Assessing age in the desert tortoise Gopherus agassizii: Testing skeletochronology with individuals of known age
Eight desert tortoises Gopherus agassizii from a long-term mark-recapture study in the Mojave Desert, Nevada, USA, afforded an opportunity to examine the accuracy of skeletochronological age estimation on tortoises from a seasonal, yet environmentally erratic environment. These 8 tortoises were marked as hatchlings or within the first 2 yr of life, and their carcasses were salvaged from predator kills. Using d blind protocol, 2 skeletochronological protocols (correction-factor and ranking) provided age estimates for a set of 4 bony elements (humerus, scapula, femur, ilium) from these tortoises of known age. The age at death of the tortoises ranged from 15 to 50 yr. The most accurate protocol - ranking using the growth layers within each of the 4 elements - provided estimates from 21 to 47 yr, with the highest accuracy from the ilia. The results indicate that skeletochronological age estimation provides a reasonably accurate method for assessing the age at death of desert tortoises and, if used with a large sample of individuals, will provide a valuable tool for examining age-related mortality parameters in desert tortoise and likely in other gopher tortoises (Gopherus). ?? Inter-Research 2008.
Citation Information
Publication Year | 2008 |
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Title | Assessing age in the desert tortoise Gopherus agassizii: Testing skeletochronology with individuals of known age |
DOI | 10.3354/esr00108 |
Authors | A.J. Curtin, G.R. Zug, P.A. Medica, J.R. Spotila |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Endangered Species Research |
Index ID | 70033739 |
Record Source | USGS Publications Warehouse |