For 6 consecutive years (2013 to 2019), we performed an annual rodent elimination by placing rodenticide in 3 villages and measuring rodent abundances. Simultaneously, we monitored the same outcome in 3 different villages without rodent elimination. This dual monitoring allowed us to evaluate the long-term impact of such an approach. We found the effect to be strong but short-lived: rodents re-invaded houses within 2-3 months after elimination, leading to a similar abundance one year after elimination (figure 2).
Figure 2: Dynamics of M. natalensis measured by the trapping success inside houses in 3 treated villages (Brissa, Dalafilani and Yarawalia), and in 3 control villages (Damania, Sokourala and Sonkonia) over 6 years. AR indicates the period of elimination by anticoagulant rodenticide.