Age and Growth Histories of Desert Tortoises Using Scute Annuli
Germano DJ. 1988. Age and Growth Histories of Desert Tortoises Using Scute Annuli. Copeia. 1988(4):914-920
Scute annuli, produced during the first 20-25 yr of initial, rapid growth, can be used to age young desert tortoises (Gopherus agassizii). Regression analysis did not show a difference between age and the number of scute rings counted on the carapace for 13 desert tortoises from the Nevada Test Site, although ring counts on most individuals were 1-2 rings less than age. The number of scute rings exactly matched the ages of six desert tortoises raised in captivity. No significant differences were found between the estimated length of the plastron based on selected scute rings and the actual length of the plastron as recorded 7-12 yr previous to my handling of individual tortoises from the Nevada Test Site, which supports the accuracy of the ring counts. The number of bone rings did not differ significantly from the number of scute rings for 16 preserved desert tortoises. Growth histories of individual tortoises can be determined from scute annuli.
- Type
- Journal Article
- Authors
- Germano, David
- Units
- MOJA
- Keywords
- Bone rings, carapace, Gopherus agassizii (Desert Tortoise), Growth rings, Plastron, Reptilia (Reptiles), Scute annuli, Scute rings, Testudines, Testudinidae (Tortoises)