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Evaluation of Accuracy and Precision of Downing Population Reconstruction
Author(s) -
DAVIS MICHELLE L.,
BERKSON JIM,
STEFFEN DAVID,
TILTON MARY K.
Publication year - 2007
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.2193/2006-427
Subject(s) - odocoileus , ursus , population , mortality rate , population growth , population size , statistics , demography , white (mutation) , geography , biology , ecology , mathematics , sociology , biochemistry , gene
ABSTRACT Downing population reconstruction uses harvest‐by‐age data and backward addition of cohorts to estimate minimum population size over time. Although this technique is currently being used for management of black bear ( Ursus americanus ) and white‐tailed deer ( Odocoileus virginianus ) populations, it had not undergone a rigorous evaluation of accuracy. We used computer simulations to evaluate the impacts of collapsing age classes and violating the assumptions of this technique on population reconstruction estimates and trends. Changes in harvest rate or survival over time affected accuracy of reconstructed population estimates and trends. The technique was quite robust to collapsing age classes as far as 3+ for bears and deer. This method would be suitable for estimating population growth rate (λ) for populations experiencing no trend in harvest rate or natural mortality rate over time. Our evaluation showed Downing population reconstruction to be a potentially valuable tool for managing harvested species with high harvest rates and low natural mortality, with possible application to black bear and white‐tailed deer populations.