Effects of roads on small mammal diversity and abundance in the northern Serengeti,Tanzania

The high biodiversity of small mammal species in the Serengeti ecosystem provides this ecosystem with important conservation value. However, whether the extensive development of roads has negative impacts on the small mammal population has not been tested. Small mammal population diversity and abundance were examined in this study using live trapping at sites close to (experimental) and away (control) from the main gravel road during the short rainy seasons in November and December 2011 and 2012. A total of 138 individuals from three orders representing six families and fourteen species were collected over 4,860 trap nights. There were no significant differences in the species richness, diversity or abundance of small mammals between the control and experimental sites (p > 0.05), suggesting that the current gravel road does not have a significant impact on the small mammal population. These findings were ascribed to the availability of favourable habitats at both distances as a result of little road usage due to poor conditions. Should the road be improved, the control of anthropogenic activities in the area should be given high priority. Continuous monitoring of the small mammal populations in the area is recommended.     

Untangling the roles of fire,grazing and rainfall on small mammal communities in grassland ecosystems

In grassland systems across the globe, ecologists have been attempting to understand the complex role of fire, grazing and rainfall in creating habitat heterogeneity and the consequences of anthropogenic control of these factors on ecosystem integrity and functioning. Using a South African grassland ecosystem as a model, we investigated the impact of fire and grazing pressure on small mammal communities during three differing periods of a rainfall cycle. Over 2 years, 15,203 trap nights revealed 1598 captures of 11 species (nine rodents, one macroscelid and one insectivore). Results highlighted the importance of the interplay between factors and showed that the role of fire, grazing and rainfall in determining small mammal abundance was species-dependant. While no two species were affected by the same environmental variables, grass cover or height was important to 56% of species. Considered independently, high rainfall had a positive influence on small mammal abundance and diversity, although the lag period in population response was species-specific. High grazing negatively affected overall abundance, but specifically in Mastomys coucha; fire alone had little immediate impact on small mammal diversity. Six months after the fire, vegetation cover had recovered to similar levels as unburned areas, although small mammal diversity and richness were higher in burned areas than unburned areas. Grazing levels influenced the rate of vegetation recovery. In conclusion, low-level grazing and burning can help to maintain small mammal biodiversity, if conducted under appropriate rainfall levels. A too high grazing pressure, combined with fire, and/or fire conducted under drought conditions can have a negative impact on small mammal biodiversity. To maintain small mammal diversity in grassland ecosystems, the combined effects of the previous year’s rainfall and existing population level as well as the inhibition of vegetation recovery via grazing pressure need to be taken into consideration before fire management is applied. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

阿拉善地区不同生境小型兽类群落多样性研究

本文对内蒙古阿拉善地区不同生境中小型兽类群落的物种组成和多样性进行了初步研究。1998 年8～9 月和1999 年8～9 月, 2002 年10 月, 在8 种不同生境类型中共布放54 个样地, 22 606 个有效铗日, 捕获小型兽类标本866 只, 分属2 目6 科, 共20 种。多样性分析结果表明: 8 种不同生境的小型兽类群落Shannon-Wiener 多样性指数在1.186～1.589 之间; Pielou 均匀性指数在0.630 9～0.861 8 之间; Simpson 生态优势度指数在0.234 9～0.415 7 之间; Margalef 丰富度指数在0.931 8～2.020 之间。根据不同生境的小型兽类群落相似性指数聚类结果,可以将8 种生境的小型兽类群落大致划分为4 种类型: 耐旱型(群落Ⅴ和群落Ⅶ)、干旱型(群落Ⅰ、Ⅱ、Ⅲ)、农林交错型(群落Ⅵ和群落Ⅷ) 和森林型(群落Ⅳ) 。生境条件的差异对小型兽类群落物种组成和多样性有一定的限制作用, 而人为干扰有明显影响。     

高寒草甸地区小哺乳动物群落多样性的初步研究

高寒苹甸地区的人工草场、半人工草场、次生杂类草草场和撩荒地中共有4个小哺乳类群落;根田鼠+高原鼢鼠群落;根田鼠+甘肃鼠兔群落;高原鼠兔+高原鼢鼠群落;长尾仓鼠+高原鼠兔群落。小哺乳类群落种的多样性与植物群落种的多样性无显著相关关系,而与植被的高度、盖度呈显著负相关关系。高原鼢鼠是各生境中的广布种。根田鼠与甘肃鼠兔在植被郁闭度高的环境中为群落的主要组成者;植被郁闭度低的环境中,高原鼠兔和长尾仓鼠是群落的主要成员。它们的空间格局主要反映空间环境条件的差异。     

滇西4市县居民区小哺乳动物的群落结构

1983～1996 年对云南瑞丽、陇川、盈江和保山4 市县居民区小哺乳动物的长期调查,经聚类分析,该地区的小哺乳动物可划分为3 种群落: (1) 以黄胸鼠+ 大臭鼠句为主的瑞丽、陇川室内外小哺乳动物群落; (2) 以黄胸鼠+ 大臭鼠句+ 小家鼠为主的盈江、保山室内和盈江室外小哺乳动物群落; (3) 以黄胸鼠+ 大臭鼠句+ 灰麝鼠句为主的保山室外小哺乳动物群落。其群落多样性指数以群落(3) 为最高(1.5897) ,群落(1) 、(2) 较低,分别为1.099 0 ,1.042 5。4 市县在同一坝区小哺乳动物室内、外唯一不能聚为同一群落的保山室外黄胸鼠数量骤减是第3 群落多样性增加的主要原因,亦是鼠疫在该坝区不能长期保存的原因。因此小哺乳动物群落结构与鼠疫的保存和传播机制之间的关系非常密切。     

Anthropogenic disturbance and the risk of flea-borne disease transmission

Anthropogenic disturbance may lead to the spread of vector-borne diseases through effects on pathogens, vectors, and hosts. Identifying the type and extent of vector response to habitat change will enable better and more accurate management strategies for anthropogenic disease spread. We compiled and analyzed data from published empirical studies to test for patterns among flea and small mammal diversity, abundance, several measures of flea infestation, and host specificity in 70 small mammal communities of five biomes and three levels of human disturbance: remote/wild areas, agricultural areas, and urban areas. Ten of 12 mammal and flea characteristics showed a significant effect of disturbance category (six), biome (four), or both (two). Six variables had a significant interaction effect. For mammal-flea communities in forest habitats (39 of the 70 communities), disturbance affected all 12 characteristics. Overall, flea and mammal richness were higher in remote versus urban sites. Most measures of flea infestation, including percent of infested mammals and fleas/mammal and fleas/mammal species increased with increasing disturbance or peaked at intermediate levels of disturbance. In addition, host use increased, and the number of specialist fleas decreased, as human disturbance increased. Of the three most common biomes (forest, grassland/savanna, desert), deserts were most sensitive to disturbance. Finally, sites of intermediate disturbance were most diverse and exhibited characteristics associated with increased disease spread. Anthropogenic disturbance was associated with conditions conducive to increased transmission of flea-borne diseases.     

Non flying mammals and landscape changes in the tropical rain forest region of Los Tuxtlas, Mexico

The rapid and extensive conversion of Neotropical rain forests to a landscape consisting of pasture lands and other agricultural habitats has meant the local disappearance fragmentation and isolation of vertebrate populations To avoid further losses in biodiversity in Neotropical rain forests, it is imperative to determine how the different species that constitute the different vertebrate communities have responded to the anthropogenic alterations of their natural habitats To provide data in this direction we sampled non flying mammals in 35 forest fragments, in six disturbed forest sites in 12 regenerating forests, in 20 arboreal agricultural habitats (cacao coffee, mixed, citrus and allspice), in four live fence sites and in four pasture sites at Los Tuxtlas, Veracruz Mexico Sampling indicated that area of forest fragments and isolating distance were important variables influencing species richness Disturbed forest had fewer species and individuals present and supported a lower non flying mammal biomass than undisturbed and regenerating forests Shaded plantations (cacao coffee and mixed) were richer in species and in individuals than unshaded ones (citrus, allspice) Species richness in forests and agricultural habitats were associated to horizontal plant diversity and vertical foliage diversity Pasture habitats were the poorest man-made habitats in non flying mammal species Live fences supported a higher biomass and species of non flying mammals than pastures and were similar to forest and shaded man-made habitats in species assemblages     

Ground dwelling mammal response to fire: A case study from Monga National Park after the 2019/2020 Clyde Mountain fire

Ground dwelling mammal communities are documented six months before and after the Clyde Mountain Wildfire of 2019/2020 in Monga National Park. Across eight sites before fire, approximately 12 ground dwelling mammal species were recorded. Survey effort post-fire increased to 40 sites, spanning three fire severity classes (low, moderate and extreme), revealed 16 ground dwelling mammal species. Species consist of small, medium and large native (one threatened species) and introduced mammals, though consistent with previous findings of ground dwelling mammal diversity in the area. Overall a greater number of species were found in low, compared to moderate and severe fire severity classes. Recovery and detection of mammals occurred in a shorter time period, again, in sites that experienced low, followed by moderate and extreme fire severity.     

四川南充城区鼠形小兽群落结构

2003年9月～2004年8月对南充城区的鼠形小兽群落进行研究,应用聚类分析将其划分为3种群落：C1以微尾鼩（Anourosorex squamipes）＋褐家鼠（Rattus norvegicus）为主的居民区附近的垃圾地带鼠形小兽群落;C2以微尾鼩＋大足鼠（Rattus nitidus）为主的河谷-风景区鼠形小兽群落;C3以微尾鼩＋褐家鼠＋黑线姬鼠（Apodernus agrarius）为主的校园鼠形小兽群落.其群落多样性指数和均匀性指数均以C3最高,C2次之,C1最低,导致其原因可能与生境和食物丰富度有关.     

Defaunation and fragmentation erode small mammal diversity dimensions in tropical forests

Forest fragmentation and defaunation are considered the main drivers of biodiversity loss, yet the synergistic effects of landscape changes and biotic interactions on assemblage structure have been poorly investigated. Here, we use an extensive dataset of 283 assemblages and 105 species of small mammals to understand how defaunation of medium and large mammals and forest fragmentation change the community composition and diversity of rodents and marsupials in tropical forests of South America. We used structured equation models to investigate the relationship between small mammal species, functional and phylogenetic diversity with forest size, forest cover and the occurrence of medium and large mammals. The best‐fit model showed that defaunation reduced functional diversity, and that species diversity of small mammals increased with forest patch size. Forest cover did not affect functional and phylogenetic diversity. Our results indicate that occurrence of medium and large sized mammals (probably acting as predators, or competitors of small mammals) and forest patch size help to retain species and functional diversity in small mammal communities. Further, the number of species in a small mammal community was critical to the maintenance of phylogenetic diversity, and may have a pronounced influence on the ecological functions played by small mammals. Identifying how phylogenetic and functional diversity change in function of human pressures allows us to better understand the contribution of extant lineages to ecosystem functioning in tropical forests.     

三峡水库运行后洞庭湖洲滩 小型兽类群落状况

为了探究三峡工程建成运行后洞庭湖区洲滩生境中小型兽类的群落状况,对洞庭湖区洲滩生境的小型兽类进行调查。调查采用铗日法,于2010至2018年,对洞庭湖区洲滩小型兽类群落的多样性进行了调查,并计算优势度、群落多样性指数、均匀性指数。对多样性指数采用t值法进行比较,各年份、生境的捕获率及鼠种组成差异则采用卡方检验。2010至2018年,共布放34 116铗日,捕获可以分辨种类的样本2 129只,主要有啮齿目(Rodentia)和鼩形目(Soricomorpha)2类,共7种,分别是啮齿目的东方田鼠(Microtus fortis)、黑线姬鼠(Apodemus agrarius)、褐家鼠(Rattus norvegicus)、巢鼠(Micromys minutes)、社鼠(Niviventer confucianus)、黄毛鼠(R. losea)和鼩形目的臭鼩(Suncus murinus)。总捕获率为6.36%,东方田鼠、黑线姬鼠捕获率较高,分别为1.83%、3.94%。从小型兽类组成看,黑线姬鼠和东方田鼠在群落中组成的比例较高,分别为63.18%和29.26%。在调查的5类生境中,植被组成以苔草(Carex sp.)、南荻(Miscanthus sp.)和美洲黑杨(Populus deltoides)为主的生境小型兽类群落多样性指数(1.0772)和均匀度指数(0.6662)均最大,其次是以苔草为主的生境(多样性指数和均匀度指数分别为0.9275、0.5723)、以南荻为主的生境(多样性指数和均匀度指数分别为0.8856、0.550 2)和以苔草加南荻为主的生境(多样性指数和均匀度指数分别为0.775 6、0.481 9),以美洲黑杨为主的生境多样性指数(0.323 6)和均匀度指数(0.180 6)最低,但其优势度最高,为0.881 2。结果表明,随着三峡工程的运行,洞庭湖区植被演替发生了变化,从而引起小型兽类群落动态的变化。在洞庭湖洲滩上,生境越复杂,小型兽类物种多样性越高。单一生境下,人类活动干扰程度越大,小型兽类物种多样性越低。目前,黑线姬鼠已经成为洞庭湖洲滩生境的第一优势鼠种。     

The importance of considering both taxonomic and habitat guild approaches in small mammal research

Studies on the effects of habitat fragmentation on small mammals often lead to confounding results as they only consider taxonomic groups in their analysis and neglect functional diversity of the communities. Here we describe the structure and composition of small mammal communities at 22 sites, ranging from 41 to 7035 ha, in a hyper‐fragmented landscape of an Amazonia‐Cerrado ecotone. Also, in considering a taxonomic and habitat guild approach, we report the effects of habitat structures and patch spatial attributes on richness, abundance and species composition. Small mammal richness reported in southern Amazonia (N = 23 species) is greater than most previous studies in the tropics. All rare small mammals captured in this study were forest interior species. Richness of forest interior species was positively related to larger patches, as shown by the species–area relationship. However, 52% of the small mammal species were in forest fragments smaller than 50 ha, highlighting the importance of preserving both large and small forest fragments in a landscape with accelerated habitat reduction. Richness of edge‐tolerant species was not associated with the tested variables, yet edge‐tolerant species were more abundant in degraded environments. Marsupials were positively associated with vertical habitat structures, while rodents were more strongly related to a ground‐level habitat structure. The landscape studied is extremely variable and has contributed to the difficulty in detecting clear patterns, particularly when considering only one approach. Because of the complementary outputs when analysing either taxonomic groups or habitat guilds, we recommend the use of multi‐taxa studies of different guilds to assist decision makers in designing conservation strategies and appropriate management of small mammal populations.     

Functional diversity and redundancy of tropical forest mammals over time

Globally, tropical rain forests comprise some of the most diverse and functionally rich ecosystems but are increasingly degraded by human impacts. Protected areas have been shown to conserve species diversity, but their effectiveness at maintaining functional diversity over time is less well known, despite the fact that functional diversity likely reveals more ecological information than taxonomic diversity. By extension, the degree to which species loss decreases functional diversity within protected areas is also unknown; functional redundancy may buffer communities from loss of functional diversity from some local extinctions. Using eight years of camera trap data, we quantified annual functional dispersion of the large mammal community in the Volcán Barva region of Costa Rica and tested for changes in functional dispersion over time in response to environmental and anthropogenic predictors. We quantified functional redundancy based on simulated declines in functional dispersion with species loss. Observed functional dispersion did not change significantly over time and was not associated with measured environmental or anthropogenic predictors. Quantitative modeling of observed functional traits over time did not identify significant changes. We did however find qualitative trends in relative trait proportions, which could be indicative of functional change in the future. We found high functional redundancy, with average simulated functional dispersion declining significantly only after 9 out of 21 large mammal species were lost from the community. We cautiously suggest that protected tropical rain forests can conserve functional diversity over the course of a decade even in heavily fragmented landscapes. Abstract in Spanish is available with online material.     

Effects of alien pine plantations on small mammal community structure in a southern African biodiversity hotspot

Commercial plantations and alien tree invasions often have substantial negative impacts on local biodiversity. The effect of plantations on faunal communities in the fire‐adapted fynbos vegetation of the Cape Floristic Region biodiversity hotspot is not yet well quantified. We studied small mammal community structure in alien Pinus radiata plantations and adjacent fynbos regenerating after clear‐felling of plantations on the Cape Peninsula, South Africa. Small mammal sampling over 1,800 trap‐nights resulted in 480 captures of 345 individuals (excluding recaptures) representing six species. Significantly more species, individuals (12 X) and biomasses (29 X) of small mammals occurred on recovering fynbos sites compared to plantations. This was commensurate with a higher diversity of plant growth forms, vegetation densities and live vegetation biomass. Only one small mammal species, the pygmy mouse (Mus minutoides), was consistently trapped within plantations. Fynbos sites were dominated by three small mammal species that are ecological generalists and early successional pioneer species, rendering the recovering fynbos slightly depauperate in terms of species richness and evenness relative to other studies done in pristine fynbos. We make three recommendations for forestry that would facilitate the restoration of more diverse natural plant communities and progressively more diverse and dynamic small mammal assemblages in a key biodiversity hotspot.     

中国云南小兽体表革螨的群落相似性

运用系统聚类分析方法对中国云南省境内17种主要小型哺乳动物(小兽)体表革螨群落相似性进行研究,每一种小兽体表的所有外寄生革螨被定义为一个相应的革螨群落。运用SPSS11.5软件完成17种革螨群落的相似性比较。研究结果表明:小兽体表革螨群落结构复杂,物种多样性高;隶属同一个属的小兽体表的革螨群落相似程度高,在系统聚类分析中聚为一类;大多数革螨群落相似性大小与相应小兽宿主在动物分类上的近缘性高低呈现高度一致,但也有一些革螨群落是例外的。这说明小兽体表革螨群落不仅受小兽宿主分类地位的影响,可能还受宿主生境的影响     

Using scats of a generalist carnivore as a tool to monitor small mammal communities in Mediterranean habitats

Owl pellets have long been used to analyze communities of small mammals, while analogous analyses of faeces of mammal carnivores are not available. We demonstrate that common genet (Genetta genetta) scats can be used as a reliable method to sample small mammal communities and to monitor their variations. We have compiled data on 6350 small mammal remains of 18 species found in scats from 51 different latrines in a 1200 km² area of northeastern Spain. Genet scats sampled effectively 95.6% of the small mammal species ranging in size from 2.7 to 385 g. Spatial patterns of diet composition along environmental gradients of elevation, climate and land-use matched expected changes in small mammal communities along these gradients according to ecological requirements of prey species. Frequencies of occurrence of prey in genet scats were strongly correlated with frequencies of occurrence in barn owl (Tyto alba) pellets. Genet scats included two forest species not preyed upon by owls, whereas only one species was not preyed upon by genets. Forests species were more frequent in genet than in barn owl diets after correcting for environmental effects, whereas the opposite was true for open-habitat and synanthropic species. Scats of generalist carnivores can be used to estimate the spatial patterns of distribution and abundance of small mammal communities. Genet scats in fact overcome some of the limitations of more traditional sampling methods (live-trapping and owl diets), as genets were less selective and their diets reflect more accurately changes in community composition.     

Ecology of mites (Acarina) on small mammals (Eulipotyphla, Rodentia) in Podunajská nížina plain

This study deals with the species distribution and structure of mite communities living in the fur of small mammals. Mesostigmatic mites (Acarina: Mesostigmata) of several small mammal species were studied at several sites of Slovakia situated in the Podunajská ní?na lowland. The aims deal with ecological evaluation of mesostigmatic mites and their small mammal hosts. The research was done from 2005 to 2007. Several small mammal species were caught at 16 sites in the research area. These represent 13 types of biotopes. On the captured small mammals we recorded 3,141 individuals of mesostigmatic mites (7 families and 22 species). The dominance and the diversity of the recorded mites were analysed. Mites being interpreted as the variable one were evaluated by cluster analysis and multifactor analysis (detrended correspondence analysis, principal components analysis, redundancy analysis). Small terrestrial mammals as hosts of mites represent “holders” of environmental factors, in the analysis they are being evaluated as explanatory variable mainly. They transform direct impact of the environment and for that reason the ecological evaluation of mites is specific comparing to other taxonomical and ecological groups of animals.     

秦岭南坡陕西洋县辖区哺乳动物物种多样性的空间分布格局

物种多样性的空间分布格局一直是生态学和生物地理学研究的一个热点问题。山地生态系统的生境异质性和物种多样性高, 适合研究物种多样性空间分布格局及其相关机制。2016年11月至2017年11月, 本研究选取秦岭南坡陕西洋县辖区作为研究区域, 采用样线法、红外相机法和笼捕/夹捕法, 系统分析了8目21科48种哺乳动物物种多样性的空间分布格局。研究结果发现秦岭南坡洋县辖区哺乳动物物种丰富度的空间分布格局大致是中南部低, 北部和东部高; 物种多样性指数大致是中南部和北部低, 东部高。啮齿类动物和非啮齿类动物的空间分布格局存在差异。哺乳动物物种丰富度和多样性指数的垂直分布格局都符合中峰模式, 但啮齿类动物和非啮齿类动物间存在差异。最优线性模型结果表明, 研究地区哺乳动物物种多样性的空间分布格局受到多种环境因素的共同影响。其中, 年均温与物种多样性的相关性最强, 在6个最优线性模型中贡献都是最大。综上, 秦岭南坡洋县辖区中高海拔区域的物种多样性较高, 应加强对中高海拔地区的保护, 以维系该区域较高的生物多样性。     

Effects of deforestation on structure and diversity of small mammal communities in the Moravskoslezské Beskydy Mts (Czech Republic)

During 1970s and 1980s, a large area of mountains in the Czech Republic was influenced by long-term industrial air pollution. Among the most degraded areas were the peaks of the Moravskoslezské Beskydy Mts, where vast clearings resulted from emissions and subsequent forest destruction. This study is aimed at determining the degree of deforestation that is necessary to cause changes in structure and species diversity of small mammal communities that were observed previously. Communities of rodents and insectivores were monitored for a minimum of 3 years at two mountain ranges of the Moravskoslezské Beskydy Mts (Czech Republic) by standard mouse snap-traps. The localities (Smrk and Kněhyně) differ by the degree of human disturbance. Clearings on Smrk Mt are very large (> 30 ha) with no remaining original forest growth as a result of intensive air pollution, unlike the same habitat type at Kněhyně Mt, where the clearings are minor (< 3 ha) and contain living solitary trees. Structure and diversity of small mammal communities in clearings were compared with those from original forests and other mountain habitats. Communities of small mammals at clearings in Smrk Mt (with dominatingMicrotus agrestis) are structurally very different from all other habitats, while structure of communities at Kněhyně clearings are very similar to those of original mountain forest (Complete linkage clustering based on Renkonen index). The community of the original mountain spruce forest at Kněhyně had the highest species diversity (according to Shannon-Weaver, Brillouin, and Simpson indices, Shannon evenness, and rarefaction), while species diversity at clearings of Smrk was the lowest. Shannon diversity of community at Kněhyně primeval forest is similar to that of Kněhyně clearings, while at Smrk Mt the forest diversity is higher than that of clearings. The species diversity of mountain forest and clearings at Kněhyně Mt was significantly higher than that in the same habitats at Smrk Mt. Our results obtained in disturbed habitats at Kněhyně and Smrk Mts suggest that the degree of deforestation may influence the presence and/or the degree of community changes. If the forest destruction is relatively small (clearings < 3 ha), the structure and diversity of small mammal communities do not differ from those of original forest.