Local coexistence and niche differences between the Lusitanian and Mediterranean pine voles (Microtus lusitanicus and M. duodecimcostatus)

Abstract

In the present study, we analyzed the coexistence pattern of the Lusitanian pine vole (Microtus lusitanicus) and the Mediterranean pine vole (Microtus duodecimcostatus) in a potential area of sympatry in a Mediterranean landscape (Portugal). We also determined the relative contribution of local, landscape, and spatial factors explaining the differences in the distribution patterns of the two species in the region. Using a kriging interpolation method, we obtained a map of sympatric and allopatric areas of species occurrence. The estimated sympatry area corresponded to a northwest-southeast belt representing 11.3% of the study area. Habitat niche differences were assessed with binomial GLMs followed by a variance partitioning. At a local scale, higher altitude, higher cover of shrubs, lower clay content in the soil, and lower cover of tree canopy were the most important factors distinguishing M. lusitanicus presence sites from those with M. duodecimcostatus. At a larger scale, the presence of forest landscape units and the low abundance of ''montado'' units were the most influencing landscape factors in the identification of M. lusitanicus occurrence sites when compared to M. duodecimcostatus. Our results suggested that local coexistence of M. lusitanicus and M. duodecimcostatus in the field is a rare event. The differences in distribution patterns of the two pine vole species were mostly explained by fine-scale environmental factors and by shared spatial effects.

Deep mitochondrial introgression and hybridization among ecologically divergent vole species

“…Although these mismatches might be explained by a resolution of the soil map, which is too coarse for representing local habitat conditions or the particular interpolation of likelihoods in geneland , it is still consistent with ecological data suggesting that M. duodecimcostatus is able to occupy a wider range of soil types, while M. lusitanicus may not (Santos et al . ,b). However, habitat features like soil thickness and the percentage of plant cover differ also in other regions of the sympatry zone between these pine voles (Borghi et al .…”

“…These pine voles differ also in a range of ecological characters, such as the type of inhabited soils and their commitment to a life underground. The Lusitanian pine vole occurs in regions dominated by fertile, well-drained and easily mobilized soils (cambisols), and colder and moister climate compared with the Mediterranean pine vole, which occupies mainly grassland landscapes with higher abundance of stony soils (leptosols) and clayey soils with lower acidity (luvisols; Santos et al 2009Santos et al , 2010a. Both voles occupy preferentially open habitats, which may be agriculturally influenced (Cotilla & Palomo 2002;Mira & Mathias 2002), typically in close association with verges (Santos et al 2011).…”

p53 gene discriminates two ecologically divergent sister species of pine voles

“…The largely allopatric distribution range of these two species may well reflect this ecological divergence. In sympatry, both the voles occupy a specialized ecological niche, in which soil characteristics seem to be particularly relevant (Borghi et al, 1994;Santos et al, 2009a, b;Santos et al, 2010;Santos et al, 2011). Niche specialization may involve distinctive physiological and genetic adaptations (Singh et al, 2009;Hadid et al, 2013), probably species and stress environmental specific, as suggested with the S104E variation observed within the P53 protein of high-altitude M. oeconomus or the R174K mutation in P53 of the subterranean Spalax (Ashur-Fabian et al, 2004;Zhao et al, 2013).…”

“…Both the species exhibit burrowing behaviour but differ in a set of ecological and morphological traits that together suggest that M. duodecimcostatus is more dependent from the subterranean habitat than M. lusitanicus (Mathias, 1990;Santos et al, 2009a,b;Santos et al, 2010). Living underground forces rebreathe of air with low oxygen (hypoxia) and high carbon dioxide tensions (hypercapnia).…”

Stable Isotopes Reveal the Dominant Species to Have the Widest Trophic Niche of Three Syntopic Microtus Voles

“…Shifts of trophic niches in relation to human-induced changes require further investigations [ 30 ]. In the case of Microtus voles, niche research has so far mostly targeted the temporal and spatial niche elements [ 31 , 32 , 33 , 34 , 35 ]. Therefore, we oriented to the evaluation of the trophic niche in agricultural habitats, considering also the opinion of Bolnick et al [ 36 ] that ecological release from interspecific competition can lead to increases in niche width.…”