal and Daily Activity of Two Zoo-Housed Grizzly Bears (Ursus arctos horribilis)

2020 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Eduardo J. Fernandez ◽  
Ellen Yoakum ◽  
Nathan Andrews
Keyword(s):  
Daily Activity ◽  
Ursus Arctos ◽  
Time Of Day ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Considerable Variability ◽  
Ursus Arctos Horribilis

Captive grizzly bears, like their wild counterparts, engage in considerable variability in their seasonal and daily activity. We documented the year-long activity of two grizzly bears located at the Woodland Park Zoo in Seattle, Washington. We found that behaviors emerged in relation to month-to-month, seasonal, and time of day (hour-to-hour) observations, and events that occurred on exhibit, such as daily feedings. Seventeen behaviors split into seven classes of behavior were observed during their on-exhibit time over a 13-month period. Inactivity was the most frequent class of responses recorded, with most inactive behaviors occurring during the winter months. Both stereotypic and non-stereotypic activity emerged during the spring and summer months, with stereotypic activity occurring most frequently in the morning and transitioning to non-stereotypic activity in the latter part of the day. Results are discussed with respect to how captive grizzly bear behaviors relate to their natural seasonal and daily activity, as well as how events, such as feeding times and enrichment deliveries, can be used to optimize overall captive bear welfare.

scholarly journals Systemic effects of a high saturated fat diet in grizzly bears (Ursus arctos horribilis)

2017 ◽  
Vol 95 (11) ◽  
pp. 797-807 ◽  
Author(s):  
D.R. Rivet ◽  
O.L. Nelson ◽  
C.A. Vella ◽  
H.T. Jansen ◽  
C.T. Robbins
Keyword(s):  
Fatty Acids ◽  
Ursus Arctos ◽  
Saturated Fatty Acids ◽  
Metabolic Effects ◽  
Food Sources ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Omega 3 ◽  
Necrosis Factor Alpha ◽  
Ursus Arctos Horribilis

Food sources for North America’s grizzly bear (Ursus arctos horribilis Ord, 1815) population have changed as habitats have fragmented, altering available resources and putting bears in contact with unnatural foods. Bears have evolved mechanisms to tolerate obesity, and do not develop adverse health consequences despite storing massive amounts of body fat. Captive adult grizzly bears were used to determine the effects of dietary fat on health. Group 1 was fed a diet high in polyunsaturated fatty acids (PUFA) wherein 9.5% of available calories came from saturated fatty acids (SFA). Group 2 was fed a diet wherein 28.8% of calories came from SFA. Plasma fatty acids, serum lipid profiles, insulin, inflammatory markers, systolic and diastolic blood pressure, and cardiac function parameters were measured. Serum lipids, SFA, and insulin did not differ between the two groups, although omega-3 fatty acids differed. Bears eating the SFA diet had significantly higher circulating adiponectin, interleukin-7 and interleukin-15, and tumor necrosis factor-alpha. Mild, asymptomatic systolic and diastolic dysfunctions were detected by strain echocardiography in the SFA group. The SFA diet group exhibited higher diastolic arterial pressures. Even though mild metabolic derangements were observed, grizzly bears were remarkably resistant to metabolic effects of diets high in SFA.

Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus)

2013 ◽  
Vol 91 (4) ◽  
pp. 227-234 ◽  
Author(s):  
Marius Robu ◽  
Jennifer K. Fortin ◽  
Michael P. Richards ◽  
Charles C. Schwartz ◽  
Jonathan G. Wynn ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Ursus Arctos ◽  
Additional Data ◽  
Bone Collagen ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Marine Isotopic Stage ◽  
Cave Bear ◽  
Dietary Flexibility ◽  
Ursus Arctos Horribilis

The proposed dietary pattern of extinct Late Pleistocene cave bears (Ursus spelaeus Rosenmüller, 1794) has become controversial, as some authors have suggested that they were strictly vegetarian, whereas others maintain they were omnivores that at times ate large amounts of animal protein. We evaluated these alternatives by compiling stable isotope data of carbon (δ13C) and nitrogen (δ15N) from the bone collagen of adult European cave bears from the Late Pleistocene (Marine Isotopic Stage 3). The data include previously published analyses and additional data from the southeastern European (Carpathian) sites of Cioclovina, Muierii, Oase, and Urşilor. The cave bear isotopic values from bone collagen were compared with those from hair keratin occurring in grizzly bears (Ursus arctos horribilis Ord, 1815) collected from 1989 to 2009 in the western United States (Yellowstone National Park). The Yellowstone bears have access to a wide diversity of plants and animals, such that their diets can range from vegetarian to carnivorous. Thus, there was considerable δ13C and δ15N variation among the grizzly bear isotopic values, and the cave bear isotopic variation was encompassed within the overall grizzly bear isotopic distribution. More importantly, the δ15N distributions, reflecting principally trophic level, were not different between the cave bears and the grizzly bears; the cave bear values are, on average, slightly higher or lower than those of the grizzly bears, depending on the criteria for inclusion in the comparisons. It is therefore no longer appropriate to view Late Pleistocene cave bears as strictly or even predominantly vegetarian but as flexible omnivores within their diverse communities.

Road visibility influences habitat selection by grizzly bears (Ursus arctos horribilis)

2020 ◽  
Author(s):  
Bethany Marie Parsons ◽  
Nicholas C Coops ◽  
Sean P Kearney ◽  
Cole Burton ◽  
Trisalyn A Nelson ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Ursus Arctos ◽  
Sensory Perception ◽  
Grizzly Bears ◽  
Grizzly Bear ◽  
Ursus Arctos Horribilis ◽  
Selection For ◽  
Step Selection ◽  
Animal Habitat

Anthropogenic disturbances, including roads, are known to influence animal habitat selection and mortality. In this study, we consider the role of sensory perception in understanding why and how animals respond to disturbances. Our goal was to investigate the effect of visual perception (visibility) around roads on grizzly bear (Ursus arctos horribilis Ord, 1815) habitat selection and mortality in Alberta, Canada. We used detailed topographic and vegetation data from airborne Light Detection and Ranging (lidar) to estimate visibility around roads. We modelled habitat selection as a function of road visibility and environmental variables using GPS telemetry data from 39 grizzly bears and integrated step selection analysis (iSSA). Finally, we assessed mortality risk in visible areas by comparing habitat selection between grizzly bears that died and those that survived. We found that grizzly bears were less likely to select visible areas when moving slowly or resting, but more likely to select visible areas when traveling. We found that grizzly bears that survived selected for areas farther from roads than grizzly bears that died. However, no difference in selection for visible areas was observed. An exploratory analysis showed that grizzly bear mortalities commonly occurred in visible areas. Our findings highlight the importance of sensory perception in understanding animal behaviour.

scholarly journals Can offsetting the energetic cost of hibernation restore an active season phenotype in grizzly bears (Ursus arctos horribilis)?

2021 ◽  
Author(s):  
Heiko T. Jansen ◽  
Brandon Evans Hutzenbiler ◽  
Hannah R. Hapner ◽  
Madeline L. McPhee ◽  
Anthony M. Carnahan ◽  
...  
Keyword(s):  
Heart Rate ◽  
Insulin Sensitivity ◽  
Metabolic Rate ◽  
Ursus Arctos ◽  
Metabolic Effects ◽  
Energetic Cost ◽  
Grizzly Bears ◽  
Flux Analysis ◽  
Active Season ◽  
Ursus Arctos Horribilis

ABSTRACTHibernation is characterized by suppression of many physiological processes. To determine if this state is reversible in a non-food caching species, we fed hibernating grizzly bears (Ursus arctos horribilis) glucose for 10 days to replace 53% or 100% of the estimated minimum daily energetic cost of hibernation. Feeding caused serum concentrations of glycerol and ketones (ß-hydroxybutyrate) to return to active season levels irrespective of the amount of glucose fed. By contrast, free-fatty acids and indices of metabolic rate, such as general activity, heart rate, and strength of the daily heart rate rhythm and insulin sensitivity were restored to roughly 50% of active season levels. Body temperature was unaffected by feeding. To determine the contribution of adipose to these metabolic effects of glucose feeding we cultured bear adipocytes collected at the beginning and end of the feeding and performed metabolic flux analysis. We found a roughly 33% increase in energy metabolism after feeding. Moreover, basal metabolism before feeding was 40% lower in hibernation cells compared to fed cells or active cells cultured at 37°C, thereby confirming the temperature independence of metabolic rate. The partial suppression of circulating FFA with feeding likely explains the incomplete restoration of insulin sensitivity and other metabolic parameters in hibernating bears. Further suppression of metabolic function is likely an active process. Together, the results provide a highly controlled model to examine the relationship between nutrient availability and metabolism on the hibernation phenotype in bears.

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.

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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