Demography of lions in relation to prey and habitat in the Maasai Mara National Reserve, Kenya

Abstract

AbstractWe studied lion demography in the Maasai Mara National Reserve between September 1990 and April 1992, with a special emphasis on the spatial and seasonal variation in demographic characteristics. Lion density (0.2–0.4 lions km−2) and pride size (range 8–48) were high because of a high resident prey biomass (10 335 kg km−2) augmented by migrant prey to 26 092 kg km−2 in the dry season. Overall, their sex ratio was almost at parity and varied neither spatially nor seasonally. Sex ratio was even among subadults but skewed toward males and females among cubs and adults, respectively. This implies an increasing differential mortality of males with age through subadulthood. The age ratio varied seasonally because of a birth peak in March–June and an influx of subadults into the reserve during July–August, coincident with increases in migrant prey. The birth peak was apparently preceded by another peak in mating activity falling between November and May. Further research should investigate the precise causes of the biased cub sex ratio, low lion density in the Mara Triangle and the higher ratio of subadults in Musiara than in the Mara Triangle or Sekenani.