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Age Estimation of African Lions Panthera leo by Ratio of Tooth Areas.

White PA, Ikanda D, Ferrante L, Chardonnet P, Mesochina P, Cameriere R - PLoS ONE (2016)

Bottom Line: Improved age estimation of African lions Panthera leo is needed to address a number of pressing conservation issues.Derived from measurements taken from lions aged 3-13 years for which exact ages were known, the formula explains 92% of the total variance.The method of calculating the pulp/tooth area ratio, which has been used extensively in forensic science, is novel in the study of lion aging.

View Article: PubMed Central - PubMed

Affiliation: Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, California, United States of America.

ABSTRACT
Improved age estimation of African lions Panthera leo is needed to address a number of pressing conservation issues. Here we present a formula for estimating lion age to within six months of known age based on measuring the extent of pulp closure from X-rays, or Ratio Of tooth AReas (ROAR). Derived from measurements taken from lions aged 3-13 years for which exact ages were known, the formula explains 92% of the total variance. The method of calculating the pulp/tooth area ratio, which has been used extensively in forensic science, is novel in the study of lion aging. As a quantifiable measure, ROAR offers improved lion age estimates for population modeling and investigations of age-related mortality, and may assist national and international wildlife authorities in judging compliance with regulatory measures involving age.

No MeSH data available.


Related in: MedlinePlus

Plots of Residuals.Plots of residuals against known ages (left, a) and of known against estimated ages (right, b) using regression model.
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pone.0153648.g003: Plots of Residuals.Plots of residuals against known ages (left, a) and of known against estimated ages (right, b) using regression model.

Mentions: The regression equation provided a point estimate of age for each given value of ROAR. The straight line obtained from reporting the estimated age as function of ROAR is presented in Fig 2. The residual standard error was 0.82 years and the median of the residuals was 0.43 years, with IQR = 0.38 years. The accuracy of the method was MAE = 0.60 years. The residual plot (Fig 3a) showed no obvious pattern, and only three observations appeared to be possible outliers. The plot of known versus estimated age (Fig 3b) showed that the regression model fits the trend of the data reasonably well. Hence, both diagnostic plots supported our chosen model.


Age Estimation of African Lions Panthera leo by Ratio of Tooth Areas.

White PA, Ikanda D, Ferrante L, Chardonnet P, Mesochina P, Cameriere R - PLoS ONE (2016)

Plots of Residuals.Plots of residuals against known ages (left, a) and of known against estimated ages (right, b) using regression model.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835051&req=5

pone.0153648.g003: Plots of Residuals.Plots of residuals against known ages (left, a) and of known against estimated ages (right, b) using regression model.
Mentions: The regression equation provided a point estimate of age for each given value of ROAR. The straight line obtained from reporting the estimated age as function of ROAR is presented in Fig 2. The residual standard error was 0.82 years and the median of the residuals was 0.43 years, with IQR = 0.38 years. The accuracy of the method was MAE = 0.60 years. The residual plot (Fig 3a) showed no obvious pattern, and only three observations appeared to be possible outliers. The plot of known versus estimated age (Fig 3b) showed that the regression model fits the trend of the data reasonably well. Hence, both diagnostic plots supported our chosen model.

Bottom Line: Improved age estimation of African lions Panthera leo is needed to address a number of pressing conservation issues.Derived from measurements taken from lions aged 3-13 years for which exact ages were known, the formula explains 92% of the total variance.The method of calculating the pulp/tooth area ratio, which has been used extensively in forensic science, is novel in the study of lion aging.

View Article: PubMed Central - PubMed

Affiliation: Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, California, United States of America.

ABSTRACT
Improved age estimation of African lions Panthera leo is needed to address a number of pressing conservation issues. Here we present a formula for estimating lion age to within six months of known age based on measuring the extent of pulp closure from X-rays, or Ratio Of tooth AReas (ROAR). Derived from measurements taken from lions aged 3-13 years for which exact ages were known, the formula explains 92% of the total variance. The method of calculating the pulp/tooth area ratio, which has been used extensively in forensic science, is novel in the study of lion aging. As a quantifiable measure, ROAR offers improved lion age estimates for population modeling and investigations of age-related mortality, and may assist national and international wildlife authorities in judging compliance with regulatory measures involving age.

No MeSH data available.


Related in: MedlinePlus