Geckos significantly alter foot orientation to facilitate adhesion during downhill locomotion

Geckos employ their adhesive system when moving up an incline, but the directionality of the system may limit function on downhill surfaces. Here, we use a generalist gecko to test whether limb modulation occurs on downhill slopes to allow geckos to take advantage of their adhesive system. We examined three-dimensional limb kinematics for geckos moving up and down a 45° slope. Remarkably, the hind limbs were rotated posteriorly on declines, resulting in digit III of the pes facing a more posterior direction (opposite to the direction of travel). No significant changes in limb orientation were found in any other condition. This pes rotation leads to a dramatic shift in foot function that facilitates the use of the adhesive system as a brake/stabilizer during downhill locomotion and, although this rotation is not unique to geckos, it is significant for the deployment of adhesion. Adhesion is not just advantageous for uphill locomotion but can be employed to help deal with the effects of gravity during downhill locomotion, highlighting the incredible multi-functionality of this key innovation.     

Blood vessel formation during tail regeneration in the leopard gecko (Eublepharis macularius): The blastema is not avascular

Unique among amniotes, many lizards are able to self‐detach (autotomize) their tail and then regenerate a replacement. Tail regeneration involves the formation of a blastema, an accumulation of proliferating cells at the site of autotomy. Over time, cells of the blastema give rise to most of the tissues in the replacement tail. In non‐amniotes capable of regenerating (such as urodeles and some teleost fish), the blastema is reported to be essentially avascular until tissue differentiation takes place. For tail regenerating lizards less is known. Here, we investigate neovascularization during tail regeneration in the leopard gecko (Eublepharis macularius ). We demonstrate that the gecko tail blastema is not an avascular structure. Beginning with the onset of regenerative outgrowth, structurally mature (mural cell supported) blood vessels are found within the blastema. Although the pattern of blood vessel distribution in the regenerate tail differs from that of the original, a hierarchical network is established, with vessels of varying luminal diameters and wall thicknesses. Using immunostaining, we determine that blastema outgrowth and tissue differentiation is characterized by a dynamic interplay between the pro‐angiogenic protein vascular endothelial growth factor (VEGF) and the anti‐angiogenic protein thrombospondin‐1 (TSP‐1). VEGF‐expression is initially widespread, but diminishes as tissues differentiate. In contrast, TSP‐1 expression is initially restricted but becomes more abundant as VEGF‐expression wanes. We predict that variation in the neovascular response observed between different regeneration‐competent species likely relates to the volume of the blastema. J. Morphol. 278:380–389, 2017. © 2017 Wiley Periodicals, Inc.     

Microsatellite DNA markers for Australian geckos

Nine highly polymorphic microsatellite markers were developed for Gehyra variegata from an enriched library screened for tetranucleotide repeats. An average of 19.44 alleles per locus and an average observed heterozygosity of 0.86 were found in 81 samples from fragmented populations in the Western Australian wheatbelt. Different gecko species exhibit varying rates of extinction in fragmented landscapes and the genetic markers were developed to test whether these difference are due to different rates of dispersal. The loci were tested for their ability to cross amplify in 12 species of Australian Gekkonidae and Pygopodidae, in an attempt to identify species which might be amenable to population genetic analysis using these microsatellite markers.     

大壁虎线粒体基因组全序列及其结构(英文)

采用长PCR扩增、克隆和引物步行等方法,测定了大壁虎(Gekkogecko)线粒体基因组全序列。序列全长16435bp,共有13个蛋白质编码基因、2个rRNA基因和22个tRNA基因。基因组的组成、顺序、编码链的选择、tRNA的结构、较低的碱基G含量、对碱基T的偏好以及GC和AT偏斜,都与大部分脊椎动物相同或相近。但有些特征揭示了壁虎类的原始性蛋白质编码基因密码子第3位表现为对碱基A的偏好,更接近两栖类和鱼类而不是羊膜动物;标准终止密码子(TAA)只出现于3个蛋白质编码基因中,比大部分脊椎动物少。tRNA基因核苷酸长度为63～76nt,除了tRNACys和tRNASer(AGY)缺少D臂,其余的二级结构均呈典型的三叶草状。     

摄食对原尾蜥虎代谢率的影响

通过测定摄食后原尾蜥虎成体的耗氧量变化,研究摄食特殊热动力作用（SDA）.蜥虎分为摄食黄粉虫幼虫实验组和禁食对照组,两组动物平均体重无显著差异.测定耗氧量前,将所有动物在30℃恒温室内禁食3天.用容积为300 ml的封闭式呼吸室测定两组蜥虎在30℃条件下连续3天的耗氧量,测定间隔时间为4～12 h.禁食组动物实验期间的耗氧量无显著的时间变异,实验组动物耗氧量的时间变异显著,这些结果表明摄食影响原尾蜥虎的代谢率.实验组动物摄食4 h后耗氧量已显著大于禁食组,摄食40 h后两组动物的耗氧量无显著差异.原尾蜥虎达到SDA峰值的平均时间约为20.0 h,SDA峰值耗氧量是禁食对照组动物耗氧量的1.5倍.原尾蜥虎单次摄食实验中的SDA具有进食后耗氧量迅速增加、达到峰值后下降至摄食前水平的典型模式.     

Calibrating a camera trap–based biased mark–recapture sampling design to survey the leopard population in the N'wanetsi concession,Kruger National Park,South Africa

Estimating large carnivore abundance can be challenging. A biased leopard (Panthera pardus) population survey was conducted in the N'wanetsi concession in the Kruger National Park (KNP), South Africa, using motion‐sensitive camera traps from April to August 2008. Survey effort included 88 trapping occasions and 586 trap days. The survey yielded 24 leopard photographs, comprising fourteen adults of eleven males and three females. The capture rate was determined to be 24.4 trap days per leopard. Estimates of population abundance stabilized at approximately 500 trap days. Precision of population estimates began to stabilize after 378 trap days. We estimated that there were nineteen leopards in an area of 150 km². Leopard density was estimated at 12.7 leopards per 100 km². We explore the possibility of employing the methods used in this study to survey the leopard population in the KNP and surrounding areas.     

国家公园生态系统完整性的内涵及评价框架: 以东北虎豹国家公园为例

保护自然生态系统的完整性是我国建立国家公园的主要目标之一, 《国家公园设立规范》(GB/T 39737-2021)已将生态系统完整性作为国家公园的准入条件生态重要性的认定指标之一, 但目前对国家公园生态系统完整性的内涵还没有统一定义, 并缺乏具体的评价体系。本文在国内外相关研究的基础上, 结合我国国家公园体制试点成果及第一批国家公园设立实践, 提出了国家公园生态系统完整性的基本内涵及评价指标体系, 以期为今后设立国家公园时划定边界范围或评估国家公园管理成效提供理论依据。作者提出, 应从生态系统结构和过程完整性、功能完整性、空间格局完整性3个维度对我国国家公园生态系统完整性进行综合评价。以东北虎豹国家公园为例, 体制试点以来, 东北虎(Panthera tigris altaica)和东北豹(P. pardus orientalis)等顶级食肉动物的食物链相对完整, 虎、豹野生种群从俄罗斯进入、定居、繁衍、扩散的路径清晰, 种群稳定增长、栖息地质量持续改善, 生物多样性日益丰富, 国家公园正式设立范围划定时充分考虑了生态系统完整性保护, 生态系统完整性评级为优秀, 为国家公园可持续发展奠定了良好基础。     

人类足迹对东北虎豹国家公园景观破碎化的影响

探讨人类活动对东北虎豹国家公园景观破碎化的影响,对于掌握东北虎豹保护与人类发展之间的矛盾,优化虎豹栖息环境具有重要意义。基于人类足迹理论构建适地化的人类足迹指标体系,结合景观格局分析、回归分析、GIS空间分析等方法,从全局和局部两个角度探讨了各人类足迹指标对东北虎豹国家公园及核心保护区、一般控制区(虎豹潜在栖息地)、一般控制区(人口聚集区)三大管控分区景观破碎化的影响范围及其空间分异特征。结果表明：(1)虎豹公园内较高、高度景观破碎化区域占公园全域面积的8.96%,且主要分布在一般控制区(人口聚集区)中,占比高达60.54%;(2)从公园全域来看,对景观破碎化的影响从高到低的人类足迹指标依次为土地利用状况,交通可达性、人口密度、工矿活动,夜间灯光强度与景观破碎化的相关性不显著;(3)从各管控分区来看,核心保护区、一般控制区(虎豹潜在栖息地)与公园全域具有相似的规律,而在一般控制区(人口聚集区)中,工矿活动的影响程度上升到第二位;(4)从区域上占主导的人类足迹指标来看,以土地利用状况影响为主的区域最为广泛;以交通可达性影响为主的区域分布在春化镇、大肚川镇、春阳镇周边地区;以人口密度影响为...     

森林放牧对东北虎豹国家公园东部有蹄类动物灌草层食物资源的影响

森林放牧是中国东北虎豹国家公园内影响最广泛且强度最大的人类干扰之一。研究放牧对有蹄类动物食物资源的影响,是估算当前状态下东北虎和东北豹主要猎物承载力的关键,可以为国家公园的管理提供有效的科学依据。本研究于2016年在中国东北虎豹国家公园东部的牧场和非牧场区域分层抽取50个林下样地设置围栏对照实验,于2017年生长季进行灌草层植被调查 (每个样地的围栏与对照各随机调查3个1m×1m的样方,共调查300个植物样方) ,并应用红外相机技术获取对照样地内有蹄类动物丰富度和活动情况,研究放牧对研究区灌草层植物及动物的影响。研究结果显示：在生长季内,森林放牧显著降低林下灌草层植物生物量 (减少约24%),牧场样地的嫩枝叶显著降低。除禾草外,牧场样地中其他类别植物的氮含量均显著高于非牧场样地 (平均超出非牧场样地25 %)。非牧场样地梅花鹿的相 对丰富度指数 (RAI) 显著高于牧场样地,而狍与野猪的相对丰富度指数 (RAI) 在这两类样地之间没有显著差别。研究结果表明,东北虎豹国家公园东部森林放牧,减少了有蹄类动物灌草层食物资源,降低了有蹄类动物的多度。建议停止森林放牧,恢复有蹄类动物栖息地。     

南海永兴岛的壁虎,兼记二新记录种

2017年12月对南海永兴岛的爬行动物进行了短期调查,发现3种壁虎科Gekkonidae动物,分别是截趾虎Gehyra mutilata、原尾蜥虎Hemidactylus bowringii和疣尾蜥虎H.frenatus。其中,截趾虎和原尾蜥虎为中国南海岛屿的新记录。