Recent studies on elephant populations from East Africa and from Zambia have suggested that as population density increases, so does the mean age at puberty and the mean calving interval. At the same time there is also an increase in the proportion of old females that are reproductively inactive. By constructing elephant population models, it is possible to investigate the extent to which these “homeostatic mechanisms” will regulate an elephant population. The models indicate that a change in the duration of the calving interval is more important as a population regulating mechanism than a change in the age at puberty, and that the proportion of old reproductively inactive females is of little significance. The importance of neonatal mortality in controlling population growth is emphasised by the models, and they also show that an annual population increase of 4% would be close to the maximum value.