Population dynamics of Lemniscomys rosalia (Muridae: Rodentia) in a Swaziland grassland: effects of food and fire

Abstract

The effects of food supplementation on a population of Lemniscomys rosalia were studied experimentally in a grassland habitat in Swaziland. Food was added bi-weekly to two I-ha grids, while a single I-ha grid served as the control. Rodent traps were set monthly over a 12 month period. Food supplementation may have affected the density of L. rosalia, but did not affect any other features of the population. Breeding commenced in September and ended in April (males) and May (females). Recruitment of juveniles occurred between January and March. Adult mean body mass increased from a low in winter (June/July) to a high in late summer (February). The drop in mean body mass in autumn was due to the disappearance of heavy adults and entry of the lighter subadults into the population. Mean survival of L. rosalia was low; 81% of all captured individuals disappeared within four months. An unscheduled fire burnt part of the study area and hence allowed an assessment of the effect of fire on L. rosalia. The fire did not cause undue mortality of L rosalia, however, burnt areas were avoided for three months until grass cover had sufficiently increased.

S. Afr.l Zool. 1997,32(4)