title: Age Estimation of African Lions Panthera leo by Ratio of Tooth Areas.
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.
authors.affiliation: Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, California, United States of America.
authors.forename: Paula A
authors.identifier: http://orcid.org/0000-0002-1814-6265
authors.initials: PA
authors.lastname: White
authors.affiliation: Tanzania Wildlife Research Institute, Arusha, Tanzania.
authors.forename: Dennis
authors.initials: D
authors.lastname: Ikanda
authors.affiliation: Center of Epidemiology, Biostatistics and Medical Information Technology, Department of Biomedical Science and Public Health, Polytechnic University of Marche, Ancona, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrante
authors.affiliation: IGF-International Foundation for Wildlife Management, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Chardonnet
authors.affiliation: IGF-International Foundation for Wildlife Management, Paris, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Mesochina
authors.affiliation: AgEstimation Project, Institute of Legal Medicine, University of Macerata, Macerata, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Cameriere
mesh_terms: D000366:Age Determination by Teeth / Q000379:methods*; D000375:Aging / Q000502:physiology*; D000818:Animals; D005260:Female; D008045:Lions; D008297:Male; D011157:Population Dynamics; D012044:Regression Analysis; D014070:Tooth / Q000000981:diagnostic imaging*; D014961:X-Ray Diffraction