家畜放牧对草地啮齿动物影响的研究进展

本文综述了截止2015年国内外文献,分析了家畜放牧对啮齿动物的影响。放牧家畜的践踏和排泄物等引起土壤理化性质改变影响了啮齿类空间利用等,家畜采食影响了啮齿类食物资源及其丰度,采食还引起植物营养成分改变及次生防御化合物的产生,而植被高度变化导致了啮齿动物捕食风险的增加和生活史策略的改变。这些方面的影响与综合作用改变了啮齿动物的微栖息环境、分布、食性,以及领域、采食和挖掘等行为,繁殖和生活史特征;影响了啮齿动物的种群结构、种群数量消长及其调节过程;改变了啮齿动物的群落结构和种间相互作用,引起其群落演替。在综述上述各方面研究进展的基础上,提出放牧对啮齿动物影响的作用途径及其方式,放牧条件下草-畜-鼠耦合机制,不同放牧制度对啮齿动物的影响以及整合现代学科发展的相关探索是未来研究的重点。     

国内巨蜥的研究现状

由于人类的乱捕滥猎和巨蜥栖息地的改变，造成巨蜥数量急剧减少。一般认为国内存在2种巨蜥，即Varanus salvator和Varanus bengalensis bengalensis，主要分布于云南、广西、海南和广东四省。巨蜥的生境多位于热带或亚热带的河流附近或沿海河口一带。穴居，且具有爬树和游泳能力。其食物十分广泛，包括小型哺乳类（如啮齿类）、鸟类、两栖爬行类（蛇、蜥蜴、小龟、蛙）、鱼和一些无脊椎动物（蟹、虾、昆虫）。其捕食方式为公开追击方式（open-pursuit）。春季和夏季是巨蜥发情交配和产卵的季节。人工条件下，巨蜥卵的孵化时间约为7个月左右。当前巨蜥保护工作的首要任务，是迅速查明国内巨蜥的种类、分布、野外种群数量及其致危因子等信息，这将是制定有效的巨蜥保护策略的基础。     

分蜂所产生的后果

１有关分蜂的解释目前有几个不同的假设。这些假设是由Ｈｏｇｇ（１９９７）和Ｇｕｅ（１９９８）总结的。幼虫食物假说这一假说认为蜂群中幼蜂过剩会产生过剩的幼虫食料 ,因而导致蜂群产生王台。幼虫拥挤假说认为过多的幼虫给蜂王造成可用于产卵的空间太小 ,因此 ,导致蜂群产生王台 ;同时又认为过于拥挤的蜂群造成蜂群通风不良 ,箱内ＣＯ２ 含量上升。内勤蜂的劳动假说认为蜂群中内勤蜂的数量远远超过外勤蜂的数量。蜂王外激素分布假说这一假说认为 ,随着工蜂数量的迅速增加 ,蜂王物质在箱内的分布呈下降趋势。群内食料过于充分假说当蜜蜂…     

研究发现较大群体社会性昆虫的免疫反应较弱卫生行为突出

<正>北卡罗来纳州立大学的一项研究发现,对于真社会性昆虫,如蚂蚁、蜜蜂和白蚁来讲,种群的个体越多,免疫反应越弱。这一发现有力证明,卫生行为,不仅仅是免疫系统,对于保持真社会性昆虫的健康起着关键作用。真社会性昆虫为群居生活,与其他个体接触,将会增加它们感染疾病的风险。"社会群体假说"认为,群居的生活方式给真社会性昆虫较强的免疫系统。第二种     

中国林蛙的生物量测定

中国林蛙(Rana temporaria chensinensis)主要分布于我国的北部。它不仅能捕食害虫,有利于农牧生产,而且其雌性的整体和输卵管干制品为名贵的滋补品(黄祝坚等,1979)因此,在保护其自然资源的同时,进行其生态学研究具有一定的实际意义。黄祝坚(1958)和马常夫等(1958、     

外来蜂种对本地传粉蜂物种多样性的影响

为了提高经济效益而从境外引入外来蜜蜂、熊蜂或胡蜂用于养殖或为设施农业授粉的现象已经很普遍。但引入外来蜂种应慎重,外来蜂种逃逸为野生种群后,因缺乏自然天敌会在短时间内大量繁殖,与本地传粉蜂形成食物竞争或捕食关系,还有可能传播病虫害、干扰本地传粉蜂的生殖,甚至破坏植物-传粉者之间的互利关系,对本地传粉蜂类多样性和自然生态系统稳定性可能产生较大危害。在大量外来蜂种进入我国的现状下,为保护本地传粉蜂的物种多样性,维持自然生态系统的稳定性,建议引种单位应充分评估引种风险并严格管理外来蜂种;政府应加大投资力度,大力开发本地熊蜂资源为设施农业授粉服务;建立中华蜜蜂保护区,保护我国本土蜂种。     

硒-动物与人类共同的保健因子

尽管人属于杂食动物,但由于各种原因有的人食素,有的人吃荤。相比,人类的祖先——灵长类动物,则是草食动物。 类人猿发展到直立行走阶段后,双手解放出来,依靠打猎和捕食谋生。因此,在很大程度上转变为肉食动物。肉食的重要性在于它不仅含有丰富的营养,同时也减少了采集大量植物性食物所需要的时间。 仅在近代,人类才成为食物的生产者(不到1万年),除了种植作物,还饲养动物。新石器时代出现的农业,不仅对食物的供应提供了更好的保障,而且使人类有时间来发展其它的技能。 人类历史经历了许多重大的里程碑(Yudkin,     

猕猴属动物冷应激休克的诊治体会

正猕猴属(Macaca)动物包括22种猕猴。主要特征是具有颊囊,躯体粗壮,前肢与后肢同等长,拇指能与其它四指相对,抓握东西灵活,前额低,有一突起的棱。猕猴属的栖息地广泛,草原、沼泽及各类森林地区皆可居留栖息,主要分布于亚洲东南部。群居,数十只乃至数百只大群。主要以树叶、嫩枝、野菜等为食,也捕食其它小动物。相互之间联系时会发出各种声音或手势,互相之间梳毛也是一项重要的社交活动。     

野狍的人工科学饲养技术

1　野狍的特点野狍俗称狍子 ,学名矮鹿 ,属双蹄目鹿科动物 ,现为国家野生保护动物。因其肉质纯瘦、味道鲜美、营养丰富、为高级宾馆野味佳肴 ,同时也是高效创汇产品 ,因此近年来产区不法分子过度偷猎 ,使野生资源非常稀少。野狍家养的成功 ,不仅有利于保护野生资源 ,也为我国广大城乡探索出一条新的致富之路。野狍素有“草上飞”之称。它反应敏捷 ,行动迅速 ,性情活泼 ,胆小易惊 ,喜欢群居。野狍体形匀称 ,体质健壮 ,适应性和抗病力极强 ,且易驯化、好管理 ,食物来源广泛 ,各种阔叶树叶、野生杂草、农作物秸杆、水果皮、蔬菜等都是野狍喜食…     

庆阳市食物消费结构与土地资源需求

随着经济的快速发展,我国居民的食物消费模式由以植物源食物为主向动物源食物为主转变。而且人口的增长和城市化、工业化进程的不断加快,耕地越来越少,对中国的食物安全造成了潜在的严重风险。本研究采用Gerbens-Leenes等和Kastner等的计算方法,分析了庆阳市食物消费模式与土地需求之间的关系。结果表明,庆阳市的食物消费模式比较单一,以植物源食物为主,肉类消费水平(2.08%)远远低于国家平均水平(9.03%)。随着未来生活水平的提高,食物消费结构将发生变化,动物源食品的消费量将增加,将需要更多的草地资源满足需求。因此,应加强草地的保护和建设,大面积恢复草地植被,大幅度提高草地生产力,提高牧草的产量和质量。这将有利于合理调整食物消费结构,更全面准确地评价食物消费结构变化对土地资源的需求,对维护国家生态安全和食物安全具有重要意义。     

Preference status does not indicate intrinsic quality differences in Drosophila pseudoobscura

The good genes hypothesis states that choosers prefer individuals of high intrinsic quality to individuals of lower intrinsic quality. Variation in longevity is thought to reflect, in part, intrinsic quality differences of individuals in addition to the costs of mating and reproduction. Here we report longevity variation of Drosophila pseudoobscura, a species in which previous experiments have demonstrated that individual mate preferences (pre-touching mate assessments) of females and males are associated with enhanced numbers of eclosed (adult) offspring and higher egg-to-adult survival (offspring viability). Using mate assessment arenas and protocols similar to those in a previous experiment that demonstrated fitness benefits to breeders and their offspring of mating with individuals they preferred, we tested the following predictions: (i) preferred discriminatees live longer than non-preferred discriminatees; (ii) males live longer than females; and (iii) virgins live longer than mated individuals. The experiment yielded 938 individuals for longevity analysis. Sex and mating status affected longevity: males lived longer than females, virgin females lived longer than mated females, but there were no differences in longevity for mated and virgin males. Non-preferred discriminatees of both sexes survived as long as preferred discriminatees, a result inconsistent with the prediction of the good genes hypothesis for mate preferences. To our knowledge, this is the first demonstration of the cost of reproduction for females in D. pseudoobscura and of longevity variation of preferred and non-preferred discriminatees.     

The biogeography of group sizes in humpback dolphins (Sousa spp.)

Humpback dolphins (Sousa spp.) are obligate shallow-water and resident species, and they typically live in fission–fusion societies composed of small-sized groups with changeable membership. However, we have scant knowledge of their behavioral ecology, starting with potential factors influencing inter-population variability of their group sizes. Here, we compiled a new global dataset of humpback dolphin group sizes based on 150 published records. Our data indicated an inter-specific consistency of group-living strategy among the 4 species in the Sousa genus, as these species preferred living in small-sized groups with a mean size of mostly no more than 10, a minimum size of single individual or small pairs, and a maximum size of several tens or ≈100. In addition, we clearly showed the geographic variations in group sizes of humpback dolphins at a global scale. We found that the geographic variations in humpback dolphin group sizes were primarily associated with the latitude, sea surface temperature, and abundance. To conclude, our findings provide insights into social dynamics and socioecological trade-offs of humpback dolphins, and help better understand how these resident animals adapted to their shallow-water habitats from the perspectives of biogeography and socioecology.     

Grazing Intensity Influences Ground Squirrel and American Badger Habitat Use in Mixed-Grass Prairies

Ground squirrel (Spermophilus spp.) and American badger (Taxidea taxus) burrowing activities are ecologically important disturbances that contribute to the heterogeneity of prairie environments. These activities also have a strong impact on habitat suitability for many other grassland species. However, effects of cattle grazing intensity on ground squirrel and American badger burrows are not well understood. From 2006 to 2012 we evaluated effects of grazing intensity and vegetation type on American badger burrow occurrence and ground squirrel burrow abundance using a manipulative grazing experiment in Grasslands National Park of Canada, Saskatchewan. The study area consisted of nine 300-ha pastures at a range of stocking rates, from very low to very high for the region. Each pasture had 10 plots (six upland and four lowland) where vegetation and burrow surveys were completed. Burrow abundance and occurrence as well as vegetation structure were assessed for 2 yr prior to the introduction of cattle to this landscape in 2008, which followed at least 15 yr without livestock, and from 2009 to 2012, following introduction of livestock. Data were analyzed using generalized linear mixed models. In upland habitats, ground squirrel burrow counts increased with increasing grazing intensity and decreasing vegetation biomass; conversely, badger burrow occurrence increased with decreased stocking rates and increasing average litter cover and vegetation biomass. Abundance and occurrence of both ground squirrel and badger burrows in lowland habitats was relatively independent of grazing intensity or vegetation. Vegetation composition had little impact on ground squirrel or badger burrows. A range of grazing intensities may contribute to maintaining diversity of burrowing mammals in prairie environments.     

Habitat fragmentation,vole population fluctuations,and the ROMPA hypothesis: An experimental test using model landscapes

Increased habitat fragmentation leads to smaller size of habitat patches and to greater distance between patches. The ROMPA hypothesis (ratio of optimal to marginal patch area) uniquely links vole population fluctuations to the composition of the landscape. It states that as ROMPA decreases (fragmentation increases), vole population fluctuations will increase (including the tendency to display multi‐annual cycles in abundance) because decreased proportions of optimal habitat result in greater population declines and longer recovery time after a harsh season. To date, only comparative observations in the field have supported the hypothesis. This paper reports the results of the first experimental test. I used prairie voles, Microtus ochrogaster, and mowed grassland to create model landscapes with 3 levels of ROMPA (high with 25% mowed, medium with 50% mowed and low with 75% mowed). As ROMPA decreased, distances between patches of favorable habitat (high cover) increased owing to a greater proportion of unfavorable (mowed) habitat. Results from the first year with intensive live trapping indicated that the preconditions for operation of the hypothesis existed (inversely density dependent emigration and, as ROMPA decreased, increased per capita mortality and decreased per capita movement between optimal patches). Nevertheless, contrary to the prediction of the hypothesis that populations in landscapes with high ROMPA should have the lowest variability, 5 years of trapping indicated that variability was lowest with medium ROMPA. The design of field experiments may never be perfect, but these results indicate that the ROMPA hypothesis needs further rigorous testing.     

Dietary patterns of two herbivorous rodents: Otomys unisulcatus and Parotomys brantsii in the Karoo

Differences and overlap in the diets of two sympatric, herbivorous rodents Otomys unisulcatus and Parotomys brantsii were investigated. Frequency of occurrence of plant species in the diets were compared with availability of the plants in the rodents' habitats. Both rodents are generalist herbivores, eating plants species in proportion to the availability in their habitats. Dietary patterns, diversity of diet and degree of overlap between rodent's diets are a function of food availability in the different habitats. It is suggested that these rodents separate niches on a spatial rather than trophic basis. Differences in dietary patterns are therefore not critical for niche separation but are the result of habitat segregation.     

Burrow architecture of the Damaraland mole-rat (Fukomys damarensis) from South Africa

The burrow architecture (length, internal dimensions, fractal dimension of tunnel systems, number of nesting chambers and surface mounds) was investigated in the Damaraland mole-rat (Fukomys damarensis). A total of 31 animals were caught from five different colonies and their burrow systems were excavated in their entirety. The mean and SD colony size was 6 ± 3.3, with a range of 2–10 mole-rats. The sex ratio tended to be male biased 1.21:1. Males had a body mass of 80.5 ± 33.8 g, but were not significantly different to those of females, which had a mean body mass of 83.4 ± 24.9 g. The burrow system of the Damaraland mole-rats follows the same general architectural plan as recorded for other species of mole-rat with either one or two more centrally based, deeper, more permanent burrows that often connect to a nest area, which is used for resting and rearing offspring. The burrow systems contained several more superficial secondary tunnels at a shallower depth. The secondary tunnels accounted for up to 80% of the total burrow system. The mean length of the burrow system was 130 m and covered an area of 1 403 m². The mean number of secondary branches in a burrow system was 10. The mean fractal dimension was 1.15, which implies the mole-rats do not explore their surrounding environment particularly efficiently when compared with that of other mole-rat species, but this may relate to the size of the main food resource, the Eland bean (Elephantorrhiza elephantina), which is randomly distributed and fed on in situ. Our study showed that colony size influences the size and complexity of the burrow system, with larger colonies having a longer burrow system covering a greater area with more secondary tunnels than that of smaller colonies.     

Interrelationship of soil moisture and temperature to sylvatic plague cycle among prairie dogs in the Western United States

Plague, caused by Yersinia pestis, is a flea-borne disease that is endemic in areas throughout the world due to its successful maintenance in a sylvatic cycle, mainly in areas with temperate climates. Burrowing rodents are thought to play a key role in the enzootic maintenance as well as epizootic outbreaks of plague. In the United States, prairie dogs (Cynomys), rodents (Muridae), and ground squirrels (Spermophilus) are susceptible to infection and are parasitized by fleas that transmit plague. In particular, prairie dogs can experience outbreaks that rapidly spread, which can lead to extirpation of colonies. A number of ecological parameters, including climate, are associated with these epizootics. In this study, we asked whether soil parameters, primarily moisture and temperature, are associated with outbreaks of plague in black-tailed prairie dogs and Gunnison's prairie dogs in the Western United States, and at what depth these associations were apparent. We collected publicly available county-level information on the occurrence of population declines or colony extirpation, while historical soil data was collected from SCAN and USCRN stations in counties and states where prairie dogs have been located. The analysis suggests that soil moisture at lower depths correlates with colony die-offs, in addition to temperature near the surface, with key differences within the landscape ecology that impact the occurrence of plague. Overall, the model suggests that the burrow environment may play a significant role in the epizootic spread of disease amongst black-tailed and Gunnison's prairie dogs.     

Geographical variation of the acoustic signals in the spot-legged treefrog (Polypedates megacephalus) of Hainan Island

Geographical divergence in acoustic signals is often affected by multiple selective pressures. Environmental factors are expected to shape signals by adjusting for greater propagation efficiency. Nevertheless, such habitat-driven hypotheses have not been well-examined with multi-signal and multi-habitat types included simultaneously. In this study, we evaluated call similarity of the spot-legged treefrog (Polypedates megacephalus), characterized by multiple call types, from 11 geographic populations across Hainan Island. We also examined multiple factors (i.e. body mass, temperature, altitude, and vegetation) among different acoustical geographic clusters, and tested whether the variation in acoustic length and frequency among different habitats was in accordance with the prediction derived from the acoustic adaptation hypothesis. We showed that P. megacephalus from Hainan Island included 3 acoustic geographic clusters: the northeastern flatlands, the southwest mountains, and the hills around the mountains. We also showed that environmental factors (i.e. altitude and vegetation) varied across these 3 acoustically distinct areas. Moreover, the duration of the different call types supported the hypothesis that they should have optimal transmission in their own habitats. Thus, our results reveal the roles of ecological selection in the geographical divergence of anuran acoustic signals.     

Social structure

Socially feral horses live in stable social groups characterized by one adult male, a number of adult females, and their offspring up to 2 years of age. Extra males either live by themselves or with other males in bachelor groups. The bands occupy nondefended home ranges that often overlap. Many abnormal behaviors seen in domestic horses occur because some aspect of their normal social behavior cannot be carried out in captivity.     

鼠类对玛多县草地表层土壤的影响及沙漠化作用

本文通过野外调查、室内试验分析方法研究了鼠类对玛多县草地表层土壤的破坏及沙漠化作用。结果表明,鼠兔挖掘洞穴,破坏草皮层,将下伏沙砾、土壤推于地表。在鼠害严重的地方,覆盖面积占草地面积的7.47%~16.41%,达到了轻度沙漠化水平。鼠洞洞口塌陷形成风蚀浅坑,风蚀浅坑不断发展,相互贯通,最终发展成"秃斑"和"黑土滩",是草地沙漠化形成的因素之一。