Since 2003, The Zambia Lion Project (ZLP) Has Been Conducting Genetic And Demographic Research On The African Lion, Panthera leo, In Zambia. The Goal Of The ZLP Is To Assess The Current Status Of Lions, And To Develop And Promote Practices That Ensure The Long- Term Sustainability And Health Of Zambia's Lion Populations.
Studies have shown that removal of older (>6 years) male lions has minimal negative impacts on the remaining population. In particular, selective removal of older males had minimal disruption effect on pride structure, reproduction, and cub survivorship. Previously however, it had been questioned whether the same standards used in assessing age of Tanzania's lions, specifically extent of mane development and nose pad coloration, could accurately be applied to lions in Zambia. A regional study was needed.
To address this data gap, the ZLP expanded its scope of work in 2006 and initiated a study to age Zambia's trophy lions. Working in partnership with Zambia Wildlife Authority (ZAWA) and in close cooperation with the Professional Hunters Association of Zambia (PHAZ) and the Safari Hunters and Operators Association of Zambia (SHOAZ), the goal of the lion aging study is to be pro-active in developing an age-based selection program for lion hunting in Zambia. Specifically, this study seeks to assess the ages of lions currently taken in Zambia, and to compare visual characteristics of trophy lions to their ages. Lions are being aged using two methods: 1) x-ray of a tooth to examine the extent of the pulp cavity, and 2) cementum annuli ring analysis.
Teeth obtained from lions taken during the 2006 season were analyzed using both of the methods described above. However, subsequent comparison of the results obtained from each of the two methods revealed some discrepancies in the aging of individual lions. For example, some lions that were aged as "adult" by the tooth x-ray analysis subsequently displayed fewer cementum rings than expected for an adult. If aged by cementum ring counts only, these animals would have been aged as < 5 years old. Conversely, other individuals whose tooth x- rays indicated they were "young adults" had more cementum rings than expected.
In Year 2 of the Lion Aging Study, lions taken during the 2007 season were again sampled in order to provide a larger e.g., statistically significant sample size of hunted lion ages, and to continue the calibration of visual characteristics with age. In addition, in efforts to address the discrepancies arising from the 2006 results, the study was broadened to include a "double- blind" test of the aging methods being employed.
Zambia's location in south-central Africa suggests it could play a crucial role in lion conservation, however, little is known regarding the country's lions. The African lion is a keystone species in biologically rich and diverse ecosystems. In addition, Zambia relies on commercial hunting and photo-tourism of lions for revenue. The Zambia Wildlife Authority (ZAWA) urgently needs empirical data on lion populations in Zambia that can be used to develop sound long-term management policies that ensure viable lion populations for both consumptive and non-consumptive purposes.