Nocturnal and diurnal foraging behaviour of brown bears (Ursus arctos) on a salmon stream in coastal British Columbia

2002 ◽  
Vol 80 (8) ◽  
pp. 1317-1322 ◽  
Author(s):  
D R Klinka ◽  
T E Reimchen
Keyword(s):  
British Columbia ◽  
Ursus Arctos ◽  
Night Vision ◽  
Black Bears ◽  
Spawning Migration ◽  
Brown Bears ◽  
Light Levels ◽  
Nocturnal Foraging ◽  
Consumption Rates ◽  
Coastal British Columbia

Brown bears (Ursus arctos) have been reported to be primarily diurnal throughout their range in North America. Recent studies of black bears during salmon migration indicate high levels of nocturnal foraging with high capture efficiencies during darkness. We investigated the extent of nocturnal foraging by brown bears during a salmon spawning migration at Knight Inlet in coastal British Columbia, using night-vision goggles. Adult brown bears were observed foraging equally during daylight and darkness, while adult females with cubs, as well as subadults, were most prevalent during daylight and twilight but uncommon during darkness. We observed a marginal trend of increased capture efficiency with reduced light levels (day, 20%; night, 36%) that was probably due to the reduced evasive behaviour of the salmon. Capture rates averaged 3.9 fish/h and differed among photic regimes (daylight, 2.1 fish/h; twilight, 4.3 fish/h; darkness, 8.3 fish/h). These results indicate that brown bears are highly successful during nocturnal foraging and exploit this period during spawning migration to maximize their consumption rates of an ephemeral resource.

scholarly journals Observations of Autumn Courtship and Breeding in Brown Bears, Ursus arctos, from Coastal British Columbia

2005 ◽  
Vol 119 (3) ◽  
pp. 449 ◽  
Author(s):  
Owen T. Nevin ◽  
Barrie K. Gilbert
Keyword(s):  
British Columbia ◽  
Ursus Arctos ◽  
Courtship Behaviour ◽  
Brown Bears ◽  
Coastal British Columbia

Over a period of four years, autumn courtship behaviour in Brown Bears (Ursus arctos) was observed on three separate occasions, with copulation observed once and two litters of cubs potentially resulting from autumn breeding. These are the first recorded observations of these behaviours.

The Relevance of Age and Gender for Public Attitudes to Brown Bears (Ursus arctos), Black Bears (Ursus americanus), and Cougars (Puma concolor) in Kamloops, British Columbia

2013 ◽  
Vol 21 (4) ◽  
pp. 341-359 ◽  
Author(s):  
Michael O’Neal Campbell
Keyword(s):  
British Columbia ◽  
Ursus Arctos ◽  
Ursus Americanus ◽  
Puma Concolor ◽  
Companion Animals ◽  
Black Bears ◽  
Middle Aged ◽  
Age And Gender ◽  
Brown Bears ◽  
And Gender

Abstract In British Columbia, brown bears (Ursus arctos), black bears (Ursus americanus), and cougars (Puma concolor) must relate to growing human populations. This study examines age- and gender-related attitudes to these animals in the urbanizing, agriculturally significant, intermontane city of Kamloops. Most respondents, especially women, feared cougars and bears, saw bears as more troublesome than cougars, and were concerned for child and adult safety. More middle-aged and older participants perceived brown bears as dangerous to companion animals, and black bears as troublesome, than did younger participants, and more middle-aged participants perceived brown bears as troublesome than did younger and older participants. Opinions favored trapping and removal of animals rather than shooting or toleration, but more younger participants opted for shooting, whereas more middle-aged and older participants opted for toleration and removal. Majorities agreed that the animals serve useful functions, women more than men for cougars, middle-aged more than old or young for bears, but saw only cougars as increasing their quality of life. These findings contribute to knowledge about human-wildlife relations, an important first step toward more efficient local and more general conservation policy.

scholarly journals Heart rate during hyperphagia differs between two bear species

2019 ◽  
Vol 15 (1) ◽  
pp. 20180681 ◽  
Author(s):  
Boris Fuchs ◽  
Koji Yamazaki ◽  
Alina L. Evans ◽  
Toshio Tsubota ◽  
Shinsuke Koike ◽  
...  
Keyword(s):  
Heart Rate ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Black Bear ◽  
Black Bears ◽  
Brown Bears ◽  
Fat Reserves ◽  
Generalized Additive Mixed Models ◽  
Additive Mixed Models ◽  
Increased Activity

Hyperphagia is a critical part of the yearly cycle of bears when they gain fat reserves before entering hibernation. We used heart rate as a proxy to compare the metabolic rate between the Asian black bear ( Ursus thibetanus ) in Japan and the Eurasian brown bear ( Ursus arctos ) in Sweden from summer into hibernation. In the hyperphagic period, black bears feed on fat- and carbohydrate-rich hard masts whereas brown bears feed on sugar-rich berries. Availability of hard masts has quantitative and spatial annual fluctuations, which might require increased activity and result in intraspecific stress. Using generalized additive mixed models we analysed the differences in heart rate between the two species. Black bears had decreased heart rates during summer but had doubled heart rate values throughout the hyperphagic period compared to brown bears. This letter illustrates the different physiological consequences of seasonal differences in food availability in two species of the same genus dealing with the same phenological challenge.

Interspecific and intraspecific mitochondrial DNA variation in North American bears (Ursus)

1991 ◽  
Vol 69 (12) ◽  
pp. 2985-2992 ◽  
Author(s):  
Matthew A. Cronin ◽  
Steven C. Amstrup ◽  
Gerald W. Garner ◽  
Ernest R. Vyse
Keyword(s):  
Mitochondrial Dna ◽  
North American ◽  
Ursus Arctos ◽  
Phylogenetic Analyses ◽  
Sequence Divergence ◽  
Black Bears ◽  
Polar Bears ◽  
Brown Bears ◽  
Dna Variation ◽  
Base Substitutions

We assessed mitochondrial DNA variation in North American black bears (Ursus americanus), brown bears (Ursus arctos), and polar bears (Ursus maritimus). Divergent mitochondrial DNA haplotypes (0.05 base substitutions per nucleotide) were identified in populations of black bears from Montana and Oregon. In contrast, very similar haplotypes occur in black bears across North America. This discordance of haplotype phylogeny and geographic distribution indicates that there has been maintenance of polymorphism and considerable gene flow throughout the history of the species. Intraspecific mitochondrial DNA sequence divergence in brown bears and polar bears is lower than in black bears. The two morphological forms of U. arctos, grizzly and coastal brown bears, are not in distinct mtDNA lineages. Interspecific comparisons indicate that brown bears and polar bears share similar mitochondrial DNA (0.023 base substitutions per nucleotide) which is quite divergent (0.078 base substitutions per nucleotide) from that of black bears. High mitochondrial DNA divergence within black bears and paraphyletic relationships of brown and polar bear mitochondrial DNA indicate that intraspecific variation across species' ranges should be considered in phylogenetic analyses of mitochondrial DNA.

Hematology of the brown bear (Ursus arctos) from southwestern Yukon Territory, Canada

1972 ◽  
Vol 50 (3) ◽  
pp. 279-286 ◽  
Author(s):  
A. M. Pearson ◽  
D. W. Halloran
Keyword(s):  
Ursus Arctos ◽  
Binding Capacity ◽  
Total Iron ◽  
Erythrocyte Count ◽  
Black Bears ◽  
Iron Binding ◽  
Total Iron Binding Capacity ◽  
Brown Bears ◽  
Erythrocyte Indices ◽  
Iron Binding Capacity

Blood samples from 22 brown bears (Ursus arctos) and 5 black bears (Ursus americanus) were examined for erythrocyte count, erythrocyte morphology, erythrocyte diameter, hematocrit, hemoglobin, erythrocyte indices, serum iron, total iron-binding capacity, leucocyte count, and leucocyte differential count.A statistically significant decrease in erythrocyte count and hematocrit and increase in erythrocyte indices was found in brown bears from spring to summer. Limited evidence suggests that the spring to summer change may be reversed in the fall.No differences were apparent between sexes at any season but it was indicated that young bears had lower red blood cell concentration, lower hematocrit, and lower hemoglobin concentration than other animals.Leucocyte differential counts in the study were similar to those reported for other bears. Anisocytosis with numerous spherocytes and burr cells characterized the erythrocytes.Serum iron and total iron-binding capacity varied but did not suggest iron-deficiency anemia.Hematology results for the black bears were similar to those of brown bears but our small sample did not allow an investigation of seasonal changes in the species.

Helminths of grizzly bears (Ursus arctos) and American black bears (Ursus americanus) in Alberta and British Columbia, Canada

2015 ◽  
Vol 93 (10) ◽  
pp. 765-772 ◽  
Author(s):  
S. Catalano ◽  
M. Lejeune ◽  
P. Tizzani ◽  
G.G. Verocai ◽  
H. Schwantje ◽  
...  
Keyword(s):  
British Columbia ◽  
Ursus Arctos ◽  
Ursus Americanus ◽  
Statistical Significance ◽  
Black Bears ◽  
Grizzly Bears ◽  
Infection Prevalence ◽  
Infection Parameters ◽  
American Black ◽  
American Black Bears

Between May 2011 and June 2013, we collected the carcasses and gastrointestinal tracts of 40 American black bears (Ursus americanus Pallas, 1780) and 13 grizzly bears (Ursus arctos L., 1758) from populations of Alberta and British Columbia, Canada. Specimens were examined for helminths, which were identified to the species level by applying an integrated morphological and molecular approach. Our goal was to investigate parasite biodiversity and infection parameters in the sampled grizzly and black bears. We found seven parasite taxa: Dirofilaria ursi Yamaguti, 1941, Baylisascaris transfuga (Rudolphi, 1819), Uncinaria rauschi Olsen, 1968, Uncinaria yukonensis (Wolfgang, 1956), Taenia arctos Haukisalmi, Lavikainen, Laaksonen and Meri, 2011, Diphyllobothrium dendriticum (Nitzsch, 1824), and Diphyllobothrium nihonkaiense Yamane, Kamo, Bylund and Wikgren, 1986. The statistical significance of infection prevalence, intensity, and abundance for each helminth species was assessed relative to host species, gender, age class, sampling season, and location. This is the first unequivocal report of the potentially zoonotic tapeworms D. dendriticum and D. nihonkaiense in North American bears. Furthermore, we provide insight into the biology and ecology of the nematodes B. transfuga, D. ursi, and species of Uncinaria Frölich, 1789, and enrich the information available on the recently described tapeworm T. arctos.

Influence of phenology on site selection by female American black bears in coastal British Columbia

Ursus ◽  
2006 ◽  
Vol 17 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Helen Davis ◽  
Richard D. Weir ◽  
Anthony N. Hamilton ◽  
John A. Deal
Keyword(s):  
British Columbia ◽  
Site Selection ◽  
Black Bears ◽  
American Black ◽  
American Black Bears ◽  
Coastal British Columbia
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