The paradox of keystone species persecuted as pests: A call for the conservation of abundant small mammals in their native range

Small mammals, such as European rabbits (Oryctolagus cuniculus), plateau pikas (Ochotona curzoniae) and prairie dogs (Cynomys spp.), traditionally have been perceived as pests and targeted for control within their native ranges, where they perform essential ecosystem roles and are considered keystone species. These species can reach high densities, and have been subjected to eradication campaigns because of their putative negative impact on natural habitats and agriculture and their competition with livestock for forage. Eradication programmes have been a main factor causing sharp declines of these species in their natural ranges. Paradoxically, they are keystone species where they are abundant enough to be perceived as pests. The term “pest” is usually a social perception that is rarely supported by scientific data, whereas there is considerable scientific evidence of the key ecological roles played by these species. We call for the conservation of these species and present a conceptual model regarding the management of their populations. Where they occur at high numbers, and hence their effects on biodiversity are still of crucial importance, the persecution of these species should be avoided and their natural habitats preserved. In areas with high conservation value, but where these species occur at low densities, management efforts should aim to increase their density. In areas of high commercial value, managers ideally should consider changing prioritization of the area to high conservation value by purchasing the land or obtaining conservation easements. In situations with high commercial value and demonstrable low conservation concern, small mammals could be reduced humanely.     

高寒地区草地放牧演替与害鼠密度关系的研究

在定性划分放牧演替的基础上，应用Ｗｈｉｔｔａｋｅｒ的生境梯度分析法，进行了演替阶段的定量校正，根据校正后演替序列的基本数据，应用关联分析分别对害鼠密度与植物群落各特性以及主要植物优势度的相关关系进行了探讨。分析结果表明，植物群落种多样性的早熟禾优势度在各自的关联分析中对害鼠（高原鼠兔）密度的关联度分别是０．８２３和０．８８６。由此，从群落角度说，物种多样性大小是调控害鼠度的主要因子，从植物种类角度     

基于SegNet模型的高原鼠兔的图像分割

针对高原鼠兔图像目标尺寸小、背景复杂、特征不显著、基于活动轮廓的图像分割模型无法有效分割的问题，采用基于卷积神经网络的SegNet语义模型对高原鼠兔图像进行分割：首先将采集的高原鼠兔图像进行预处理，尺度归一化后制作成与Pascal VOC数据集格式一致的数据集；然后将数据集分为训练集与测试集，采用训练集对SegNet模型训练，测试集对模型进行分割测试。对高原鼠兔图像分割的试验结果表明：与基于活动轮廓的Chan_Vese模型相比，基于卷积神经网络的SegNet模型对高原鼠兔图像分割时的交并比、平均像素精度、Dice相似性指数和Jaccard指数分别提高了68.33%、9.35%、30.61%和47.98%，过分割率和欠分割率分别降低了87.20%、16.52%。     

基于时空域联合信息的高原鼠兔运动目标检测

自然场景下的高原鼠兔序列图像对比度低,边缘较弱,目标包含多色彩且目标运动具有突变性。针对传统运动目标检测方法不能精确提取多色彩目标轮廓的问题,提出一种基于时空域联合信息的运动目标检测方法。首先,利用背景减法确定当前帧图像中目标的形心位置,得到粗分割图像及初始轮廓,然后用改进Chan-Vese(CV)模型对粗分割图像进行分割,改进Chan-Vese模型对多色彩目标图像适应性强,从而获得精确的目标轮廓。鉴于几何活动轮廓模型在图像分割过程中需不断初始化水平集函数,且初始化计算量随图像规模的增大而增多,该文在背景减法获得目标形心的基础上,以形心为中心,截取包含目标的图像块作为粗分割图像,然后利用改进Chan-Vese模型对粗分割图像精确分割,以减少分割耗时。该文对包含50帧图像的视频处理,试验结果显示:该文方法耗时仅为15.25 s,相似度指数平均为0.852 929,Jaccard指数平均为0.744 57。和背景减与CV模型相结合的运动目标检测方法相比,该文方法过分割率低,无冗余轮廓,且耗时短;和背景减与改进CV模型相结合的运动目标检测方法相比,该文实时性更高;该文所提出的目标检测方法可精确提取目标轮廓且实时性高。     

高原鼠兔的精确性可持续控制技术研究——-几种杀鼠剂的对比试验

 于２００７年４－５月份在甘肃肃南县对防治高原鼠兔精确用药进行试验,将５种常见杀鼠剂的推荐用药浓度、用药量按等比级数增、减剂量进行插组,作正交对比试验,结果表明,推荐用药浓度、用药量和饵料种类与调整后的用药浓度、用药量和饵料种类对高原鼠兔的灭洞率有一定的差异性。影响灭洞率的主、次因子顺序是：杀鼠剂＞用药浓度＞投饵量＞饵料种类。以防效为评价指标,５种参试杀鼠剂的排序为：大隆（８３．９％）＞Ｄ 型肉毒梭菌生物毒素（８２．６％）＞溴敌隆（７９．４％）＞Ｃ 型肉毒梭菌生物毒素（７５．０％）＞ 敌鼠钠盐（６８．９％）。最佳处理组合是：１）用０．１５％的Ｄ 型肉毒梭菌生物毒素、小麦饵料、２５ 粒投饵量;２）０．０１％ 大隆、青稞饵料、５ｇ投饵量;３）０．０１％ 溴敌隆、小麦饵料、３ｇ投饵量。     

Cloning and sequencing of heme oxygenase-1 gene from Ochotona curzo-niae

[ABSTRACT] AIM: To clone and analyze the heme oxygenase-1 (HO-1) gene from Ochotona curzoniae (plateau pika). METHODS: The cDNA of HO-1 was cloned by RT-PCR and rapid amplication of cDNA ends (RACE) from the liver of Ochotona curzoniae. The bioinformatic analysis of HO-1 gene was performed. RESULTS: The cDNA of HO-1 gene in Ochotona curzoniae was obtained. The data of the sequence was deposited into GenBank and the accession number is JX035934. The full length of cDNA was 1 466 bp, including 873 bp encoding sequence (290 amino acids). Homology comparison showed that the DNA sequence of the HO-1 gene was highly homologous with Oryctolagus cuniculus (89%), Homo sapiens (87%), Bos taurus (85%), Mus musculus (79%), Rattus norvegicus (84%), Sus scrofa (85%) and Equus caballus (85%), and the amino acid sequence of HO-1 was identified with the homology of 89%, 85%, 84%, 80%, 79%, 82% and 67%, respectively. Phylogenetic analysis suggested that the structure of HO-1 was highly similar to that in Oryctolagus cuniculus. CONCLUSION: The HO-1 gene of Ochotona curzoniae was successfully cloned and provides essential information for elucidating the possible roles of HO-1 in adapting of Ochotona curzoniae to extremely high altitude.     

红松阔叶林带高山鼠兔贮草种类的分析

根据红松阔叶林带高山鼠兔一些贮食点的调查资料,分析了高山鼠兔在红松阔叶林带贮草的种类情况.结果表明:高山鼠兔在收集贮草时具有较大的选择性,其食物组成与其栖息地植被的组成结构有密切关系,具有多样性的特点.     

高原鼠兔消化管的解剖学形态特征

对 1 6例 (雄 1 0 ,雌 6 )高原鼠兔 (Ochotonacurzoni ae)的消化管进行了观察描述 :高原鼠兔的舌上有丝状、菌状、轮廓和叶状乳头 ;齿式为 2 2 0 321 0 2 3;单室胃 ,容积 3 2～8 0mL ;小肠平均长度为 970 1 7 88 0 8mm ,为体长的 7 31±0 2 8倍 ;大肠平均长度为 5 5 8 39± 6 6 39mm ,为体长的 4 2 1± 0 36倍 ;小肠与大肠总长度为 1 5 2 8 95± 1 4 7 78mm ,为体长 (1 32 78mm )的 1 1 5 2± 0 5 9倍 ;盲肠为 2 0 4 34±2 6 98mm ,为体长的 1 5 4倍。回盲口有盲小管 ,盲肠螺旋褶上有长丝状乳头 ,盲结口有盲结口瓣 ,盲结口下接结肠网状部。     

The pikas of China: a review of current research priorities and challenges for conservation

Of the approximately 30 extant species of pika (Ochotona; Ochotonidae; Lagomorpha), at least 23 occur in China. Of these, 8 are endemic, and 3 are classified as Endangered by the IUCN. Research into most Chinese species is scarce, and there is much to learn about basic aspects of their ecology. We reviewed the literature on the 23 Chinese Ochotona species, with the aim of highlighting knowledge gaps and biases in research allocation. Specifically, we identify (1) which pika species receive the most attention from researchers, (2) which topics are the most frequently studied, and (3) how well research satisfies conservation priorities. We covered a total of 879 articles, most of which were written in English or Chinese. Around 75% of all publications focused on the plateau pika Ochotona curzoniae. Seven species were represented by 10 or fewer publications each. Endangered and endemic species were particularly poorly represented. 204 papers treated pikas as a pest, while 13 studied conservation issues. Nine species were considered possible targets for pest control, including some poorly known endemics. We make some recommendations on how research into Chinese Ochotona could be improved, including: (1) recognizing that the current species-level taxonomy may be an ineffective way to prioritize conservation research in Ochotona, (2) directing more research toward threatened and endemic species, subspecies, and populations, (3) researching the ecosystem engineering effects of pikas, (4) collecting basic data on natural history of the many understudied species, and (5) researching threats, including climate change and pest control campaigns.     

植被均匀度与高原鼠兔种群数量相关性研究

通过在高原鼠兔不同密度区对植被地上生物量、盖度、高度三项指标分布均匀度的测定与分析,对高原鼠兔种群密度与植被均匀度间的关系进行了研究。结果表明,凡高原鼠兔分布地,植被三项指标均表现为不均匀性分布,在一定范围内,鼠群密度随植被均匀度的下降而增加,两者间存在极显著线性相关关系。植被的斑块状极度破坏是诱使高原鼠兔迁入的重要因素,尤以斑块状裸地的诱迁作用为甚。