首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
During the winter of 2003–2004 feces were collected from a winter colony of the long-fingered bat (Myotis capaccinii) in the Hazorea cave (north-west Israel). Of the 1913 feces that were examined, 234 contained scales of Gambusia affinis – a small fish that had been introduced to Israel around 1920 in order to control mosquito larvae. The remains of spiders and five insect orders were also represented in the feces. This is the first report of a piscivorous bat in the Middle East and the first finding of fish remains in the feces of M. capaccinii. The findings show that in the north of Israel this species does not hibernate but remains active throughout the winter. It appears that the consumption of G. affinis reflects a change in the diet of these bats from insectivory to semi-piscivory.  相似文献   

2.
Plecotus auritus, a small, gleaning bat species, lives in small, isolated summer colonies in which both males and females show a high degree of natal philopatry. Despite this, colonies have high gene diversities and low inbreeding coefficients. It has been suggested that inbreeding is avoided because mating occurs during autumnal and spring swarming at hibernation sites. We tested this hypothesis by comparing microsatellite profiles, based on eight loci, of bats from six summer colonies and two swarming sites they were known to visit from radiotelemetry studies. We found high gene diversities (H s = 0.77) at both swarming sites and summer colonies which were not statistically different. There was no detectable isolation by distance and FST was low (0.001). Together, these results suggest high gene flow between sites. Despite this, there was small but significant genetic differentiation amongst summer colonies and between summer colonies and the primary swarming site. We suggest that swarming is important for gene flow and for maintaining genetic diversity in this highly philopatric species and discuss possible reasons for the genetic differentiation observed. The identification and protection of swarming sites should be a major conservation priority for this and other temperate bat species.  相似文献   

3.
The outflying and homeflying activity pattern of a colony of the Indian pygmy bat Pipistrellus mimus occupying a tunnel was studied under natural conditions. Before leaving the tunnel for foraging, the bats made circling flights outside to sample the environmental light conditions. The onset and end of activity was related to the times of sunset and sunrise respectively. The onset of flight during evening commenced after sunset from mid-September to mid-April, before sunset during the rest of the year. Onset of activity occurred at higher light intensities compared to light intensities prevailing during the return flight to the roost in the morning. The duration of activity time showed a curvilinear relationship with the duration of the night. The phase relationship between onset and end of activity, and sunset and sunrise, showed marked seasonal variations in the values of Ψonset, Ψend, and Ψmidpoint. However, such changes in the phase angle properties did not obey Aschoff's seasonal rule. Based upon the data obtained on the onset and end of activity patterns for five species of bats, including the data from this study, we report that P. mimus is the earliest to set out for foraging in the evening and among the last to return home in the morning. This might be due to dusk and dawn peaks in activity of the prey insects.  相似文献   

4.
We studied the short-term impact of sediment load on the photosynthetic performance of Saccharina latissima sporophytes exposed to ultraviolet radiation (UVR). The algae were collected from different sediment-influenced environments in Svalbard in August 2007. Initial optimum quantum yield (F v/F m) of sediment-covered sporophytes was significantly higher compared to sediment-free sporophytes. Experimental sediment coating on blade discs had a photoprotective function by screening out 92% of the weighted UV-B (UVery) treatment. No UVR-induced photoinhibition was observed in sediment-coated blade discs while sediment removal caused a reduction in F v/F m not only after 12-h UVR exposure but also after 6-h recovery in low white light compared to the initial value. Thus, sediment coating has a short-term functional significance in mitigating the negative effect of UVR on photosynthesis of an important kelp species and set a baseline for further studies. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

5.
Seedlings of spring barley, meadow fescue, and winter rape were fumigated with 180 μg kg−1 of ozone for 12 d, and effect of O3 on photosynthesis and cell membrane permeability of fumigated plants was determined. Electrolyte leakage and chlorophyll fluorescence were measured after 6, 9, and 12 d of fumigation, while net photosynthetic rate (P N) and stomatal conductance (g s) were measured 9 d after the start of ozone exposure. O3 treatment did not change membrane permeability in fescue and barley leaves, while in rape a significant decrease in ion leakage was noted within the whole experiment. O3 did not change the photochemical efficiency of photosystem 2 (PS2), i.e., Fv/Fm, and the initial fluorescence (F0). The values of half-rise time (t1/2) from F0 to maximal fluorescence (Fm) decreased in fescue and barley after 6 and 9 d of fumigation. P N decreased significantly in ozonated plants, in the three species. The greatest decrease in P N was observed in ozonated barley plants (17 % of the control). The ozone-induced decrease in P N was due to the closure of stomata. Rape was more resistant to ozone than fescue or barley. Apparently, the rape plants show a large adaptation to ozone and prevent loss of membrane integrity leading to ion leakage. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

6.
Ferrell DL 《Oecologia》2005,142(2):184-190
Clear boundaries often separate adjacent conspecific competitors. These boundaries may reflect bordering animal territories or regions of inter-organism contact in mobile and non-mobile organisms, respectively. Sessile, clonal organisms often form persistent inter-clonal boundaries despite great variation in competitive ability among genotypes within a population. I show that neighboring clones in the sea anemone Anthopleura elegantissima and three species of the marine hydroid genus Hydractinia are more evenly matched in terms of competitive ability than expected by chance. Hypotheses of genetic relatedness or similar environmental regime shared by neighboring clones are inconsistent with the observed similarities between adjacent competitors in one or both taxa. Instead, inter-clonal borders evidently persist as standoffs between evenly matched competitors. Large differences in competitive ability between bordering clones were rarely observed, suggesting that dominant clones quickly displace or eliminate others in competitive mismatches. This ecological parallel between taxa (i.e., competitive equivalence) exists despite several fundamental differences (e.g., geographical distribution, habitat, body size, longevity), suggesting that competitive equivalence may be a widespread determinant of boundary persistence between adjacent competitors.  相似文献   

7.
Redondo RA  Santos FR 《Genetica》2006,126(1-2):199-213
Comparative studies of salivary glands showed that they maybe related to the adaptive radiation of bats, especially in the family Phylostomidae. In this study we have been searching for a likely relationship between different feeding habits found in bats and possible adaptive changes in a coding segment of the α-amylase enzyme. We have also tested some hypothesis about the phylogenetic relationship of bats and other mammals. A 663 bp segment of the α-amylase gene, corresponding to the exon 4 and part of the intron c, was sequenced in nine bat species. The exon 4 was also sequenced in further ten mammalian species. The phylogenetic trees generated with different methods produced the same results. When the intron c and the exon 4 were independently analyzed, they showed distinct topologies involving the bat species Sturnira lilium, different from the traditional bat phylogeny. Phylogenetic analysis of bats, primates and rodents supports the Euarchontoglires-Laurasiatheria hypothesis about the relationship among these groups. Selection tests showed that the α-amylase exon 4 is under strong purifying selection, probably caused by functional constraints. The conflicting bat phylogenies could not be explained by evolutionary convergence due to adaptive forces, and the different topologies may be likely due to the retention of plesiomorphic characters or the independent acquisition by evolutionary parallelism.  相似文献   

8.
9.
Studying the diet of echolocating, insectivorous bats can provide important insights into their foraging behaviors and ecological constraints they are facing. By examining an extensive data set covering a period of 2 years, the present study identifies the dietary composition of three sympatric insectivorous bat species in rural areas of Beijing municipality. Each species clearly has different preferences for particular food items. Greater horseshoe bats, Rhinolophus ferrumequinum, preferred to catch nocturnal, actively flying insects, mostly moths (Lepidoptera), and to a lesser percentage flies (Diptera), beetles (Coleoptera), and flying ants and termites (Hymenoptera). Other nocturnal insects which do not exhibit any perceptible wing movements, such as true bugs (Homoptera), or strictly diurnal insects that hardly ever fly in the dark, such as grasshoppers (Orthoptera) and dragon- and damselflies (Odonata), were never found in droppings of horseshoe bats. Large mouse-eared bats, Myotis chinensis, preferentially glean relatively large terrestrial prey of the order Coleoptera (mostly carabid beetles) and Orthoptera, whereas greater tube-nosed bats, Murina leucogaster, consume predominantly smaller, diurnal Coleoptera (mostly soldier beetles, Cantharidae, and ladybugs, Coccinellidae). Our findings also indicate previously not described, significant spectro-temporal differences in the echolocation signals of M. chinensis and M. leucogaster. The results suggest that in our study area the dramatic differences in the dietary composition of these three bat species are mainly based upon differences in their foraging behaviors, including differences in their echolocation signal structure. The dietary data provide important background information for conservational efforts, such as habitat protection.  相似文献   

10.
【背景】壳聚糖是广泛存在于甲壳动物的一种多糖,具有广谱的抗真菌活性,但壳聚糖是否影响炭黑曲霉(Aspergillus carbonarius)和硫色镰刀菌(Fusarium sulphureum)生长和发育尚未见报道。【目的】明确不同浓度壳聚糖对A. carbonariusF. sulphureum生长和发育的影响。【方法】通过在PDA培养基中添加不同浓度壳聚糖,测定两种真菌的菌落直径、生物量和菌丝干重,观察产孢量、孢子萌发和芽管长度,比较抑菌的差异。【结果】壳聚糖处理可显著改变两种真菌的菌落形态,处理浓度越高菌落皱缩和变形越明显;壳聚糖还可以有效抑制两种真菌的菌落生长、菌丝干重和菌丝生物量,抑制效果呈明显的浓度依赖,对F. sulphureum的抑制效果更好。壳聚糖可抑制两种真菌的产孢量、孢子萌发和芽管伸长,处理浓度越高抑制效果越好,对F. sulphureum的抑制效果更为明显。壳聚糖对A. carbonariusF. sulphureumEC50值分别为0.12 mg/mL和0.075 mg/mL。【结论】壳聚糖可有效抑制A. carbonariusF. sulphureum的生长发育,抑制效果呈浓度依赖,F. sulphureum对壳聚糖更为敏感。  相似文献   

11.
We report bat visits to the inflorescences of Marcgravia pittieri. The animals were videotaped visiting the nectaries of the inflorescences in short hovering flight. Nectarivorous bats caught in front of the inflorescences were Anoura cultrata and Hylonycteris underwoodi (both Phyllostomidae: Glossophaginae). Furthermore, we provide a short overview on inflorescence architecture within the genus Marcgravia with a special focus on functional morphology in chiropterophilous species.  相似文献   

12.
The rapid decline of Acropora cervicornis and Acropora palmata has often been linked with coral reef deterioration in the Caribbean; yet, it remains controversial whether these species are currently recovering or still declining. In this study, the status of ten populations of A. palmata in Los Roques National Park (LRNP), Venezuela is presented. Six of these populations showed signs of recovery. Ten 80 m2 belt-transects were surveyed at each of the ten reef sites. Within belt-transects, each colony was measured (maximum diameter and height) and its status (healthy, diseased or injured) was recorded. Populations in recovery were defined by a dominance of small to medium-sized colonies in densities >1 colony per 10 m2, together with 75% undamaged colonies, a low prevalence of diseases (<10%), and a low density of predators (0.25 snails per colony). Based on allozyme analysis of seven polymorphic loci in four populations (N = 30), a moderate to high-genetic connectivity among these populations (F ST = 0.048) was found with a predominance of sexual over asexual reproduction (N* : N = 1; N go : N = 0.93–1). Both ecological and molecular data support a good prognosis for the recovery of this species in Los Roques.  相似文献   

13.
Rogas lymantriae Watanabe was reared onLymantria dispar (L.) for 125 generations in the laboratory following importation from Japan. No deleterious effects of colonization were observed and one measured parameter, successful parasite emergence, significantly improved over time. Decreased density of the host or conspecific female parasites resulted in higher levels of parasitism and numbers of females in the next generation. During 3 different years, colony production was significantly increased with little difficulty to provide parasites for inoculative releases in the field.   相似文献   

14.
In Cyprus, there are 16 species of bats most of which are threatened with extinction. With the exception of the megachiropteran Egyptian Fruit bat Rousettus aegyptiacus that feeds on fruit, the rest of them are insectivorous microchiropterans. The Fruit bat was declared as a pest by the Department of Agriculture of the Ministry of Agriculture, Natural Resources and Environment of Cyprus since the early 1900s. To reduce the number of this “pest”, the above-mentioned Department, since 1927, used fumigation, shooting, and the purchase of dead bats. Fumigating and closing caves not only destroyed Fruit bats by direct poisoning, but the entire cave ecosystems, including highly beneficial and protected insectivorous species. The first attempt to protect bats on the island was in 1988 with law No. 24 of 1988, ratifying the Convention on the Conservation of European Wildlife and Natural Habitats, 82/72/EEC. This convention protects all microchiroptera species except Pipistrellus pipistrellus that is strictly protected. R. aegyptiacus is rare, with small populations that are not at present endangered or vulnerable but at risk. Cyprus recently became a member state of the European Union. This provided the opportunity to include R. aegyptiacus in the Annexes II and IV of the council directive 92/42/EEC of May 21, 1993 on the conservation of natural habitats and of wild fauna and flora, which will guarantee the long-range protection and survival of this species.  相似文献   

15.
Summary Dietary overlap and competition between frugivorous birds and bats in the Neotropics have been presumed to be low, but comparative data have been lacking. We determined the diets of volant frugivores in an early successional patch of Costa Rican wet forest over a one month period. Ordination of the diet matrix by Reciprocal Averaging revealed that birds and bats tend to feed on different sets of fruits and that diets differed more among bat species than among bird species. However, there was overlap between Scarlet-rumped Tanagers and three Carollia bat species on fruits of several Piper species which comprised most of the diet of these bats. Day/night exclosure experiments on P. friedrichsthalli treetlets provided evidence that birds deplete the amount of ripe fruit available to bats. These results indicate that distantly related taxa may overlap in diet and compete for fruit, despite the apparent adaptation of animal-dispersed plant species for dispersal by particular animal taxa.  相似文献   

16.
We investigated the population genetics of seven maternity roosts of Bechstein’s bats widely distributed across the south of England. Across all of the populations sampled, two mitochondrial DNA microsatellite loci were fixed for single haplotypes. Genetic diversity across eight nuclear microsatellite loci was similar in all seven populations, with a mean He of 0.727. However, six of the populations showed substantial homozygote excess, with F IS estimates greater than zero, indicative of recent inbreeding. Bottleneck tests also implied that six of the populations have experienced recent declines. Genetic differentiation among the populations was low, with a mean intersite F ST estimate of 0.041. There was no significant isolation by distance using allele frequency-based criteria (F ST and genetic distances), however, a weak correlation was found using the allele size-based R ST criterion. Assignment tests were unable to distinguish the seven sampling sites as distinct clusters. Mean intra-roost relatedness (r) was 0.079, indicative of recent inbreeding relative to German populations. All but one of the bats had one or more half or full siblings in its maternity roost. In addition, family relationships of individuals within a colony were significantly commoner than family relationships among four proximal roosts <8 km apart. The results are discussed in the context of conservation requirements for this rare British bat.  相似文献   

17.
Laboratory bioassays of overwintering field populations of the California red scale parasitoidAphytis melinus DeBach showed a shift in sex ratio of F1 progeny after prolonged exposure to winter temperatures in Tulare County, California. In 7 of 8 tests, short-term winter field exposure (<75 days) did not result in a significant male bias in sex ratios of F1 progeny when compared to sex ratios observed in laboratory cultures maintained at 27°C. Long term exposure (109–139 days), however, resulted in significantly (P<0.05) higher male bias in F1 sex ratios in 5 of 6 tests. These results from field populations ofA. melinus agree with conclusions of low temperature laboratory tests onAphytis species (lingnanensis, melinus) by other workers. Mention of a proprietary or commercial product in this paper does not constitute an endorsement of this product by the University of California.  相似文献   

18.
Bat populations continue to decline worldwide because of myriad human activities. To enhance bat conservation, human behavior needs to change. Such change can occur, in part, through an understanding of what motivates human actions toward bats. We used a Bat Attitude Questionnaire (BAQ) to investigate attitudes toward bats in people (n = 394) living around Arabuko-Sokoke Forest (ASF), Kenya. Belief in myths seemed to prevail among those surveyed and that these myths were significantly associated with low tolerance of bats (ordinal regression, p < 0.05). Older and more educated people reported more positive attitudes toward bats than others. Multiple linear regression revealed that females showed more negative attitudes toward, and more belief in, myths about bats than males (both p < 0.01). Ordinal regression showed that hostile behavior toward bats was more common among males (p < 0.001). Nearly one-third of the respondents reported actively killing bats or destroying bat roosts. A similar proportion did not see any benefits of bats to humans, while the majority of respondents associated bats with the destruction of farmers’ fruits. To address prevailing negative attitudes about bats, we recommend conducting evening school-based bat study tours, specifically targeting youths in schools around the forest, to examine whether physical contacts with bats would help positively influence human attitudes toward bats. Additionally, since mango (Mangifera indica) farming is an important source of income to people around ASF, an assessment of the quantity of mangoes destroyed by bats would be important to determine whether there is a need for controlling bat access to crops through appropriate schemes.  相似文献   

19.
Summary A colchicine-doubled F1 hybrid (2n=118) of a cross between PI 360841 (Glycine max) (2n=40) x PI 378708 (G. tomentella) (2n=78), propagated by shoot cuttings since January 1984, produced approximately 100 F2 seed during October 1988. One-fourth of the F2 plants or their F3 progeny have been analyzed for chromosome number, pollen viability, pubescence tip morphology, seed coat color, and isoenzyme variation. Without exception, all plants evaluated possessed the chromosome number of the G. max parent (2n=40). Most F2 plants demonstrated a high level of fertility, although 2 of 24 plants had low pollen viability and had large numbers of fleshy pods. One F2 plant possessed sharp pubescence tip morphology, whereas all others were blunt-tipped. All evaluated F2 and F3 plants expressed the malate dehydrogenase and diaphorase isoenzyme patterns of the G. max parent and the endopeptidase isoenzyme pattern of the G. tomentella parent. Mobility variants were observed among progeny for the isoenzymes phosphoglucomutase, aconitase, and phosphoglucoisomerase. This study suggests that the G. Tomentella chromosome complement has been eliminated after genetic exchange and/or modification has taken place between the genomes.Journal Paper No. J-13776 of the Iowa Agriculture and Home Economics Experiment Station, Ames, IA, USA, Project 2763  相似文献   

20.
Krieger  Kenneth J.  Wing  Bruce L. 《Hydrobiologia》2002,489(1-3):83-90
Our study showed that one species of water strider (Aquarius najas) dominated the insect fauna (>90% of the biomass) on and near the surface of a small stream in southern Sweden, but the diet of Daubenton's bats (Myotis daubentonii), regularly feeding over the same stream, contained <1% of these insects. To explain why the bats did not eat water striders in proportion to the apparent abundance of these insects, we tested three hypotheses, with the following results: (1) The water striders did not respond to artificial bat calls and therefore their defence against bats is not based on ultrasonic hearing. (2) Water striders hand-fed to the bats were eaten with similar frequency as palatable controls (caddis flies), so there is no evidence that water striders are unpalatable to bats. (3) Attempted prey-captures by the bats occurred less often than expected within 1 m of the bank of the stream (the bank consisted of a stone wall), indicating that the bats' flight or, alternatively, their detection or capture of insects, was difficult within that area, possibly constrained by clutter. At dusk and just before the bats emerged to feed, the water striders moved away from the open water. They remained motionless close to the bank for as long as the bats were active.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号