Spatial variation in population abundance of invasive Rattus rattus across coastal habitats of East African island archipelago

Abstract

It is well established that animal species exhibit variation in population across different habitats. Environmental and anthropogenic factors may contribute a lot to this. However, to what extent these factors affect species populations remains largely unexplained in most rodent species. We assessed the influence of environmental and anthropogenic factors on the variation in population abundance of Rattus rattus in the East African island archipelago. Sherman® live traps were used to capture R. rattus in various habitats categorised as mosaic landscape, coastal forest and shrub mosaic. High abundancies of R. rattus were recorded in mosaic landscapes and comparatively lower abundancies in coastal forests and shrub mosaics. Areas with higher abundancies of R. rattus were close to farmlands and human settlements characterized by low EVI and NDVI implying that areas with low EVI and NDVI associated with anthropogenic activities support high population abundance of R. rattus. Since R. rattus is a pest reported to cause significant food losses and a potential reservoir host of many zoonotic diseases, we advocate the implementation of management and control measures to control its population. Control measures should focus on managing species' populations through environmentally friendly approaches to avoid damage to other biodiversity. This goes in line with updating and formulating effective Integrative Pest Management plans and control measures for vertebrate pests in human habitats.