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1.
九连山国家级自然保护区是我国中亚热带与南亚热带常绿阔叶林的过渡地带,动植物种类丰富多样。为进一步掌握该保护区野生动物资源现状,我们于2014年11月至2015年7月在保护区布设了31个红外相机监测点,对大中型兽类和林下活动鸟类进行了初步摸底调查。相机累计工作4 692个捕获日,共获得有动物的独立有效照片3 341张,鉴定出鸟兽物种共10目16科33种(兽类12种,鸟类21种)。属于国家Ⅱ级重点保护动物有斑灵狸(Prionodon pardicolor)、白鹇(Lophura nycthemera)和灰脸鵟鹰(Butastur indicus)等。兽类以赤腹松鼠(Callosciurus erythraeus)、白腹鼠种类(Niviventer rats)、小泡巨鼠(Leopoldamys edwardsi)和倭松鼠(Tamiops maritimus)等物种的相对丰富度指数较高。相对丰富度指数较高的鸟类物种依次为白鹇、紫啸鸫(Myophonus caeruleus)和黑领噪鹛(Garrulax pectoralis)等。结合以往记录,灰头绿啄木鸟(Picus canus)、乌灰鸫(Turdus cardis)、绿翅金鸠(Chalcophaps indica)、白眉鸫(Turdus obscurus)和白冠燕尾(Enicurus leschenaulti)等为保护区的鸟类新记录种。本研究的调查结果为进一步在九连山自然保护区开展鸟兽资源的长期监测奠定了基础。  相似文献   

2.
Fire is a fundamental process in savannas and is widely used for management. Pyrodiversity, variation in local fire characteristics, has been proposed as a driver of biodiversity although empirical evidence is equivocal. Using a new measure of pyrodiversity (Hempson et al.), we undertook the first continent‐wide assessment of how pyrodiversity affects biodiversity in protected areas across African savannas. The influence of pyrodiversity on bird and mammal species richness varied with rainfall: strongest support for a positive effect occurred in wet savannas (> 650 mm/year), where species richness increased by 27% for mammals and 40% for birds in the most pyrodiverse regions. Range‐restricted birds were most increased by pyrodiversity, suggesting the diversity of fire regimes increases the availability of rare niches. Our findings are significant because they explain the conflicting results found in previous studies of savannas. We argue that managing savanna landscapes to increase pyrodiversity is especially important in wet savannas.  相似文献   

3.
为了系统掌握甘肃安西极旱荒漠国家级自然保护区野生动物的种类、数量、分布以及种群动态变化趋势, 我们于2017年8月至2019年9月, 在保护区选取3个样地布设60台红外相机, 对保护区兽类和鸟类多样性进行调查。红外相机累计观测29,147个工作日, 采集独立有效照片11,134张。共观测到兽类6目10科18种, 鸟类7目16科31种。国家I级重点保护野生动物有5种, 国家Ⅱ级重点保护野生动物有11种。兽类中相对多度较高的物种有蒙古兔(Lepus tolai, RAI = 12.749)、岩羊(Pseudois nayaur, RAI = 4.690)、北山羊(Capra sibirica, RAI = 4.333)、蒙古野驴(Equus hemionus, RAI = 3.163)、赤狐(Vulpes vulpes, RAI = 2.601), 分布最普遍的是赤狐和蒙古兔; 鸟类中相对多度较高的物种有石鸡(Alectoris chukar, RAI = 1.678)、岩鸽(Columba rupestris, RAI = 1.142)、漠䳭(Oenanthe deserti, RAI = 0.865)、赭红尾鸲(Phoenicurus ochruros, RAI = 0.374)和沙䳭(Oenanthe isabellina, RAI = 0.196), 其中漠䳭和石鸡的分布最广。豺(Cuon alpinus)、石貂(Martes foina)、黄鼬(Mustela sibirica)和白唇鹿(Cervus albirostris)为保护区新记录物种, 雪豹(Panthera uncia)也是保护区建立以来首次观测到。保护区人为干扰减少是造成物种新分布、数量增多的主要原因。  相似文献   

4.
Resident and migrant birds and several mammal species utilize natural forest openings to exploit foraging opportunities that are otherwise rare or absent in the dense forest of equatorial Africa. Certain bird species exhibit protocooperative and commensal relationships with these mammals. In a large marshy opening, five species of birds exploited the actions of large terrestrial mammals to flush prey, two species of birds used two species of aquatic mammals to expose prey, and another bird species fed directly on mammalian ectoparasites. African jacanas had a higher foraging rate when associated with gorillas and elephants than when alone, and great egrets had a higher capture efficiency when elephants were present. In a second opening, covered by a shallow, algae-laden pond, African jacanas, finfeet, and Hartlaub's ducks competed to remove arthropod ectoparasites from forest buffalo and bongo antelope, both of which consistently reacted to the alarm calls of jacanas and Hartlaub's ducks. At least ten species of birds directly benefit from associations with mammals. Indirect benefits were also noted as African jacanas, black crakes, and palm-nut vultures selected food items from elephant and buffalo dung.  相似文献   

5.
社群学习对植食性鸟类和哺乳动物觅食行为的作用   总被引:1,自引:0,他引:1  
社群学习是动物的一种可塑性行为表现型式。综述了社群学习对植食性鸟类和哺乳动物觅食行为的作用,并述评了其学习机制。社群同伴对动物个体觅食地点、时间和取食方式均有影响,母体摄食的食物信息可通过胎盘和乳汁显著影响幼体的食物选择。动物通过观察学习、嗅闻学习以及味觉厌恶学习,不仅能更快找到食物资源,提高觅食效率,而且能有效降低中毒与被捕食的风险,从而提高其适合度。  相似文献   

6.
7.
Huddling can be defined as “an active and close aggregation of animals”. It is a cooperative group behaviour, permitting individuals involved in social thermoregulation to minimize heat loss and thereby lower their energy expenditure, and possibly allowing them to reallocate the saved energy to other functions such as growth or reproduction. Huddling is especially important in the case of animals faced with high heat loss due to a high surface‐to‐volume ratio, poor insulation, or living in cold environments. Although numerous experimental studies have focused on the huddling behaviour of a wide range of species, to our knowledge, this is the first attempt to review the various implications of this widely used behavioural strategy. Huddling allows individuals to maximise energy savings by (1) decreasing their cold‐exposed body surface area, (2) reducing their heat loss through warming of ambient temperatures surrounding the group, and (3) eventually lowering their body temperature through physiological processes. Huddling provides substantial energy savings and is estimated to reduce energy expenditure by between 6 and 53%. Broad variations in the energetic benefits of huddling depend on the number of individuals and species involved in huddles, the ambient temperatures to which individuals are exposed and the density of the aggregations. It has been shown that huddling individuals have increased survival, a lower food intake, a decreased body mass loss, increased growth rate, reduced water loss, and/or a more constant body temperature together with a significant reduction in metabolic rate. Though huddling has been studied widely, this review reveals the intricacies of this adaptive behaviour.  相似文献   

8.
Aim To investigate the relative contributions of current vs. historical factors in explaining broad‐scale diversity gradients using a combination of contemporary factors and a quantitative estimate of the temporal accessibility of areas for recolonization created by glacial retreat following the most recent Ice Age. Location The part of the Nearctic region of North America that was covered by ice sheets during the glacial maximum 20 000 BP. Methods We used range maps to estimate the species richness of mammals and terrestrial birds in 48 400 km2 cells. Current conditions in each cell were quantified using seven climatic and topographical variables. Historical conditions were estimated using the number of years before present when an area became exposed as the ice sheets retreated during the post‐Pleistocene climate warming. We attempted to tease apart contemporary and historical effects using multiple regression, partial regression and spatial autocorrelation analysis. Results A measure of current energy inputs, potential evapotranspiration, explained 76–82% of the variance in species richness, but time since deglaciation explained an additional 8–13% of the variance, primarily due to effects operating at large spatial scales. Because of spatial covariation between the historical climates influencing the melting of the ice sheet and current climates, it was not possible to partition their effects fully, but of the independent effects that could be identified, current climate explained two to seven times more variance in richness patterns than age. Main Conclusions Factors acting in the present appear to have the strongest influence on the diversity gradient, but an historical signal persisting at least 13 000 years is still detectable. This has implications for modelling changes in diversity patterns in response to future global warming.  相似文献   

9.
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.  相似文献   

10.
Restoration of damaged ecosystems has become an important tool to slow down biodiversity loss and to maintain ecosystem services. Peatland bird populations have shown a substantial decline during the recent decades in Northern Europe as a consequence of peatland drainage. We studied whether restoration of peatlands drained for forestry affects bird communities. We conducted bird surveys at 11 peatlands in Western Finland, where each of the restored and their pristine counterparts were surveyed before restoration and yearly after restoration during 2010–2018. We used linear mixed effect models to analyze whether restoration affected the number of species and territories of peatland specialist and non‐specialist species and permutational multivariate analysis of variance to analyze the change in community composition. Drained parts of the peatlands had higher number of territories of non‐specialist species before restoration, and restoration seemed to decrease these numbers towards the level of pristine parts. By contrast, restoration did not affect the number of peatland specialists and their territories, which was lower in drained than in pristine parts of the peatlands. Bird communities in restored parts remained different from pristine parts in terms of community composition after restoration. Thus, despite the effect of restoration on non‐specialists, a substantially long time may be required for a recovery of the peatland bird communities. Based on our results, it seems that long‐term monitoring of the restored and pristine peatlands is needed to determine whether restoration is effective in recovering the peatland specialist bird species and bird communities in general.  相似文献   

11.
Birds that depend on grassland and successional-scrub vegetation communities are experiencing a greater decline than any other avian assemblage in North America. Habitat loss and degradation on breeding and wintering grounds are among the leading causes of these declines. We used public and private lands in northern Virginia, USA, to explore benefits of grassland management and associated field structure on supporting overwintering bird species from 2013 to 2016. Specifically, we used non-metric multidimensional scaling and multispecies occupancy models to compare species richness and habitat associations of grassland-obligate and successional-scrub species during winter in fields comprised of native warm-season grasses (WSG) or non-native cool-season grasses (CSG) that were managed at different times of the year. Results demonstrated positive correlations of grassland-obligate species with decreased vegetation structure and a higher percentage of grass cover, whereas successional-scrub species positively correlated with increased vegetation structure and height and increased percentages of woody stems, forb cover, and bare ground. Fields of WSG supported higher estimated total and target species richness compared to fields of CSG. Estimated species richness was also influenced by management timing, with fields managed during the previous winter or left unmanaged exhibiting higher estimated richness than fields managed in summer or fall. Warm-season grass fields managed in the previous winter or left unmanaged had higher estimated species richness than any other treatment group. This study identifies important winter habitat associations (e.g., vegetation height and field openness) with species abundance and richness and can be used to make inferences about optimal management practices for overwintering avian species in eastern grasslands of North America. © 2019 The Authors. Journal of Wildlife Management Published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.  相似文献   

12.
Summary A factorial field experiment was designed to test the effects of small mammals and above- and below-ground invertebrates on plant species richness and composition in native tallgrass prairie at Konza Prairie Research Natural Area, northeast Kansas. Over a 4-year period, Microtus ochrogaster densities were maintained by live-trapping in fenced plots, and invertebrate levels were reduced using the pesticides carbaryl for above-ground invertebrates and an organophosphate (isofenphos) for belowground invertebrates. ANOVA according to a split-plot design of plant species biomass data harvested in 1984 and 1986 revealed few significant effects of either small mammal densities or pesticide application. Of 54 species harvested from both sample dates, only 10 were significantly affected by either treatment. Analysis of species richness according to 8 life-form classes provided a clearer pattern of response than did biomass either by species or life-form class. For example, numbers of C4 grasses were reduced by increasing small mammal densities, whereas numbers of C4 annual forbs were lowest when above-ground herbivory was reduced. While consumers have been shown to have strong effects on successional communities, the few significant results observed in this study suggests that the manipulated levels of small mammals and insects had few effects on a mature tallgrass prairie.Deceased May, 1986  相似文献   

13.
14.
James G. Hallett 《Oecologia》1991,88(3):383-393
Summary I examined questions about the local and global stability and resilience characteristics of six small mammal faunas and their relationship to connectance, average interaction strength, community covariance, and indirect competitive pathways. Community matrices estimated elsewhere were used in the analyses. The faunas had from three to nine species and represented several habitat types. The following properties were observed: (1) all community matrices were globally stable, (2) return rates to equilibrium were generally maximized, and (3) competitive interactions were strictly hierarchical. Global stability resulted from a reduction in connectance with increasing species and not from structural characteristics (i.e., community covariance). Average interaction strength did not change with the number of species in these faunas. Increased resilience was due largely to reduced community covariance. Two of the six faunas showed some evidence for indirect pathways, but this appeared to be artifactual. Randomizations of the original community matrices showed that indirect pathways have a high probability of occurrence. Monte Carlo simulations indicated that the probability of indirect pathways increases with increasing number of species or magnitude of competition. These results bring into question previous observational studies invoking indirect competitive pathways. Communities without indirect pathways have a special linear hierarchical structure. This structure has greater resilience than when indirect pathways are present. The observed patterns in community structure are discussed with regard to current theories of habitat selection.  相似文献   

15.
Metabolic rate is traditionally assumed to scale with body mass to the 3/4-power, but significant deviations from the '3/4-power law' have been observed for several different taxa of animals and plants, and for different physiological states. The recently proposed 'metabolic-level boundaries hypothesis' represents one of the attempts to explain this variation. It predicts that the power (log-log slope) of metabolic scaling relationships should vary between 2/3 and 1, in a systematic way with metabolic level. Here, this hypothesis is tested using data from birds and mammals. As predicted, in both of these independently evolved endothermic taxa, the scaling slope approaches 1 at the lowest and highest metabolic levels (as observed during torpor and strenuous exercise, respectively), whereas it is near 2/3 at intermediate resting and cold-induced metabolic levels. Remarkably, both taxa show similar, approximately U-shaped relationships between the scaling slope and the metabolic (activity) level. These predictable patterns strongly support the view that variation of the scaling slope is not merely noise obscuring the signal of a universal scaling law, but rather is the result of multiple physical constraints whose relative influence depends on the metabolic state of the organisms being analysed.  相似文献   

16.
Aim Conservation of species is an ongoing concern. Location Worldwide. Methods We examined historical extinction rates for birds and mammals and contrasted island and continental extinctions. Australia was included as an island because of its isolation. Results Only six continental birds and three continental mammals were recorded in standard databases as going extinct since 1500 compared to 123 bird species and 58 mammal species on islands. Of the extinctions, 95% were on islands. On a per unit area basis, the extinction rate on islands was 177 times higher for mammals and 187 times higher for birds than on continents. The continental mammal extinction rate was between 0.89 and 7.4 times the background rate, whereas the island mammal extinction rate was between 82 and 702 times background. The continental bird extinction rate was between 0.69 and 5.9 times the background rate, whereas for islands it was between 98 and 844 times the background rate. Undocumented prehistoric extinctions, particularly on islands, amplify these trends. Island extinction rates are much higher than continental rates largely because of introductions of alien predators (including man) and diseases. Main conclusions Our analysis suggests that conservation strategies for birds and mammals on continents should not be based on island extinction rates and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.  相似文献   

17.
The distribution of mammal body masses   总被引:1,自引:0,他引:1  
How the diversity of organisms relates to their body sizes has long been a question of interest to biologists, an interest that has grown as data have become available from an increasing number of taxa at ever larger spatial scales. Here, we examine the form of this relationship for a large proportion of the global placental mammal fauna. In common with other large-scale assemblages, the frequency distribution of mammal body masses is strongly right-skewed, even after logarithmic transformation. The modal body mass is slightly lower than predicted by a recent energetic fitness model, but the exact modal value depends on the taxonomic inclusivity of the analyses. Moreover, threatened species are larger bodied than expected by chance, suggesting that extinct species may also have been so. Therefore, the loss of large-bodied species from the global mammalian fauna could potentially have lowered the mode of the distribution. However, this loss must be balanced against evidence that most mammal species for which body mass data were not available for our analyses are small-bodied, which may in turn raise the apparent mode of the distribution. Clearly, tests of explanations for patterns in body size frequency distributions will be complicated by the fact that present-day distributions may be significantly biased by species that are missing from them.  相似文献   

18.
Little is known of the composition of the outer egg coats. We aimed to quantify secretion during embryonic development, identify precursor secreting cells and investigate protein composition. The study was based on 259 egg coats and 14 reproductive tracts of 104 T. vulpecula undergoing natural and induced cycles and 341 coats from 35 Sminthopsis macroura undergoing natural cycles. Following PAGE, Western blotting, and amino acid sequencing of egg coats, the short peptide sequences obtained from T. vulpecula and S. macroura coats were found to be dissimilar to each other and to any known protein. However, in T. vulpecula, S. macroura coat polyclonal antibody cross-reacted with coat precursors, suggesting similar epitopes, and showed mucoid precursors in secretory cells in oviduct epithelia and shell precursors in glands in the utero-tubal junction and uterus. Immuno-electron microscopy located shell coat precursors in various previously unidentified cell types, including pre-ovulatory apoptotic cells, early post-ovulatory holocrine cells, and milk-producing cells, found at blastocyst stages. Ultrastructural and quantitative volumetric analysis of the intact shell coat suggested a second wave of secretion at the blastocyst stages in T. vulpecula. Despite differences in protein composition, it was concluded that marsupial egg coats are homologous to each other because of similarities in ultrastructure and time and location of secretion.  相似文献   

19.
误捕及其对海兽种群的影响   总被引:5,自引:1,他引:4  
几乎在全世界都有误捕海兽的记录.有误捕记录的海兽有鲸目14科62种,鳍脚目3科12种,海牛目2科2种及食肉目1科1种.误捕海兽的渔具包括刺网、拖网、围网、张网、插网和陷阱等.误捕可导致种群数量的下降及生活史特征的改变.我国需要开展这方面的研究工作.  相似文献   

20.
Species richness and diversity of rodents and insectivores were investigated at relict forest patches of Mukogodo, Laikipia, Kenya using Sherman's live traps and pitfall traps. Two hundred and nineteen individuals were captured in 3021 trap‐nights. There were eleven species in two taxonomic groups, Rodentia and Insectivora. Two other rodent species were sighted but not captured. Thirteen bats belonging to four species (Epomophorous wahlbergi, Pipistrellus kuhlii, Scotophilus dingani and Nycteris thebaica) were opportunistically trapped using mist nets. Two of the four species accumulation curves for forest patches did not reach an asymptote. Species richness and diversity were highest at Kurikuri compared with other patches because of habitat variability. The results support the prediction that forest disturbance and degradation lead to an increase in generalist species as compared with specialists and highlight the importance of relict afromontane forests in the conservation of small mammals in Kenya.  相似文献   

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