Abstract:
Small mammals particularly rodents, are considered the primary natural hosts of plague.
Literature suggests that plague persistence in natural foci has a root cause in soils. The objective of this
study was to investigate the relationship between on the one hand landforms and associated soil
properties, and on the other hand small mammals and fleas in West Usambara Mountains in Tanzania, a
plague endemic area. Standard field survey methods coupled with Geographical Information System (GIS)
technique were used to examine landform and soils characteristics. Soil samples were analysed in the
laboratory for physico-chemical properties. Small mammals were trapped on pre-established landform
positions and identified to genus/species level. Fleas were removed from the trapped small mammals and
counted. Exploration of landform and soil data was done using ArcGIS Toolbox functions and descriptive
statistical analysis. The relationships between landforms, soils, small mammals and fleas were established
by generalised linear regression model (GLM) operated in R statistics software. Results show that
landforms and soils influence the abundance of small mammals and fleas and their spatial distribution. The
abundance of small mammals and fleas increased with increase in elevation. Small mammal species
richness also increases with elevation. A landform-soil model shows that available phosphorus, slope
aspect and elevation were statistically significant predictors explaining richness and abundance of small
mammals. Fleas’ abundance and spatial distribution were influenced by hill-shade, available phosphorus
and base saturation. The study suggests that landforms and soils have a strong influence on the richness
and evenness of small mammals and their fleas’ abundance hence could be used to explain plague
dynamics in the area.
