Figure 1.
All trapping investigated localities within the city of Niamey (a): circles, squares and triangles indicate sites investigated through SP, OP and SP+OP protocols, respectively.
Mapping of SP localities only, with their acronyms referring to Table 1 (b). On both maps, colors of the background correspond to GIS-based categories of landscape elements: yellow for non-covered soil; red for buildings; dark and light green for trees and diverse vegetation, respectively; dark and light blue for Niger River and other water surfaces, respectively.
Table 1.
Trapping efforts and results, environment type, number of sites and GPS coordinates in all localities investigated using the standardized (SP) and opportunistic (OP) protocols.
Figure 2.
Spatial distribution of each of the seven species captured in Niamey.
Each circle corresponds to one OP and/or SP trapping site (see Table 1 and Figure 1). The circle size is proportional to the total number of rodent captures. Each color stands for a given species: red for Mastomys natalensis, white for Mus musculus, blue for Rattus rattus, green for Arvicanthis niloticus, orange for Cricetomys gambianus, yellow for Taterillus gracilis and rose for Nannomys hausa.
Figure 3.
Geostatistical analysis of M. natalensis and R. rattus spatial distributions across the city of Niamey, Niger.
(a) Indicator variograms for a threshold value Zk = 0. Blue circles and red squares indicate empirical variograms for M. natalensis and R. rattus, respectively. Solid lines correspond to fitted exponential variogram models. (b) Cross indicator variogram for M. natalensis and R. rattus with a threshold value Zk = 0.
Figure 4.
Indicator maps of M. natalensis (a) and R. rattus (b) spatial distribution across the city of Niamey (Niger).
Mapped values were estimated by ordinary kriging using fitted indicator variograms for threshold value Zk = 0. Values correspond to probabilities of observing abundances >0, i.e., probabilities of presence.