Lancet Dynamics in Greater Horseshoe Bats,Rhinolophus ferrumequinum

Echolocating greater horseshoe bats (Rhinolophus ferrumequinum) emit their biosonar pulses nasally, through nostrils surrounded by fleshy appendages (‘noseleaves’) that diffract the outgoing ultrasonic waves. Movements of one noseleaf part, the lancet, were measured in live bats using two synchronized high speed video cameras with 3D stereo reconstruction, and synchronized with pulse emissions recorded by an ultrasonic microphone. During individual broadcasts, the lancet briefly flicks forward (flexion) and is then restored to its original position. This forward motion lasts tens of milliseconds and increases the curvature of the affected noseleaf surfaces. Approximately 90% of the maximum displacements occurred within the duration of individual pulses, with 70% occurring towards the end. Similar lancet motions were not observed between individual pulses in a sequence of broadcasts. Velocities of the lancet motion were too small to induce Doppler shifts of a biologically-meaningful magnitude, but the maximum displacements were significant in comparison with the overall size of the lancet and the ultrasonic wavelengths. Three finite element models were made from micro-CT scans of the noseleaf post mortem to investigate the acoustic effects of lancet displacement. The broadcast beam shapes were found to be altered substantially by the observed small lancet movements. These findings demonstrate that—in addition to the previously described motions of the anterior leaf and the pinna—horseshoe bat biosonar has a third degree of freedom for fast changes that can happen on the time scale of the emitted pulses or the returning echoes and could provide a dynamic mechanism for the encoding of sensory information.     

Three-Dimensional and Histological Observations on Male Genital Organs of Greater Horseshoe Bat,Rhinolophus ferrumequinum

Journal of Mammalian Evolution - Anatomy of bat genital organs has been conventionally studied by gross and microscopic observations to date. Here, we employ both histological observation and...     

中华菊头蝠不同组织基因组DNA甲基化分析

DNA甲基化在动物组织发育和分化等生物过程中发挥至关重要的作用.本研究采用荧光标记甲基化敏感扩增多态性(fluorescence-labeled methylation sensitive amplified polymorphism,F-MSAP)技术分析了中华菊头蝠(Rhinolophus sinicus)脑、心、...     

Origins of Horseshoe Bats (Rhinolophus, Rhinolophidae) in Southern Africa: Evidence from Allozyme Variability

Morphological analyses indicate that horsehose bats in the genus Rhinolophus constitute a monophyletic group which most likely originated in southeastern Asia but which presently inhabits Oriental, Australian, Palaearctic, and Ethiopian zoogeographical provinces. Ten species occur in southern Africa, but it is uncertain which species represent dispersals from Eurasia through North Africa and which have resulted from speciation in Africa. Analyses of 34 allozyme encoding loci in these 10 species and in 2 southern African species of leafnose bats in the sister genus Hipposideros reveal the presence of at least three lineages of Rhinolophus in southern Africa. One lineage includes R. clivosus, R. darlingi, R. fumigatus, and R. hildebrandtii, all of which, except R. clivosus, are endemic to sub-Saharan Africa. Rhinolophus blasii is genetically allied with, but distinct from this group, and appears to be a recent migrant from another lineage centered on the Mediterranean. A third lineage, including at least R. capensis, R. denti, R. simulator, and R. swinnyi, is endemic to sub-Saharan Africa. The phylogenetic position of R. landeri is uncertain, most likely because of the small sample size used to estimate allelic frequencies for this species. The biochemical genetic definitions of these lineages largely agree with previous morphological analyses of Rhinolophus species. Divergences between species within two lineages (R. clivosus, R. darlingi, R. fumigatus, and R. hildebrandtii; and R. capensis, R. denti, R. simulator, and R. swinnyi) appear to reflect two bursts of speciation in the Plio-Pleistocene period within Africa.     

辽宁省翼手目分布新记录种大耳菊头蝠

翼手目(蝙蝠)物种独特的飞行能力、夜间活动模式及相近的形态学特征,增大了科研人员在野外对其进行准确鉴别和调查的难度,因此翼手目物种的多样性和分布信息亟需综合多种调查技术开展广泛深入研究。2019年8月,作者在辽宁省朝阳市野外调查发现1种蝙蝠,经分子标记比对、系统发育关系重建及形态学数据鉴定为大耳菊头蝠(Rhinolophus macrotis),是辽宁省翼手目物种新记录。     

Echolocation sounds and hearing of the greater Japanese horseshoe bat (Rhinolophus ferrumequinum nippon)

Summary The relationship between the orientation sounds and hearing sensitivity in the greater Japanese horseshoe bat,Rhinolophus ferrumequinum nippon was studied.An orientation pulse consisted of a constant frequency (CF) component followed by a short downward frequency-modulated (FM) component. Sometimes, an initial upward FM component preceded the CF component. Duration of pulses was about 30 ms and the CF of resting pulses (RF) averaged 65.5 kHz. The best frequency (BF) at the lowest threshold in audiograms as measured by the pinna reflex averaged 66.1 kHz. Audiograms showed remarkable sharp cut-offs on both sides near the BF. The frequency difference between the BF and the RF was about 0.6 kHz, and the RF was always below the BF. The values of RF and BF were characteristically different from those of the European subspecies,Rhinolophus ferrumequinum ferrumequinum.Abbreviations BF best frequency - CF constant frequency - FM frequency modulated - RF resting frequency     

Outbreeding increases offspring survival in wild greater horseshoe bats (Rhinolophus ferrumequinum)

The factors influencing the survival of greater horseshoe bat (Rhinolophus ferrumequinum) offspring born over seven years at a maternity colony in south-west Britain were studied. The effects of a range of phenotypic and maternal variables were analysed using a historical data set. In addition, the influence of two genetic measures on mortality, individual heterozygosity and a new measure of outbreeding, termed mean d(2), was assessed. Logistic regressions were undertaken with survival modelled as a binary response variable. Survival to two life stages was studied for each variable and all models were developed for both sexes separately and together. Only one variable, mean d(2), was significantly associated with survival. Male offspring with high mean d(2) scores were more likely to survive to their first and second summers. The influence of mean d(2) was not due to a single locus under selection but a wider multilocus effect and probably represents heterosis as opposed to solely inbreeding depression. Therefore, the extent to which an individual is outbred may determine survival more than widely used phenotypic characteristics such as size and mass. Mean d(2) may reflect immunocompetence, which influences mortality. Protection of mating sites in order to facilitate gene flow and, therefore, outbreeding may help to promote population stability and growth.     

四川产中菊头蝠喜马拉雅亚种和马铁菊头蝠日本亚种外部形态及头骨的比较

对四川产中菊头蝠喜马拉雅亚种(Rhinolophus affinis himalayanus)和马铁菊头蝠日本亚种(R.ferrumequinum nippon)的23项外部形态指标和22项头骨形态指标进行了测量,并进行数理统计分析。结果表明,(1)中菊头蝠喜马拉雅亚种和马铁菊头蝠日本亚种的23项外部形态测量指标中有2项差异显著(P<0.05),16项差异极显著(P<0.01),其中:中菊头蝠喜马拉雅亚种(n=14)体长小于59 mm(47.30~58.40),尾长小于26 mm(21.69~25.68),耳长小于22 mm(18.36~21.88),前臂长小于56 mm(50.9~54.20),第Ⅲ掌骨第一指节长小于16 mm(13.2~15.53),第Ⅲ掌骨第二指节小于32 mm(27.38~31.74);而马铁菊头蝠日本亚种(n=6)体长大于62 mm(62.43~66.76),尾长大于30 mm(30.56~36.18),耳长大于24 mm(24.47~27.20),前臂长大于56 mm(58.78~63.46),第Ⅲ掌骨第一指节大于19 mm(19.38~21.39),第Ⅲ掌骨第二指节大于34 mm(34.42~38.11),这些差异可作为区分四川产这两个种的依据。(2)中菊头蝠喜马拉雅亚种和马铁菊头蝠日本亚种的22项头骨形态测量指标中,除颅高、听泡间距差异不显著(P>0.05)外,其他20项指标都存在极显著差异(P<0.01)。     

Parentage, reproductive success and breeding behaviour in the greater horseshoe bat (Rhinolophus ferrumequinum)

Female greater horseshoe bats form maternity colonies each summer in order to give birth and raise young. During the mating period, females visit males occupying territorial sites, copulation takes place and sperm are stored until ovulation occurs, normally in April. Using microsatellite markers and a likelihood method of parentage analysis, we studied breeding behaviour and male reproductive success over a five-year period in a population of bats in south-west Britain. Paternity was assigned with 80% confidence to 44% of young born in five successive cohorts. While a small annual skew in male reproductive success was detected, the variance increased over five years due to the repeated success of a few individuals. Mating was polygynous, although some females gave birth to offspring sired by the same male in separate years. Such repeated partnerships probably result from fidelity for either mating sites or individuals or from sperm competition. Females mated with males born both within and outside their own natal colony; however, relatedness between parents was no less than the average recorded for male female pairs. Gene flow between colonies is likely to be primarily mediated by both female and male dispersal during the mating period rather than more permanent movements.     

Lineage Divergence and Historical Gene Flow in the Chinese Horseshoe Bat (Rhinolophus sinicus)

Closely related taxa living in sympatry provide good opportunities to investigate the origin of barriers to gene flow as well as the extent of reproductive isolation. The only two recognized subspecies of the Chinese rufous horseshoe bat Rhinolophus sinicus are characterized by unusual relative distributions in which R. s. septentrionalis is restricted to a small area within the much wider range of its sister taxon R. s. sinicus. To determine the history of lineage divergence and gene flow between these taxa, we applied phylogenetic, demographic and coalescent analyses to multi-locus datasets. MtDNA gene genealogies and microsatellite-based clustering together revealed three divergent lineages of sinicus, corresponding to Central China, East China and the offshore Hainan Island. However, the central lineage of sinicus showed a closer relationship with septentrionalis than with other lineages of R. s. sinicus, in contrary to morphological data. Paraphyly of sinicus could result from either past asymmetric mtDNA introgression between these two taxa, or could suggest septentrionalis evolved in situ from its more widespread sister subspecies. To test between these hypotheses, we applied coalescent-based phylogenetic reconstruction and Approximate Bayesian Computation (ABC). We found that septentrionalis is likely to be the ancestral taxon and therefore a recent origin of this subspecies can be ruled out. On the other hand, we found a clear signature of asymmetric mtDNA gene flow from septentrionalis into central populations of sinicus yet no nuclear gene flow, thus strongly pointing to historical mtDNA introgression. We suggest that the observed deeply divergent lineages within R. sinicus probably evolved in isolation in separate Pleistocene refugia, although their close phylogeographic correspondence with distinct eco-environmental zones suggests that divergent selection might also have promoted broad patterns of population genetic structure.     

马铁菊头蝠捕食活动与猎物资源的关系

捕食者与猎物的关系研究对了解物种捕食行为及种群空间格局具有重要意义。采用Avisoft Bioacoustics超声波仪录制马铁菊头蝠自然状态下的声波以确定其捕食活动强度,用灯诱法、扫网法和飞行阻隔法相结合采集昆虫,搜集蝙蝠粪便并分析其食物组成。结果表明,马铁菊头蝠在8月份活动最频繁,昆虫丰富度在8月份最丰富,马铁菊头蝠捕食活动与鳞翅目丰富度呈显著正相关。马铁菊头蝠主要以鳞翅目和鞘翅目为食,但食性存在明显的月份变化。卡方检验结果表明,马铁菊头蝠捕食的猎物与环境中可利用的昆虫猎物存在显著差异。在食物资源丰富时,马铁菊头蝠选择性地捕食营养丰富的鞘翅目昆虫。     

马铁菊头蝠幼蝠能够辨别种群间回声定位声波差异

蝙蝠的回声定位声波普遍存在地理变化,然而尚不清楚幼蝠在扩散前能否辨别不同种群间的声波差异。本文采用"双选择声学回放实验",研究马铁菊头蝠(Rhinolophus ferrumequinum)幼蝠(1月龄)对回声定位声波地理变化的辨别能力及行为反应。采用4个行为参数衡量幼蝠对本种群(CC)与外种群(JN)回声定位声波的行为反应:每一回放室飞入的次数、飞行时间、停留次数、探测时间。Mann-Whitney U tests表明,马铁菊头蝠1月龄个体对回放声波的行为反应,除每一回放室停留的次数外,其他3个参数均存在显著差异(P0.05),且在本种群声波回放室(CC)的飞行次数和时间以及探测时间均高于外种群声波回放室(JN)。对4个行为参数进行主成分分析,Mann-Whitney U tests表明,回放本种群声波(CC)与外种群声波(JN)之间,第一主成分得分(PC1)存在显著差异(P0.01)。配对T检验表明,幼蝠对本种群声波反应更加强烈(PC1:t10=5.25,P0.001;PC2:t10=2.34,P0.05)。本研究说明马铁菊头蝠幼蝠能够辨别不同种群间回声定位声波的差异。     

菲菊头蝠不同地理种群回声定位声波差异及其影响因子

回声定位声波地理差异及其形成原因是蝙蝠生态学研究领域一个基本而关键的问题,对于探索物种生存机制、物种形成及其保护具有重要科学意义。本研究从较大地理尺度上(9个地理种群)研究了菲菊头蝠(Rhinolophus pusillus)回声定位声波结构的地理差异,并进一步探讨了影响回声定位声波地理种群差异的因素。结果表明,菲菊头蝠雌性的体型较雄性略大,其主频较高。不同地理种群之间回声定位声波差异明显,包括脉冲持续时间、脉冲间隔、主频以及带宽在不同的地理种群之间均表现出一定程度的差异。进一步分析发现,不同地理种群之间的雌性菲菊头蝠前臂长和体重均与主频呈较弱的负相关,降雨量与雌性的主频呈较强的正相关;而不同地理种群之间的雄性前臂长、体重和降雨量与回声定位声波参数均无相关性;此外,地理距离、温度、湿度均与雌雄回声定位声波参数无相关性。本研究结果表明,菲菊头蝠不同地理种群间的回声定位声波出现明显差异,其中,体型和降雨量为主要影响因子,说明蝙蝠回声定位叫声的进化主要受到了当地生境的影响,表现出动物对不同生境的适应性进化。     

Directional sensitivity of echolocation in the horseshoe bat,Rhinolophus ferrumequinum

Summary The directionality of sound emission by a horseshoe bat (Rhinolophus ferrumequinum) has been determined for the constant frequency component of its orientation sounds. The bat was fixed in the center of an acoustic perimeter and the SPL of the orientation sounds measured with a scanning microphone at different angles compared with the SPL measured by another microphone located in the direction perpendicular to the plane of the horseshoe-like structure of the nose-leaf. The maximum SPL was always found in this direction which also corresponds to the flight direction of a bat in horizontal flight. Above and lateral to this direction the SPL decreases steadily with -6 dB-points at 24 above and 23 lateral. Below the flight direction we found a prominent side lobe with a -6 dB-point at 64 .When the present data are combined with measurements of the behavioral directionality of hearing at the same frequency (Grinnell and Schnitzler, 1977), the directionality diagram of the entire echolocation system is very narrow and points in the flight direction. The prominent downward side lobe of emission does not conspicuously increase echolocation effectiveness in the direction of the ground, since hearing sensitivity is falling off so steeply in that direction. However, without this downward beam of emission, signals from below the bat would be that much less effective.Interference with the structure of the nose-leaf by covering the upper part with vaseline or plugging the left nostril destroyed the smoothness of the normal sound field and demonstrated that this complex organ is a highly functional structure optimized in the course of evolution.With differences in mood or attention, the emitted pulses varied by as much as 20 dB (80–100 dB). The emission directionality pattern also varied. In most cases, as orientation sounds increased in SPL, the acoustic beam became smaller.Supported by Deutsche Forschungsgemeinschaft, grant No. Schn 138/1-6, Stiftung Volkswagenwerk, grant No. 111 858, and the Alexander von Humboldt StiftungWe thank W. Hollerbach and C. Nitsche for technical assistance.