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1.
The globally Vulnerable Grey Parrot (Psittacus erithacus) has been seen in Kampala, Uganda’s capital city, in increasing numbers in recent years. This apparently new behaviour of a typically forest species is helped by the presence of many large trees, which provide roosting and nesting sites, and fruiting trees where they feed. Grey Parrots in Kampala potentially come from three sources: escapees, releases of captive birds or wild birds moving into a suburban environment. Birds mostly exhibit behaviours typical of wild birds, but as most, if not all, of the Grey Parrots in captivity are wild-caught and would revert to wild-caught behaviours when released, it is difficult to distinguish them from the wild population. However, we believe that at least some of the birds seen in Kampala are wild.  相似文献   

2.

Background  

An avian papillomavirus genome has been cloned from a cutaneous exophytic papilloma from an African grey parrot (Psittacus erithacus). The nucleotide sequence, genome organization, and phylogenetic position of the Psittacus erithacus papillomavirus (PePV) were determined. This PePV sequence represents the first complete avian papillomavirus genome defined.  相似文献   

3.
Summary Keratinized structures from the African Grey Parrot (feather, down, claw, scale, rhamphotheca, soft lingual epithelium, and lingual nail) were compard by combining biochemical and functional-morphological approaches. At the molecular level, the keratinized structures of Psittacus erithacus are organized essentially like those of other avian species. Correlations were established (or verified) between the mechanical properties of the tissues and the molecular size of the keratin monomers, between the mechanical properties and the x-ray diffraction patterns of the tissues, and between the Polyacrylamide gel electrophoresis (PAGE) patterns of the keratins and certain aspects of growth patterns of the structures. The keratin proteins of the lingual nail, described here for the first time, resemble those of the claw and rhamphotheca. Morphological, biochemical and functional differences between the lingual nail and the rest of the lingual epithelium were established.  相似文献   

4.
This study describes 12 microsatellite loci identified in the African grey parrot Psittacus erithacus. Eleven were polymorphic, with observed heterozygosities 42–94% (average 68) and exclusion powers of PE1 = 0.996 and PE2 = 0.999. Microsatellites have previously been developed for a number of other parrots but showed limited cross‐species polymorphism. Here high levels of cross‐species amplification were observed: 71% of 32 Psittacines (22 genera). At least seven loci, 58%, were polymorphic in other African parrots as well as Neotropical and Australasian parrots, which diverged from the African parrots c30.6 and over 41.4 million years ago, respectively.  相似文献   

5.
To produce a model to explain the acoustic properties of human speech sounds produced by Grey parrots (Psittacus erithacus) and to compare these properties across species (e.g., with humans, other psittacine and nonpsittacine mimics), researchers need adequate measurements of the chambers that constitute the parrot vocal tract. Various methods can provide such data. Here we compare results for tracheal measurements provided by a) magnetic resonance imaging (MRI) of a live bird, b) caliper measurements of four preserved specimens, and c) electron beam computed tomography (EBCT) of three of these preserved specimens. We find that EBCT scans provide data that correspond to the inner area of the dissected trachea, whereas MRI results correspond to area measurements that include tracheal ring thickness. We briefly discuss how these data may predict formant values for Grey parrot reproduction of human vowels. Our results suggest how noninvasive techniques can be used for cross-species comparisons, including the coevolution of structure and function in avian mimicry. J. Morphol. 238:81–91, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

6.
Mirids (Sahlbergella singularis and Distantiella theobroma) are the most important insect pests affecting cocoa production across West Africa. Understanding the population dynamics of mirids is key to their management; however, the current recommended hand‐height assessment method is labour intensive. The objective of the study was to compare recently developed mirid sex pheromone trapping and visual hand‐height assessment methods as monitoring tools on cocoa farms and to consider implications for a decision support system. Ten farms from the Eastern and Ashanti regions of Ghana were used for the study. Mirid numbers and damage were assessed fortnightly on twenty trees per farm, using both methods, from January 2012 to April 2013. The mirid population increased rapidly in June, reached a peak in September and began to decline in October. There was a significant linear relationship between numbers of mirids sampled to hand‐height and mirid damage. High numbers of male mirids were recorded in pheromone traps between January and April 2012 after which there was a gradual decline. There was a significant inverse relationship between numbers of trapped adult mirids and mirids sampled to hand‐height (predominantly nymphs). Higher temperatures and lower relative humidities in the first half of the year were associated with fewer mirids at hand‐height, but larger numbers of adult males were caught in pheromone traps. The study showed that relying solely on one method is not sufficient to provide accurate information on mirid population dynamics and a combination of the two methods is necessary.  相似文献   

7.
Haemoproteus psittaci n. sp., a microsomal halteridial haemoproteid, is described from the African grey parrot Psittacus erithacus. This species differs from Haemoproteus handai, the only other haemoproteid described from the Psittaciformes, in that it is halteridial, not circumnuclear, is much smaller in all dimensions and has only 10–12 pigment granules compared to 20–24 noted in the latter species.  相似文献   

8.
Reproductive strategies of closely related species distributed along successional gradients should differ as a consequence of the trade‐off between competition and colonization abilities. We compared male reproductive strategies of Quercus robur and Q. petraea, two partly interfertile European oak species with different successional status. In the studied even‐aged stand, trees of the late‐successional species (Q. petraea) grew faster and suffered less from intertree competition than trees of the early‐successional species (Q. robur). A large‐scale paternity study and a spatially explicit individual‐based mating model were used to estimate parameters of pollen production and dispersal as well as sexual barriers between species. Male fecundity was found to be dependent both on a tree's circumference and on its environment, particularly so for Q. petraea. Pollen dispersal was greater and more isotropic in Q. robur than in Q. petraea. Premating barriers to hybridization were strong in both species, but more so in Q. petraea than in Q. robur. Hence, predictions based on the competition–colonization trade‐off are well supported, whereas the sexual barriers themselves seem to be shaped by colonization dynamics.  相似文献   

9.
Summary Scattered trees, or ‘paddock trees’, are keystone structures, which provide multiple ecological values. However, they are in decline in many places. This has serious implications for species that use them, such as the vulnerable Superb Parrot (Polytelis swainsonii) of south‐eastern Australia. We outline three key aspects of the ecology, biology and distribution of the species that illustrate the implications of scattered tree decline. These are that (i) it depends on trees; (ii) it lives across agricultural landscapes; and (iii) it uses scattered tree landscapes dynamically in response to climate variation. We outline the dual challenge of maintaining populations of both scattered trees and the Superb Parrot over large scales and over the long term. Without urgent restoration action, a narrow bottleneck (where there are few mature trees) will make the long‐term future of the Superb Parrot precarious in these landscapes. We outline a vision for future landscapes that addresses this challenge, including the development of a form of Australian ‘wood‐pasture’. We suggest some ways that might be implemented at two scales. At the farm scale, we suggest (i) protecting what remnant vegetation we currently have; (ii) recruiting future large, old trees; (iii) sequentially setting aside land to ensure whole‐of‐farm tree regeneration; (iv) use of incentives to encourage restoration actions; and (v) using a revolving land fund to purchase and reorganize farms into economically and ecologically sustainable units. At the landscape scale, we suggest (i) the need for coordination of long‐term landscape restoration plans; (ii) the possible collaborative management of adjacent farms to ensure economic and ecological sustainability. We conclude that addressing the large‐scale and long‐term challenges of restoring scattered trees in landscapes occupied by the Superb Parrot could restore lost or diminished ecological services. This challenge illustrates the need for action at both the farm and the landscape scale that is planned over the short, medium and long term.  相似文献   

10.
Shade coffee plantations are considered important habitats for frugivorous bats. However, it is not known if bats use this agricultural habitat for shelter, food resources, or both. This study addresses these questions using the highland yellow‐shouldered bat (Sturnira hondurensis) as an example. Twenty‐six adult individuals of S. hondurensis were captured, 50 percent in tropical montane cloud forest (TMCF) and 50 percent in shade coffee plantations (SCP) in Veracruz, Mexico, and each was fitted with a radio transmitter for locating roosts and feeding areas. Data were obtained from 24 of them. The fieldwork was conducted between October 2010 and October 2011 covering all seasons. Twenty‐two day roosts were located in the cavities of twelve different species of tree. Roosts located in TMCF differed significantly from those in SCP, having a smaller crown area and a greater species richness and density of plants around the roost. In SCP, both the average home range and the average core use area were smaller than in TMCF, but the differences were not statistically significant. Distances travelled by bats were generally longer and more variable in the SCP; the distance between capture site and foraging site was significantly greater in SCP than in TMCF. In SCP, there were fewer understory chiropterochorous plants, which are the main item in the diet of this bat and many other sympatric species of frugivorous bats. Although S. hondurensis does use roosts and foraging sites in the SCP, it is important to note that this species and others with similar requirements primarily depend on the preservation of intact forest adjacent to modified landscapes, where roosts and fruit are constantly available in abundance. Management practices should guarantee a greater density and diverse of trees and the preservation of understory plants with fruits in the coffee plantations that allow a long‐term survival of frugivorous bats populations.  相似文献   

11.
We identified species‐ and community‐level dietary characteristics for a species‐rich Amazonian parrot assemblage to determine relationships among dietary metrics and use of geophagy sites. Previous studies suggest that soil is consumed at geophagy sites in this region mainly to supplement dietary sodium. We accumulated 1400 feeding records for 16 parrot species over 2 yr and found that seeds, flowers, and fruit pulp featured prominently in diets, while bark, insects, and lichen were consumed in small quantities. Food availability across 1819 trees was measured, and we found that flower availability was highest in the dry season and fruit production peaked in the wet season, but that phenology patterns of the 20 most commonly foraged plant species suggest no serious food bottlenecks. Partitioning of available food resources among the 13 most commonly encountered parrots is suggested by an ordination analysis (DCA), which placed the large macaws (Ara) with the Amazona parrots at the ‘primary forest’ end of a dietary resource axis and four smaller species at the ‘successional forest’ end of the axis. Parrot species associated with successional forest also consumed less plant species overall. Furthermore, these parrot species consuming successional forest resources had higher claylick visitation rates than those consuming primary forest resources suggesting they derive the greatest benefits from soil consumption.  相似文献   

12.
《Ostrich》2013,84(3-4):195-205
A review of the taxonomic status of the critically endangered Cape Parrot Poicephalus robustus Gmelin 1788 has important implications concerning the conservation of this species and illegal trade. It is distinguishable from the Brown-necked Parrot P. fuscicollis fuscicollis Kuhl 1820 on the morphometrics of the body and bill, two mitochondrial DNA sequences and its ecology and behaviour. The Grey-headed Parrot P. f. suahelicus Reichenow 1898 is geographically and genetically isolated from the other taxa. Grey-headed Parrots and Brown-necked Parrots are more closely related to each other than either is to the Cape Parrot. Geographically, the Grey-headed Parrot is marginally parapatric with the Cape Parrot, and this account focusses on these taxa. The Cape Parrot is a dietary specialist, and its diet differs from that of the Grey-headed Parrot, which has a wider trophic niche, although both feed on the kernels of unripe fruit. Their feeding behaviour changes in response to seasonally available food and may involve long distance movements. Both species share similar breeding habits, but they breed at different seasons in different habitat types. The two taxa have distinct habitat requirements and distributions. Cape Parrots inhabit, nest and feed in Afromontane mixed Podocarpus forest above 1 000m asl in South Africa, whereas Grey-headed Parrots inhabit a wide range of lowland woodland habitats across south-central Africa. In parapatry, there is no record of hybridisation, probably because of spatial (geographical and altitudinal) and temporal segregation (different breeding seasons). On the basis of these criteria, the Cape Parrot is, and must be recognised, as an independent species.  相似文献   

13.
The tapeworm species Spirometra erinaceieuropaei was documented mainly in Asia and Europe. In recent years, plerocercoid larvae (spargana) of this parasite have been found in different hosts in north‐eastern Poland. The evolutionary history and way of S. erinaceieuropaei spreading across Eurasia have been not described yet. However, this phenomenon could be closely related to the evolutionary history and migration routes of studied tapeworm host species. We investigated the genetic variability and divergence pattern among S. erinaceieuropaei populations in intermediate and paratenic hosts from north‐eastern Poland based on complete mitochondrial sequences of cytochrome b (cytb) and cytochrome c oxidase subunit I (cox1) genes. Analysis of 319 consolidated sequences of these two genes showed no genetic structure across study area. Comparison of sequences from Poland and China showed distinct separation of S. erinaceieuropaei populations from these two regions. They split from their common ancestor approximately 28.6 million years ago. Demographic expansion of Polish population of S. erinaceieuropaei started from glacial refugia approximately 12.5 thousand years ago, and recent population expansion has been observed in the tapeworm population from north‐eastern Poland.  相似文献   

14.
Human‐induced changes in atmospheric composition are expected to affect primary productivity across terrestrial biomes. Recent changes in productivity have been observed in many forest ecosystems, but low‐latitude upper tree line forests remain to be investigated. Here, we use dendrochronological methods and isotopic analysis to examine changes in productivity, and their physiological basis, in Abies religiosa (Ar) and Pinus hartwegii (Ph) trees growing in high‐elevation forests of central Mexico. Six sites were selected across a longitudinal transect (Transverse Volcanic Axis), from the Pacific Ocean toward the Gulf of Mexico, where mature dominant trees were sampled at altitudes ranging from 3200 to 4000 m asl. A total of 60 Ar and 84 Ph trees were analyzed to describe changes in growth (annual‐resolution) and isotopic composition (decadal‐resolution) since the early 1900s. Our results show an initial widespread increase in basal area increment (BAI) during the first half of the past century. However, BAI has decreased significantly since the 1950s with accentuated decline after the 1980s in both species and across sites. We found a consistent reduction in atmosphere to wood 13C discrimination, resulting from increasing water use efficiency (20–60%), coinciding with rising atmospheric CO2. Changes in 13C discrimination were not followed, however, by shifts in tree ring δ18O, indicating site‐ and species‐specific differences in water source or uptake strategy. Our results indicate that CO2 stimulation has not been enough to counteract warming‐induced drought stress, but other stressors, such as progressive nutrient limitation, could also have contributed to growth decline. Future studies should explore the distinct role of resource limitation (water vs. nutrients) in modulating the response of high‐elevation ecosystems to atmospheric change.  相似文献   

15.
Eucalypts are among the most widely planted forest trees in the world, and outside their native Australian range, the main arthropod pests are sap‐sucking insects, defoliators, gall‐making insects and xylophagous beetles. We report on a new association between a polyphagous wood‐boring beetle and Tasmanian blue gum (Eucalyptus globulus Labill.) in Central Portugal. Unidentified wood‐boring insects were found attacking two three‐year‐old E. globulus trees showing signs of decline among otherwise healthy trees in a commercial plantation, in June 2018. Declining trees presented dead twigs and branches, and recently developed epicormic sprouts evident on the trunks. Insects emerging from logs were identified as Ambrosiodmus rubricollis (Eichhoff), a species native to eastern and southern Asia, with the taxonomic identification validated by molecular analysis. To our knowledge, this is the first record of A. rubricollis associated with a eucalypt species worldwide. It is not clear whether the beetles played any significant role on the decline of the trees, but Ambrosiodmus may be potential pests for several tree and shrub species in Europe, as these beetles can transport pathogenic fungi.  相似文献   

16.
The California Floristic Province (CFP) in western North America is a globally significant biodiversity hotspot. Elucidating patterns of endemism and the historical drivers of this diversity has been an important challenge of comparative phylogeography for over two decades. We generated phylogenomic data using ddRADseq to examine genetic structure in Uroctonus forest scorpions, an ecologically restricted and dispersal‐limited organism widely distributed across the CFP north to the Columbia River. We coupled our genetic data with species distribution models (SDMs) to determine climatically suitable areas for Uroctonus both now and during the Last Glacial Maximum. Based on our analyses, Uroctonus is composed of two major genetic groups that likely diverged over 2 million years ago. Each of these groups itself contains numerous genetic groups that reveal a pattern of vicariance and microendemism across the CFP. Migration rates among these populations are low. SDMs suggest forest scorpion habitat has remained relatively stable over the last 21 000 years, consistent with the genetic data. Our results suggest tectonic plate rafting, mountain uplift, river drainage formation and climate‐induced habitat fragmentation have all likely played a role in the diversification of Uroctonus. The intricate pattern of genetic fragmentation revealed across a temporal continuum highlights the potential of low‐dispersing species to shed light on small‐scale patterns of biodiversity and the underlying processes that have generated this diversity in biodiversity hotspots.  相似文献   

17.
The objective of the current study was to identify pathogens of the large larch bark beetle, Ips cembrae, which is a secondary pest that has produced several local outbreaks across Europe in recent years. Beetles were collected from pheromone traps, trap trees and emergence traps (Larix decidua) during 2007 to 2011 at 10 study sites in central Europe. A total of 3379 mature and callow beetles were examined with a light microscope, and only two microsporidian pathogens [Chytridiopsis typographi and a diplokaryotic microsporidium (probably Nosema sp.)] and two gregarines (Gregarina typographi and Mattesia schwenkei) were found. Within the I. cembrae populations, the infection rate for C. typographi ranged from 2 to 58%. Nosema sp. occurred in only two beetles in 2007 (at two study sites). G. typographi was recorded only in Austria and Croatia and only in 1–2% of the beetles in those countries. Mattesia schwenkei was observed solely in Croatia in 0.6% of the beetles in that country. Only one fungal pathogen in the genus Fusarium was found and only in two mature beetles (0.7%) in 2010. The pathogen species found during our study of I. cembrae were very similar to the pathogens previously identified for Ips typographus. No species‐specific pathogen was detected.  相似文献   

18.
Most Cape Parrot, Poicephalus robustus, nests have been recorded in snags (standing dead trees) making monitoring of nest contents and nest activities difficult and dangerous. Here the breeding activity of a Cape Parrot pair in the cavity of a live Henkell's Yellowwood (Podocarpus henkellii) is presented. Four eggs were laid in early-August and three chicks successfully raised. Incubation period was estimated at 30–32 days. Two nestlings fledged successfully and one (the youngest) was removed because it was injured in the nest and would not have survived. Fledging period was estimated at 80 days.  相似文献   

19.
Large‐seeded plants may suffer seed dispersal limitation in human‐modified landscapes if seed dispersers are absent or unable to disperse their seeds. We investigated dispersal limitation for the large‐seeded tree Virola surinamensis in a human‐modified landscape in southern Costa Rica. During two fruiting seasons, we monitored crop size, seed removal rates, the number of fruiting conspecifics within 100 m, and feeding visitation rates by frugivores at trees located in high and low forest disturbance conditions. Seed removal rates and the total number of seeds removed were high regardless of the disturbance level, but these parameters increased with tree crop size and decreased with the number of fruiting V. surinamensis trees within a 100 m radius. Trees at low disturbance levels were more likely to be visited by seed dispersers. Black mandibled toucans (Ramphastos ambiguus) and spider monkeys (Ateles geoffroyi) were the most important seed dispersers, based on visitation patterns and seed removal rates. Spider monkey feeding visits were more frequent at high disturbance levels, but the monkeys preferentially visited isolated trees with large yields and surrounded by a low number of fruiting Virola trees within 100 m. Toucan visitation patterns were not constrained by any of the predictors and they visited trees equally across the landscape. We suggest that isolated and highly fecund Virola trees are an important food resource for spider monkeys in human‐modified landscapes and that toucans can provide resilience against seed dispersal limitations for large‐seeded plants in human‐modified landscapes in the absence of hunting.  相似文献   

20.
Sahlbergella singularis Haglund and Distantiella theobroma (Distant) (Heteroptera: Miridae) are the key insect pests of cacao in Ghana and elsewhere in West Africa. Since 1954, spraying with synthetic insecticides has been the principal means of controlling these pests. In West Africa, environmental concerns, economic stimuli, and unreliable access to insecticides have stimulated interest in ecologically more benign mirid control strategies as an alternative to a total reliance on insecticides. Males of both mirid species, and those of the less damaging Bryocoropsis laticollis Schumacher, respond to the same synthetic sex pheromone blend, so pheromone‐based strategies may provide control as well as monitoring opportunities. Pheromone traps were deployed for 3 months at nine densities between two and 30 traps per 0.1 ha plot (20–300 traps ha?1) plus an untreated control treatment in a replicated large‐scale field experiment on mature mixed Upper Amazon hybrid cacao in Ghana, in order to determine the optimal dispenser density for mass trapping, lure‐and‐kill, and/or lure‐and‐infect. At the end of the trapping period, mirid populations in the various treatments were assessed by insecticide knockdown on 400 trees and by searches to hand height on 1 200 trees, together with an assessment of mirid damage. In total 781 S. singularis and 235 D. theobroma were captured in the pheromone traps. The optimal dispenser density for S. singularis was 150 traps ha?1. Over 300 traps ha?1 was probably optimal for D. theobroma as a smaller proportion of the population was captured, and numbers caught per trap displayed no decline with increasing trap density. From insecticide knockdowns, mirid population density was estimated at 220–230 ha?1, 63% of which were D. theobroma. Too few pods and orthotropic shoots were damaged by mirids to establish the efficacy of pheromone trapping for mirid control.  相似文献   

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