Abstract:
Rodents can quickly respond to land use changes whether the change positively or negatively
influences their life. In the case of positive influence, rodents exploit the additional food resources
and increase their numbers to potential pest level, especially in the absence of predators. Such a
population increase can potentially be harmful to humans due to the diseases that rodents carry and
the costs due to damage to crops, stored foods and personal possessions that they may cause to small
holder farmers. Small holder farmers live in a mixed landscape that is constantly changing. Such
changes are changes in land use and they do not only affect rodent population dynamics and species
composition, but also their ecosystem services and integrity. Understanding how rodents respond to
these land use changes (crop, grazing and settlement) will not only improve the implementation of
Ecologically Based Rodent Management (EBRM), but might also enable the monitoring of
ecosystem integrity. Rodent trapping was conducted in two different study sites which experience
different rainfalls during wet and dry season. A 70 m x 70 m grid was set in three different land uses
(crops, grazing and settlement) per study site. A mark-recapture technique was applied and all
captures were processed on a temporal station on site. In all grids at a distance of 30 m a line of 20
snap traps were set. With the tapping effort of 1470 trap nights per season for both seasons in this
study we captured 839 rodents and 2 shrews, which represented 469 individual rodents and 1
individual shrew. At Vyeboom, cropping land use had the highest number capture (210) and the
highest in species richness (9) rodent species and 1 shrew. The settlement land use was second at 144
captures for 8 rodent species and lastly the grazing land use at 80 captures with 7 rodent species. On
the other hand, at Ka-Ndengeza also cropping land use had the highest capture (186) with highest
richness at 7 rodent species. When it comes to settlement and grazing, settlement was second (129)
to cropping in terms of the number of capture but last in terms of richness (5) whilst grazing was last
in terms of number of captures 92 and second in terms of richness (6). Despite the high diversity of
rodents, only Mastomys natalensis, Gerbilliscus leucogaster, Steatomys pratensis and Rattus rattus
were captured in meaningful sample sizes to allow for robust density estimation. Similarly there
were strong seasonal effects on rodent captures, with almost no captures during the wet season.
