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1.
? Premise of the study: Highly portable microsatellite primers were developed for Ficus to facilitate investigation of genetic structure of complete regional floras using a single set of markers. ? Methods and Results: Pyrosequencing of five species of Ficus produced a library of 5723 potential primers. Potential primers found in at least two species and presenting identical annealing temperatures were tested on a set of five additional Ficus species. A set of 20 primer pairs producing well-defined and easily readable peaks was retained and tests showed their potential utility for analyzing population genetic structure of 24 Ficus species from Taiwan. Numbers of alleles per locus ranged from one to six in the least variable species and from one to 17 in the most variable species. ? Conclusions: The results indicate that our set of primers can be used to analyze polymorphism and compare levels of polymorphism among Ficus species.  相似文献   

2.
Figs (Ficus, Moraceae) are either monoecious or gynodioecious depending on the arrangement of unisexual florets within the specialized inflorescence or syconium. The gynodioecious species are functionally dioecious due to the impact of pollinating fig wasps (Hymenoptera: Agaonidae) on the maturation of fig seeds. The evolutionary relationships of functionally dioecious figs (Ficus subg. Ficus) were examined through phylogenetic analyses based on the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and morphology. Forty-six species representing each monoecious subgenus and each section of functionally dioecious subg. Ficus were included in parsimony analyses based on 180 molecular characters and 61 morphological characters that were potentially informative. Separate and combined analyses of molecular and morphological data sets suggested that functionally dioecious figs are not monophyletic and that monoecious subg. Sycomorus is derived within a dioecious clade. The combined analysis indicated one or two origins of functional dioecy in the genus and at least two reversals to monoecy within a functionally dioecious lineage. The exclusion of breeding system and related characters from the analysis also indicated two shifts from monoecy to functional dioecy and two reversals. The associations of pollinating fig wasps were congruent with host fig phylogeny and further supported a revised classification of Ficus.  相似文献   

3.
The majority of species in the mulberry family (Moraceae) are figs (Ficus), marked by a specialized inflorescence (syconium) and an obligate mutualism with pollinating fig wasps. Because of the unique morphology of the syconium, it has been difficult to investigate the evolutionary position of the fig. We sequenced the chloroplast gene ndhF to examine relationships in Moraceae and to elucidate shifts in reproductive traits. The reclassification of tribes is warranted, and the limits of Artocarpeae, Moreae, and Castilleae are revised to reflect evolutionary relationships. The results point to ancestral dioecy in Moraceae and multiple origins of monoecy, androdioecy, and gynodioecy. Ancestral wind pollination gave way to insect pollination at least twice. Strong support for the sister-group relationship of a revised Castilleae with Ficus suggests that entomophily and involucral bracts encircling the flowers preceded the evolution of the syconium. Bracts surround flowers in Castilleae only during early development, but in Ficus the involucre and the receptacle enclose the fruit as well. Molecular dating suggests that fig pollination is at least 80-90 million years old. The diversity of Ficus relative to its sister group is a likely consequence of ancient specialization and cospeciation with pollinating fig wasps.  相似文献   

4.
Parasitoid diversity in terrestrial ecosystems is enormous. However, ecological processes underpinning their evolutionary diversification in association with other trophic groups are still unclear. Specialisation and interdependencies among chalcid wasps that reproduce on Ficus presents an opportunity to investigate the ecology of a multi-trophic system that includes parasitoids. Here we estimate the host-plant species specificity of a parasitoid fig wasp genus that attacks the galls of non-pollinating pteromalid and pollinating agaonid fig wasps. We discuss the interactions between parasitoids and the Ficus species present in a forest patch of Uganda in context with populations in Southern Africa. Haplotype networks are inferred to examine intraspecific mitochondrial DNA divergences and phylogenetic approaches used to infer putative species relationships. Taxonomic appraisal and putative species delimitation by molecular and morphological techniques are compared. Results demonstrate that a parasitoid fig wasp population is able to reproduce on at least four Ficus species present in a patch. This suggests that parasitoid fig wasps have relatively broad host-Ficus species ranges compared to fig wasps that oviposit internally. Parasitoid fig wasps did not recruit on all available host plants present in the forest census area and suggests an important ecological consequence in mitigating fitness trade-offs between pollinator and Ficus reproduction. The extent to which parasitoid fig wasps exert influence on the pollination mutualism must consider the fitness consequences imposed by the ability to interact with phenotypes of multiple Ficus and fig wasps species, but not equally across space and time.  相似文献   

5.
In the present study, effects of d-amphetamine on sensitivity to reinforcement amount under concurrent schedules were examined using a rapid-acquisition procedure. Four pigeons key pecked under single concurrent variable-interval 30-s schedules of grain presentation. Two different reinforcer-amount ratios (7:1 and 1:7) changed across sessions according to a 31-step pseudo-random binary sequence (PRBS). After at least four times through the PRBS, response ratios generally tracked the session-to-session changes in amount ratios; estimates of sensitivity ranged from 0.26 to 0.31 across the four pigeons. Effects of a range of doses of d-amphetamine (0.3-5.6 mg/kg) then were determined. For 3 of 4 pigeons, at least one dose, which did not dramatically alter overall response output or bias, decreased sensitivity to reinforcement amount. These results suggest that reducing sensitivity of responding to reinforcement amount may be one behavioral mechanism of stimulants, which may have implications for interpreting drug effects on self-control.  相似文献   

6.
Summary 16 releases, centrally symmetrical by pairs and involving distances of displacement from 25 to 172 km, were conducted with homing pigeons pre-treated in different ways: FIL birds were, until few minutes before release, confined to containers ventilated with ambient air that had passed through filters consisting of activated charcoal. NOFIL birds were confined to containers ventilated with unfiltered air, either from departure at the loft onwards (4 experiments) or for at least 4 h at the release site (after transport under FIL conditions; 12 experiments). The olfactory epithelia of XYL birds were locally anaesthetized a few minutes before release, while NOXYL birds were not treated with xylocain. FIL/NOFIL conditions were combined with XYL/NOXYL conditions, resulting in 4 types of experimental treatment.On average, the untreated pigeons (NOFILNOXYL) were best homeward oriented and the double-treated pigeons (FIL-XYL) poorest. More importantly, the effect of olfactory deprivation during initial flight alone (NOFIL-XYL) was small, whereas long-term filtration of environmental air was quite effective even if the pigeons could smell during release time (FIL-NOXYL) (Fig. 5).These findings indicate that pigeons usually need to be exposed to local odorous air for more than only few minutes in order to utilize information extricated from this air for site localization.Additional experiments showed that homeward orientation is also prevented, if the pigeons, although breathing natural air, are ventilated with restricted volumes of fresh air.Our results are discussed with regard to the homing mechanism of pigeons as well as to their methodological consequences.Abbreviations FIL breathing air filtered by charcoal - NOFIL breathing air unfiltered - XYL xylocain applied to pigeons' nostrils - NOXYL no xylocain applied (see p. 140)  相似文献   

7.
Feral pigeons (Columba livia, Gmelin 1789) cause different problems for building owners when using structures for daytime perching, sleeping, and breeding. Problems include fouling of building facades and pavements, transmission of allergens and pathogenic microorganisms, and infestations with ectoparasites emanating from breeding sites. Owners are primarily interested in keeping away unwanted pigeons from their property. Pest control companies offer different deterrent systems, of widely varying efficacy, for proofing buildings against feral pigeons. A better solution is avoiding attractive structures during building design or subsequent alterations of existing structures used by feral pigeons. With our study, we elaborate the relevant structural data to help to maintain a building free of pigeons. We performed experiments with free ranging feral pigeons in a feral pigeon loft in the City of Basel, Switzerland. The maximum outlet width a pigeon is not able to pass through is 4 cm; the respective outlet height is 5 cm and a pigeon-safe square opening is not larger than 6 × 6 cm. The maximum ledge width a pigeon is not able to sit on is 4 cm. The pigeon-safe angle of inclination for smooth construction materials (tinplate, glass, plastics) is 25°, for medium rough materials (wood, plane concrete) 35°, and for rough materials (sandstone, rough concrete) at least 50°. Additionally, we studied the behavioral strategies used by feral pigeons to surmount our experimental constructional restrictions, ledge width, and ledge inclinations. Our data provide the essential data to prevent feral pigeons from using building structures.  相似文献   

8.
比较了昆虫取食与人工损伤对五种生活型相同但来自不同演替阶段的榕树挥发物释放的影响。在叶片无损伤情况下,先锋种对叶榕(Ficushispida)释放挥发物最多,顶级种高榕(F.altissima)释放最少,中间种木瓜榕(F.auriculata)、苹果榕(F.oligodon)和聚果榕(F.racemosa)居中。人工损伤处理后五种植物挥发物的释放均显著增加,挥发物释放量的大小顺序和无损伤情况下相一致。一点拟灯蛾幼虫取食后,先锋树种对叶榕的挥发物的释放被明显抑制,木瓜榕和苹果榕挥发物释放量释放显著增加,并同时释放一种广谱杀虫物质——桉油精。一点拟灯蛾幼虫不取食高榕叶片因而没有高榕被昆虫取食挥发物释放量释放数据。本研究表明来自不同演替阶段的榕树对昆虫取食与人工损伤对挥发物释放的影响确存在明显的差异。  相似文献   

9.
Red-tailed monkeys (Cercopithecus ascanius) were observed hunting green pigeons (Treron calva) in the Kalinzu Forest in Uganda. During 2 h 39 min, I observed two cases of successful hunting and one case of unsuccessful hunting in a Ficus saussureana tree. Red-tailed monkeys stalked the pigeons until they were within 2–3 m, and then jumped and caught them. In both successful cases, blue monkeys (C. mitis) ran to the hunting site from adjacent trees in order to poach the prey, and the red-tailed monkeys fled. One of these red-tailed monkeys dropped the pigeon while fleeing, and the blue monkey climbed down from the tree to search for it. This is the first record of cercopithecoid monkeys hunting birds that are outside of the nest and moving freely, and also the first record of red-tailed monkeys hunting vertebrates. However rare it may be, the repeated hunting attempts using similar techniques and the immediate attempt of blue monkeys to poach the prey suggest that this type of hunting was not a one-time event that happened by chance. Blue monkeys and an adult chimpanzee (Pan troglodytes schweinfurthii) in and around the fig tree did not attempt to hunt. The hunting of volant birds may be enabled by the small body size and the quick movements of red-tailed monkeys.  相似文献   

10.
Fig-eating by vertebrate frugivores: a global review   总被引:10,自引:0,他引:10  
The consumption of figs (the fruit of Ficus spp.: Moraceae) by vertebrates is reviewed using data from the literature, unpublished accounts and new field data from Borneo and Hong Kong. Records of frugivory from over 75 countries are presented for 260 Ficus species (approximately 30% of described species). Explanations are presented for geographical and taxonomic gaps in the otherwise extensive literature. In addition to a small number of reptiles and fishes, 1274 bird and mammal species in 523 genera and 92 families are known to eat figs. In terms of the number of species and genera of fig-eaters and the number of fig species eaten we identify the avian families interacting most with Ficus to be Columbidae, Psittacidae, Pycnonotidae, Bucerotidae, Sturnidae and Lybiidae. Among mammals, the major fig-eating families are Pteropodidae, Cercopithecidae, Sciuridae, Phyllostomidae and Cebidae. We assess the role these and other frugivores play in Ficus seed dispersal and identify fig-specialists. In most, but not all, cases fig specialists provide effective seed dispersal services to the Ficus species on which they feed. The diversity of fig-eaters is explained with respect to fig design and nutrient content, phenology of fig ripening and the diversity of fig presentation. Whilst at a gross level there exists considerable overlap between birds, arboreal mammals and fruit bats with regard to the fig species they consume, closer analysis, based on evidence from across the tropics, suggests that discrete guilds of Ficus species differentially attract subsets of sympatric frugivore communities. This dispersal guild structure is determined by interspecific differences in fig design and presentation. Throughout our examination of the fig-frugivore interaction we consider phylogenetic factors and make comparisons between large-scale biogeographical regions. Our dataset supports previous claims that Ficus is the most important plant genus for tropical frugivores. We explore the concept of figs as keystone resources and suggest criteria for future investigations of their dietary importance. Finally, fully referenced lists of frugivores recorded at each Ficus species and of Ficus species in the diet of each frugivore are presented as online appendices. In situations where ecological information is incomplete or its retrieval is impractical, this valuable resource will assist conservationists in evaluating the role of figs or their frugivores in tropical forest sites.  相似文献   

11.
W Koek  J H Woods  P Ornstein 《Life sciences》1986,39(11):973-978
A selective N-methyl-D-aspartate antagonist, DL-2-amino-5-phosphonovalerate, was found to produce PCP-like catalepsy, discriminative stimulus effects, and stereotyped operant responding in pigeons when administered intramuscularly. These results support the hypothesis that the behavioral effects of PCP-like drugs result at least in part from reduced neurotransmission at excitatory amino acid synapses utilizing N-methyl-D-aspartate preferring receptors.  相似文献   

12.
The importance of visual landmarks during homing in pigeons (Columba livia) remains a contentious issue. Three experiments which explore the role of visual landmarks at release sites are reported here. The effects of releasing homing pigeons after a 5-minute period in either a clear or an opaque sided release box were investigated. In the clear sided box pigeons were able to observe local surroundings at a release site, but this view was obstructed in the opaque sided box. In experiment 1 pigeons were released from familiar locations close to home (between 2 and 5.6 km): being unable to view landmarks prior to release significantly slowed homing speeds. In experiment 2 pigeons were released at familiar locations further from home (between 8.4 and 10 km): being unable to view landmarks prior to release did not significantly affect homing speeds. In experiment 3 pigeons were trained to home from distant release sites but were tested at closer, unfamiliar sites located on the likely homing routes used by the pigeons in training. No significant difference in homing speeds were observed when pigeons were released from either the clear or opaque sided box. The significance of these results for understanding the role of visual landmarks within a pigeon's familiar area is discussed.  相似文献   

13.
The species richness, taxonomic diversity, and geographic distribution of pigeons and doves (Columbidae) have been altered irreversibly in Polynesia by 3500 years of human activity. Natural (without human influence) columbid faunas are estimated primarily by studying prehistoric bones. In all Polynesian island groups studied (except outlying Easter Island, Hawaiian Islands, or New Zealand), the prehistoric columbid faunas had more species, more genera, and more species per genus than modern faunas from the same island. Congeneric species pairs or triplets occurred on many islands for Ducula , Ptilinopus , and Gallicolumba. The losses of Polynesian columbids include the extinction of at least 9 species in the genera Ducula , Ptilinopus , Macropygia , Caloenas , Gallicolumba , and Didunculus as well as the extirpation of numerous island populations of extant species. If not for human impact, a typical East Polynesian island would support at least 5–6 species of columbids in 3–4 genera (compared to 0–3 species in 0–3 genera today). A typical West Polynesian island would support at least 6–7 species in 4–5 genera (compared to 1–6 species in 1–5 genera today). Since all Polynesian pigeons and doves are frugivorous and/or granivorous, their decline in recent millennia probably has affected the composition of Polynesian forests by limiting inter- and intra-island dispersal of plant propagules.  相似文献   

14.
The potential role of rock pigeons (Columba livia) in the epidemiology of shiga toxin-producing Escherichia coli (STEC) and Salmonella enterica is unclear. Our objective was to determine the prevalence of STEC and S. enterica in pigeons at urban and dairy settings as a function of season. Prevalence of STEC and S. enterica was estimated by bacteriologic culture of cloacal swabs collected from pigeons trapped at urban and dairy locations in and around Fort Collins, Colorado from January to November 2003. Presumptive E. coli isolates were tested for the presence of virulence genes SLT-1, SLT-2, eae, hlyA, K1, CNF-1, CNF-2, and LT using polymerase chain reaction. Shiga toxins were not isolated from any of 406 samples from pigeons, but virulence genes typically associated with disease in humans were identified in isolates from 7.9% (95% CI: 5.5% to 10.9%) of captured pigeons. S. enterica were detected in 3.2% of 277 samples from pigeons, with all positive samples originating from dairy locations (nine of 106 [8.5%]; 95% CI: 4.0-15.5%). The results suggest that although pigeons may acquire S. enterica from cattle and play a role in recirculation and persistence of the microorganism at dairies, pigeons are not important carriers of STEC.  相似文献   

15.
Attempts are made to meet discrepancies between the botanical classification of Ficus and the zoological classification of its pollinators. They are discussed as Ficus elastica , subgen. Pharmacosycea , subsect. Palaeomorphe , dioecism in Ficus , the Ceratosolen complex, and sect. Conosycea. It seems from the botanical side that the evolution of Ficus into subgenera and sections preceded that of its insects into genera. On the whole there are no grounds for reclassification of Ficua , but leaf structure indicates that some rearrangement of the species of subgen. Urostigma sect. Conosycea may be needed to fit the entomology. Ficus asperiuscula poses a problem in sect. Sycidium.  相似文献   

16.
Tumors induced in pigeons by inoculation with the Schmidt-Ruppin strain of Rous sarcoma virus regressed after about 6 weeks. Sera from these pigeons, taken 8 weeks after inoculation, had complement-fixing group-specific antibody titers of 1:2 to 1:256. In immunoelectrophoresis with the pigeon serum, disrupted BAI strain A (myeloblastosis) avian tumor virus showed at least five precipitin arcs. The pattern of precipitin lines was dependent in part on the means used for virus disruption, and ethyl ether and nonionic detergents appeared to be both effective and relatively mild reagents. Immunoelectrophoretic comparison of pigeon serum with serum from a tumor-bearing hamster and that from virus-inoculated rabbits yielded similar, though not identical, results.  相似文献   

17.
Abstract. Fig trees ( Ficus ) have closed inflorescences. Closure is an efficient protection of flowers against non-specialist predators and harsh external environmental conditions. Each Ficus species is pollinated by a single insect species, an agaonid wasp, capable of forcing its way through a bract-covered pore, the ostiole, to gain access to the flowers. Figs also provide oviposition sites for the wasps. The fig/pollinator interaction is a classic example of mutualism. It has been widely assumed that, once pollinators have entered a fig, oviposited and pollinated, they die trapped within the fig. In this paper, we present observations under natural conditions and results of field experiments on three very different fig species ( Ficus aurea Nutt., F. carica L. and F. microcarpa L.) showing that some pollinators do exit or try to exit from the fig after pollination and oviposition. Moreover, experimental results demonstrate that in at least one species ( F. carica ), the pollinator is able to oviposit successively in two different figs.
The frequency of re-emergences from figs after pollination varies among species and this may be related to variations in pollination dynamics depending on environmental constraints such as the abundance of trees and tree phenology. Several factors that may favour pollinators that leave figs after pollination and oviposition are discussed. They include competition between pollinators for oviposition sites, and minimising of the risk of vertical transmission of parasites and pathogens.  相似文献   

18.
JONATHAN S. WALKER 《Ibis》2007,149(2):345-356
Over 20 months I collected data on the diet composition and fruit availability for 23 frugivorous bird species (pigeons, parrots, hornbills and passerines) in two lowland rain forests on Sulawesi, Indonesia. Using these data I determined species dependency on fruit, diet composition, diet breadth and the availability of their fruit resources. Fruit dependency ranged from 44 to 100% of diets across the assemblage, with significant inter-order differences reflecting shared evolutionary history within orders. By contrast, diet breadths did not differ between bird orders owing to high within-order variability, possibly as a result of species-specific foraging strategies. Overall, no significant relationship existed between fruit dependency and diet breadth, which indicated that they are not interchangeable measures of dietary specialization, but that each provided important information on dietary specialization, and enabled assessment of resource requirements and availability. The assemblage consumed the fruits of 120 species representing 40 plant families. Figs ( Ficus spp.) were of great importance across the assemblage and comprised 57% of all fruit-eating records. For hornbills, passerines and pigeons, figs accounted for substantial proportions of monthly feeding records (= 58%) and were consumed whatever the availability of other fruits. Figs were therefore a fundamental part of species' diets, possibly every month, and not merely important during times of relative scarcity of other fruit. Conservation of fig trees both inside and outside protected areas is likely to be important in maintaining healthy populations of figs and the frugivorous birds that depend on them.  相似文献   

19.
Summary In an attempt to learn more about the so-called map component in pigeon navigation, nine series of tests comprising 34 test releases were performed at a release site, 89 miles NNE of Ithaca, New York, where Cornell pigeons regularly depart nonrandomly but with a large clockwise deviation from the true home direction. The tests included releases of: (1) experienced pigeons new to the site, under sun; (2) pigeons with previous experience at the site, under sun; (3) experienced pigeons new to the site, under total overcast; (4) pigeons with previous experience at the site, under total overcast; (5) first-flight youngsters, under sun; (6) directionally trained pigeons; (7) pigeons from two other Ithaca-area lofts; (8) pigeons from two more distant lofts; (9) Bank Swallows from an Ithaca colony; (10) clock-shifted pigeons; (11) radio- and airplane-tracked pigeons.The results of these tests indicate that the directional bias of the Cornell pigeons is, in general, not dependent on weather conditions or on the previous experience of the birds. Moreover, a similar bias is shown by both pigeons from other Ithacaarea lofts and Bank Swallows from Ithaca. And a similar bias from their respective home directions is shown by birds from other areas. Clock-shifted pigeons departing more directly toward home have poorer homing success than controls. It is concluded that some environmental factor basic to the avian homing process is rotated clockwise at this release site, that biologically the birds are not making an error but are probably reading correctly a distorted map.I thank Irene Brown and Timothy Larkin for their aid in all phases of this project; Donald Windsor for help in two releases; Charles Walcott and Martin Michener for aid in airplane tracking; J. Downhower for collaboration in the radio tracking and swallow releases; Andre Gobert, Howard French, A. E. Newton, and Ludwig Karl for permitting me to use their pigeons, George Yerdon, Forest Ranger, and Andy Misura, District Ranger, New York State Department of Environmental Conservation, for their cooperation in making the facilities of the Castor Hill Fire Tower available to us; Monica Howland for preparing the drawings; and Bertha Blaker for typing. Research supported in part by NSF Grants GB-13046X and GB-35199X, and in part by Federal Hatch funds.  相似文献   

20.
The mechanisms of pigeon homing are still not understood, in particular how they determine their position at unfamiliar locations. The “gravity vector” theory holds that pigeons memorize the gravity vector at their home loft and deduct home direction and distance from the angular difference between memorized and actual gravity vector. However, the gravity vector is tilted by different densities in the earth crust leading to gravity anomalies. We predicted that pigeons reared on different gravity anomalies would show different initial orientation and also show changes in their flight path when crossing a gravity anomaly. We reared one group of pigeons in a strong gravity anomaly with a north-to-south gravity gradient, and the other group of pigeons in a normal area but on a spot with a strong local anomaly with a west-to-east gravity gradient. After training over shorter distances, pigeons were released from a gravitationally and geomagnetically normal site 50 km north in the same direction for both home lofts. As expected by the theory, the two groups of pigeons showed divergent initial orientation. In addition, some of the GPS-tracked pigeons also showed changes in their flight paths when crossing gravity anomalies. We conclude that even small local gravity anomalies at the birth place of pigeons may have the potential to bias the map sense of pigeons, while reactivity to gravity gradients during flight was variable and appeared to depend on individual navigational strategies and frequency of position updates.  相似文献   

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