Unveiling the factors shaping the distribution of widely distributed alpine vertebrates, using multi-scale ecological niche modelling of the bat Plecotus macrobullaris

Abstract

Several alpine vertebrates share a distribution pattern that extends across the South-western Palearctic but is limited to the main mountain massifs. Although they are usually regarded as cold-adapted species, the range of many alpine vertebrates also includes relatively warm areas, suggesting that factors beyond climatic conditions may be driving their distribution. In this work we first recognize the species belonging to the mentioned biogeographic group and, based on the environmental niche analysis of Plecotus macrobullaris, we identify and characterize the environmental factors constraining their ranges. Distribution overlap analysis of 504 European vertebrates was done using the Sorensen Similarity Index, and we identified four birds and one mammal that share the distribution with P. macrobullaris. We generated 135 environmental niche models including different variable combinations and regularization values for P. macrobullaris at two different scales and resolutions. After selecting the best models, we observed that topographic variables outperformed climatic predictors, and the abruptness of the landscape showed better predictive ability than elevation. The best explanatory climatic variable was mean summer temperature, which showed that P. macrobullaris is able to cope with mean temperature ranges spanning up to 16°C. The models showed that the distribution of P. macrobullaris is mainly shaped by topographic factors that provide rock-abundant and open-space habitats rather than climatic determinants, and that the species is not a cold-adapted, but rather a cold-tolerant eurithermic organism. P. macrobullaris shares its distribution pattern as well as several ecological features with five other alpine vertebrates, suggesting that the conclusions obtained from this study might be extensible to them. We concluded that rock-dwelling and open-space foraging vertebrates with broad temperature tolerance are the best candidates to show wide alpine distribution in the Western Palearctic.Electronic supplementary materialThe online version of this article (doi:10.1186/s12983-014-0077-6) contains supplementary material, which is available to authorized users.

Confirmation of the presence of Plecotus macrobullaris Kuzyakin, 1965 in Liguria (North-West Italy) (Chiroptera: Vespertilionidae)

“…The Sanremo records also confirm the tendency of the species to occupy areas at lower altitudes, as has been previously recorded in Mediterranean France and in other parts of the Alps (Drousie et al 2016, Alberdi et al 2013. In particular, Plecotus macrobullaris tends to occupy the mountain reliefs with steep slopes and rocky outcrops, such as those observed in Western Liguria, not only in the Sanremo area (Alberdi et al 2014). The place where the specimen has been found, even if it is characterized by habitats not perfectly suitable for the species, is not that far from the ecological optimum areas of the Ligurian and Maritimes Alps (Alberdi et al 2014).…”

Modelling bat distributions and diversity in a mountain landscape using focal predictors in ensemble of small models

“…700 km 2 , which encompass an elevation gradient ranging from 372 m to 3,210 m a.s.l. However, for this study with bats, only the potentially forested areas up to 2,000 m were considered for sampling and modelling, ignoring the 40 km 2 area above the treeline that are less occupied by bats (Ancillotto et al, ; Lisón & Calvo, ), as only a few bat species are adapted to survive in high mountains (Alberdi, Aizpurua, Aihartza, & Garin, ; Le Roux et al, ; Weier, Linden, Gaigher, White, & Taylor, ). The study area and its vegetation are considerably influenced by the topography and human activity with the plain (Rhône valley) being densely populated and intensively farmed while the subalpine areas are essentially shaped by touristic activity and more extensive agricultural exploitations constituting a mosaic of meadows, pastures and forest patches (for more information about this area, see also http://rechalp.unil.ch; Guisan, ; Pellissier et al, ; Pradervand, ).…”

Contrasting population‐level responses to Pleistocene climatic oscillations in an alpine bat revealed by complete mitochondrial genomes and evolutionary history inference

“…To determine how changes in environmental suitability during the Pleistocene could have affected the demographic history of P. macrobullaris populations, we used Maxent 3.3.3 (Phillips et al, 2004) to generate geographical suitability maps for the Western Palaearctic region under different climatic conditions. The reference model was selected from the 45 candidate models generated by Alberdi et al (2014) with different combinations of climatic and topographic variables and regularization parameters. It included six climatic variables (BIO4, temperature seasonality; BIO8, mean temperature of the wettest quarter; BIO10, mean temperature of the warmest quarter; BIO12, annual precipitation; BIO15, precipitation seasonality; BIO17, precipitation of the warmest quarter; Hijmans et al, 2005) and a single topographic variable (ABR, abruptness of landscape, defined as the maximum elevational difference within a 5-km buffer around each cell; Alberdi et al, 2014).…”