Patterns of range formation in Palaearctic mice (Murinae) based on ecological niche modelling

Abstract

The home ranges of 25 non-synanthropic Murinae species from the Palaearctic were estimated by modelling their ecological niches using 19 bioclimatic variables. On average, the area with a predicted probability of species presence in suitable habitats of >50% (hereafter referred to as the home range) exceeds the species’ range by 10%; the area with a probability of >75% is the same size as the range; and the area with a probability of >95% is 11% smaller than the range. Meanwhile, the area projected as suitable for species presence at a probability level >50% under the climatic conditions expected in the period 2061–2080 does not differ in size from the current home range. However, as the range increases, the proportion of climatically suitable habitat not occupied by the species decreases. Consequently, the mean potential expansion is approximately 1.5% in the Euro-Siberian bioregion, where ranges are largest; 10.5% in the Mediterranean bioregion; and 14% in the Central-East Asian bioregion. The reason for the limitations of species’ ranges at the northern limit of the subfamily’s distribution is that home ranges are more fully realised with respect to bioclimatic factors. This implies that geographic constraints on dispersal act as the principal limitation of ranges in the south, determining their smaller size. The diffuse range expansion model is likely to be adequate for species in the Euro-Siberian bioregion, whereas the salvo-invasion model is more suitable for species in the Mediterranean and Central-East Asian bioregions. This suggests that southern mouse species could be considered potential invaders.