贵州发现毛翼管鼻蝠和华南菊头蝠及其回声定位声波特征

2017年5月分别在贵州省兴义市和安龙县用雾网采集到1只大体型雌性管鼻蝠和2只小体型雄性菊头蝠,经鉴定为毛翼管鼻蝠(Harpiocephalus harpia)和华南菊头蝠(Rhinolophus huananus),属贵州省翼手目新分布记录。所采集的毛翼管鼻蝠雌性个体可能为怀孕个体,故测量相关数据并鉴定后原地放归野外。华南菊头蝠标本保存于东北师范大学环境学院。毛翼管鼻蝠(1♀):鼻部呈短管状,全身被毛厚密而柔软,后足、翼膜和尾膜均被覆黄褐色绒毛;体重14.01 g,前臂长48.23 mm;回声定位声波为调频(FM)型,静止状态下声波峰频为(56.04±4.52)k Hz。华南菊头蝠(2♂):耳大,对耳屏相对较小;鼻叶之蹄状叶宽大,完全覆盖吻部;鞍状叶小,其高略超过其宽,近乎矩形;体毛烟褐色;2只样本体重分别为4.52 g、4.12 g,前臂长40.70 mm、40.00 mm;头骨狭长,颅全长16.35 mm、16.46 mm,颅宽8.11 mm、8.14 mm;回声定位声波属调频-恒频-调频(FM-CF-FM)型,静止状态下峰频分别为(68.48±0.08)k Hz、(67.18±0.06)k Hz。2种蝙蝠物种在贵州省为首次发现,扩大了其在国内的分布范围,丰富了生态资料,为进一步的研究和保护提供了基础资料。     

毛翼管鼻蝠分布的最北发现地——四川蝙蝠新记录

正2017年8月15日,在四川省巴中市通江县芝苞乡(海拔500 m)采集到1只雌性亚成体蝙蝠,根据其外形及头骨特征鉴定为毛翼管鼻蝠Harpiocephalus harpia,是四川翼手类动物一属和种的新记录,也是该物种迄今为止在国内外的最北分布记录。标本现保存于绵阳师范学院动物学标本室,编号为MNU17815。1外形及头骨特征     

毛翼管鼻蝠在广西和江西分布新纪录及其性二型现象

于2013年分别在广西北流大容山和江西井冈山用蝙蝠竖琴网分别采集到1只和9只蝙蝠标本,主要特征为:体型中型,鼻部前端呈短管状,背部毛基黄褐色,毛尖褐栗色,头骨和牙齿均粗壮。在室内使用Pettersson D500X超声波接收仪录制其静止和飞行状态下的回声定位信号,其超声波为FM型,飞行状态下主频率51.3~59.0 k Hz。根据形态特征鉴定该蝙蝠为毛翼管鼻蝠Harpiocephalus harpia,是广西和江西两省翼手目分布新纪录。对该种蝙蝠雌雄标本进行对比发现,6项外部形态和头骨指标上的差异有统计学意义,支持该种具有性二型现象。标本现保存于广州大学。     

贵州省发现高鞍菊头蝠

2012年7月和11月在对贵州省毕节市织金县及贵阳市乌当区进行翼手类动物多样性调查研究过程中,于织金县两洞穴及贵阳市乌当区一个洞穴中捕获到32只菊头蝠个体,其中雄性10只,雌性22只,经鉴定为高鞍菊头蝠(Rhinolophus paradoxolophus),为贵州省首次记录,后保留16号标本(雌11,雄5),标本现保存于贵州师范大学生命科学学院。     

雌雄异熟植物露蕊乌头开花时间对雌雄功能期及表型性别的影响

开花时间决定了植物雌雄功能的交配机会,最终影响繁殖成功。交配环境假说认为雌雄异熟植物开花时间的差异能引起植物表型性别的变异,改变种群内的交配环境,影响植物对雌雄功能的最佳性分配。为了研究开花时间对雌雄异熟植物的雌雄性别时期及表型性别的影响,本文以毛茛科雄性先熟植物露蕊乌头(Aconitum gymnandrum)为实验材料,记录了雄性和雌性功能期,分析了植株开花时间、花的雌雄功能期和表型性别的关系。结果表明:在植物同一花序内,较晚开放的花有更长的雄性期和更短的雌性期,性分配在时间上偏雄。雌雄功能期在时间上的相对分配随植物开花时间的变化表现出相似的趋势:较晚开的花或较晚开花的个体,花的雄性功能期相对于雌性功能期更长,在时间上更偏向雄性功能。而且,开花时间的差异影响种群内花的性比和植物个体的表型性别动态。随着开花时间由早到晚的变化,种群内早期以雄花为主,末期以雌花为主,种群内性别环境由偏雄向偏雌变化,因此植株个体的平均表型性别则从偏雌转向偏雄。本文结果支持交配环境假说,雄性先熟的露蕊乌头开花早期,种群内花的性别比偏雄,种群表型性别环境偏雄,因而植物个体平均表型性别偏雌,性别分配(即时间分配)偏向雌性功能,而晚开花个体的平均性别偏雄,更偏向雄性功能的分配。     

湖南发现渡濑氏鼠耳蝠与中管鼻蝠

2022年7月和9月，本研究组在湖南开展翼手目多样性资源调查时，于常德市桃源县、湘西州保靖县、永州市双牌县和邵阳市绥宁县使用蝙蝠竖琴网分别采集到9只鼠耳蝠（7♂，2♀）和5只管鼻蝠（2♂，3♀），结合传统形态学和分子系统发育学方法对上述标本进行物种鉴定。该批鼠耳蝠体型中等，前臂长43.41～50.89 mm，全身毛发呈红褐色，耳廓端部、鼻孔周围、五趾与爪及尾末端均呈黑褐色，翼膜掌指间有三角形状的红褐色斑直达翼缘；头骨顶部平缓，颧弓发达，脑颅高而凸显，其形态特征和度量数据均与渡濑氏鼠耳蝠（Myotis rufoniger）相符。同时，采集的管鼻蝠标本体型中等，前臂长33.83～37.53 mm，背毛棕褐色，腹毛呈浅黄色；颅全长16.74～17.29 mm，颧弓平直而宽厚，其外形特征和度量数据均与中管鼻蝠（Murinahuttoni）相符。基于Cytb和COI基因构建的系统发育树均支持以上形态学鉴定结果。该报道为渡濑氏鼠耳蝠和中管鼻蝠在湖南省分布的新发现。标本现存于广州大学华南生物多样性保护与利用重点实验室，其中渡濑氏鼠耳蝠标本号为GZHU22429、GZHU22430、GZHU 2245...     

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±26.980m,n=37)比雌性(517.4±25.308m,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。     

湖南省翼手目新纪录——贵州菊头蝠

在湘西土家族苗族自治州吉首市矮寨镇四方洞和寨阳乡堂乐洞分别采到菊头蝠雌、雄性标本各1只,通过将其外形及头骨的测量数据同文献记载的外形相似的高鞍菊头蝠(Rhinolophus paradoxolophus)和马氏菊头蝠(R.marshalli)的特征进行对比,鉴定为贵州菊头蝠(R.rex),属湖南省翼手目新纪录,标本保存于吉首大学动物标本室.本文对其分布与保护现状也作了简要报道.     

菲菊头蝠冬眠期的精子储存

菲菊头蝠是分布于亚热带和热带的翼手目种类,在中国大陆南部和海南岛有广泛分布.为探讨热带菲菊头蝠是否具有冬眠期（12月至翌年2月）储精现象及生殖腺组织结构的变化,对海南岛的菲菊头蝠成年雄蝠和成年雌蝠生殖系统在冬眠期间的变化进行了石蜡切片观察.结果显示：成年雄蝠在冬眠期间附睾内储存大量精子,推测其储存时间超过2个月;冬眠期间曲细精管横截面积、精子细胞数量和间质细胞数量在冬眠期逐月显著性减少,精原细胞和精母细胞的数量在12月与翌年1月间均无显著性变化,而在冬眠末期的2月显著增多.在雌蝠子宫和卵巢内均未发现精子储存现象,但卵巢内具有初级卵泡和次级卵泡,雄蝠在冬眠期间曲细精管逐月萎缩,但生精上皮精母细胞的数量在冬眠末期明显上升.     

江西省发现泰坦尼亚彩蝠

2013年7月和8月,在江西井冈山国家级自然保护区石溪村(26°37.143′N,114°10.875′E,海拔777 m)和朱砂冲林场(26°33.703'N,114°11.232'E,海拔805 m)使用竖琴网分别采集到7号(6雄1雌)和5号(全雌)森林性蝙蝠标本。上述蝙蝠标本体型较小,前臂长30.16~33.85 mm,颅全长13.90~14.76 mm;无鼻叶,耳廓呈漏斗状,耳屏略呈披针形;脑颅骨略显扁平,齿式为2.1.3.3/3.1.3.3=38;核型中染色体数(2n)为32,常染色体臂数(FN)为52。经鉴定均为泰坦尼亚彩蝠(Kerivoula titania),是江西省翼手目分布新纪录,同时也为中国大陆地区(除海南和台湾)翼手目分布新纪录。本文给出了泰坦尼亚彩蝠的外形和头骨特征及其相关测量数据,并对江西产该种蝙蝠雌雄性标本间的形态数据以及江西产标本与东南亚产该种标本测量数据分别进行t检验,该种性二型分化不明显,但江西和东南亚两地区种群在形态上出现了一定的分化;同时对其染色体核型、生态及保护地位进行了分析和讨论。标本现保存于广州大学生命科学学院。     

Sexual Dimorphism in Sturnira lilium (Chiroptera,Phyllostomidae): Can Pregnancy and Pup Carrying Be Responsible for Differences in Wing Shape?

Competition is one of the most cited mechanisms to explain secondary sexual dimorphism in animals. Nonetheless, it has been proposed that sexual dimorphism in bat wings is also a result of adaptive pressures to compensate additional weight caused by fetus or pup carrying during the reproductive period of females. The main objective of this study is to verify the existence of sexual dimorphism in Sturnira lilium wings. We employed geometric morphometrics techniques using anatomical landmarks superimposition to obtain size (Centroid Size) and shape variables of wings, which were reduced by Linear Discriminant Analysis (LDA). We also employed classical morphometrics using wing length measurements to compare efficiency between these two morphometric approaches and make comparisons using wing area measurements. LDA indicated significant differences between wing shapes of males and females, with 91% (stepwise classification) and 80% (leave-one-out cross validation) of correct classification. However, the size variable obtained did not contribute to such classifications. We have observed larger areas in female wings, but we found no differences in wing length measurements and no allometric effects in wing length, shape and area measurements. Interestingly, our study has provided evidences of morphological differences where classical morphometrics have failed. LDA and area measurements analyses revealed that females have a different area distribution in distinct portions of the wing, with wider dactylopatagia and plagiopatagia, and wingtips more triangular than males. No differences in body length or relative wing length were observed between the sexes, but pregnant females have more body weight than non-pregnant females and males. Our findings suggest that sexual dimorphism in the wing shape of S. lilium is probably related to the increase in flight efficiency of females during reproductive period. It decreases wing loading in specific portions of the wing and reduces energy cost to maintain a faster and maneuverable flight.     

Wing shape variation of Finnish and Central European Willow Warblers Phylloscopus trochilus and Chiffchaffs P. collybita

Wing shape variation of European Willow Warblers Phylloscopus trochilus and Chiffchaffs P. collybita was studied using indices calculated from wing formulae. Our data were from free-living local populations of P. t. acredula and P. c. abietinus from southern Finland, and P. t. trochilus and P. c. collybita from southwestern Germany.
There were no significant shape differences between the subspecies of the Willow Warbler in which sexual dimorphism was pronounced. The subspecies of the Chiffchaff were significantly different while the sexes were not. There were also significant differences between adult and immature individuals in the autumn. The intrapopulation variation must be considered in attempts to recognize different subspecies or populations in data on birds caught during migration.
In the Willow Warbler at least, the difference between age-groups was larger in males than in females. If the change in wing formula due to the complete pre-nuptial moult is similar in both sexes, juvenile males intermediate between adult females and adult males suffer disproportionately high mortality. It was earlier suggested that sexual selection increases body size in Willow Warbler males, but the present results imply additional selection pressures for increasing sexual dimorphism.     

Extra-pair paternity and sexual dimorphism in birds

Differences in the strength of sexual selection between males and females can lead to sexual dimorphism. Extra-pair paternity (EPP) can increase the variance in male reproductive success and hence the opportunity for sexual selection. Previous research on birds suggests that EPP drives the evolution of dimorphism in plumage colour and in body size. Because EPP increases the intensity of sexual selection in males, it should lead to increased dimorphism in species with larger or more colourful males, but decreased dimorphism in species with larger or more colourful females. We explored the covariation between EPP and sexual dimorphism in wing length and plumage colouration in 401 bird species, while controlling for other, potentially confounding variables. Wing length dimorphism was associated positively with the frequency of EPP, but also with social polygamy, sex bias in parental behaviour and body size and negatively with migration distance. The frequency of EPP was the only predictor of plumage colour dimorphism. In support of our prediction, high EPP levels were associated with sexual dichromatism, positively in species in which males are more colourful and negatively in those in which females are more colourful. Contrary to our prediction, high EPP rates were associated with increased wing length dimorphism in species with both male- and female-biased dimorphism. The results support a role for EPP in the evolution of both size and plumage colour dimorphism. The two forms of dimorphism were weakly correlated and predicted by different reproductive, social and life-history traits, suggesting an independent evolution.     

Geography of sexual dimorphism in the tooth size of the red fox Vulpes vulpes (Mammalia, Carnivora)

Geographic variation in sexual dimorphism of tooth size was assessed for the red fox Vulpes vulpes (Linnaeus, 1758) across the whole northern range of the species. Twenty-one measurements of tooth size and skull length were taken from 2849 specimens (1577 males and 1272 females) originating from 12 Nearctic and 25 Palearctic localities. The index of sexual dimorphism was calculated as a quotient of the mean measure of certain characters in males by the respective mean in females ( M _m/ M _f). In the whole range, the males were larger than females and mean dimorphism index of tooth size ranged from 1.01 to 1.06. On average, the tooth measurements in males were 3.6% larger than in females. The highest dimorphism was observed in the canines. Dimorphism of tooth size was higher in the Palearctic than Nearctic. Statistically significant differences between regions were found for lengths of C¹, C₁ and M₁. In the Palearctic, higher values of the dimorphism indices were observed particularly in the southern parts of the Eurasian range of the red fox and in Great Britain. For a few metrical traits, sexual dimorphism indices presented significant relations to some geo-climatic variables. The geographic pattern of size dimorphism in the red fox seems to be shaped by sexual selection, intraspecific and interspecific competition and population density.     

蓝尾石龙子的头部两性异形和食性

通过测量头、体大小和胃检研究浙江泰顺产蓝尾石龙子 (Eumeceselegans)个体发育过程中两性异形和食性的变化。蓝尾石龙子成体个体大小和头部大小的两性差异显著 ,雄性大于雌性。不同发育阶段雌性头长与SVL的线性回归斜率无显著差异 ,头宽与SVL线性回归斜率的差异显著 ,成体和SVL <5 0mm幼体头宽随SVL的增长速率显著小于SVL为 5 0 - 6 9mm的幼体。雄性头部相对于SVL呈加速式异速生长。两性比较发现 :雌雄幼体头长和头宽随SVL的增长速率无显著差异 ,SVL <5 0mm幼体特定SVL的头长和头宽无显著的两性差异 ,但SVL为 5 0 - 6 9mm的雄性幼体头长和头宽大于SVL相同的雌性幼体 ;雄性成体头长和头宽随SVL的增长速率显著大于雌性。SVL <5 0mm的雌性幼体头部相对小于SVL为 5 0 - 6 9mm的同性幼体 ,性成熟雌体头部相对小于SVL为 5 0 - 6 9mm的同性幼体。雌性幼体、雄性幼体、雌性成体和雄性成体食物生态位宽度分别为 12 3、 12 5、 4 8和 14 4。雌雄幼体食物生态位重叠度最高 ,雌雄成体食物生态位重叠度次之 ,成体与幼体食物生态位重叠度较小。成体摄入食饵的大小 (用胃内完整食物长度的平均值表示 )和变化范围大于幼体。两性成、幼体摄入的食饵大小差异显著。两性个体摄入的食饵大小均与其SVL呈正相关 ,表明较大     

利安德水鼩在中国地理分布范围的讨论与修订

利安德水鼩很长时间被认为是喜马拉雅水鼩的亚种，但近年来的研究发现利安德水鼩是进化关系上与日本水鼩更加接近的独立物种。而喜马拉雅水鼩一直被认为是分布区横跨古北界和东洋界广域分布的物种，但基于Cyt b基因序列测定和系统进化关系的构建，我们确定最近在四川、浙江和湖南等地采集的水鼩标本均为利安德水鼩。基于基因序列和对馆藏标本的比对，我们修订喜马拉雅水鼩和利安德水鼩在中国的分布。四川、湖北、湖南、陕西、贵州、广西、福建、台湾、浙江等地区都是利安德水鼩的分布区，而喜马拉雅水鼩在中国确定的分布区仅在云南。这一分布格局很可能是由于在地形地貌的影响下产生隔离分化的结果。     

奇台沙蜥生长过程中的两性异形

研究奇台沙蜥Phrynocephalus grumgrzimailoi头、尾、腋胯距大小在个体发育过程中的变化.成体体长(SVL)无显著的两性差异,两性异形主要表现为雄性个体有较大的头部(头长和头宽)和尾部,雌性具有较大的腋胯距.头、尾、腋胯距大小的两性异形在幼体就已存在,并随个体发育的进行变得更加显著.不同年龄组两性个体头部、尾部、腋胯距随SVL呈异速增长,表现为两性头部的增长速率在个体发育过程中逐渐增大,尾部的增长速率逐渐减慢,腋胯距在雌性蜥蜴中增长速率逐渐增大,在雄性中逐渐变小.     

大山雀身体大小的性二态及其季节变化

动物中普遍存在雌雄个体身体大小的性二态现象。了解近缘种之间身体大小性二态现象的差异，可为深入探讨身体大小性二态现象的潜在驱动机制提供证据。国外对欧亚大山雀（Parus major）的研究发现，其喙长、跗跖长、翅长等 6 项身体大小指标存在着明显的性二态，且喙长的性二态存在季节间差异。大山雀（P. cinereus）曾被作为欧亚大山雀的一个亚种，其形态和行为与欧亚大山雀存在着诸多相似之处。为探讨大山雀是否也存在身体大小性二态及季节性差异，本研究分析了 2018 至 2020 年间在河南董寨国家级自然保护区捕捉的 226 只（雌性 96 只和雄性 130 只）大山雀的喙长、头喙长、跗跖长、翅长、尾长和体长这 6 项体征指标的两性差异及其季节变化。结果显示，大山雀上述 6 项身体大小指标均存在不同程度的性二态现象，且雄性个体仅喙长与雌性的差异不显著，其余 5 项指标均显著大于雌性。此外，身体大小指标的两性差异不随季节显著变化，但两性的跗跖长在秋季均显著短于冬季和繁殖季，尾长在繁殖季均显著长于秋季和冬季。上述结果表明，大山雀身体大小的性二态及其季节性差异与欧亚大山雀并不完全相似。无论其身体大小存在性二态和季节变化的原因，还是其与欧亚大山雀在身体大小性二态模式上的差别，都有待今后进一步的研究。     

Is natural selection promoting sexual dimorphism in the Green-backed Firecrown Hummingbird ( Sephanoides Sephaniodes )?

In many hummingbird species there is an opposite pattern of sexual dimorphism in bill length and other morphometric measures of body size. These differences seem to be closely related with differences in foraging ecology directly associated with a different resource exploitation strategy. The aim of this study was to assess if natural selection is acting on wing length and bill size in hummingbird males and females with different resource exploitation strategies (i.e., territorial males and non-territorial females). If competition for resources promotes sexual dimorphism as a selective pressure, males should be subjected to negative directional selection pressure for wing length and no selection pressure over bill size, while females should undergo positive directional selection pressure for both bill size and wing length. The morphometric data we collected suggests that there is no selection for wing length and bill size in male hummingbirds. In contrast, our females exhibited positive directional selection for both wing length and bill size. Although we cannot reject sexual selection acting on sexually dimorphic traits, this study suggests that natural selection may promote sexual dimorphism in traits that are closely related with hummingbird foraging ecology and resource exploitation strategies.     

Sexual size dimorphism in greater mouse‐eared bat Myotis myotis (Chiroptera: Vespertilionidae) from a Mediterranean region

Although sexual size dimorphism (SSD) is common among mammals, there is no clear explanation for its maintenance in nature. Bats are one of the few groups of mammals where reverse SSD appears. In this group, the size of individuals may have very important ecological consequences related with flight. In this study, we examine sexual dimorphism in the wing measurements of 195 adult individuals (141 males and 54 females) of the greater mouse‐eared bat Myotis myotis in the south‐east of the Iberian Peninsula. We also investigated size differences between paired and single males in a swarming roost. The results indicate that there are significant differences in the wing measurements between sexes, females being bigger than males in this respect. While no significant differences in the wing measurements of paired and single males were observed, significant differences were found in their relative weight and fitness, single males being significantly heavier and having a better physical condition. We discuss the implications of SSD for the female of M. myotis in terms of reproductive advantages, trophic niche segregation and a greater ability to move, which may favour gene flow between populations.