AGE CRITERIA FOR THE AFRICAN ELEPHANT

作者：R. M. Laws · 发表于：African Journal of Ecology · 年份：1966 · DOI：10.1111/j.1365-2028.1966.tb00878.x · 被引用次数：486 · 研究领域：Wildlife Ecology and Conservation、Genetic and phenotypic traits in livestock、Animal Diversity and Health Studies

Summary 1. The paper is based on a collection of 385 lower jaws of the African elephant (Loxodonta a. africana Blumenbach) from western Uganda. 2. Thirty age groups are described and illustrated, which are related to the progress of eruption and wear of the six teeth in each side of the lower jaw. 3. Correct identification of individual teeth in the series is essential and several checks are described. Thus, when length is plotted against width for the six teeth the points fall into six well ‐ defined groups. Frequency distributions of laminary indices and lamella numbers support the belief that teeth have been correctly identified, but overlapping, distributions preclude identification on these characters alone. 4. The presence of abnormal seventh molars in four jaws is described. 5. Chronological ages have been assigned to the relative age groups. Information on age and growth of captive animals has been considered and the general form of the growth curve established. Arbitrary estimates of the intervals between successive age groups were made and subsequently checked against growth and seasonal ridges on the roots. These indicate an upper age limit of about 60 years, which is compatible with fuller information on Indian elephants. 6. Growth curves support the validity of the ages assigned. Asymptotic heights at shoulder (∞) are respectively 317 cm and 298 cm for males from Murchison Falls and Queen Elizabeth National Parks. For females no distinction is made (because the s...