Spatial Structure of the community of bats (Chiroptera: Vespertilionidae) hibernating in artificial caves of Samarskaya Luka

Specific features of the spatial distribution and localization of bats have been studied during their hibernation in artificial caves of Samarskaya Luka. The proportion of cave area occupied by bats varies from 70 to 93% in large caves (>60000 m²), decreasing to 50% in medium-sized caves (10000–60000 m²) and to less than 30% in small caves (<10000 m²). Approximately 9% of bats choose sites near cave openings, up to 25% prefer central parts, but most bats (about 66%) concentrate in the deepest parts of caves. Among wintering species, higher rates of occurrence and shelter occupancy are characteristic of Plecotus auritus, Myotis daubentonii, and M. mystacinus, whereas M. dasycneme and M. brandtii show the highest degree of aggregation. The optimal temperature range for the wintering of all bat species is 2–4°C. Myotis brandtii, Eptesicus nilssonii, and M. daubentonii prefer to hibernate in open spaces of cave ceilings; M. mystacinus, E. serotinus, and Pl. auritus usually occupy the middle and upper parts of walls; while M. dasycneme and M. nattereri occur mainly in hollows on ceilings.     

Single and group organizations of individual animals in the community of bats (Chiroptera: Vespertilionidae) hibernating in artificial caves of the Samarskaya Luka

The spatial arrangement of individual bats of seven species and their tendency to form groups were studied in artificial caves of the Samarskaya Luka during five winter periods (1999 and 2003–2006). It was demonstrated that formation of dense groups did not depend on the hibernating population size or density and was related to the biological characteristics of the species. Most Myotis brandtii and M. dasycneme (60–80% of the populations) wintered in groups. M. mystacinus, M. daubentonii, Plecotus auritus, M. nattereri, and Eptesicus nilssonii usually wintered singly (87% of the animals). In M. brandtii and M. dasycneme, as many as 78% of individual animals were in conspecific groups, whereas this proportion for the other species was no higher than 11%. All pairs of species exhibited negative assortativeness, which indicated a higher preference of spending winter in conspecific groups than in groups containing representatives of other species. Estimation of the ratios between groups containing animals of one and several species showed that conspecific groups were prevailing in M. brandtii and M. dasycneme, whereas all other species usually formed mixed groups.     

Biochemical systematics of the Savi's bat (Hypsugo savii) (Chiroptera: Vespertilionidae)

In order to assess the controversial systematic position of the Savi's bat (Hypsugo savii), 43 ves-pertilionid bats belonging to 10 species were analyzed by mean of isozyme electrophoresis. The results were interpreted in two ways: first, we found that the amount of genetic differentiation between Hypsugo and the true Pipistrellus (D # 0.719) is of the same magnitude as the mean distance which separates the other pipistrelloid genera (D = 0.738). Secondly, the cladogram based on these biochemical results confirms the splitting of these “pipistrelles”, as Hypsugo is more closely related to Vespertilio than to any other palearctic genus. The other species analyzed in this study group themselves in a different clade, including Pipistrellus, Eptesicus and Nyctalus. This phylogenetic interpretation presents a testable hypothesis, which could be confirmed by an analysis of other loci or other allied species.     

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.     

扁颅蝠的扩散行为研究

我们于2002 ～ 2007 年在广西龙州县和宁明县采用标记重捕法对扁颅蝠的扩散行为进行研究, 共标记669 只(成体316 只,亚成体353 只;雌雄分别为293 只和376 只),重捕到139 只(重捕率20. 8% )。结果表明,大部分扁颅蝠雌雄后代在性成熟前发生扩散,其亚成体扩散率无性别差异(雄
性82.2% ,雌性66.7% ;P > 0.05)。对成年雌雄两性扩散率(雄性76.5% ,雌性58.5% )的分析亦未见性别差异(P > 0.05),但亚成体和成体合并结果显示雄蝠扩散率(80.7% )高于雌蝠(62.3% ,P < 0.01)。此外,我们还测量了扩散的距离,雄性后代的扩散距离(787. 5 ± 26.980 m,n = 37)比雌
性(517.4 ± 25.308 m,n = 24)远(P < 0. 01);在出现扩散的61 只后代中,仅有一只(0. 7% )雄性亚成体扩散到其它的竹林,其余个体均在出生竹林内的不同竹筒之间进行扩散。     

A new species of bamboo bat (Chiroptera: Vespertilionidae: Tylonycteris) from southwestern China

Bamboo bats are a group of small bats with unique skull and morphology. They roost inside hollow bamboo stems in tropical and subtropical Asia and the Ambon Islands (Moluccas). We examined 53 specimens of Tylonycteris from southern and southwestern China. Comparisons of skull and external characteristics, pelage color, shapes of thumbpads and footpads, and statistical analysis of cranial measurements revealed that specimens from Damenglong, Jinghong County, Xishuangbanna, Yunnan, are distinctly different from the other two species of Tylonycteris described so far. The Yunnan specimens are the smallest in size; have dark blackish brown pelage color; and have larger upper premolars, smaller first lower premolars, and longer C-M(3). They are sympatric with the previously described species. Here we review the genus Tylonycteri and describe a new species, Tylonycteris pygmaeus, from the Yunnan material.     

Molecular systematics and biogeography of the bent-wing bat complex Miniopterus schreibersii (Kuhl, 1817) (Chiroptera: Vespertilionidae)

The complete mitochondrial ND2 gene (1037 bp) was sequenced to examine relationships within the bent-wing bat complex, Miniopterus schreibersii (Family Vespertilionidae). It was found that M. schreibersii is a paraphyletic assemblage comprising several species. Two major lineages were identified, one of which was restricted to the Palearctic-Ethiopian regions and the other to the Oriental-Australasian regions. This pattern of differentiation was mirrored by the genus as a whole. Speciation and differentiation within the genus Miniopterus appears to have a hierarchical geographical pattern. The earliest divergence corresponds to the Ethiopian-Palearctic and the Oriental-Australasian biogeographical zones. This early divergence is then followed by radiations within each of the Ethiopian, Oriental and Australasian regions. The study also revealed that the number of species currently recognized (11 or 13) is a gross underestimate of the number of actual species. The emerging picture is one of a relatively speciose genus with most species having relatively restricted distributions; few, if any, occur in more than one biogeographical region.     

Flight performance, foraging tactics and echolocation in the trawling insectivorous bat Myotis adversus (Chiroptera: Vespertilionidae)

The bat Myotis adversus hunts for prey by aerial hawking and by taking prey from the water surface with its feet (trawling). The flight performance and echolocation of this species were studied in Queensland, Australia, and comparisons were made with Myotis daubentoni , a bat filling a similar ecological niche in the Palaearctic Region. The bats foraged in very similar ways, using the same foraging tactics and feeding in similar habitats, yet they were not geometrically similar in shape. The slightly larger Myotis adversus had relatively larger wings than M. daubentoni , conferring a slightly lower wing-loading. Nevertheless, M. adversus flew faster than M. daubentoni during the searching phase of foraging. Myotis daubentoni turned in tighter circles than M. adversus . Both species used short frequency-modulated (FM) echolocation calls of a characteristic sigmoidal structure, and nulls typically observed in the calls were an observational artefact. Myotis adversus also adopted an unusual 'long'FM call while foraging. The relations between echolocation frequencies and body size were explored in male M. adversus . Specialized morphological and acoustic adaptations for prey capture by trawling in insectivorous bats are discussed.     

Complete mitochondrial genome of the Hodgson's bat Myotis formosus (Mammalia, Chiroptera, Vespertilionidae)

The first complete mitochondrial genome (17,159 bp) of the Hodgson's bat Myotis formosus, which is an endangered species in South Korea, was sequenced and characterized. The genome included 13 protein-coding, 22 tRNA, and 2 rRNA genes, and 1 control region. It has high AT content and the same gene arrangement pattern as those of typical vertebrate mitochondrial genome. Within the control region, a 80 bp tandem repeat unit was iterated five times which was found in Domain I. It has been observed only in the vespertilionid bat group, and could contribute to identifying the species or genus, and also distinguishing it from other bat families.     

Ecology of nutrition and differentiation of the trophic niches of bats (Chiroptera: Vespertilionidae) in floodplain ecosystems of the Samara Bend

A complex analysis of the food range of 15 bat species inhabiting floodplain ecosystems of the Samara Bend has been performed. It is shown that, in bats, an important component of the structuring of their communities is the division of food resources. The guild structure and position of species in the trophic space are described. Seven food guilds consisting of nonspecialized and specialized species are distinguished. It is noted that most species are characterized by a wide overlapping of their trophic niches, which may be a consequence of their weak competition in an environment that is rich in food resources.     

Temperature regulation and metabolism of an Australian bat, Chalinolobus gouldii (Chiroptera: Vespertilionidae) when euthermic and torpid

The thermal and metabolic physiology of Chalinolobus gouldii, an Australian vespertilionid bat, was studied in the laboratory using flow-through respirometry. Chalinolobus gouldii exhibits a clear pattern of euthermic thermoregulation, typical of endotherms with respect to body temperature and rate of oxygen consumption. The basal metabolic rate of euthermic Chalinolobus gouldii is approximately 86% of that predicted for a 17.5-g mammal and falls into the range of mass-specific basal metabolic rates ascribed to vespertilionid bats. However, like most vespertilionid bats, Chalinolobus gouldii displays extreme thermolability. It is able to enter into torpor and spontaneously arouse at ambient temperatures as low as 5 °C. Torpid bats thermoconform at moderate ambient temperature, with body temperature ≈ ambient temperature, and have a low rate of oxygen consumption determined primarily by Q ₁₀ effects. At low ambient temperature (< 10 °C), torpid C. gouldii begin to regulate their body temperature by increased metabolic heat production; they tend to maintain a higher body temperature at low ambient temperature than do many northern hemisphere hibernating bats. Use of torpor leads to significant energy savings. The evaporative water loss of euthermic bats is relatively high, which seems unusual for a bat whose range includes extremely arid areas of Australia, and is reduced during torpor. The thermal conductance of euthermic C. gouldii is less than that predicted for a mammal of its size. The thermal conductance is considerably lower for torpid bats at intermediate body temperature and ambient temperature, but increases to euthermic values for torpid bats when thermoregulating at low ambient temperature. Accepted: 22 August 1996     

Evolutionary Mechanisms Affecting the Multivariate Divergence in Some Myotis Species (Chiroptera, Vespertilionidae)

Phenotypic evolutionary rates were measured for 27 craniometric characters in 12 extant OTUs from the bat genus Myotis (Chiroptera, Vespertilionidae). Squared Mahalanobis distance was used as a multivariate measure for amount of divergence, and squared Mahalanobis distance weighted by time was used as a measure for the rate of divergence. Estimates for the rates of divergence were found to be consistent with random walk hypothesis. Thus, the divergence in Myotis could be guided by random drift and mutations. The high dispersion in rate estimates suggests also a possible input of randomly fluctuating selection. The highest rates were recorded for divergence between M. myotis–M. blythii species group and the other OTUs. Rates of divergence between the subspecies of M. blythii occur to be lesser than rates of divergence between the earlier diverged species, their divergence could probably be slowed down by stabilizing selection. Size-adjusted data appeared to be lesser then the initial data, and it can be concluded that both size and shape were involved in divergence of Myotis species. The skeletal characters in bats are known to be extremely conservative during long-term evolution, however, the possibility for random walk at short time interval implies that bat evolution is constrained rather ecologically and biomechanically than genetically or developmentally.     

Molecular ecology and phylogeography of the bent-wing bat complex (Miniopterus schreibersii) (Chiroptera: Vespertilionidae) in Asia Minor and adjacent regions

In this study we investigate population genetic structure and phylogeography of the bent-wing bat complex ( Miniopterus schreibersii ) in Asia Minor and adjacent regions. PCR amplification and sequencing of the first hypervariable domain of the mitochondrial control region were used to obtain the genetic data. Morphometric differentiation between lineages was analysed by comparing forearm lengths. We found two reciprocally monophyletic lineages within the M . schreibersii complex, identified as M.   s. schreibersii and M. s . pallidus . Distributions of the lineages were allopatric with a U-shaped suture zone passing through Central Anatolia. The suture zone separated coastal regions occupied by M.   s. schreibersii from inland, higher altitude regions occupied by M.   s. pallidus . The lineages showed a considerable sequence divergence of c . 9%, accompanied by a corresponding difference in forearm length. The presence of the genetically distinct lineages, with allopatric distribution and corresponding morphometric differences, probably reflects their long isolation during the ice-age in the Balkans and the Caspian/Caucasus refugia, followed subsequently by expansion into different habitats. Based on the present data, the lineages can be recognized as evolutionary significant units.