Relative efficiency of three types of small mammal traps in an African rainforest

Numerous studies have compared the efficiency of different types of traps for the survey of small mammals in temperate Countries, but such comparative studies are strikingly fewer in tropical habitats. We compared the efficiency of three types of traps for sampling small mammals in an African rainforest : one type of interception trap (pitfall traps with drift fences) and two types of baited traps (Sherman live trap and metal snap trap). We captured 1884 individuals belonging to 9 shrew and 11 murid rodent species. Pitfall traps were more efficient (higher number of species trapped and higher trap success) than baited traps for capturing shrews. In contrast, they were less efficient for capturing rodents, even if some rare species were captured in pitfall traps only. Sherman and snap traps have complementary qualities for the capture of rodents. Sherman traps are more effective for trapping smaller rodent species, while snap traps tend to be more effective for trapping larger ones. Moreover, light individuals of the largest species are better captured than heavy ones in Sherman, while no significant difference was observed for small species. No sex ratio difference was detected between populations sampled by each of the three types of traps. The three types of traps used in this study have complementary effects onto the capture of small mammals in African rainforest. An assortment of traps should always be employed in studies of small mammal communities in African rainforest in order to obtain a wider range of taxa, and thus a better representation of the community.