关键词： Hyla japonica   Agricultural intensification   Flood irrigation management   Misgurnus anguillicaudatus   Rice paddies   Structural equation modeling  

摘要： In Japan, the density of Japanese tree frogs (Hyla japonica) may not be necessary high in traditional rice fields compared to modern fields because the modernization of drainage systems from shallow earthen ditches to deep concrete-line ones reduces the abundance of predators/competitors for tadpoles, such as dojo loach (Misgurnus anguillicaudatus). This hypothesis was tested using two approaches. First, laboratory experiments revealed that the presence of the loach significantly reduced the survival of tree frog eggs and tadpoles. Second, observational studies in rice fields showed that the direct effect of modernization on tadpoles was not significant but the indirect (and thus total) effects were weakly positive due to the reduction in the density of dojo loach. Our study suggests that recent agricultural intensification in rice fields does not negatively impact all aquatic species but that some species may not be affected or can even flourish by having tolerance for the changes and release from potential predators or competitors.

关键词： Tree hypothesis   Species hypothesis   Seasonality hypothesis   Ecosystem size hypothesis   Brown food web   Litter arthropods   Predator to prey ratios  

摘要： Litter arthropod abundance in tropical forests is patchily distributed in space and time. This patchiness can be described by three general hypotheses relating plant-based effects to litter arthropod distribution. The tree hypothesis (H1) posits that environments maintained underneath tree canopies are different from those between canopies in ways that shape arthropod abundance. The species hypothesis (H2) refines this scenario, positing that different plant species might maintain distinct litter environments to which arthropod abundances respond. Without regard to specific plant effects, seasonal changes in litter profiles (H3) can account for temporal patchiness in arthropod abundance. The ecosystem size hypothesis provides a mechanism for tree, species and seasonal effects. It links increasing food chain length with habitat availability and its heterogeneity. In a Panamanian rainforest we sampled litter arthropods in quadrats located near (1 m) and far away (30 m) from the parent trunk of 93 tree individuals (to test the tree hypothesis) from 10 tree species (to test the species hypothesis) in the early wet season, when litter is deepest. To test for effects of seasonal changes of litter profiles, we then resampled 25 trees (i.e., five individuals from each of five species) in the late wet season, when climatic conditions are similar, but litter is shallowest. We found weak support for all tree, species and seasonality hypotheses. With few exceptions, trees and species did not sustain different arthropod abundances, neither early nor late in the wet season. Collembola abundance increased late in the wet season, when litter is shallowest. Supporting the ecosystem size hypothesis, accumulated litter either due to trees, species and seasonality sustained higher predator abundance and higher predator to prey ratios. Our results suggest that plants may account for detrital, brown, food web structure;but these effects are mostly through plant-based provision of structu

关键词： Cawston Ranch   conservation   hollows   small animals   stags   utilization  

摘要： The objective of this study was to characterize hollows found in selected tree species (in Cawston Ranch in Zimbabwe) as a potential habitat for small mammals because cavities are important as resources for wildlife: for foraging, shelter, roosting and nesting purposes. Four vegetation types were chosen for analysis: Baikiaea plurijuga, Colophospermum mopane, Combretum molle and Commiphora mollis according to abundance and dominance in the plots they occurred. Transect sampling was performed to collect vegetation data. The total number of living trees and stags was recorded in each plot. Trees in a plot were thoroughly inspected for hollows. The following dimensions were measured on cavity trees: hollow size (diameter), hollow location and diameter at breast height. The results indicate that the rate of hollow formation and utilization is significantly dependent on tree species. There was a significant difference in the provision of hollows in stem and crown of a tree in each of the vegetation classes analysed. *** hollows had the highest utilization, whilst *** had the least utilization. Hollows are utilized irrespective of their location as long as the animal finds a niche, and stags at advanced stages of decay are not important in providing habitats for animals.

关键词： LEMURS -- Behavior   SLEEP behavior in animals  

摘要： The article reports that researchers from the Duke Lemur Center in Durham, North Carolina have discovered two species of Lemurs that hibernate underground.

关键词： Canopy crane   feeding guilds   flower-visitors   herbivory   wet tropics  

摘要： Reliable estimates of host specificity in tropical rainforest beetles are central for an understanding of food web dynamics and biodiversity patterns. However, it is widely assumed that herbivores constitute the majority of host specific species, and that most herbivore species feed on leaves. We tested the generality of this assumption by comparing both plant host- and microhabitat-specificity between beetle communities inhabiting the foliage (flush and mature), flowers, fruit, and suspended dead wood from 23 canopy plant species in a tropical rainforest in north Queensland, Australia. Independent of host tree identity, 76/77 of the most abundant beetle species (N12 individuals) were aggregated on a particular microhabitat. Microhabitat specialization (measured by Sm and Lloyd's indices) was very high and did not differ between flower and foliage communities, suggesting that each newly-sampled microhabitat has a large additive effect on total species richness. In accordance with previous studies, host specificity of foliage-inhabiting beetles was most pronounced among herbivorous families (Curculionidae, Chrysomelidae). By contrast, host specificity among flower-visitors was equally high among herbivorous and nonherbivorous families (e.g. Nitidulidae, Staphylinidae, Cleridae). Effective specialization (FT) measures showed that traditional correction factors used to project total species richness in nonherbivorous groups fail to fully capture diversity in the flower-visiting beetle fauna. These results demonstrate that host specialization is not concentrated within folivores as previously assumed.(c) 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 215228.

关键词： determinants of plant community diversity and structure   extinction   functional diversity   Kruger National Park   phylogenetics  

摘要： There has been much debate on the impact of large herbivores on biodiversity, especially given that large mammals are becoming locally extinct in many places. The use of evolutionary information on community structure has typically been limited to evaluating assembly processes, for example, competition or habitat filtering, whereas a lack of long-term experiments has precluded the test of predictions considering more complex biotic interactions. Reconstructing the complete phylogeny of the trees and shrubs of the Kruger National Park from DNA data, we tested for phylogenetic signal in antiherbivory traits and compared the phylogenetic structure of communities under various degrees of herbivore pressure using experimental plots spanning several decades. We show that all antiherbivory traits examined demonstrated weak but significant phylogenetic signal, and that exclusion of large herbivores results in impoverished species diversity in restructured communities. Surprisingly, we also show that reduction in species diversity coupled with community reorganization does not necessarily result in a decrease in phylogenetic diversity, and that community responses to herbivore exclusion depend on initial structure. Synthesis. Extinction of large mammal herbivores will have cascading effects on plant diversity;however, impacts on plant community structure are contingent on initial conditions. This research has implications for best practice when managing large herbivores and natural habitats.

关键词： Nesting habits   Grasslands   Trees   Birds   Snakes   Predation   Squirrels   Raccoons  

摘要： Globally, grasslands and the wildlife that inhabit them are widely imperiled. Encroachment by shrubs and trees has widely impacted grasslands in the past 150 years. In North America, most grassland birds avoid nesting near woody vegetation. Because woody vegetation fragments grasslands and potential nest predator diversity and abundance is often greater along wooded edge and grassland transitions, we measured the impacts of removing rows of trees and shrubs that intersected grasslands on potential nest predators and the three most abundant grassland bird species (Henslow's sparrow [Ammodramus henslowii], Eastern meadowlark [Sturnella magna], and bobolink [Dolichonyx oryzivorus]) at sites in Wisconsin, U. S. A. We monitored 3 control and 3 treatment sites, for 1 yr prior to and 3 yr after tree row removal at the treatment sites. Grassland bird densities increased (2-4 times for bobolink and Henslow's sparrow) and nesting densities increased (all 3 species) in the removal areas compared to control areas. After removals, Henslow's sparrows nested within <= 50 m of the treatment area, where they did not occur when tree rows were present. Most dramatically, activity by woodland-associated predators nearly ceased (nine-fold decrease for raccoon [Procyon lotor]) at the removals and grassland predators increased (up to 27 times activity for thirteen-lined ground squirrel [Ictidomys tridecemlineatus]). Nest success did not increase, likely reflecting the increase in grassland predators. However, more nests were attempted by all 3 species (175 versus 116) and the number of successful nests for bobolinks and Henslow's sparrows increased. Because of gains in habitat, increased use by birds, greater production of young, and the effective removal of woodland-associated predators, tree row removal, where appropriate based on the predator community, can be a beneficial management action for conserving grassland birds and improving fragmented and degraded grassland ecosystems.

关键词： 树鼩   人类疾病动物模型  

摘要： 由于树鼩的生理、生化和解剖学等生物学特性与人类相似,人们利用树鼩建立了多种人类病毒性疾病动物模型,并在细菌感染疾病、呼吸系统、内分泌、神经系统疾病和肿瘤等方面有广泛的研究和应用,本文就树鼩在人类疾病动物模型研究中应用的新进展进行概述。

关键词： 树鼩   动物福利   措施  

摘要： 树鼩在生物学特性、生理生化、新陈代谢和基因组等方面近似于人类,被广泛应用于生理学、病理学、病毒学、免疫学、药理学及遗传学等多个领域。迄今为止用于生物医学研究的树鼩大部分来自野生,实验树鼩尚无国家质量控制标准。为了保证树鼩引种、驯化、饲养、繁殖、质量控制及福利的规范化和科学化,提高树鼩繁殖率和成活率,本文从兽医公共卫生及实验动物科学的角度,对野生树鼩的捕捉、运输、检疫、饲养及繁育等方面的基本原则及技术操作和福利要求作一简述,为从事树鼩工作的有关人员及树鼩实验动物化研究提供参考。

关键词： Frankliniella   Faramea cyanea   Hancornia speciosa   Solanum lycocarpum   plantanimal interactions   Brazil  

摘要： This study shows that three Frankliniella (Thysanoptera) species have species-specific associations with their hosts: F. varipesFaramea cyanea (Rubiaceae);F. musaeperdaHancornia speciosa (Apocynaceae) and F. fulvipesSolanum lycocarpum (Solanaceae). All thrips species had a marked preference for flowers in anthesis, as in this stage flowers provide food and protection from environment. Frankliniella musaeperda and F. varipes populations were female-biased while F. fulvipes was male-biased. Since many species of Frankliniella have economic importance, studies on the ecology of these species are essential, given the possibility of invasion of agricultural systems in the future.