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1.
In the last 25 years, the cases of human and animal cryptococcosis have increased significantly. This is mostly due to the improvement in the survival of immunocompromised patients. The disease is frequently related to the exposure of this type of patients to avian droppings. Among birds, pigeon, Columba livia, is undoubtedly the most important reservoir for the Cryptococcus species. Nevertheless, the study of a large number of bird's species demonstrated that pigeons are not the only Cryptococcus spp. carriers. The suspicion of the birds being the source for the infection is now becoming a demonstrable fact thanks to the use of molecular typing methods. These methods allow the comparison between strains from birds to patients living around them, with high level of discrimination. 相似文献
2.
食干果鸟对种子传播的作用 总被引:7,自引:0,他引:7
食干果鸟对种子传播的作用鲁长虎袁力(东北林业大学,哈尔滨150040)EffectofDry_fruitEatingBirdstoSeedDispersal.Luchanghu,YuanLi(NortheastForestryUniversity,... 相似文献
3.
Convergent evolution of sunbird pollination systems of Impatiens species in tropical Africa and hummingbird systems of the New World
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Štěpán Janeček Michael Bartoš Kevin Yana Njabo 《Biological journal of the Linnean Society. Linnean Society of London》2015,115(1):127-133
The bird pollination systems of the New and Old Worlds evolved independently, and differ in many aspects. New World plants are often presented as those adapted to hovering birds while Old World plants to perching birds. Most Neotropical studies also demonstrate that in hummingbird species rich assemblages, only a small number of highly specialized birds exploits the most specialized plants with long corollas. Nevertheless, recent research on bird–plant pollination interactions suggest that sunbird pollination systems in the Old World have converged more with the highly specialized hummingbird pollination systems than previously thought. In this study we focus on the pollination systems of the bird pollination syndrome Impatiens species on Mt. Cameroon, West Africa. We show that despite the high diversity of sunbirds on Mt. Cameroon, only Cyanomitra oritis appear to be important pollinator of all Impatiens species. This asymmetry indicates the absence of pair wise co‐evolution and points to a diffuse co‐evolutionary process resulting in guilds of highly specialized plants and birds; a situation well known from hummingbirds and specialized plant communities of the New World. Additionally, the herbaceous habits of Impatiens species, the frequent adaptations to pollination by hovering birds, and the habitat preference for understory in tropical forests or epiphytic growth, resemble the highly specialized Neotropical plants. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 127–133. 相似文献
4.
We investigated factors affecting seed rain beneath nine fleshy-fruited fruiting plant species growing in a 1-ha plot of planted
Pinus thunbergii in central Japan. We tested whether the numbers of seeds and seed species dropped by birds beneath fruiting plants were correlated
with the number of fruits removed by birds from the plants. Most of fruiting plant species with high fruit removal had significantly
high seed rain. Both the numbers of seeds and seed species dropped were significantly, positively correlated with the number
of fruits removed across for all fruiting plant species. Therefore, fruit removal predicted the difference among heterospecific
fruiting plants in seed rain. We also tested whether the number of fruits removed from fruiting plants by birds was related
with fruit crop size, fruit size, and height of the plants, and the numbers of fruits and fruit species of neighboring plants
near the plants. Most of fruiting plant species with high fruit crop size had significantly high fruit removal. The number
of fruits removed was significantly, positively correlated with both the fruit crop size and the number of neighboring fruits
across the nine fruiting plant species. However, the effect of the neighboring fruit density on fruit removal was lower remarkably
than that of fruit crop size. Therefore, fruit crop size best predicted the differences among heterospecific fruiting plants
in fruit removal. We suggest that fruiting plant species with high fruit crop size and high fruit removal contribute to intensive
seed rain beneath them.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
5.
Owen Francis Price 《Austral ecology》2004,29(2):137-144
Abstract Rainforests are naturally fragmented in the Northern Territory of Australia. A census of fruit and frugivorous bird abundance was taken monthly in 10 rainforest patches for 1 year and quarterly for a second year to investigate spatial and temporal patterns among the patches. Fruit abundance showed a marked annual cycle, with a peak around December in the wet season. Four of six bird species showed a significant seasonal fluctuation in abundance, and for three of them, these patterns were different among rainforest types. Three species also showed a significant tendency to be most abundant in the rainforest type with the most fruit in any month. We interpret these results as evidence that birds track fruit resources among rainforest patches of different types. The abundance of two of the species (figbird and pied imperial‐pigeon) was highly variable and did not reveal significantly different temporal trends among rainforest types. These species are probably even more mobile than the other species, although the data in the present study cannot be used to test this theory. The conservation of frugivorous birds and of the plants whose seeds they disperse will require the protection of networks of rainforest patches. 相似文献
6.
Equipped to cope with climate change: traits associated with range filling across European taxa
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Alba Estrada Ignacio Morales‐Castilla Catarina Meireles Paul Caplat Regan Early 《Ecography》2018,41(5):770-781
In order to understand the ecological effects of climate change it is essential to forecast suitable areas for species in the future. However, species’ ability to reach potentially suitable areas is also critical for species survival. These ‘range‐shift’ abilities can be studied using life‐history traits related to four range‐shift stages: emigration, movement, establishment, and proliferation. Here, we use the extent to which species’ ranges fill the climatically suitable area available (‘range filling’) as a proxy for the ability of European mammals and birds to shift their ranges under climate change. We detect which traits associate most closely with range filling. Drawing comparisons with a recent analysis for plants, we ask whether the latitudinal position of species’ ranges supports the assertion that post‐glacial range‐shift limitations cause disequilibrium between ranges and climate. We also disentangle which of the three taxonomic groups has greatest range filling. For mammals, generalists and early‐reproducing species have the greatest range filling. For birds, generalist species with high annual fecundity, which live longer than expected based on body size, have the greatest range filling. Although we consider traits related to the four range‐shift stages, only traits related to establishment and proliferation ability significantly influence range filling of mammals and birds. Species with the greatest range filling are those whose range centroid falls in the latitudinal centre of Europe, suggesting that post‐glacial range expansion is a leading cause of disequilibrium with climate, although other explanations are also possible. Range filling of plants is lower than that of mammals or birds, suggesting that plants are more range‐limited by non‐climatic factors. Therefore, plants might be face greater non‐climatic restraints on range shifts than mammals or birds. 相似文献
7.
8.
Hans‐Heiner Bergmann 《当今生物学》2016,46(6):384-387
The terrestrial birds of La Graciosa The small island La Graciosa is part of an archipelago north of Lanzarote, the northern‐ and easternmost of the Canary Islands. Its habitats are mainly semi‐desert made up of sand dunes covered with dry shrubbery. They house only a small number of terrestrial birds, among them endemic species and subspecies of the Canary Islands. Birds are more common around the settlement of Caleta del Sebo where fresh water and more plant species are available. 相似文献
9.
10.
Summary The hypothesis that more plant species with vertebrate-dispersed fruits occur on fertile soils because there is a greater probability of fruit removal from the parent plant was tested at 16 sites around Sydney, Australia. Removal rates from artificial fruit spikes were two and a half times greater on fertile than infertile soil sites, although this was not quite statistically significant. High variability in removal rate between sites was evident irrespective of fertility. Most removal occurred during the day indicating that birds were important consumers, rather than nocturnal mammals. Bird abundance and diversity did not differ between soil types. More frugivorous species were found in plant communities growing on fertile soil. Two models could explain the patterns observed. Firstly, plants with vertebrate-dispersed fruits could be favoured on fertile soils because of a high abundance of frugivorous birds accomplishing seed dispersal. Alternatively, plants with vertebrate-dispersed fruits could be favoured on fertile soil sites for some other reason and frugivorous birds could be attracted to these areas of abundant food. The correlation between soil fertility and the percentage of vertebrate-dispersed fruits was stronger than the correlation between soil fertility and removal rates and suggests that the second model is more likely to be true. Frugivorous birds are unlikely to be responsible for the high percentage of species with vertebrate-dispersed fruits in fertile soil environments. 相似文献
11.
ABSTRACT. In tropical ecosystems, birds play a relevant role in plant reproduction. Although hummingbirds are regarded as the most important vertebrate pollinators in the Neotropics, the possible role of perching birds as pollinators has been neglected. From 2003 to 2005, we observed 68 species of plants visited by birds in an Atlantic rainforest in southeastern Brazil, including three canopy species: Spirotheca rivieri (Malvaceae, Bombacoidea), Schwartzia brasiliensis (Marcgraviaceae), and Psittacanthus dichrous (Loranthaceae). Flowers of these three species were visited by 15 different species of perching birds and by hummingbirds. The flowers of these three plants are colorful, ranging from deep red or purple to orange. Spirotheca rivieri blooms during the austral winter and Schwartzia brasiliensis during the summer. The flowers of these two species produce copious amounts of dilute nectar in easily accessible structures and both species appear to depend primarily on perching birds as pollinators, with hummingbirds being secondary or minor pollen vectors. The tubular, narrow flowers of P. dichrous are produced during the austral summer and are visited primarily by hummingbirds. Perching birds also visit the flowers, but destroy them. Our results suggest that previous estimates of the number of perching birds that feed on nectar may be too low and that flowers pollinated by perching birds may be more common in the canopy of Neotropical forests than previously thought. 相似文献
12.
Evidence for significant losses of species richness or biodiversity, even within protected natural areas, is mounting. Managers are increasingly being asked to monitor biodiversity, yet estimating biodiversity is often prohibitively expensive. As a cost-effective option, we estimated the spatial and temporal distribution of species richness for four taxonomic groups (birds, mammals, herpetofauna (reptiles and amphibians), and plants) within Sequoia and Kings Canyon National Parks using only existing biological studies undertaken within the Parks and the Parks'' long-term wildlife observation database. We used a rarefaction approach to model species richness for the four taxonomic groups and analyzed those groups by habitat type, elevation zone, and time period. We then mapped the spatial distributions of species richness values for the four taxonomic groups, as well as total species richness, for the Parks. We also estimated changes in species richness for birds, mammals, and herpetofauna since 1980. The modeled patterns of species richness either peaked at mid elevations (mammals, plants, and total species richness) or declined consistently with increasing elevation (herpetofauna and birds). Plants reached maximum species richness values at much higher elevations than did vertebrate taxa, and non-flying mammals reached maximum species richness values at higher elevations than did birds. Alpine plant communities, including sagebrush, had higher species richness values than did subalpine plant communities located below them in elevation. These results are supported by other papers published in the scientific literature. Perhaps reflecting climate change: birds and herpetofauna displayed declines in species richness since 1980 at low and middle elevations and mammals displayed declines in species richness since 1980 at all elevations. 相似文献
13.
生物入侵对鸟类的生态影响 总被引:1,自引:0,他引:1
生物入侵是全球生物多样性面临的最主要威胁之一, 入侵种在改变入侵地环境的同时也使当地的生物受到极大影响。鸟类在生态系统中处于较高的营养级, 生态系统中任何一个环节的变化都可能对鸟类造成一定的影响。本文回顾了哺乳动物、鸟类、无脊椎动物和植物等不同生物类群的入侵对本地鸟类生态影响方面的研究进展。外来生物对鸟类的影响主要表现在以下几方面: (1)外来哺乳动物对成鸟、幼鸟或鸟卵的捕食作用; (2)外来鸟类与本地鸟类竞争栖息地和食物资源, 与当地的近缘种杂交而造成基因流失; (3)外来无脊椎动物改变本地鸟类的栖息环境和食物状况, 甚至直接捕食本地鸟类; (4)外来植物入侵改变入侵地的植物群落组成和结构, 造成本地鸟类的栖息地丧失或破碎化, 并通过改变入侵地生态系统的食物链结构而对高营养级的鸟类产生影响。最后, 作者还提出了该领域有待解决的问题和今后可能的研究方向。 相似文献
14.
Lennart Hansson 《Biodiversity and Conservation》2001,10(11):1865-1873
Species richness of vascular plants and birds were examined in relation to five types of management (including abandonment) of oak-hazel woodland in south-central Sweden. The biodiversity of this type of woodland is affected by lengthy management in contrast to present emphasis on the fragmentation of more or less pristine forests. The woodlands derive from old deciduous forests but were a source of agricultural commodities from medieval time to end of the 19th century. Vascular plants and birds were censused during spring–summer for four years. Total number of plant species, species of field layer forbs, breeding birds and migrant birds were more numerous at simulated original management with mowing of small interior grasslands than at mechanical clearing or abandonment. Summer grazing led to intermediate numbers. Exotic plants were more common at long-time abandonment. Species richness of trees and shrubs, graminoids, all spring birds, resident birds and non-passerine birds did not exhibit any difference between treatments. Inter-site variation in species richness was usually smaller at abandonment than at true management. Species richness of plants and birds showed positive correlation in the particularly large sites examined. The general findings were in accordance with the intermediate disturbance hypothesis. Original management would secure most potential plant and bird species but extensive cattle grazing would also retain many species. 相似文献
15.
The loss of bird species following human colonization of New Zealand has raised concerns about the consequences for crucial ecosystem functions such as pollination. The understorey shrub Alseuosmia macrophylla (Alseuosmiaceae) exhibits characteristics typical of a bird pollination syndrome, but populations still persist in northern North Island forest remnants despite the local extinction of most endemic bird pollinators, leading to the suggestion that moths – rather than birds – may be the primary pollinators. The aim of this study was to quantify the importance of endemic birds as pollinators of A. macrophylla over several years by comparing plants on Little Barrier Island (LBI), where all extant endemic bird pollinators still occur, to plants at sites on the adjacent North Island in the Waitakere Ranges (WTK), where only one of these species remains common. Flowers on LBI were visited by endemic bellbirds (Anthornis melanura) and stitchbirds (Notiomystis cincta), while at WTK sites the most common visitors were the recently arrived silvereye (Zosterops lateralis) and the introduced honeybee (Apis mellifera), both of which acted principally as nectar robbers. Caged flowers on LBI had significantly lower fruit set than open flowers, and plants at WTK were significantly more pollen‐limited than plants on LBI. This provides evidence that the loss of endemic pollinating birds is the most likely reason for the high pollen limitation found in some North Island A. macrophylla populations, and the very low seed set of these populations could have serious implications for the long‐term persistence of this species. 相似文献
16.
基于最受关注濒危物种分布的国家级自然保护区空缺分析 总被引:2,自引:0,他引:2
我们收集整理了中国96个最受关注濒危物种的分布点信息, 利用Maxent分布模型模拟其中分布点信息较为充分的46个物种的潜在分布区, 将其余50个分布信息极少物种的分布点直接标示在地图上。通过分析单个物种分布被国家级自然保护区覆盖的比例, 以及国家级自然保护区覆盖最受濒危物种分布热点地区的比例, 对国家级自然保护区进行了空缺分析。截至2014年底, 仅16个最受关注濒危物种的预测分布区被保护区覆盖超过10%。在分布有最受关注濒危物种的数目可能超过10种的像元(0.8421º)中, 仅有8.27%得到国家级自然保护区保护; 另外, 仅有10.9%的最受关注濒危哺乳动物分布热点地区、1.13%的最受关注濒危鸟类分布热点地区和7.26%的最受关注濒危植物分布热点地区得到国家级自然保护区覆盖。结果显示国家级自然保护区对大部分最受关注濒危物种覆盖不足, 尤其是对其中的所有长距离迁徙鸟类; 国家级自然保护区对最受关注濒危物种分布热点地区覆盖也不足, 尤其是在中国东部和南部地区, 自然保护区在这些地区的布局亟待优化。 相似文献
17.
Impacts of urbanisation on biodiversity: the role of species mobility,degree of specialisation and spatial scale
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Elena D. Concepción Marco Moretti Florian Altermatt Michael P. Nobis Martin K. Obrist 《Oikos》2015,124(12):1571-1582
Urbanisation has an important impact on biodiversity, mostly driving changes in species assemblages, through the replacement of specialist with generalist species, thus leading to biotic homogenisation. Mobility is also assumed to greatly affect species’ ability to cope in urban environments. Moreover, specialisation, mobility and their interaction are expected to greatly influence ecological processes such as metacommunity dynamics and assembly processes, and consequently the way and the spatial scale at which organisms respond to urbanisation. Here we investigate urbanisation impacts on distinct characteristics of species assemblages – namely specialisation degree in resource use, mobility and number of species, classified according to both characteristics and their combination – for vascular plants, butterflies and birds, across a range of spatial scales (from 1 × 1 km plots to 5 km‐radius buffers around them). We found that the degree of specialisation, mobility and their interaction, greatly influenced species’ responses to urbanisation, with highly mobile specialist species of all taxonomic groups being affected most. Two different patterns were found: for plants, urbanisation induced trait divergence by favouring highly mobile species with narrow habitat ranges. For birds and butterflies, however, it reduced the number of highly mobile specialist species, thus driving trait convergence. Mobile organisms, across and within taxonomic groups, tended to respond at larger spatial scales than those that are poorly mobile. These findings emphasize the need to take into consideration species’ ecological aspects, as well as a wide range of spatial scales when evaluating the impact of urbanisation on biodiversity. Our results also highlight the harmful impact of widespread urban expansion on organisms such as butterflies, especially highly mobile specialists, which were negatively affected by urban areas even at great distances. 相似文献
18.
Pollination systems in the cool temperate mixed coniferous and broad-leaved forest zone of Yakushima Island 总被引:2,自引:1,他引:1
Takakazu Yumoto 《Ecological Research》1988,3(2):117-129
Animal pollination was observed in a cool temperate mixed coniferous and broadleaved forest, and in shrubby vegetation on
a mountain summit, on Yakushima Island (30.2°N, 130.3°E), to the south of Kyushu, Japan. In the mixed forest, two groups of
plants were recognized: exclusively canopy-flowering species, and understory-flowering species. All of the canopy-flowering
species had dish-shaped flowers or flowers without petals, were visited by opportunist insects, and most of them showed a
mass-flowering pattern. Each segregated its flowering time from those of the others. On the other hand, most of the understory-flowering
species had bell-or funnel-shaped flowers which were pollinated by birds or bumble bees, and showed an extended flowering
pattern. Their phenological flowering series (exceptCamellia japonica that was pollinated by birds), without a break, coincided very well with the active period of a bumble bee species,Bombus ardens. In the shrubby vegetation on the mountain summit, two types of species were recognized: one type also grew in the forest,
whereas the other type only grew in the shrubby vegetation. The former type of species in this vegetation was visited by a
more diverse range of insects than that in the forest. In particular, species visited mainly by bumble bees in the forest
attracted many opportunist insects. All but one of the species that only grew in the shrubby vegetation were visited only
by opportunist insects and never by bumble bees. 相似文献
19.
Frugivorous birds are involved in the distribution of fleshy-fruited plants. In a temperate forest in northern Europe, we investigated how fruit-eating birds and habitat variation affect the local distribution of these plants and what the consequences are to the species composition of the fruit-bearing plant community. We subdivided the forest into 25×25 quadrates and mapped the distribution of all fleshy-fruited plant species (18 species) expected to have their seeds dispersed by birds. Our specific aims were (i) to test if the distribution of the fleshy-fruited species in the forest was clumped, (ii) nested, and (iii) to describe the set of species as an interacting network. Our results show that bird-dispersed fleshy-fruited species in a temperate forest constitute a set of orchards with a strong spatial structure. The distributions of species were highly correlated and nested. We suggest that factors involved in dispersal and colonization are mainly responsible of a nested structure, where rare species are only found together with more widespread species and species-poor sites only contain widespread species. Besides, the community had small-world topology with high clustering and short path length between species. This makes the network robust against random perturbations. 相似文献
20.
Linking structure and functionality in mutualistic networks: do core frugivores disperse more seeds than peripheral species?
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Seed dispersal networks are often organized in nested structures in a way that a few core species can disproportionally affect the remaining species in a network, in both the ecological and evolutionary sense. Yet, the relative importance of core and peripheral species has not been properly tested in seed dispersal network studies. We determined core species from 10 local seed dispersal networks composed by fleshy‐fruited plants and frugivorous birds. Each of those local quantitative networks was characterized with a core quality value, a core score for each species and a threshold value between core and peripheral species. From a total of 52 bird and 69 plant species that interacted in the study area, only 8 and 15, respectively, were identified as core. Each local network had a core that comprised a small number of birds and plants, always lower than 30% of the interacting species. There was no difference in the quantitative component of seed dispersal effectiveness (QC) provided by the frugivorous bird assemblage to plant functional groups clustered according to their growth form and fruit characteristics. Core birds dispersed seeds from each of these plant functional groups with a higher QC than peripheral species. Thus, we empirically demonstrate for the first time that seed dispersal networks at a regional scale have a small core set of fruit‐eating birds, upon which heavily rely most fleshy‐fruited plants for their seed removal. Hence, the activity of just a few core frugivores could deeply impact the demography of an entire assemblage of fleshy‐fruited plants. 相似文献