Phylogenetic affinities and inter-island differentiation in the Vitelline Warbler Dendroica vitellina, a West Indian endemic

The Vitelline Warbler Dendroica vitellina is endemic to the Cayman Islands and Swan Islands in the West Indies. This study examined the phylogenetic affinities of the Vitelline Warbler and assessed mitochondrial differentiation among the three Cayman Island populations. Species-level phylogenetic analyses based on 3639 nucleotides of mitochondrial DNA (mtDNA) sequence were used to place the Vitelline Warbler in the larger Dendroica radiation. These analyses confirmed that the Vitelline Warbler is the sister taxon of the Prairie Warbler Dendroica discolor, a species that breeds in continental North America. The magnitude of mitochondrial differentiation between these sister taxa (2.4%) supports their current classification as separate taxonomic species. Additional comparisons based on the 1041-nucleotide NDII gene sequence from 26 Vitelline Warblers provided evidence of within-species genetic structure. NDII haplotypes from Grand Cayman vs. Cayman Brac/Little Cayman differed by 6–10 nucleotide substitutions, and no haplotypes were shared among these island groups, supporting the current separation of the Cayman Island populations into two subspecies. These patterns support the biogeographical scenario that the Vitelline Warbler was derived from a mainland population of the Prairie Warbler. This may have occurred due to a loss of migration in ancestral populations or from over-water dispersal of a mainland resident population.     

Spatio-temporal population genetic structure of the parasitic mite Spinturnix bechsteini is shaped by its own demography and the social system of its bat host

Information about the population genetic structures of parasites is important for an understanding of parasite transmission pathways and ultimately the co-evolution with their hosts. If parasites cannot disperse independently of their hosts, a parasite's population structure will depend upon the host's spatial distribution. Geographical barriers affecting host dispersal can therefore lead to structured parasite populations. However, how the host's social system affects the genetic structure of parasite populations is largely unknown. We used mitochondrial DNA (mtDNA) to describe the spatio-temporal population structure of a contact-transmitted parasitic wing mite ( Spinturnix bechsteini ) and compared it to that of its social host, the Bechstein's bat ( Myotis bechsteinii ). We observed no genetic differentiation between mites living on different bats within a colony. This suggests that mites can move freely among bats of the same colony. As expected in case of restricted inter-colony dispersal, we observed a strong genetic differentiation of mites among demographically isolated bat colonies. In contrast, we found a strong genetic turnover between years when we investigated the temporal variation of mite haplotypes within colonies. This can be explained with mite dispersal occuring between colonies and bottlenecks of mite populations within colonies. The observed absence of isolation by distance could be the result from genetic drift and/or from mites dispersing even between remote bat colonies, whose members may meet at mating sites in autumn or in hibernacula in winter. Our data show that the population structure of this parasitic wing mite is influenced by its own demography and the peculiar social system of its bat host.     

Small-Scale Fragmentation Effects on Local Genetic Diversity in Two Phyllostomid Bats with Different Dispersal Abilities in Panama

Habitat fragmentation is one of the greatest threats to biodiversity. Despite their importance for conservation, the genetic consequences of small-scale habitat fragmentation for bat populations are largely unknown. In this study, we linked genetic with ecological and demographic data to assess the effects of habitat fragmentation on two species of phyllostomid bats ( Uroderma bilobatum and Carollia perspicillata ) that differ in their dispersal abilities and demographic response to fragmentation. We hypothesized that population differentiation and the effect of habitat fragmentation on levels of genetic diversity will be a function of the species' mobility. We sequenced mtDNA from 232 bats caught on 11 islands in Gatún Lake, Panamá, isolated from the mainland for ca 90 yr, and in adjacent, continuous forest on the mainland. Populations of both species showed significant genetic differentiation ( F _ST). Consistent with our prediction, population subdivision was lower in the highly mobile U. bilobatum ( F _ST= 0.01) compared to the less vagile C. perspicillata ( F _ST= 0.06), and only the latter species showed a pattern indicative of isolation by distance and, in addition, an effect of fragmentation. Genetic erosion as a result of fragmentation was also only detectable in the less mobile species, C. perspicillata , where haplotype diversity was lower in island compared to mainland populations. Our results suggest that some Neotropical bat species are prone to loss of genetic variation in response to anthropogenic small-scale habitat fragmentation. In this context, our findings point toward mobility as a good predictor of a species' vulnerability to fragmentation and altered population genetic structure.     

An incipient invasion of brown anole lizards (<Emphasis Type="Italic">Anolis sagrei</Emphasis>) into their own native range in the Cayman Islands: a case of cryptic back-introduction

Human-mediated dispersal has reshaped distribution patterns and biogeographic relationships for many taxa. Long-distance and over-water dispersal were historically rare events for most species, but now human activities can move organisms quickly over long distances to new places. A potential consequence of human-mediated dispersal is the eventual reintroduction of individuals from an invasive population back into their native range; a dimension of biological invasion termed “cryptic back-introduction.” We investigated whether this phenomenon was occurring in the Cayman Islands where brown anole lizards (Anolis sagrei) with red dewlaps (i.e., throat fans), either native to Little Cayman or invasive on Grand Cayman, have been found on Cayman Brac where the native A. sagrei have yellow dewlaps. Our analysis of microsatellite data shows strong population-genetic structure among the three Cayman Islands, but also evidence for non-equilibrium. We found some instances of intermediate multilocus genotypes (possibly 3–9% of individuals), particularly between Grand Cayman and Cayman Brac. Furthermore, analysis of dewlap reflectance data classified six males sampled on Cayman Brac as having red dewlaps similar to lizards from Grand Cayman and Little Cayman. Lastly, one individual from Cayman Brac had an intermediate microsatellite genotype, a red dewlap, and a mtDNA haplotype from Grand Cayman. This mismatch among genetic and phenotypic data strongly suggests that invasive A. sagrei from Grand Cayman are interbreeding with native A. sagrei on Cayman Brac. To our knowledge, this is the first evidence of cryptic back-introduction. Although we demonstrate this phenomenon is occurring in the Cayman Islands, assessing its frequency there and prevalence in other systems may prove difficult due to the need for genetic data in most instances. Cryptic back-introductions may eventually provide some insight into how lineages are changed by the invasion process and may be an underappreciated way in which invasive species impact native biodiversity.     

Seeing in the dark: molecular approaches to the study of bat populations

Whilst the use of molecular genetic techniques is widespread in the fields of population and evolutionary biology, their application within the mammalian order Chiroptera neither reflects the species richness nor the ecological and behavioural diversity of the order. This is despite the fact that the Chiroptera are problematic to study using more direct observational techniques. Here, we standardize and synthesise the current data, assess the contribution of molecular research to the study of bat species and highlight the importance of its continued and expanded use. At an inter-population level, molecular studies have demonstrated a great diversity of population genetic structure within the order. Among populations of migratory species, genetic structure appears universally low, and hence seasonal movement is likely to be the prevailing influence. However, for sedentary species an array of factors including dispersal ability, extrinsic barriers to gene flow and historical events may determine the extent of genetic partitioning among populations. Intrinsic factors such as wing morphology or roost requirements may also influence population genetic structure in sedentary bat species, a proposal which requires further research. Molecular studies have also made important contributions towards an understanding of social organisation in bats. Evidence indicates that in many polygynous species male mating success does not translate directly into reproductive success, perhaps as a result of multiple mating by females. Estimates of relatedness within and genetic structure among colonies are, in general, very low; a finding which has important implications regarding theories concerning the formation and persistence of bat social groups. Molecular studies have provided new and important insights into the ecology of bats, and have opened up exciting and previously unexplored avenues of research. The data from these studies suggest not only a predictive framework for future studies, but also the use of genetic data in the management and conservation of bat species.     

Conserving the endangered Mexican fishing bat (<Emphasis Type="Italic">Myotis vivesi</Emphasis>): genetic variation indicates extensive gene flow among islands in the Gulf of California

The endangered Mexican fishing bat, Myotis vivesi, appears to have suffered widespread extinction and population decline on islands throughout the Gulf of California, largely due to predation by introduced cats and rats. To restore populations of fishing bats and other native species, conservation efforts have focused on eradicating introduced vertebrates from several Gulf islands. These efforts assume that individuals from existing populations will recolonize islands and that continued dispersal will help sustain vulnerable populations thereafter. However, the extent of inter-island dispersal in fishing bats is unknown. In this study we analyzed patterns of genetic variation to gauge the extent of gene flow and, thus, potential dispersal among islands. DNA was sampled from 257 fishing bats on 11 Gulf islands (separated by ca. 6–685 km of open water), and individuals were genotyped at six microsatellite loci and haplotyped at a 282 bp fragment of the mtDNA control region. With microsatellites, we found weak population genetic structure and a pattern of isolation by distance, while with mtDNA we found strong structure but no isolation by distance. Our results indicate that island subpopulations separated by large expanses of open water are nonetheless capable of maintaining high genetic diversity and high rates of gene flow. Unfortunately, little is known about the spatial patterns of dispersal or mating system of fishing bats, and these behavioral factors, in particular female philopatry, might reduce the probability of the species recolonizing Gulf islands.     

Population structure of a widespread bat (Tadarida brasiliensis) in an island system

Dispersal is a driving factor in the creation and maintenance of biodiversity, yet little is known about the effects of habitat variation and geography on dispersal and population connectivity in most mammalian groups. Bats of the family Molossidae are fast‐flying mammals thought to have potentially high dispersal ability, and recent studies have indicated gene flow across hundreds of kilometers in continental North American populations of the Brazilian free‐tailed bat, Tadarida brasiliensis. We examined the population genetics, phylogeography, and morphology of this species in Florida and across islands of The Bahamas, which are part of an island archipelago in the West Indies. Previous studies indicate that bats in the family Phyllostomidae, which are possibly less mobile than members of the family Molossidae, exhibit population structuring across The Bahamas. We hypothesized that T. brasiliensis would show high population connectivity throughout the islands and that T. brasiliensis would show higher connectivity than two species of phyllostomid bats that have been previously examined in The Bahamas. Contrary to our predictions, T. brasiliensis shows high population structure between two groups of islands in The Bahamas, similar to the structure exhibited by one species of phyllostomid bat. Phylogenetic and morphological analyses suggest that this structure may be the result of ancient divergence between two populations of T. brasiliensis that subsequently came into contact in The Bahamas. Our findings additionally suggest that there may be cryptic species within T. brasiliensis in The Bahamas and the West Indies more broadly.     

Implications of isolation and low genetic diversity in peripheral populations of an amphi-Atlantic coral

Limited dispersal and connectivity in marine organisms can have negative fitness effects in populations that are small and isolated, but reduced genetic exchange may also promote the potential for local adaptation. Here, we compare the levels of genetic diversity and connectivity in the coral Montastraea cavernosa among both central and peripheral populations throughout its range in the Atlantic. Genetic data from one mitochondrial and two nuclear loci in 191 individuals show that M. cavernosa is subdivided into three genetically distinct regions in the Atlantic: Caribbean-North Atlantic, Western South Atlantic (Brazil) and Eastern Tropical Atlantic (West Africa). Within each region, populations have similar allele frequencies and levels of genetic diversity; indeed, no significant differentiation was found between populations separated by as much as 3000 km, suggesting that this coral species has the ability to disperse over large distances. Gene flow within regions does not, however, translate into connectivity across the entire Atlantic. Instead, substantial differences in allele frequencies across regions suggest that genetic exchange is infrequent between the Caribbean, Brazil and West Africa. Furthermore, markedly lower levels of genetic diversity are observed in the Brazilian and West African populations. Genetic diversity and connectivity may contribute to the resilience of a coral population to disturbance. Isolated peripheral populations may be more vulnerable to human impacts, disease or climate change relative to those in the genetically diverse Caribbean-North Atlantic region.     

Small Tent-Roosting Bats Promote Dispersal of Large-Seeded Plants in a Neotropical Forest

In Neotropical regions, fruit bats are among the most important components of the remaining fauna in disturbed landscapes. These relatively small-bodied bats are well-known dispersal agents for many small-seeded plant species, but are assumed to play a negligible role in the dispersal of large-seeded plants. We investigated the importance of the small tent-roosting bat Artibeus watsoni for dispersal of large seeds in the Sarapiquí Basin, Costa Rica. We registered at least 43 seed species > 8 mm beneath bat roosts, but a species accumulation curve suggests that this number would increase with further sampling. Samples collected beneath bat feeding roosts had, on average, 10 times more seeds and species than samples collected 5 m away from bat feeding roosts. This difference was generally smaller in small, disturbed forest patches. Species-specific abundance of seeds found beneath bat roosts was positively correlated with abundance of seedlings, suggesting that bat dispersal may influence seedling recruitment. Our study demonstrates a greater role of small frugivorous bats as dispersers of large seeds than previously thought, particularly in regions where populations of large-bodied seed dispersers have been reduced or extirpated by hunting.     

Phylogeography and conservation genetics of Eld's deer (Cervus eldi)

Eld's deer (Cervus eldi) is a highly endangered cervid, distributed historically throughout much of South Asia and Indochina. We analysed variation in the mitochondrial DNA (mtDNA) control region for representatives of all three Eld's deer subspecies to gain a better understanding of the genetic population structure and evolutionary history of this species. A phylogeny of mtDNA haplotypes indicates that the critically endangered and ecologically divergent C. eldi eldi is related more closely to C. e. thamin than to C. e. siamensis, a result that is consistent with biogeographic considerations. The results also suggest a strong degree of phylogeographic structure both between subspecies and among populations within subspecies, suggesting that dispersal of individuals between populations has been very limited historically. Haplotype diversity was relatively high for two of the three subspecies (thamin and siamensis), indicating that recent population declines have not yet substantially eroded genetic diversity. In contrast, we found no haplotype variation within C. eldi eldi or the Hainan Island population of C. eldi siamensis, two populations which are known to have suffered severe population bottlenecks. We also compared levels of haplotype and nucleotide diversity in an unmanaged captive population, a managed captive population and a relatively healthy wild population. Diversity indices were higher in the latter two, suggesting the efficacy of well-designed breeding programmes for maintaining genetic diversity in captivity. Based on significant genetic differentiation among Eld's deer subspecies, we recommend the continued management of this species in three distinct evolutionarily significant units (ESUs). Where possible, it may be advisable to translocate individuals between isolated populations within a subspecies to maintain levels of genetic variation in remaining Eld's deer populations.     

Dispersal and group formation dynamics in a rare and endangered temperate forest bat (Nyctalus lasiopterus,Chiroptera: Vespertilionidae)

For elusive mammals like bats, colonization of new areas and colony formation are poorly understood, as is their relationship with the genetic structure of populations. Understanding dispersal and group formation behaviors is critical not only for a better comprehension of mammalian social dynamics, but also for guiding conservation efforts of rare and endangered species. Using nuclear and mitochondrial markers, we studied patterns of genetic diversity and differentiation among and within breeding colonies of giant noctule bats (Nyctalus lasiopterus), their relation to a new colony still in formation, and the impact of this ongoing process on the regionwide genetic makeup. Nuclear differentiation among colonies was relatively low and mostly nonsignificant. Mitochondrial variation followed this pattern, contrasting with findings for other temperate bat species. Our results suggest that this may indicate a recent population expansion. On average, female giant noctules were not more closely related to other colony members than to foreign individuals. This was also true for members of the newly forming colony and those of another, older group sampled shortly after its formation, suggesting that contrary to findings for other temperate bats, giant noctule colonies are not founded by relatives. However, mother–daughter pairs were found in the same populations more often than expected under random dispersal. Given this indication of philopatry, the lack of mitochondrial differentiation among most colonies in the region is probably due to the combination of a recent population expansion and group formation events.     

Comparative phylogeography of mainland and insular species of Neotropical molossid bats (Molossus)

Historical events, habitat preferences, and geographic barriers might result in distinct genetic patterns in insular versus mainland populations. Comparison between these two biogeographic systems provides an opportunity to investigate the relative role of isolation in phylogeographic patterns and to elucidate the importance of evolution and demographic history in population structure. Herein, we use a genotype‐by‐sequencing approach (GBS) to explore population structure within three species of mastiff bats (Molossus molossus, M. coibensis, and M. milleri), which represent different ecological histories and geographical distributions in the genus. We tested the hypotheses that oceanic straits serve as barriers to dispersal in Caribbean bats and that isolated island populations are more likely to experience genetic drift and bottlenecks in comparison with highly connected ones, thus leading to different phylogeographic patterns. We show that population structures vary according to general habitat preferences, levels of population isolation, and historical fluctuations in climate. In our dataset, mainland geographic barriers played only a small role in isolation of lineages. However, oceanic straits posed a partial barrier to the dispersal for some populations within some species (M. milleri), but do not seem to disrupt gene flow in others (M. molossus). Lineages on distant islands undergo genetic bottlenecks more frequently than island lineages closer to the mainland, which have a greater exchange of haplotypes.     

Higher genetic diversity in introduced than in native populations of the mussel Mytella charruana: evidence of population admixture at introduction sites

Aim  Levels of genetic diversity can be used to determine haplotype frequency, population size and patterns of invasive species distribution. In this study, we sought to investigate the genetic structure of the invasive marine mussel Mytella charruana and compare variation from invasive populations with variation found within three native populations.
Location  Invaded areas in the USA (Florida, Georgia); native areas in Ecuador, Colombia and Brazil.
Methods  We sequenced 722 bp of the mitochondrial COI gene from 83 M. charruana samples from four invasive populations (USA) and 71 samples from two natural populations (Ecuador, Columbia). In addition, we sequenced 31 individuals of a congeneric species, Mytella guyanensis , from Salvador, Brazil. We constructed the phylogenetic relationship among all haplotypes and compared diversity measures among all populations.
Results  We found significantly higher levels of nucleotide diversity in invasive populations than in native populations, although the number of haplotypes was greater in the native populations. Moreover, mismatch distribution analyses resulted in a pattern indicative of population admixture for the invasive populations. Conversely, mismatch distributions of native populations resulted in a pattern indicative of populations in static equilibrium.
Main conclusion  Our data present compelling evidence that the M. charruana invasion resulted from admixture of at least two populations, which combined to form higher levels of genetic diversity in invasive populations. Moreover, our data suggest that one of these populations originated from the Caribbean coast of South America. Overall, this study provides an analysis of genetic diversity within invasive populations and explores how that diversity may be influenced by the genetic structure of native populations and how mass dispersal may lead to invasion success.     

Correlates of dispersal extent predict the degree of population genetic structuring in bats

Dispersal is essential for maintaining demographic and genetic connectivity. For bats, correlates of dispersal extent such as morphology and movement dynamics are reported as having an influence on population genetic structure although these traits exhibit co-variance which has not been previously examined. We used a principal components framework with phylogenetically independent contrasts to compare five dispersal extent predictors (wing loading, aspect ratio, geographic range size, migratory status and median latitude) with population genetic structure among bats. We found that high wing loading values and migration negatively correlate with genetic structure after accounting for co-variance. These findings suggest that bats that can achieve higher flight speeds and migrate seasonally have higher gene flow and resultant genetic connectivity relative to bats that fly slower and do not migrate. These results represent a step towards understanding factors that shaped the genetic structure of bat populations.     

Spatial isolation and genetic differentiation in naturally fragmented plant populations of the Swiss Alps

Aims The effect of anthropogenic landscape fragmentation on the genetic diversity and adaptive potential of plant populations is a major issue in conservation biology. However, little is known about the partitioning of genetic diversity in alpine species, which occur in naturally fragmented habitats. Here, we investigate molecular patterns of three alpine plants (Epilobium fleischeri, Geum reptans and Campanula thyrsoides) across Switzerland and ask whether spatial isolation has led to high levels of population differentiation, increasing over distance, and a decrease of within-population variability. We further hypothesize that the contrasting potential for long-distance dispersal (LDD) of seed in these species will considerably influence and explain diversity partitioning.Methods For each study species, we sampled 20–23 individuals from each of 20–32 populations across entire Switzerland. We applied Random Amplified Polymorphic Dimorphism markers to assess genetic diversity within (Nei's expected heterozygosity, H e; percentage of polymorphic bands, P p) and among (analysis of molecular variance, Φ st) populations and correlated population size and altitude with within-population diversity. Spatial patterns of genetic relatedness were investigated using Mantel tests and standardized major axis regression as well as unweighted pair group method with arithmetic mean cluster analyses and Monmonier's algorithm. To avoid known biases, we standardized the numbers of populations, individuals and markers using multiple random reductions. We modelled LDD with a high alpine wind data set using the terminal velocity and height of seed release as key parameters. Additionally, we assessed a number of important life-history traits and factors that potentially influence genetic diversity partitioning (e.g. breeding system, longevity and population size).Important findings For all three species, we found a significant isolation-by-distance relationship but only a moderately high differentiation among populations (Φ st : 22.7, 14.8 and 16.8%, for E. fleischeri, G. reptans and C. thyrsoides, respectively). Within-population diversity (H e : 0.19–0.21, P p : 62–75%) was not reduced in comparison to known results from lowland species and even small populations with <50 reproductive individuals contained high levels of genetic diversity. We further found no indication that a high long-distance seed dispersal potential enhances genetic connectivity among populations. Gene flow seems to have a strong stochastic component causing large dissimilarity between population pairs irrespective of the spatial distance. Our results suggest that other life-history traits, especially the breeding system, may play an important role in genetic diversity partitioning. We conclude that spatial isolation in the alpine environment has a strong influence on population relatedness but that a number of factors can considerably influence the strength of this relationship.     

Population genetic structure of Venezuelan chiropterophilous columnar cacti (Cactaceae)

We conducted allozyme surveys of three Venezuelan self-incompatible chiropterophilous columnar cacti: two diploid species, Stenocereus griseus and Cereus repandus, and one tetraploid, Pilosocereus lanuginosus. The three cacti are pollinated by bats, and both bats and birds disperse seeds. Population sampling comprised two spatial scales: all Venezuelan arid zones (macrogeographic) and two arid regions in northwestern Venezuela (regional). Ten to 15 populations and 17-23 loci were analyzed per species. Estimates of genetic diversity were compared with those of other allozyme surveys in the Cactaceae to examine how bat-mediated gene dispersal affects the population genetic attributes of the three cacti. Genetic diversity was high for both diploid (P(s) = 94.1-100, P(p) = 56.7-72.3, H(s) = 0.182-0.242, H(p) = 0.161-0.205) and tetraploid (P(s) = 93.1, P(p) = 76.1, H(s) = 0.274, H(p) = 0.253) species. Within-population heterozygote deficit was detected in the three cacti at macrogeographic (F(IS) = 0.145-0.182) and regional (F(IS) = 0.057-0.174) levels. Low genetic differentiation was detected at both macrogeographic (G(ST) = 0.043-0.126) and regional (G(ST) = 0.009-0.061) levels for the three species, suggesting substantial gene flow among populations. Gene exchange among populations seems to be regulated by distance among populations. Our results support the hypothesis that bat-mediated gene dispersal confers high levels of genetic exchange among populations of the three columnar cacti, a process that enhances levels of genetic diversity within their populations.     

Phylogeographic structuring and volant mammals: the case of the pallid bat (Antrozous pallidus)

Aim To examine the phylogeographic pattern of a volant mammal at the continental scale. The pallid bat (Antrozous pallidus) was chosen because it ranges across a zone of well‐studied biotic assemblages, namely the warm deserts of North America. Location The western half of North America, with sites in Mexico, the United States, and Canada. Methods PCR amplification and sequencing of the mitochondrial control region was performed on 194 pallid bats from 36 localities. Additional sequences at the cytochrome‐b locus were generated for representatives of each control‐region haplotype. modeltest was used to determine the best set of parameters to describe each data set, which were incorporated into analyses using paup *. Statistical parsimony and measurements of population differentiation (amova , F_ST) were also used to examine patterns of genetic diversity in pallid bats. Results We detected three major lineages in the mitochondrial DNA of pallid bats collected across the species range. These three major clades have completely non‐overlapping geographic ranges. Only 6 of 80 control‐region haplotypes were found at more than a single locality, and sequences at the more conserved cytochrome‐b locus revealed 37 haplotypes. Statistical parsimony generated three unlinked networks that correspond exactly to clades defined by the distance‐based analysis. On average there was c. 2% divergence for the combined mitochondrial sequences within each of the three major clades and c. 7% divergence between each pair of clades. Molecular clocks date divergence between the major clades at more than one million years, on average, using the faster rates, and at more than three million years using more conservative rates of evolution. Main conclusions Divergent haplotypic lineages with allopatric distributions suggest that the pallid bat has responded to evolutionary pressures in a manner consistent with other taxa of the American southwest. These results extend the conclusions of earlier studies that found the genetic structuring of populations of some bat species to show that a widespread volant species may comprise a set of geographically replacing monophyletic lineages. Haplotypes were usually restricted to single localities, and the clade showing geographic affinities to the Sonoran Desert contained greater diversity than did clades to the east and west. While faster molecular clocks would allow for glacial cycles of the Pleistocene as plausible agents of diversification of pallid bats, evidence from co‐distributed taxa suggests support for older events being responsible for the initial divergence among clades.     

Communally breeding Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations

Investigating macro-geographical genetic structures of animal populations is crucial to reconstruct population histories and to identify significant units for conservation. This approach may also provide information about the intraspecific flexibility of social systems. We investigated the history and current structure of a large number of populations in the communally breeding Bechstein's bat ( Myotis bechsteinii ). Our aim was to understand which factors shape the species' social system over a large ecological and geographical range. Using sequence data from one coding and one noncoding mitochondrial DNA region, we identified the Balkan Peninsula as the main and probably only glacial refugium of the species in Europe. Sequence data also suggest the presence of a cryptic taxon in the Caucasus and Anatolia. In a second step, we used seven autosomal and two mitochondrial microsatellite loci to compare population structures inside and outside of the Balkan glacial refugium. Central European and Balkan populations both were more strongly differentiated for mitochondrial DNA than for nuclear DNA, had higher genetic diversities and lower levels of relatedness at swarming (mating) sites than in maternity (breeding) colonies, and showed more differentiation between colonies than between swarming sites. All these suggest that populations are shaped by strong female philopatry, male dispersal, and outbreeding throughout their European range. We conclude that Bechstein's bats have a stable social system that is independent from the postglacial history and location of the populations. Our findings have implications for the understanding of the benefits of sociality in female Bechstein's bats and for the conservation of this endangered species.     

Implications of contrasting patterns of genetic variability in two vespertilionid bats from the Indonesian archipelago

Wallacean island populations of two Vespertilioninae bats, Myotis muricola and Scotophilus kuhlii , which have similar geographical ranges, showed marked contrast in the amount and pattern of genetic variation. Within islands, genetic variation was on average much higher in M. muricola but declined from west to east, whereas all populations of S. kuhlii had uniformly low levels of genetic variation by mammalian standards. S. kuhlii showed little genetic differentiation between islands and estimates of gene flow were substantial whereas island populations of M. muricola differed markedly and there was a strong isolation-by-distance effect associated with the extent of the sea crossing between islands. Furthermore, the lower mean heterozygosity and small genetic distances between eastern island populations of M. muricola is evidence that there has been a bottleneck associated with the colonization of this area. The attenuation of genetic diversity to the east is also seen in some other mammalian species and may indicate limits to dispersal and have implications for species management. The patterns of variability in S. kuhlii may be a consequence of its strong dispersal capacity and close association with human activity, which, together with other factors, suggest a panmictic population.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 83 , 421–431.     

Strong population genetic structure and cryptic diversity in the Florida bonneted bat (Eumops floridanus)

Knowledge of the genetic structure and cryptic diversity is essential for the conservation of endangered species. We conducted a genetic survey of the federally endangered Florida bonneted bat (Eumops floridanus) sampled from its USA range in southern Florida. Florida bonneted bats are primarily found in four regions separated by approximately 100 to 250 km, including three western natural areas: Babcock Webb WMA (BW), Polk County (PC), and Collier County (CC) and one urban population on the east coast, Miami-Dade County (MD). We used 22 microsatellite loci and cytochrome b sequences to assess the extent of connectivity and levels of genetic diversity. Populations were highly differentiated at microsatellite loci (overall F_ST?=?0.178) and model-based and ordination analyses showed that MD was the most distinct among pairwise comparisons. Regional populations were small (N_e?<?100) with no evidence of inbreeding. Contemporary migration and historic gene flow suggested that regional populations have not frequently exchanged migrants, and thus the divergence among western regions was likely a result of genetic drift. Significantly, mitochondrial DNA revealed that haplotypes from MD were similar or shared with those recognized as Eumops ferox from Cuba and Jamaica, and divergent (1.5%) from the remainder of bonneted bats in Florida. Our data support the management of each of the four populations as distinct population segments, and that BW, PC and CC combined are on an independent evolutionary trajectory from bats in MD. Bonneted bats in Florida appear to harbor cryptic diversity that will require a reassessment of their taxonomy.