Variation in body condition of impala and nyala in relation to social status and reproduction

The influence of social class and reproduction on the body condition of impala Aepyceros melampus and nyala Tragelaphus angasi was investigated using the Kidney Fat Index (KFI). Territorial male impala lost condition during the rut, while the KFls of bachelor impala remained unchanged. By the end of the dry season both territorial and bachelor impala males were in poorer condition. Male nyala had relatively low KFls with no significant seasonal variation. Pregnant impala and nyala had higher KFls than non-pregnant females. It is suggested that if the KFI is used to assess body condition the differences attributable to social classes and reproductive state must be considered.