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Aim: Understanding speciation mechanisms requires disentangling processes that promote and erode population‐level divergence. Three hypotheses are raised that contemporary population structure is mainly shaped by refugial isolation, gene flow or both. Testing these hypotheses requires range‐wide phylogeography and integrative analyses across scales. Here we aimed to (1) re‐estimate the previously unresolved nuclear divergence within a widespread bat; (2) test the above three phylogeographical hypotheses and (3) inform conservation management under climatic change. Location: North America including the Caribbean. Taxon: The big brown bat (Eptesicus fuscus). Methods: We collected range‐wide samples and genome‐wide markers using restriction site‐associated DNA sequencing. Population structure was analysed by clustering methods and spatial estimations. Nuclear phylogeographical divergence was estimated using tree methods (concatenation and coalescence) and network analyses (TreeMix). Phylogeographical hypotheses were tested by comparing alternative evolutionary scenarios using demographic modelling. Species distribution modelling was used to help identify Pleistocene refugia and predict future range shifts under climatic change. Results: We identified three populations in the Caribbean, eastern and western North America. The western population further split into three phylogeographical clades: Pacific, southwestern North America and Mexico. Discordance among mitochondrial and nuclear topologies reflected strong impacts of gene flow without sex bias. Demographic modelling supported scenarios of historical isolation followed by secondary gene flow and estimated Holocene divergence times. Species distribution was essentially continuous during glaciation with possible regional isolation, and northward range shifts were predicted under future climatic change. Main Conclusions: Contemporary population divergence of big brown bats was shaped by both historical isolation and secondary gene flow, supporting the third phylogeographical hypothesis. While climatic change likely triggered initial divergence, ongoing gene flow has largely impacted the dynamic within‐species evolution and generated population divergence without speciation. [ABSTRACT FROM AUTHOR]

Aim: The fungal pathogen Pseudogymnoascus destructans and resultant white‐nose syndrome (WNS) continues to advance across North America, infecting new bat hibernacula. Western North America hosts the highest bat diversity in the United States and Canada, yet little is known about hibernacula and hibernation behaviour in this region. An improved understanding of the distribution of suitable hibernacula is critical for land managers to anticipate conservation needs of WNS‐susceptible species in currently uninfected regions. Location: United States, Canada. Taxon: Bats. Methods: We estimated suitability of potential winter hibernaculum sites across five bat species' ranges. We estimated winter survival capacity from a mechanistic survivorship model based on bat bioenergetics and climate conditions. We then used boosted regression trees to relate these estimates, along with key landscape attributes, to bat occurrence data in a hybrid correlative‐mechanistic approach. Results: Winter survival capacity, topography, land cover and access to subterranean features were important predictors of winter hibernaculum selection, but the shape and relative importance of these relationships varied amongst species. This suggests that the occurrence of bat hibernacula can, in part, be predicted from readily mapped above‐ground features, not just below‐ground characteristics for which spatial data are lacking. Furthermore, our mechanistic estimate of winter survivorship was, on average, the third strongest predictor of winter occurrence probability across focal species. Main conclusions: Winter distributions of North American bat species were driven by their physiological capacity to survive winter conditions and duration in a given location, as well as selection for topographic and other landscape features but in species‐specific ways. The influence of winter survivorship on several species' distributions, the underlying influence of climate conditions on winter survivorship and the anticipated influence of WNS on bats' hibernation physiology and survivorship together suggest that North American bat distributions may undergo future shifts as these species are exposed not only to WNS but also to climate change. [ABSTRACT FROM AUTHOR]

Aim The goals of our study were to assess the population history and genetic structure of the widespread bat Hipposideros armiger, and to evaluate the effect of palaeoclimatic changes and dispersal patterns on this species. Location South China, mainland Southeast Asia and the South Himalayas. Methods We amplified two mitochondrial DNA (mt DNA) regions (cyt b and D-loop) and seven nuclear microsatellite loci (n SSRs) from 216 individuals of H. armiger. To examine the evolutionary history of this species, we constructed maximum likelihood and Bayesian phylogenetic trees based on the two mt DNA regions. From the mt DNA and/or n SSR data, we assessed population genetic structure using analysis of molecular variance ( AMOVA) and median-joining network and structure analyses. We also estimated demographic history and gene flow using a Bayesian skyline plot and the program I Ma2. Results Phylogenetic and median-joining network analyses revealed that H. armiger comprises two distinct mt DNA clades divided into seven subclades. The results of AMOVA suggested strong population genetic structure based on mt DNA, but weak structure based on n SSRs. structure analysis identified three population clusters and also showed weak genetic structure at the nuclear level. Demographic analyses revealed two population expansion events c. 0.62 Ma and c. 0.25 Ma. The basic phylogeographical structure of H. armiger was established by 0.24 Ma. I Ma2 analysis demonstrated that substantial gene flow has occurred between different regions since then. Additionally, non-significant population structure and significant gene flow were detected between Taiwan and Hainan island populations and those from mainland China. Main conclusions Our results suggest that divergence and population expansion of H. armiger occurred in association with Pleistocene climatic changes and that multiple refugia may have existed for this species. Post-glacial male-biased dispersal was likely to be the primary contributor to the contemporary genetic structure of H. armiger populations. Gene flow may have contributed greatly to the genetic structure of insular populations and populations from mainland China. [ABSTRACT FROM AUTHOR]

Aim The causes of a zoogeographic divide in peninsular Thailand around the Isthmus of Kra have not been adequately resolved. We explored climatic, historical and geological perspectives to gain insights into factors that may have contributed to the development and maintenance of this zoogeographic transition, and to determine whether a faunal transition occurs for bats. Location Southeast Asia, focusing on the Thai Peninsula. Methods Spatial principal components analysis was used to determine the relationship between climate and species distribution patterns. We studied bats (order Chiroptera) because of their ability to bypass small-scale geophysical barriers. Spatial data on bat species distributions on the Thai Peninsula were analysed in relation to multivariate measures of climate to determine the possible influence of climatic zonation on distribution patterns. We assessed the effects of the interaction of climatic zonation with the highly dynamic environmental conditions the area has undergone in relation to species distribution patterns. Results A zoogeographic transition was found, with 44 species (out of 127) restricted to the north of the Isthmus of Kra and 29 restricted to the south, although there were relatively few abrupt changes in distribution at the exact position of the isthmus. Northern and southern species were associated with specific climatic conditions. Major transitions in the distribution of bat species exist at 6-6.5° N and 13-13.5° N, with a smaller peak at 11.0° N. These major peaks fall in the same areas as the borders of climatic zones, and the 6-6.5° N peak falls in the same area as a floristic divide (the Kangar-Pattani Line). Main conclusions On the mainland, climatic zones cause gradual changes in species distributions. However, in addition to climatic factors, repeated changes in the breadth of the Sunda Shelf during recent glacial cycles may have caused locally high extinction rates at narrow points on the peninsula, exacerbating transitions in species distribution patterns along the region, in the context of a peninsula effect that reduces opportunities for recolonization. [ABSTRACT FROM AUTHOR]