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).