Population biology of African buffalo (Syncerus caffer) at Hluhluwe-iMfolozi Park, South Africa

Abstract

This study examines the population biology of African buffalo (Syncerus caffer Sparrman) at Hluhluwe-iMfolozi Park (HiP), South Africa. An analysis of buffalo census data covering the period from 1956 to 2006 shows that the population has a moderate intrinsic growth rate at around 12% per annum, which is similar to growth rates of buffalo populations measured elsewhere. The population is subject to density dependence when the number of buffalo in the park exceeds approximately 3500 animals. In most years over the past 25 years, the population has exceeded this threshold, and net annual population growth has averaged around 5%. Periods of buffalo population decline always coincided with heavy buffalo removals, suggesting limited resilience of the population to such disturbances. Demographic data from 826 buffalo in 12 herds, captured in 2001–2002, were used to parameterize an age-structured buffalo population model. The model yields an annual population growth rate of 4.05%, similar to recent growth estimates from buffalo censuses at HiP. The predicted stable age distribution is very similar to the age distribution observed in the captured population sample. Elasticity analysis of the model indicates that population growth in buffalo is most sensitive to adult and juvenile survival, and less sensitive to recruitment parameters and survival of old animals. Buffalo populations might therefore be expected to be more vulnerable to mortality factors affecting prime-aged adults than those affecting juveniles or senescent individuals.