Effects of Hunting on Age Structure and Survival Rates of Red Fox in Eastern Hokkaido

1982 ◽  
Vol 46 (3) ◽  
pp. 781 ◽  
Author(s):  
Masaaki Yoneda ◽  
Koji Maekawa
Keyword(s):  
Age Structure ◽  
Red Fox ◽  
Survival Rates

Estimating Survival Rates with Age-Structure Data

1998 ◽  
Vol 62 (2) ◽  
pp. 779 ◽  
Author(s):  
Mark S. Udevitz ◽  
Brenda E. Ballachey
Keyword(s):  
Structure Data ◽  
Age Structure ◽  
Survival Rates

scholarly journals Forecast of the Number of Doctorate Holders in Russia

2019 ◽  
Vol 29 (4) ◽  
pp. 510-528
Author(s):  
Valery A. Gurtov ◽  
Liudmila V. Shchegoleva ◽  
Sergey I. Pakhomov
Keyword(s):  
Age Structure ◽  
Statistical Data ◽  
Survival Rates ◽  
Age Distribution ◽  
Cumulative Distribution ◽  
High Tech ◽  
Teaching Staff ◽  
Scientific Publications ◽  
Aggregated Data ◽  
Age Category

Introduction. Personnel of the highest scientific qualification are the basis of staffing the competitive development all sectors of the national economy of the Russian Federation. At the same time, there is no reliable statistical information about the total number of Candidates and Doctors of Sciences and their age structure. Scientific publications do not present approaches to carry out the estimate of the number of persons with scientific degrees. Materials and Methods. The article proposes a model for calculating the age-specific number of Candidates and Doctors of Sciences on the basis of annual statistical data on the number of defenses of candidate and doctoral theses and survival rates. Since the detailed data are presented only for the period starting from 2008, and the aggregated data are not known for all years, the corresponding interpolation methods are proposed to restore the missing data. According to the proposed models, calculations of estimates of the number of Candidates and Doctors of Sciences are made, approximation functions are constructed. The results of the calculations were verified on the basis of statistical data on the number of researchers with a degree of Candidate and Doctor of Sciences in different sectors of the economy and the number of Candidates and Doctors of Sciences among the teaching staff of universities. Results. The results of the study are 6 models for calculating the number of Candidates and Doctors of Sciences, approximation function of the multiplicative survival coefficient for persons with scientific degrees, approximation functions of the age distribution of the applicants of degrees of Candidate and Doctor of Science, approximation functions of agerelated and cumulative distribution of the number of Candidates and Doctors of Sciences, quantitative estimates of the number of Candidates and Doctors of Sciences in 2019. Discussion and Conclusion. The proposed models have shown their adequacy. As a result of the calculations, it was found that the number of Candidates of Sciences in the age category of 20–80 years is 468,000 people, and the number of Doctors of Sciences in the age category of 30–90 years is 72,000 people. According to the obtained numerical values, approximating functions were constructed to get the number of Candidates and Doctors of Sciences in any age range. Since the system of personnel of the highest scientific qualification is sufficiently inert, the data obtained of age structure of the personnel of the highest scientific qualification will retain its character for at least another 10 years. The obtained estimates of the number of persons with scientific degrees allow us to characterize the personnel potential for decision-making in the management of high-tech sectors of the economy. The constructed models can be used to solve the problems of forecasting in the field of development of science-intensive technologies and in higher education for the training of highly qualified scientific personnel and replenishment of the scientific community.

Cranial ontogenetic variability, sex ratio and age structure of the Red fox

2010 ◽  
Vol 5 (6) ◽  
pp. 894-907 ◽  
Author(s):  
Martina Hartová-Nentvichová ◽  
Miloš Anděra ◽  
Vlastimil Hart
Keyword(s):  
Sex Ratio ◽  
Age Structure ◽  
Growth Pattern ◽  
Red Fox ◽  
Growth Patterns ◽  
First Year ◽  
Red Foxes ◽  
Female Ratio ◽  
One Year ◽  
First Year Of Life

AbstractDescribing the sex ratio, age structure of the population and ontogenetic variability of Red fox, Vulpes vulpes (Canidae, Carnivora) skull parameters, this study is based on 416 male and 289 female skulls collected in the Czech Republic. The skulls analysed came from feral individuals, that were shot by hunters. The male to female ratio was 1:0.69 regarding the whole population. Individuals younger than one year prevailed in the population (54% males, 48% females were in their first year of life). Four growth patterns of skull dimensions were described. The first group included mainly skull length dimensions (e.g. condylobasal length). They grew rapidly until the sixth month of life, becoming stabilised afterwards. The second group comprised parameters that were stable throughout the life (e.g. cheek tooth rows). Measurements representing the third growth pattern showed continual growth (mainly width dimensions, e.g. zygomatic breadth). Conversely, smaller dimensions of postorbital breadth were observed after the sixth month of life. Postorbital breadth represented the fourth growth pattern. It was concluded, that male and female Red foxes had similar ontogenetic skull development, even though there were some differences, e.g. in jugular breadth, which increased after the age of six months in males unlike in females.

scholarly journals Incorporating habitat suitability and demographic data for developing a reintroduction plan for the critically endangered yellow spotted mountain newt, Neurergus derjugini

2019 ◽  
pp. 282-294
Author(s):  
Somaye Vaissi
Keyword(s):  
Age Structure ◽  
Captive Breeding ◽  
Demographic Data ◽  
Life Stage ◽  
Survival Rates ◽  
Age Groups ◽  
Old Adults ◽  
Before And After ◽  
Maximum Entropy Modelling ◽  
Age At Maturation

In reintroduction programmes for amphibians, data on age structure in hosting populations and choices of life stage or age groups in releasing captive bred individuals are often missing. Similarly, employing site selection procedures for selecting appropriate reintroduction locations are often neglected. Here, we obtained data on longevity, age at maturation, and age structure from skeletochronological data in a free living population of the yellow spotted mountain newt, Neurergus derjugini. A maximum longevity of 13 years for males and 12 years for females showed that N. derjugini is a long living newt with a stable age structure. We also employed maximum entropy modelling, geographic information system, and multicriteria decision analysis to obtain ranked suitability scores for reintroduction sites. Finally, we determined post-release survival rates for different life stage and age groups of N. derjugini including 30 eggs and 60 individuals of six-months old larvae, one and three-year old juveniles, and six-year old adults (15 each) born and raised in a captive-breeding facility and released into mesh enclosures in a selected stream. Over 10 visits to the site before and after overwintering, the survival rates for eggs, larvae, one and three-year juveniles and six-year old adults were 25, 80, 86.66, 93.33 and 53.33 % respectively. Applying survival rates obtained from current experimental reintroductions through a static life table suggest that an optimal release strategy to arrive at a numerical target of 100 adults aged three can be achieved by reintroduction of 650 fertilised eggs and fostering them in meshed enclosures in the selected stream.

scholarly journals Population Aging in Russia and China: Features and Socioeconomic Risks

2020 ◽  
Vol 16 (4) ◽  
pp. 36-48
Author(s):  
Valentina Dobrokhleb ◽  
Vitaly Barsukov
Keyword(s):  
Age Structure ◽  
World Economy ◽  
Aging Process ◽  
Population Aging ◽  
Survival Rates ◽  
Negative Consequences ◽  
Healthy Life ◽  
Brics Countries ◽  
Demographic Challenges ◽  
Demographic Aging

The article is devoted to one of the main demographic challenges for Russia and China - population aging. In the first part of the work, the main trends in the transformation of the age structure are considered, and the conclusion is drawn about the heterogeneity of the demographic aging process in the studied countries. It was revealed that Russia, which entered the phase of population aging earlier than China, practically does not progress in terms of growth in survival rates and healthy life expectancy of the population, which is reflected in a noticeably lower rate of deepening of old age in the age structure. The aging process of the Chinese population is noticeably more balanced due to the absence of serious gender differences in mortality rates, as well as due to the significantly lower internal differentiation of regions. The second part of the article analyzes the existing and probable socio-economic risks caused by the aging of the age structure of the population of Russia and China. It has been determined that for both countries, the problem of intensive aging of the population is becoming one of the key ones. Even now, the BRICS countries (all of which, with the exception of Russia, have seen a significant increase in the share and size of the older generation) are showing a decline in economic growth. After the completion of the stage of implementation of the demographic dividend, these indicators may fall to extremely low values, which, under a certain scenario, may become a catalyst for the emergence of a new planetary economic crisis, given the contribution of the BRICS countries to the world economy (especially China). Overcoming the negative consequences of the phenomenon of population aging is possible only with the development of a systematic policy for maintaining sustainable socio-economic development in new demographic conditions

scholarly journals Estimating survival rates with time series of standing age-structure data

Ecology ◽  
2012 ◽  
Vol 93 (4) ◽  
pp. 726-732 ◽  
Author(s):  
Mark S. Udevitz ◽  
Peter J. P. Gogan
Keyword(s):  
Time Series ◽  
Structure Data ◽  
Age Structure ◽  
Survival Rates

A Fur Seal Population Model Based on Age Structure Data

1990 ◽  
Vol 47 (1) ◽  
pp. 122-127 ◽  
Author(s):  
L. L. Eberhardt
Keyword(s):  
Adult Female ◽  
Structure Data ◽  
Age Structure ◽  
Survival Rates ◽  
Reproductive Rate ◽  
Chi Square ◽  
Female Population ◽  
Fur Seals ◽  
Female Survival ◽  
Major Period

About 16 000 female fur seals from the Pribilof Islands population were aged in pelagic collections from 1958 through 1974. A simple simulation model of the female population was used to vary population parameters until a minimum chi-square value was achieved for the fit of simulated annual age structures to those observed in the pelagic collection. Population trajectories resulting from either a diminishing reproductive rate or diminishing adult female survival rate approximated estimated pup population sizes, which were not used in developing the model, except that a subset of five observations was used to constrain model trajectories to the general neighborhood of the observed pup populations. The main finding of the study was that adult female survival rates varied sharply during the 1964 through 1974 period, after the major period of harvests of female fur seals. Further study of the age structure data may thus be useful in evaluating the poorly understood long-term reduction in abundance of Pribilof fur seals.

Populations of the Murray River Tortoise, Emydura (Chelodina): the Effect of Egg Predation by the Red Fox, Vulpes vulpes

1983 ◽  
Vol 10 (2) ◽  
pp. 363 ◽  
Author(s):  
MB Thompson
Keyword(s):  
Age Structure ◽  
Vulpes Vulpes ◽  
Red Fox ◽  
South Australia ◽  
Egg Predation ◽  
Murray River ◽  
Nesting Sites ◽  
Chelodina Longicollis

Regular inspection of tortoise nesting sites along the Murray River in South Australia showed that over 96% of eggs were taken by predators. Endemic predators accounted for less than 3% of this total. Foxes took the rest. Comparison of the age structure of the Emydura species in the Murray and Cooper Creek revealed that the populations were very different. The Murray population of Emydura rnacquarii contained a disproportionately large number of old individuals; this difference was attributed to egg losses. The same was true for Chelodina longicollis. As these old animals die recruitment of juveniles into the population will probably fall even further. As a result tortoise populations in the Murray will decline.

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