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1.
The sundew genus Drosera consists of carnivorous plants with active flypaper traps and includes nearly 150 species distributed mainly in Australia, Africa, and South America, with some Northern Hemisphere species. In addition to confused intrageneric classification of Drosera, the intergeneric relationships among the Drosera and two other genera in the Droseraceae with snap traps, Dionaea and Aldrovanda, are problematic. We conducted phylogenetic analyses of DNA sequences of the chloroplast rbcL gene for 59 species of Drosera, covering all sections except one. These analyses revealed that five of 11 sections, including three monotypic sections, are polyphyletic. Combined rbcL and 18S rDNA sequence data were used to infer phylogenetic relationships among Drosera, Dionaea, and Aldrovanda. This analysis revealed that all Drosera species form a clade sister to a clade including Dionaea and Aldrovanda, suggesting that the snap traps of Aldrovanda and Dionaea are homologous despite their morphological differences. MacClade reconstructions indicated that multiple episodes of aneuploidy occurred in a clade that includes mainly Australian species, while the chromosome numbers in the other clades are not as variable. Drosera regia, which is native to South Africa, and most species native to Australia, were clustered basally, suggesting that Drosera originated in Africa or Australia. The rbcL tree indicates that Australian species expanded their distribution to South America and then to Africa. Expansion of distribution to the Northern Hemisphere from the Southern Hemispere occurred in a few different lineages.  相似文献   

2.
本研究主要探讨黄龙自然保护区森林生态系统年净初级生产力水平和栖息地复杂程度对小型兽类物种多样性的影响。将调查区按海拔高度分为4 个调查点,每点的年净初级生产力水平各不相同,分别为: 24.9 MJ / (m2·a) ; 21.5 MJ / (m2·a) ; 17.5 MJ / (m2·a) 和14.1 MJ / (m2·a) 。在选择调查点时,同时考虑栖息地复杂程度,在生产力水平较高的调查点选择栖息地复杂程度较低的地点,而在生产力较低的调查点选择栖息地复杂程度较高的地点调查,以便分析森林生态系统年净初级生产力水平与栖息地复杂程度对小型兽类物种多样性的影响。采用鼠铗捕获小型兽类。结果表明,小型兽类物种多样性与森林生态系统年净初级生产力水平有密切关系,随着海拔升高,森林生态系统年净初级生产力的降低,所捕获的小型兽类生物量随之降低,其物种多样性也随之下降。小型兽类物种多样性也与栖息地复杂程度有关,森林生态系统年净初级生产力水平在一定范围内,大于17.5 MJ / (m2·a) ,栖息地复杂度的增加可以降低年净初级生产力水平对小型兽类物种多样性的影响。然而,森林生态系统年净初级生产力水平降低到一定程度时,小于14.1 MJ / (m2·a) ,生产力水平则为影响小型兽类物种多样性的主要因子。此外,小型兽类的生物量与森林生态系统年净初级生产力和栖息地复杂程度也有类似的关系。  相似文献   

3.
We propose that researchers integrate ethics, performance criteria, techniques, and common sense when developing research trapping programs and in which members of institutional animal care and use committees address these topics when evaluating research protocols. To ask questions about ethics is in the best tradition of science, and researchers must be familiar with codes of ethics and guidelines for research published by professional societies. Researchers should always work to improve research methods and to decrease the effects on research animals, if for no other reason than to minimize the chances that the methods influence the animals' behavior in ways that affect research results. Traps used in research should meet performance criteria that address state-of-the-art trapping technology and that optimize animal welfare conditions within the context of the research. The proposal includes the following criteria for traps used in research: As Criterion I, killing-traps should render >/= 70% of animals caught irreversibly unconscious in /= 70% of animals with 相似文献   

4.
A comparison of pitfall traps with bait traps for sampling leaf litter ants was studied in oak-dominated mixed forests during 1995-1997. A total of 31,732 ants were collected from pitfall traps and 54,694 ants were collected from bait traps. They belonged to four subfamilies, 17 genera, and 32 species. Bait traps caught 29 species, whereas pitfall traps caught 31 species. Bait traps attracted one species not found in pitfall traps, but missed three of the species collected with pitfall traps. Collections from the two sampling methods showed differences in species richness, relative abundance, diversity, and species accumulation curves. Pitfall traps caught significantly more ant species per plot than did bait traps. The ant species diversity obtained from pitfall traps was higher than that from bait traps. Bait traps took a much longer time to complete an estimate of species richness than did pitfall traps. Little information was added to pitfall trapping results by the bait trapping method. The results suggested that the pitfall trapping method is superior to the bait trapping method for leaf litter ant studies. Species accumulation curves showed that sampling of 2,192+/-532 ants from six plots by pitfall traps provided a good estimation of ant species richness under the conditions of this study.  相似文献   

5.
The occurrence of aphid-transmitted viruses in agricultural crops of the Midwest and northeastern United States has become more frequent since the arrival and establishment of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae). A. glycines is a competent vector of plant viruses and may be responsible for recent virus epidemics in Wisconsin snap bean, Phaseolus vulgaris L., fields. To determine whether vegetation surrounding crop fields could serve as sources of virus inocula, we examined the settling activity ofA. glycines and other aphid species in agricultural crops and noncrop field margins adjacent to snap bean fields. Noncrop field margins were made up of numerous virus-susceptible plant species within 10 m from snap bean field edges. During summers 2006 and 2007, horizontal pan traps were placed in commercial soybean [Glycine max (L.) Merr.], snap bean, and surrounding field margins to characterize aphid flight activity patterns in the different habitat types. Alate abundance and peak occurrence across years varied between crop and noncrop field margins and differed among patches of plants in field margins. Overall aphid activity peaked late in the season (21 August in 2006 and 28 July in 2007); with the majority (52%) of total aphids trapped in all habitats being A. glycines. Susceptibility to viral infection and confirmed visitation of A. glycines to these forage plants suggests the importance ofnoncrop habitats as potential sources of primary virus inoculum. Viral disease onset followed peak aphid flights and further implicates A. glycines as a likely vector of viruses in commercial bean and other crops in Wisconsin.  相似文献   

6.
A study on the ecology of rodents and insectivores on Mount Chilalo and the Galama Mountain range was conducted during August, 2007–April, 2008. Study grids were marked in nine randomly selected habitats. Sherman live traps and snap traps were used to capture the small mammals. A total of 2525 (including recaptures) individual rodents and insectivores were captured in 5488 (Sherman) and 1590 (snap) trap‐nights. Among the live‐trapped animals, 2037 (96.2%) and 80 (3.8%) were rodents and insectivores, respectively, that comprised 17 species. These were as follows: Arvicanthis abyssinicus, Arvicanthis blicki, Arvicanthis dembeensis, Lophuromys flavopunctatus, Lophuromys melanonyx, Mastomys natalensis, Mus mahomet, Otomys typus, Rattus rattus, Stenocephalemys albipes, Stenocephalemys albocaudata, Stenocephalemys griseicauda, Crocidura glassi, Crocidura flavescens and Crocidura thalia. Tachyoryctes splendens and Hystrix cristata were sighted but not captured. Endemics to Ethiopia constituted 60% of the trapped small mammals. Lophuromys flavopunctatus was the most abundant and widely distributed rodent species, while M. mahomet was the least. The altitudes between 3301 and 3400 m asl had the highest species composition and abundance although it is second in number of catches per trap‐nights. The majority of rodents and insectivores were associated with montane forest habitat, whereas the least were in the shrubland. Anthropogenic effects were witnessed affecting the distribution of small mammals.  相似文献   

7.
To understand habitat preferences, seasonal abundance and diets of rodents in wet and dry season surveys were conducted in Alage, Southern Ethiopia. Sherman and snap traps were used to capture rodents from the four habitats: bushland, Acacia woodland, maize and wheat farmlands. A total of 3312 trap nights, from the four trapping habitats, yielded 776 individuals that represented 11 species of rodents. The distribution of rodents varied between habitats and seasons. Wet season rodent abundance was 52.3% while in the dry season it was 47.7%. Seasonal differences in species abundance were insignificant. Bushland habitat had high wet and dry season abundances with 137 and 211 individuals, respectively. Abundance was low in maize farm (57 individuals) in the wet season and wheat farm (10 individuals) in the dry season. Stomach content composition analysis of snap‐trapped rodents from different habitats showed differences between species and across seasons. Six rodent species were recorded as pests on the farmlands in this study area. In conclusion, variation in habitat preferences and diet of rodents in different habitats and across seasons might be due to the role of ground cover and food sources.  相似文献   

8.
Tropical forest mammal assemblages are widely affected by the twin effects of habitat loss and habitat fragmentation. We evaluated the effects of forest patch metrics, habitat structure, age of patch isolation, and landscape metrics on the species richness, abundance and composition of small mammals at 23 forest fragments (ranging in size from 43 to 7,035 ha) in a highly deforested 3,609-km2 landscape of southwestern Brazilian Amazonia. Using pitfall traps and both terrestrial and arboreal traplines of Sherman, Tomahawk and snap traps, we captured a total of 844 individuals over 34,900 trap-nights representing 26 species and 20 genera of small-mammals, including 13 rodent and 13 marsupial species. We also consider the effects of distance from forest edges on species occupancy and abundance. Overall small mammal abundance, species richness and species composition were primarily affected by the quality of the open-habitat matrix of cattle pastures, rather than by patch metrics such as fragment size. Ultimately, small mammal community structure was determined by a combination of both landscape- and patch-scale variables. Knowledge of the anthropogenic factors that govern small mammal community structure is of critical importance for managing the persistence of forest vertebrates in increasingly fragmented neotropical forest landscapes.  相似文献   

9.
How carnivorous plants outsmart their prey The non‐muscular movements of plants, especially the fast traps of carnivorous plants, might appear as natural “wonders”, but they are all evoked by the interplay of functional morphological structures developed during evolution with well‐described biophysical and chemical processes. Hydraulic “motors”, which are based on water displacement in the respective cells and tissues, entail rather slow motions. Large and fast structures, as e.g., the snap‐traps of the carnivorous Venus flytrap, often depend on the release of stored elastic energy (relaxation) which acts as a speed boost and significantly speeds up the motion. The fast traps presented here and the deformation principles involved, including some mechanical “tricks”, can be rebuild in simple and low‐cost physical models which are especially useful for an application in teaching.  相似文献   

10.
Hunting for wild animals is stimulated by the many different human uses of faunal resources, and these animals constitute important subsistence items in local communities in the Caatinga region. In order to gain access to these resources, hunters have developed a series of techniques and strategies that are described in the present work. The principal hunting techniques encountered were: waiting, especially directed towards hunting diurnal birds; calling ("arremedo"), a technique in which the hunters imitate the animal's call to attract it to close range; hunting with dogs, a technique mostly used for capturing mammals; tracking, a technique used by only a few hunters who can recognize and follow animal tracks; and "facheado", in which the hunters go out at night with lanterns to catch birds in their nests. Additionally, many animal species are captured using mechanical traps. The types of traps used by the interviewees were: dead-fall traps ("quixó"), iron-jaw snap traps ("arataca"), wooden cages with bait ("arapuca"), iron-cage traps ("gaiola'), "visgo", multi-compartment bird cages ("alçapão"), buried ground traps with pivoted tops ("fojo"), and nooses and cages for carnivorous. The choice of which technique to use depends on the habits of the species being hunted, indicating that the hunters possess a wide knowledge of the biology of these animals. From a conservation perspective, active hunting techniques (waiting, imitation, hunting with dogs, and "facheado") have the greatest impact on the local fauna. The use of firearm and dogs brought greater efficiency to hunting activities. Additional studies concerning these hunting activities will be useful to contribute to proposals for management plans regulating hunting in the region – with the objective of attaining sustainable use of faunal resources of great importance to the local human communities.  相似文献   

11.
王巍  马克平 《生态学报》2001,21(2):204-210
动物对辽东栎(Quercus liaotungensis Koidz.)坚果的捕食被认为是影响辽东栎坚果命运的主要因素,因此直接影响幼苗的建立和自然更新。在东灵山一个落叶阔叶林中调查了辽东栎坚果被脊椎动物转运和就地消耗状况。在排除部分小型啮齿目动物前后,辽东栎坚果的丢失动态曲线不同。到实验结束时,基本上所有放置的辽东栎坚果都消失了。排除动物前的曲线上有一个拐点,而排除动物后的丢失曲线上有多个拐点。两曲线相似的地方是:最初一两天辽东栎坚果的丢失非常迅速。排除小型啮齿目动物对辽东栎坚果的丢失有影响,然而坚果尺寸和微生境条件对坚果的丢失没有影响。任意2个因子的交互作用以及3个因子的交互作用对辽东栎坚果的丢失也都没有影响。排除啮齿目动物和坚果尺寸对辽东栎坚果的就地消耗有影响,微生境以及其它因子的交互作用对坚果的就地消耗没有影响。在9月份3d捕鼠的时间里,共捕到啮齿目动物3种:大林姬鼠(Apodemus speciosus)、社鼠(Niviveniter confucianus )和花鼠(Tantias sibiricus)。研究结果表明,尽管啮齿目动物的排除能够降低辽东栎坚果的丢失速度,但它们(或者和其它的脊椎动物一起)有足够的能力将辽东栎坚果捕食或搬运到其它地方分散埋藏或将它们搬运到它们的洞穴中用作漫长冬季的主要食物来源。  相似文献   

12.
The attraction of female tabanids to unbaited and single-baited canopy traps using 4-methylphenol, 3-isopropylphenol, and naphthalene was studied in three forest localities in eastern Croatia. Tabanids were collected in a significantly higher number in traps baited with these chemicals compared to unbaited control traps. The number of females of Tabanus bromius, Tabanus sudeticus, Tabanus tergestinus, Hybomitra ciureai, Haematopota pluvialis, and Tabanus maculicornis collected from 4-methylphenol baited canopy traps and traps baited with other attractants differed significantly. A total of 89.0% of tabanids collected belonged to these six species. The response of the other species to used chemicals was not analyzed because of small sample sizes. Moreover, the results with 3-isopropylphenol and naphthalene are very similar and not significant for some tabanids. Tabanus bromius was the most abundant species with 48.4% in the sample collected by canopy traps. Finally, the 4-methylphenol baited canopy traps collected 16 times more tabanids than unbaited traps, while 3-isopropylphenol and naphthalene baited traps collected 3.5 and 2 times as many tabanids, respectively, than unbaited traps. Also, 4-methylphenol appeared to be a very effective attractant for Lucilia caesar (Calliphoridae), Sarcophaga carnaria (Sarcophagidae), and Musca domestica (Muscidae).  相似文献   

13.
14.
Whilst studies have shown that climatic (North Atlantic Oscillation (NAO)) and biotic (acorn production) factors influence rodent populations, mechanisms driving temporal and spatial fluctuation of rodent populations are understudied. This study evaluates relationships between the influence of environmental factors (biotic and abiotic) and phenotypic characteristics across two rodent feeding guilds (granivorous and non-granivorous species) represented by four species of rodents in Central Europe. We hypothesise that the relationship between acorn density and population growth rate are indirectly affected by climatic factors (winter NAO) and that these effects differ amongst herbivorous and granivorous species. In addition, we also tested whether effects of weather and competition on individual phenotype characteristic vary amongst mast and non-mast years. Rodent populations were estimated by catching individuals in snap traps during the growing season (from March to November) over a period of 9 years at three sites. The results of the generalised linear model provide evidence that acorn production best explained the population fluctuations. We therefore conclude that the between-year population fluctuations in rodent abundance were governed by density dependence and initiated primarily by acorn mast years. Auto-regressive models also revealed direct density dependence in combination with the direct effects of mast years. Therefore, strong intraspecific competition for food is likely in years following mast years. Our results also showed that abundance of non-granivorous species is mainly influenced by local weather conditions which could regulate food quality and abundance. On the other hand, population dynamics of granivorous species are caused directly by acorn density and indirectly by climatic condition influencing acorn production.  相似文献   

15.
16.
Malaise traps are typically used to sample a range of flying insect groups; however non-target taxa such as spiders may also be collected in large numbers. In this study, spiders were sampled in peatlands and wet grasslands and catches in Malaise and pitfall traps were compared in order to determine the adequacy of Malaise traps for use in spider biodiversity assessment. Overall, the number of species and individuals caught in Malaise and pitfall traps were comparable, although more species were sampled in Malaise traps in locations with a greater structural diversity of the vegetation. The spider fauna sampled by the Malaise traps differed from that of the pitfall traps, but both methods consistently separated the species assemblages by biotope. These results demonstrate that Malaise traps are effective at sampling spiders and indicate that they can be used in biodiversity assessment. In addition the complementary species sampled by each method mean that employing both techniques will be useful where a full inventory of the species is required. The authors do not suggest that Malaise traps should be used solely to sample spiders; however, if traps are set to collect insects, identification of the spiders sampled may reduce the need to employ additional sampling techniques.  相似文献   

17.
The global initiatives of monitoring and conserving pollinators require worldwide assessments with comparable data sets collected through standardized methods. The use of pan traps is a passive method widely applied to sample flower visitors, standing out for its simplicity. Despite its wide use to sample pollinator diversity, the influence of color on trap efficiency is not well understood. The available studies are particularly scarce in the tropics and have generated divergent results. The main goal of the present study was to assess whether blue, yellow and white pan traps are complementary to sample Hymenoptera community. For this, we placed 49 sample units of blue, white and yellow pan traps in agricultural and natural (savanna-like) areas in Chapada Diamantina, Bahia, Brazil. We found that the species richness from blue and yellow pan traps were not significantly different, but both were significantly greater than the species richness from white pan traps. However, bees were significantly more attracted to the blue pan traps and wasps to the yellow ones; thus, color attractiveness was group-specific. Pan traps of different color showed low species composition overlap with 61 % of species collected exclusively in one of the three pan trap colors, and the species composition in the blue traps differed consistently from that in the traps of the other colors. In the article we discuss the implication of the results and defend the combined use of pan traps with different colors as a solution for the differential variable sample bias.  相似文献   

18.
19.
A. Liro  J. Szacki 《Oecologia》1987,74(3):438-440
Summary Movements of field mice (Apodemus agrarius) were studied using snap traps and coloured bait. The presence of coloured bait was recorded in 35% of field mice captured. Of animals with coloured bait, 60% had moved further than 100 m. The longest distances traversed by field mice exceeded 1000 m. It is suggested that live-trapping on a grid of several hectares is not an adequate method of studying small-mammal movements.  相似文献   

20.
Lethal spring traps are widely used for killing small mammals in the UK. Many require government approval, based primarily on humaneness. However, mole traps and break-back traps for rats and mice are exempt; those available vary widely in price and apparent quality. The EU is considering implementing a Trapping Directive that would alter UK legislation, and a recent report advised the EU that trapping legislation should cover all trapped species and encourage improvement of traps. Mechanical trap performance is often used as an indicator of welfare impact. We examined the mechanical evidence for scope to improve the welfare standards of rat, mouse and mole spring traps. We measured mechanical performance among a range of rat, mouse and mole traps. Impact momentum values varied 6-8 fold, and clamping force values 4-5.5 fold, among traps for killing each species. There was considerable overlap in the performance of rat and mouse traps. Trap-opening angle and spring type were related to impact momentum and clamping force in traps for both species. There was no relationship between price and mechanical performance in traps for any species, except talpa mole traps. We are unable to judge the direct welfare impact of the traps tested, but rather the potential welfare threat associated with their exemption from approval. The wide variation in mechanical performance in traps for each species, overlap in performance between rat and mouse traps and increasing availability of weaker plastic rodent traps indicate considerable scope for improving the humaneness of spring traps for rats, mice and moles. We conclude that all such traps should be subject to the UK approval process. New welfare categories might improve trap standards further. Our results could also help improve rodent trap design and assist consumers in selecting more powerful traps. Many thousands of rats, mice and moles might benefit.  相似文献   

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