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.

scholarly journals Movements of Subadult Male Grizzly Bears, Ursus arctos, in the Central Canadian Arctic

2004 ◽  
Vol 118 (2) ◽  
pp. 239 ◽  
Author(s):  
Robert J. Gau ◽  
Philip D. McLoughlin ◽  
Ray Case ◽  
H. Dean Cluff ◽  
Robert Mulders ◽  
...  
Keyword(s):  
Home Range ◽  
Long Range ◽  
Rangifer Tarandus ◽  
Ursus Arctos ◽  
Canadian Arctic ◽  
Grizzly Bears ◽  
Home Ranges ◽  
Adult Males ◽  
Subadult Male ◽  
Daily Movement

Between May 1995 and June 1999, we equipped eight subadult male (3-5 yrs old) Grizzly Bears (Ursus arctos) with satellite radio-collars within a study area of 235,000 km2, centred 400 km northeast of Yellowknife, Northwest Territories, Canada. Subadult male annual home ranges were extraordinarily large (average = 11,407 km2, SE = 3849) due, in part, to their movement's occasional linear directionality. We believe their long-range linear movements may reflect some individuals tracking the migration of Caribou (Rangifer tarandus). Seasonal daily movement patterns were similar to adult males that were previously reported. The areas used by these bears are the largest ranges reported for any Grizzly Bears and the scale of their movements may put individual bears in contact with humans even when developments are hundreds of kilometres from the central home range of an animal.

Natal dispersal of grizzly bears

2001 ◽  
Vol 79 (5) ◽  
pp. 838-844 ◽  
Author(s):  
Bruce N McLellan ◽  
Frederick W Hovey
Keyword(s):  
Home Range ◽  
Ursus Arctos ◽  
Natal Dispersal ◽  
Conservation Strategies ◽  
Grizzly Bears ◽  
Home Ranges ◽  
Adult Males ◽  
Gradual Process ◽  
The Social ◽  
Dispersal Distances

We studied natal dispersal of grizzly bears (Ursus arctos), a solitary nonterritorial carnivore with a promiscuous mating system, between 1979 and 1998. Dispersal distances for 2-year-olds did not differ between males and females, but by 3 years of age, males had dispersed farther than females, and farther still by 4 years of age. Dispersal of both sexes was a gradual process, occurring over 1–4 years. From the locations of death, or last annual ranges, it was estimated that 18 males dispersed 29.9 ± 3.5 km (mean ± SE) and 12 females dispersed 9.8 ± 1.6 km. Eleven of these males dispersed the equivalent of at least the diameter of 1 adult male home range, whereas only 3 of the females dispersed at least the diameter of 1 adult female home range. The longest dispersals recorded were 67 km for a male and 20 km for a female. Because the social system consists of numerous overlapping home ranges of both sexes, long dispersal distances may not be required to avoid inbreeding or competition with relatives. Simple models suggest that 61% of the ranges of brother and sister pairs would not overlap, but the home range of every daughter would overlap her father's range. The home range of an estimated 19 ± 4 (mean ± SD) adult males, however, would overlap at least a portion of each female's range, thereby reducing the chance of a female mating with her brother or father. Understanding the dispersal behaviour of grizzly bears is essential for developing conservation strategies. Our results suggest that meta-population reserve designs must provide corridors wide enough for male grizzly bears to live in with little risk of being killed.

Dynamics of a grizzly bear population during a period of industrial resource extraction. I. Density and age–sex composition

1989 ◽  
Vol 67 (8) ◽  
pp. 1856-1860 ◽  
Author(s):  
Bruce N. McLellan
Keyword(s):  
Outdoor Recreation ◽  
Ursus Arctos ◽  
Timber Harvest ◽  
Resource Extraction ◽  
Grizzly Bear ◽  
Adult Males ◽  
Sex Composition ◽  
Adult Females ◽  
Rate Of Increase ◽  
Industrial Resource

The characteristics of a grizzly bear (Ursus arctos) population in southeastern British Columbia were studied between 1979 and 1986, a period of timber harvest, gas exploration, and outdoor recreation, including grizzly hunting. I investigated the hypothesis that collectively these activities were detrimental to the grizzly population. I predicted a low density of bears compared with other interior populations and (or) a negative rate of increase. The sex ratio of cubs and yearlings captured was 50:50 and they represented 21.5 and 17.5% of the population, respectively. Although more adult males than adult females were captured, I estimated that there were more adult females than males in the population. I used two methods of population estimation and assumed saturation trapping : one method was based on home range characteristics and the other on the proportion of aerial locations in the study area. The average estimated bear density was 6.4/100 km2, which was high for an interior population, and increased from approximately 5.7/100 km2 in 1981 to 8.0/100 km2 in 1986, for an average annual observed rate of increase of r = 0.07.

scholarly journals Home range of the Tropidurid lizard Liolaemus lutzae: sexual and body size differences

1999 ◽  
Vol 59 (1) ◽  
pp. 125-130 ◽  
Author(s):  
C. F. D. ROCHA
Keyword(s):  
Body Size ◽  
Home Range ◽  
Mutual Exclusion ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Adult Males ◽  
Adult Females ◽  
The Mean ◽  
Janeiro State

The home range of the Tropidurid lizard Liolaemus lutzae, an endemic species of the costal sand dune habitats of Rio de Janeiro State, was studied in the beach habitat of Barra de Maricá restinga, Maricá County. Home ranges were studied using a mark-recapture technique in a delimited area at the beach habitat. I considered for estimates and analysis the home ranges of those lizards with a minimum of four positions. The size of L. lutzae home ranges varied according to the segment of the population. The mean home range size of adult males (x = 59.8 ± 33.7 m²) was significantly larger than that of adult females (x = 22.3 ± 16.1 m²). Juvenile mean home range size was significantly smaller than that of adult males, but did not differ from that of adult females (t = 1.058; p = 0.149). The overlap between male home ranges was usually low (3.6%), being in general only peripheral. Conversely, there was a considerable overlap between home ranges of adult females with those of adult males, the home range areas of two or three females being enclosed in the home range of one adult male. The small overlap between home ranges of adult males suggested mutual exclusion. The observed between-sex differences in the size of L. lutzae home range may be explained by the sexual dimorphism in body size in this species, and by the need of adult males to establish larger areas so as to include many females in their areas, during the reproductive season. The differences in home range along ontogeny probably result from differences in body size of the different segments of the population, due to trophic differences (carnivory and herbivory levels), and the dispersal of young after birth. Because L. lutzae is omnivorous, but primarily herbivorous when adult, and due to its sit-and-wait foraging behavior (mainly on arthropods), it does not need to move around over large areas to find food, which in turn reduces the area necessary for it to live.

scholarly journals Site fidelity and effects of body mass on home-range size of Egyptian mongooses

1994 ◽  
Vol 72 (3) ◽  
pp. 465-469 ◽  
Author(s):  
F. Palomares
Keyword(s):  
Home Range ◽  
Body Mass ◽  
Site Fidelity ◽  
Home Range Size ◽  
Range Size ◽  
Adult Males ◽  
Spatial Strategies ◽  
Adult Females ◽  
Egyptian Mongoose ◽  
Herpestes Ichneumon

Home-range size has been found to be related to body mass of some animals both across species and within species when the spatial strategies of the sexes differ. I studied home-range size in a polygynous carnivore, the Egyptian mongoose (Herpestes ichneumon), and compared observed home-range size with predictions based on body mass. First, I tested whether mongooses actually exhibited site fidelity (for daily and multiday periods). Mongooses always showed site fidelity for a multiday home range, but in only 59% of the cases for daily home range. Adult males exhibited less daily site fidelity than did adult females or young. Multiday home-range size was similar among age–sex classes, but males had significantly more core areas than females or young. Multiday home-range size was positively correlated with body mass for adult males (r2 = 0.98, P = 0.0122) and negatively correlated with body mass of adult females (r2 = 0.40, P = 0.0374). Differences in these relationships and daily site fidelity between adult males and females suggest that the spatial strategies of male and female Egyptian mongooses are different, with the larger females defending the areas richer in resources and the larger males having more access to females.

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.

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.

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.

Salmon consumption by Kodiak brown bears (Ursus arctos middendorffi) with ecosystem management implications

2013 ◽  
Vol 91 (3) ◽  
pp. 164-174 ◽  
Author(s):  
M.B. Van Daele ◽  
C.T. Robbins ◽  
B.X. Semmens ◽  
E.J. Ward ◽  
L.J. Van Daele ◽  
...  
Keyword(s):  
Total Mass ◽  
Ursus Arctos ◽  
Adult Males ◽  
Management Implications ◽  
Brown Bears ◽  
Adult Females ◽  
Commercial Harvest ◽  
Maximum Sustained Yield ◽  
Large Predators

The ecological role of large predators in North America continues to spark heated public debate. Although brown bears (Ursus arctos L., 1758) and the salmon (genus Oncorhynchus Suckley, 1861) they feed on have declined in many areas, the Kodiak archipelago is famous for large brown bears and abundant salmon. Salmon have generally been managed for maximum sustained yield in a fisheries sense, but those levels may be well below what is necessary for maximum ecosystem productivity. Consequently, we used stable isotopes and mercury accumulated in hair to estimate intake of salmon by Kodiak brown bears (Ursus arctos middendorffi Merriam, 1896). Salmon intake increased from subadult males (592 ± 325 kg·bear−1·year−1) to adult males (2788 ± 1929 kg·bear−1·year−1) and from subadult females (566 ± 360 kg·bear−1·year−1) to adult females (1364 ± 1261 kg·bear−1·year−1). Intake within each group increased 62% ± 23% as salmon escapement increased from ∼1 500 to ∼14 000 kg·bear−1·year−1. The estimated population of 2300 subadult and adult bears consumed 3.77 ± 0.16 million kg of salmon annually, a mass equal to ∼6% of the combined escapement and commercial harvest (57.6 million kg). Although bears consume a small portion of the total mass of adult salmon, perpetuation of dense populations of large bears requires ecosystem-based management of the meat resources and environments that produce such bears.

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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