Niche beadth and overlap
Niche breadth and niche overlap values are presented in Table 3. They did not show any differences beween exotic and native species. Niche breadth ranges between 2.9 for Praomys daltoni and 4.2 forA. niloticus . Niche breadth of the domestic mouse is higher than of the black rat (4 vs 3.2). Niche overlap values are generally high, ranging between 0.74 and 0.99. Arvicanthis niloticus shows the lower mean value (0.84) and C. olivieri the highest (0.95). Mean niche overlap values of M. musculus and R. rattus with other species are the same and are high (0.94), suggesting regular co-occurrence of these invasive species with native ones at the room scale (see hereunder).