Using Age Structure Data from Changing Populations

1988 ◽  
Vol 25 (2) ◽  
pp. 373 ◽  
Author(s):  
L. L. Eberhardt
Keyword(s):  
Structure Data ◽  
Age Structure

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 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.

scholarly journals Rapid Lateral Extraction of Otoliths that Maintains the Integrity of Fish Product to Improve Access to Catches and Reduce Potential Sampling Biases

2016 ◽  
Vol 9 (1) ◽  
pp. 26-28 ◽  
Author(s):  
Corey B. Wakefield ◽  
Dion K. Boddington ◽  
Stephen J. Newman
Keyword(s):  
Structure Data ◽  
Age Structure ◽  
Sample Collection ◽  
Simple Method ◽  
External Appearance ◽  
Representative Sampling ◽  
Stock Assessments ◽  
Fish Product ◽  
Data Representative ◽  
Improve Access

The capacity to sample otoliths of fish from commercial, recreational, artisanal or subsistence catches can be constrained if the dissection process results in alterations to their external appearance and thus reduces its value and/or shelf life. There can also be significant biases incorporated into the collection of otolith samples if access is only granted relative to the size of the fish (i.e. if smaller fish are sold whole). To reduce such limitations, we herein describe a rapid and simple method of lateral otolith extraction that maintains the integrity of the fish product, and thus reduces potential biases in sample collection for age structure data. Representative sampling is an important consideration for the collection of age structure data when it is intended to be used in fisheries stock assessments.

A Test of Paleodemographic Models

1978 ◽  
Vol 43 (4) ◽  
pp. 715-729 ◽  
Author(s):  
Roberta L. Hall
Keyword(s):  
Population Structure ◽  
Life Expectancy ◽  
Life Table ◽  
Structure Data ◽  
Age Structure ◽  
Census Data ◽  
Research Tool ◽  
Aged Sample ◽  
Demographic Processes ◽  
Archaeological Reconstruction

AbstractPaleodemography is a useful adjunct to archaeological reconstruction, but as a research tool it is relatively new and requires further study. This paper reports on a project in which the life-table method of modeling demographic processes, based on a sexed and aged sample from the community ossuary, was tested against census records of the population structure. Data were taken from cemetery headstones in a township in central Indiana, spanning the period from its first settlement by Euroamerican farmers in 1830 through 1972. Life-expectancy estimates produced from the life tables were essentially identical to those produced from federal census data. Paleodemographic models of population structure were statistically different from census tabulations but were similar in form, representing a "smoothed" estimate of age structure.

Age structure, survivorship and life expectancy for future in Murree forests

2020 ◽  
Vol 53 (3) ◽  
Author(s):  
Afsheen Khan ◽  
S. Shahid Shaukat ◽  
Moinuddin Ahmed
Keyword(s):  
Life Expectancy ◽  
Age Structure

Age Structure and Some Growth Parameters in a Population of Bombina bombina (L., 1761) from Turkey

2018 ◽  
Vol 25 (3) ◽  
pp. 221 ◽  
Author(s):  
Ufuk Bülbül ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
Zeynep Mutanoğlu Kaya ◽  
Halime Koç ◽  
...  
Keyword(s):  
Age Structure ◽  
Growth Parameters ◽  
Bombina Bombina
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