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).

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 Short Term Outcomes of Gastric Cancer at University Teaching Hospital of Kigali (CHUK), Rwanda.

2020 ◽  
Author(s):  
Irénée Niyongombwa ◽  
Irénée David Karenzi ◽  
Isaie Sibomana ◽  
Vital Muvunyi ◽  
Jean Marie Vianney Kagimbangabo ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Survival Rate ◽  
Mortality Rate ◽  
Hospital Mortality ◽  
Cox Regression ◽  
Advanced Disease ◽  
Survival Rates ◽  
University Teaching ◽  
Short Term ◽  
The Mean

Abstract Background: Gastric cancer is the 4th most common cause of cancer death worldwide with an annual global incidence of 985,600; two thirds of them being in the developing countries. Gastric cancer is endemic in the so called stomach cancer region comprising Rwanda, Burundi, South Western Uganda and eastern Kivu province of Democratic Republic of Congo and its incidence in Rwanda is estimated around 13 to 15 per 100,000 population. To date, the outcomes of gastric cancer in the East African region are under investigated, and the survival rate in Rwanda is not known. The aim of this study was to describe the short term outcomes (in-hospital mortality rate, length of hospital stay, 3, 6, 12 and 24 months survival rates) in patients treated for gastric cancer at CHUK.Methods: We retrospectively reviewed the data collected from records of patients who consulted CHUK over a period of 10 years from September 2007 to August 2016. Patients were followed in hospital and after discharge for survival length. Descriptive statistics were used for baseline demographic data, Kaplan-Meier model and univariate cox regression were used for survival analysis.Results: Of the 199 patients enrolled in the study, 92 (46%) were males and 107 (54%) females. The mean age was 55.4 ranging between 24 and 93. The mean symptoms duration was 15 months. Most patients consulted with advanced disease, 62.3% with distant metastases. Treatment with curative intent was offered for only 19.9% of patients. The in-hospital mortality rate was 13.3%. The 3, 6, 12 and 24 months survival rate was 52%, 40.5%, 28% and 23.4% respectively. The Overall survival rate was 7 months.Conclusion: Patients with gastric cancer have delayed consultations and advanced disease at the time of presentation. This cancer is associated with poor outcomes in terms of hospital mortality and post discharge survival rates.

The 1997 Report of the Japanese National Registry Data on Pediatric Peritoneal Dialysis Patients

1999 ◽  
Vol 19 (2_suppl) ◽  
pp. 473-478 ◽  
Author(s):  
Masataka Hondaa
Keyword(s):  
Peritoneal Dialysis ◽  
Survival Rate ◽  
Survival Rates ◽  
National Registry ◽  
Catheter Survival ◽  
Technique Survival ◽  
The Mean ◽  
National Registry Data ◽  
Patient Survival Rate

Objective We have collected data on pediatric patients less than 16 years of age from the National Registry of Chronic Peritoneal Dialysis (PD). We present our experience with this population. Design The database details the patient numbers, age, outcome, cause of death, reason for terminating PD therapy, type of PD therapy, peritonitis, and catheter survival. Patients Of 807 patients, 70 patients (8.7%) were under 1 year of age, and 268 patients (33.2%) were under 6 years of age, clearly indicating that PD was the treatment of choice in young children. The duration on PD was 5 years or more in 200 patients (24.8%), which showed an increase in long-term PD patients from 11% in 1991. Patients on automated PD (APD) increased to 75% in 1997 from 9% in 1991. Results The outcomes for the total patient population of 807 as of the end of 1997 is: 253 patients (31.4%) were being successfully treated with PD, 87 patients (10.8%) died, 238 patients (29.5%) received a kidney transplant, and 121 (15.0%) were transferred to hemodialysis. The patient survival rate was 91% in 3 years and 86% in 5 years. The technique survival rate was 83% in 3 years and 71% in 5 years. The rate of peritonitis was 1 episode per 30 patient -months. The mean catheter duration was 2.25 years. Conclusion The patient and technique survival rates, the peritonitis rate, and the catheter survival improved recently. However, these data were worse in younger children (less than 6 years of age), indicating that extra-careful management is needed for this young age group.

Overestimation of the Effectiveness of Cardiopulmonary Resuscitation

1997 ◽  
Vol 84 (3_suppl) ◽  
pp. 1409-1410 ◽  
Author(s):  
Nathan M. Kostoulakos ◽  
Drake R. Bradley
Keyword(s):  
College Students ◽  
Survival Rate ◽  
Cardiopulmonary Resuscitation ◽  
Survival Rates ◽  
The Mean ◽  
Actual Survival

38 college students estimated the survival rates of people administered cardiopulmonary resuscitation. The mean estimated survival rate (54.5%) was significantly higher than the actual survival rate (10%).

Twenty Years of Renal Transplantation in Children

PEDIATRICS ◽  
1986 ◽  
Vol 77 (4) ◽  
pp. 465-470
Author(s):  
Donald Potter ◽  
Nicholas Feduska ◽  
Juliet Melzer ◽  
Marvin Garovoy ◽  
Susan Hopper ◽  
...  
Keyword(s):  
Overall Survival ◽  
Renal Transplantation ◽  
Survival Rate ◽  
Living Donor ◽  
Patient Survival ◽  
Survival Rates ◽  
Overall Survival Rate ◽  
Creatinine Concentration ◽  
The Mean ◽  
Cadaver Donor

Two-hundred three children 1 to 16 years of age received kidney transplants during a 20-year period, 100 from living donors and 103 from cadaver donors. The overall survival rate was 79%. Actuarial patient and kidney survival rates at 15 years were 79% and 52%, respectively, for recipients of living donor kidneys and 57% and 19%, respectively, for recipients of cadaver donor kidneys. One of two children who received transplants in 1964 was alive 20½ years later. Twenty-nine children had kidneys that had functioned more than 10 years; their mean serum creatinine concentration was 1.7 mg/dL and 24 were fully rehabilitated. Eighteen were more than 2 SD below the mean height of normal chidren, however. Comparison of survival rates during successive 5-year intervals showed significant improvement in patient survival during the 20-year period and smaller improvements in kidney survival after 1979. Patient survival after living donor transplants during the last 10 years was 100%, and kidney survival during the last 5 years was 92%. Improvement was attributed to the effect of experience, as well as to changes in immunosuppressive therapy in 1972 and the introduction of donor-specific transfusions in 1978.

Clinical and endoscopic aspects of metastases to the gastrointestinal tract

Endoscopy ◽  
2019 ◽  
Vol 51 (07) ◽  
pp. 646-652 ◽  
Author(s):  
Luiza Haendchen Bento ◽  
Mauricio Kazuyoshi Minata ◽  
Clelma Pires Batista ◽  
Bruno da Costa Martins ◽  
Luciano Henrique Lenz Tolentino ◽  
...  
Keyword(s):  
Survival Rate ◽  
Palliative Treatment ◽  
Survival Rates ◽  
Case Series ◽  
Gastric Body ◽  
Gi Tract ◽  
Cancer Disease ◽  
Primary Tumors ◽  
The Mean ◽  
Single Center Observational Study

Abstract Background Studies that describe metastases to the gastrointestinal (GI) tract are restricted to small case series. An increase in the frequency of this condition is expected, so it would be useful to better characterize the endoscopic aspects of metastasis to the GI tract. The aims of this study were to describe the frequency and endoscopic features of the lesions, and to analyze the survival rate after diagnosis of metastasis. Methods This was a retrospective, single-center, observational study, conducted between 2009 and 2017. Patients with metastasis to the GI tract were included. Results 95 patients were included. Melanoma (25.3 %), lung (15.8 %), and breast (14.7 %) were the most frequent primary tumors. The most common endoscopic presentation was a solitary, ulcerated lesion in the gastric body. Conventional biopsy was diagnostic in 98.9 % of the cases. The mean and median survival rates were 13.3 months (95 % confidence interval [CI] 8.2 – 18.3) and 4.7 months (95 %CI 3.7 – 5.6), respectively. Palliative treatment with chemo- and/or radiotherapy after the diagnosis of the metastasis was related to a higher survival rate. Conclusions Melanoma, lung, and breast cancer were the most common primary tumors to metastasize to the GI tract. The endoscopic features could not predict the primary site of the tumor. The finding of metastasis in the GI tract is related to the final stage of the cancer disease but patients who received palliative treatment with chemo- and/or radiotherapy after diagnosis of GI metastasis had higher survival rates.

Age distribution of breeding female Antarctic fur seals in relation to changes in population growth rate

1990 ◽  
Vol 68 (10) ◽  
pp. 2209-2213 ◽  
Author(s):  
I. L. Boyd ◽  
N. J. Lunn ◽  
P. Rothery ◽  
J. P. Croxall
Keyword(s):  
Population Growth ◽  
Survival Rates ◽  
Age Distribution ◽  
Adult Survival ◽  
South Georgia ◽  
Breeding Female ◽  
Fur Seals ◽  
Rate Of Increase ◽  
The Mean ◽  
Antarctic Fur Seals

The age distribution of breeding female Antarctic fur seals at Bird Island, South Georgia, in 1988 was compared with the age distribution of a sample obtained in 1971–1973. The mean age in 1971–1973 was 7.41 (SE = 0.26) years and in 1988 it was 6.93 (SE = 0.20) years. After correction for age-dependent arrival time at the pupping beach in 1988, the mean age was 6.22 (SE = 0.14 years), which was significantly lower than in 1971–1973. Indicators of population size suggested that population growth at Bird Island had declined to below 3% annually by 1988 compared with rapid growth (17%) in 1958–1972. Exponential models fitted to the frequency distribution of age-classes greater than age 5 years and corrected for the rate of increase of the population gave adult survival rates of 0.66 (SE = 0.03) and 0.88 (SE = 0.02) for the 1988 and 1971–1973 samples, respectively. The reduced apparent adult survival rate in the 1988 sample was probably caused by emigration brought about by high densities of females on the pupping beaches. There are few signs from this analysis that the fur seal population at South Georgia is close to carrying capacity.

scholarly journals No difference of survival between cruciate retaining and substitution designs in high flexion total knee arthroplasty

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gun-Woo Kim ◽  
Quan He Jin ◽  
Jun-Hyuk Lim ◽  
Eun-Kyoo Song ◽  
Jong-Keun Seon
Keyword(s):  
Survival Rate ◽  
Survival Rates ◽  
Cruciate Retaining ◽  
High Flexion ◽  
Significant Difference ◽  
Ankle Angle ◽  
Total Knee ◽  
The Mean ◽  
Hip Knee Ankle Angle

AbstractThe aim of this study was to compare the long-term implant survival and outcomes in patients with high-flexion cruciate-retaining (CR) or high-flexion posterior cruciate-substituting (PS) knee implants. A total of 253 knees (CR group: 159 vs. PS group: 94) were available for examination over a mean follow-up of 10 years. Clinical outcomes were assessed including the Hospital for Special Surgery score, Knee Society score and Western Ontario and McMaster Universities Osteoarthritis Index score at the final follow-up. Radiologic measurements were also assessed including the hip-knee-ankle angle and radiolucent lines according to the KSS system at the final follow-up. The survival rate was analyzed using the Kaplan–Meier method. At the final follow-up, the mean total HSS scores were similar between the two groups (p = 0.970). The mean hip-knee-ankle angle at the final follow-up was similar between groups (p = 0.601). The 10- and 15-year survival rates were 95.4% and 93.3% in the CR group and 92.7% and 90.9% in the PS group, respectively, with no significant difference. Similar clinical and radiographic outcomes could be achieved with both the high-flexion CR and high-flexion PS total knee designs without a difference in survival rate after a 10-year follow-up.

Sign in / Sign up

Export Citation Format

Share Document