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.

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 Predispersal home range shift of an ocelot Leopardus pardalis (Carnivora: Felidae) on Barro Colorado Island, Panama

2007 ◽  
Author(s):  
Rafael Mares ◽  
Ricardo S. Moreno ◽  
Roland W. Kays ◽  
Martin Wikelski
Keyword(s):  
Home Range ◽  
Radio Telemetry ◽  
Barro Colorado Island ◽  
Range Shift ◽  
Range Shifts ◽  
Home Ranges ◽  
Adult Size ◽  
Subadult Male ◽  
Leopardus Pardalis ◽  
Natal Home

Home range shifts prior to natal dispersal have been rarely documented, yet the events that lead a subadult to abandon a portion of its home range and venture into unfamiliar territories, before eventually setting off to look for a site to reproduce, are probably related to the causes of dispersal itself. Here, we used a combination of manual radio-tracking and an Automated Radio Telemetry System to continuously study the movements of a subadult male ocelot (Leopardus pardalis), a solitary carnivore with sex-biased dispersal, on Barro Colorado Island, Panama, for 18 months from May 2003 through October 2004. The subadult ocelot?s parents were also radio-tracked to record possible parent-offspring interactions within their home ranges. At the age of ca. 21 months the subadult gradually began to shift its natal home range, establishing a new one used until the end of the study, in an area that had previously been used by another dispersing subadult male. Only three parent-offspring interactions were recorded during the four months around the time the range-shift occurred. The apparent peaceful nature of these encounters, along with the slow transition out of a portion of his natal home range, suggest the subadult was not evicted from his natal area by his parents. The timing of the shift, along with the subadult?s increase in weight into the weight range of adult ocelots four months after establishing the new territory, suggests that predispersal home range shifts could act as a low risk and opportunistic strategy for reaching adult size, while minimizing competition with parents and siblings, in preparation for an eventual dispersal into a new breeding territory.

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.

Feral Cats (Felis Catus L.) On New Zealand Farmland. Ii. Seasonal Activity.

1992 ◽  
Vol 19 (6) ◽  
pp. 707 ◽  
Author(s):  
NPE Langham
Keyword(s):  
New Zealand ◽  
Home Range ◽  
Social Behaviour ◽  
Activity Patterns ◽  
Felis Catus ◽  
Home Ranges ◽  
Seasonal Activity ◽  
Adult Males ◽  
Feral Cats ◽  
Resident Population

The activity patterns of a resident population of 15 feral cats (Felis catus L.) on New Zealand farmland were investigated from March 1984 until February 1987 by radiotelemetry. Females could be divided into two separate groups: (1) those denning in barns and (2) those denning in the swamp and willows. Females denning in barns were mainly nocturnal except in spring and summer when rearing kittens. Barn cats moved significantly further between dusk and dawn, except in autumn-winter, than those denning in swamp and willows which were active over 24 h. When not breeding, related females occupied the same barn. In both groups, the home range of female relatives overlapped. Males ranged over all habitats, and dominant adult males moved significantly further and had larger home ranges than other males in all seasons, except in summer when they rested, avoiding hot summer days. Only adult males were active during the day in spring and autumn-winter. The importance of a Zeitgeber in synchronising cat activity with that of the prey is examined. The significance of female den site is discussed in relation to proximity of food, predators, social behaviour and male defence.

Demography of barren-ground grizzly bears

2003 ◽  
Vol 81 (2) ◽  
pp. 294-301 ◽  
Author(s):  
Philip D McLoughlin ◽  
Mitchell K Taylor ◽  
H Dean Cluff ◽  
Robert J Gau ◽  
Robert Mulders ◽  
...  
Keyword(s):  
Survival Rate ◽  
Litter Size ◽  
Birth Interval ◽  
Ursus Arctos ◽  
Survival Rates ◽  
Grizzly Bears ◽  
Adult Males ◽  
Barren Ground ◽  
Rate Of Increase ◽  
The Mean

Between May 1995 and June 1999, we equipped 81 barren-ground 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. We used data from radiotelemetry to estimate survival rates, reproductive parameters, and the finite rate of increase of the population (λ). The annual survival rate of adult females was estimated at 0.979 (95% confidence intervals (CI) = 0.955–0.998), while the survival rate of adult males was 0.986 (95% CI = 0.942–1.0). The cub survival rate was 0.737 (95% CI = 0.600–0.844) and the yearling survival rate was 0.683 (95% CI = 0.514–0.821). Cub litter size averaged 2.23 (SE = 0.13, n = 35), while yearling litter size decreased to a mean of 1.86 (SE = 0.12, n = 35). The mean litter size of females with 2-year-olds was 1.85 (SE = 0.15, n = 20). The mean birth interval was 2.8 years (SE = 0.3 years, n = 17). The mean reproductive interval, which is calculated by excluding the loss of whole litters from the sample, was 3.9 years (SE = 0.4 years, n = 9). Mean litter size divided by mean birth interval yielded an annual natality rate of 0.81 cubs per adult female per year. The mean age at first parturition was 8.1 years (SE = 0.5 years, n = 10). We believe the population to be currently stable or slightly increasing (λ = 1.033, 95% CI = 1.008–1.064).

Spatial-use patterns, movements, and interactions among adult coyotes in central Mississippi

2000 ◽  
Vol 78 (12) ◽  
pp. 2087-2095 ◽  
Author(s):  
Michael J Chamberlain ◽  
Charles D Lovell ◽  
Bruce D Leopold
Keyword(s):  
Home Range ◽  
Spatial Scales ◽  
Core Area ◽  
Home Ranges ◽  
Adult Males ◽  
Movement Rates ◽  
Use Patterns ◽  
Pair Bonds ◽  
Northern Regions ◽  
Range Overlap

Recently, coyotes (Canis latrans) have expanded their range to include most areas of the southeastern United States. However, most research on coyotes has been conducted in western and northern regions of North America. We radio-monitored 38 adult coyotes from 1993 to 1997 in central Mississippi. Home-range sizes (P = 0.681) and core-area (area of concentrated use) sizes (P = 0.736) were similar across seasons, but females maintained larger home ranges (P = 0.006) and core areas (P < 0.001) than males. Male-male, female-female, and male-female home-range overlap was greatest during whelping and pup rearing. Except for mated pairs, core-area overlap was negligible across all seasons for adults maintaining neighboring home ranges. Coyote habitat selection varied across spatial scales, though selection was similar between males and females at all scales. Coyote movement rates differed (P < 0.001) temporally, being highest during nocturnal periods. Overall, the highest movement rates for the monitored population were observed for females during summer. Two males and 2 females were suspected of forming pair bonds and frequently traveled together within shared home ranges, as did 2 adult males. Our data indicate that interactions among individual adults are influenced by sex, as most confirmed instances of direct contact occurred between pairs or suspected social groups. In our study area, neighboring adult coyotes exhibited territoriality at the core-area level.

scholarly journals Ain’t Nothing like Family—Female Brown Bears Share Their Home Range with Relatives

Diversity ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 41
Author(s):  
Astrid Olejarz ◽  
Jouni Aspi ◽  
Ilpo Kojola ◽  
Vesa Nivala ◽  
Alina K. Niskanen ◽  
...  
Keyword(s):  
Home Range ◽  
Spatial Data ◽  
Ursus Arctos ◽  
Home Ranges ◽  
Brown Bears ◽  
Home Range Overlap ◽  
Animal Populations ◽  
Centroid Distance ◽  
Range Overlap ◽  
Eastern Finland

Sociality in animal populations is a continuum, and interactions between conspecifics are meaningful for all vertebrates. Ignorance of social structures can lead to misunderstanding their ecology and, consequently, to unsuccessful species management. Here, we combined genetic and spatial data on radio-collared brown bears (Ursus arctos) to investigate kin-related home range overlap and kin-related centroid distance within central and eastern Finland. We found that the extent of home range overlap was positively correlated with relatedness among adult females. In addition, home range centroid distance decreased as relatedness increased. Moreover, there were significant differences between the two studied regions: female brown bears in central Finland were more closely related to each other, and the sizes of their home ranges were larger than those in eastern Finland. The smaller home ranges and lower degree of relatedness among bears in eastern Finland might be a result of the substantially higher hunting pressure in the area, combined with immigration of new unrelated individuals from Russia.

Spatial Organisation of Urban Feral Cats (Felis Catus) in Jerusalem.

1995 ◽  
Vol 22 (3) ◽  
pp. 299 ◽  
Author(s):  
V Mirmovitch
Keyword(s):  
Home Range ◽  
Home Range Size ◽  
Home Ranges ◽  
Adult Males ◽  
Mating Season ◽  
Minimum Convex Polygon ◽  
Spatial Organisation ◽  
Similar Frequency ◽  
Feral Cats ◽  
Young Males

Feral cats were studied for 10 months in a residential area in Jerusalem and their spatial distribution compared during two 1-month periods, the first in the autumn prior to the mating season and the second during the mating season (winter). Cat locations were recorded by direct observations, and home-range sizes were calculated with the minimum convex polygon method. No significant change in home-range size of adult males or females was found between the 2 periods. Young males expanded their home ranges considerably during their first mating season. Home ranges of males were significantly larger than those of females in both periods (0.56 and 0.30 ha, respectively, in autumn; 0.75 and 0.27 ha in winter). The home ranges of both sexes overlapped considerably with individuals of the same sex. Overlap among home ranges of females indicated a group pattern. High overlap (80%) was found among females that fed from the same set of garbage bins with similar frequency. Lower overlap (20%) was found between individual females that shared only a subset of their food resources and used it with different frequency. It is suggested that the distribution of food patches (garbage bins), the amount of food available and the rate of food renewal determined the cats' spatial organisation.

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.

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