Estimation of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park using a capture–recapture survey

Abstract

A previous estimate of the lion (Panthera leo) population in the southwestern  Kgalagadi Transfrontier Park (KTP) was made over 20 years ago. This together with increased fears regarding the viability of the population as a result of recent killings of roaming animals, an observed increase in non-violent mortalities during 1996, and possible reduced genetic viability due to suspected isolation, prompted another investigation. Between October 1996 and December 1996, 68 lions were captured and marked and subjected to two recapture (resighting) samples. The minimum estimate derived from direct enumeration of marked and unmarked individuals is between 100–103 individuals. Assessment of the adult and subadult population using the Lincoln-Petersen estimator and the software program NOREMARK gives a figure between 92 and 125. The current estimate is below the previous estimate of between 113 and 140 lions. Lion densities of 1.2 adult and subadult lions/100 km2 in the semi-arid southern Kalahari are considerably lower than those in more mesic regions. Furthermore, there appears to be some demographic variability with the ratio of females to males being twice as high as that recorded 20 years ago.

Keywords: Lincoln-Petersen, Kalahari, semi-arid, carnivore, population estimate, demography.