Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Parakeets”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Mycobacteriosis in psittacine birds.

Mycobacteriosis was diagnosed in five psittacine birds: a blue-headed pionus parrot (Pionus menstruus), three grey-cheeked parakeets (Brotogeris pyrrhopterus), and a red-crowned Amazon parrot (Amazona dufresniana rhodocorytha). Signs were marked muscular wasting, anemia, recurrent diarrhea, and dulling or loss of feathers. Lesions were commonly present in the intestines, livers, and spleens, suggesting an oral route of infection. Other tissues in which granulomas were found were the oropharynx, pancreas, and kidneys. The pionus parrot had pulmonary tuberculosis involving both lungs and air sacs. One grey-cheeked parakeet exhibited no gross tubercular lesions. Microscopic lesions varied from noncaseous histiocytic foci to granulomatous "tubercles" with caseous necrosis.

Animals↗
PubMed1980

Psittacine tuberculosis.

Two cases of tuberculosis in psittacine birds were reported and the literature reviewed. One case was in a parakeet and this species was reported to be resistant to mycobacterial infection. No other case of parakeet tuberculosis was found in the literature. The other case was in a parrot. Historically, tuberculosis in parrots was common in European aviary collections, but case reports in the United States were few. The disease in parrots is of zoonotic interest, as they are unique among birds in being susceptible to mammalian strains of mycobacteria. The tuberculomatous aspect of the intestinal lesion in the parrot case described was unusual.

Animals↗
PubMed1996

[Studies on the ecological behavior of Cryptococcus neoformans].

Tenacity studies of Cryptococcus neoformans in bird droppings originated from different ornamental birds and chickens showed that there is less chance for this fungus species to survive in non-sterile or bacteria-free droppings of large parakeets and chickens in comparison with droppings of small parakeets. Survival rates of Cr. neoformans in buffer solutions with pH-values ranging from 8.5-9.5 allow to conclude that this species is not alkali-sensitive. Therefore, the increase of pH is not regarded responsible for the survival of Cr. neoformans in bird droppings. Possibly fungistatic substances present in droppings are involved.

Animals↗
PubMed2005

The evolution of the spindlin gene in birds: sequence analysis of an intron of the spindlin W and Z gene reveals four major divisions of the Psittaciformes.

The Psittaciformes (parrots, parakeets) are among the most widely held captive birds. Yet, their evolution and their phylogenetic relationships have been relatively little studied. This paper describes the phylogenetic relationships between a number of Psittaciformes as derived from the sequences of the third intron of the Z-chromosomal and W-chromosomal spindlin genes. The Z-chromosomal sequences of the kakapo (Strigops habroptilus), the kea (Nestor notabilis), and the kaka (Nestor meridionalis) from New Zealand form a cluster which is the sister group to all other Psittaciformes. The results show further that the Z-chromosomal sequences of the other species can be divided into two groups based on the occurrence of a sequence element ACCCT. The group with the insert (A) is mainly from species with an Australasian geographical distribution and includes such species as the Lories (Lorius, etc.), the budgerigar (Melospittacus undulatus), and the rosellas (Platycercus). It also includes the African lovebirds (Agapornidae), which are the only representative of group A outside Australasia. Group B, without the insert, includes the neotropical parrots and parakeets such as the amazons (Amazona, etc.), the macaws (Ara, etc.), and the conures (Aratinga, etc.), the Australian Cacatuini and the African species such as the African grey parrot (Psittacus erithacus) as well as Coracopsis vasa from Madagascar and Psittrichas fulgidus from New Guinea. The W-chromosomal sequence data show that another division of the Psittacidae is found in the replacement of a pyrimidine-rich segment occurring in many non-psittacines as well as the kakapo (S. habroptilus), the kea (N. notabilis), the kaka (N. meridionalis), and the Cacatuini by a microsatellite consisting of a variable number of TATTA monomers in the other Psittaciformes. The results support a Gondwanan origin of the Psittaciformes and the suggestion that paleogeographic events were a major force in psittacine divergence.

Animals↗
PubMedDate not supplied

Metabolic and developmental responses of alcid chicks to experimental variation in food intake.

I tested whether the ability of chicks to suspend growth and developmental processes in response to food shortages is greater among alcids with food resources that fluctuate over short time periods than it is among close relatives with food that is continuously available. I examined changes in chick resting metabolic rate (RMR) in response to short-term food deprivation in horned and tufted puffins (intermittent food provisioning) and crested and parakeet auklets (continuous food provisioning). RMR was based on measurements of chick oxygen consumption rates (Vo2) under thermoneutral conditions. RMR of postabsorptive chicks scaled allometrically with body mass, and regression slopes were statistically indistinguishable among species. Mass-independent RMR of the same individuals decreased significantly after 48 h of food deprivation. The decrease in the mass-independent RMR was greater in puffins (46.8% in horned and 47.4% in tufted puffins) than in auklets (29.4% in crested and 23.7% in parakeet auklets). To test whether the observed decrease in RMR was due to less energy being allocated to growth, I examined developmental responses of horned and tufted puffins to experimental variation in rates of food intake. I found retarded growth rates in body mass, skeletal elements, and feathers in chicks experiencing low rates of food intake. The retardation of growth processes extended the developmental period. My findings suggest that developmental plasticity in juvenile alcids might be related to temporal variability of prey in oceanic environments.

Adaptation, Physiological↗
PubMed1996

[A family outbreak of Chlamydia psittaci infection].

A family outbreak (3 cases) of Chlamydia psittaci infection was reported. The first case, a 56-year-old man was admitted with fever and general fatigue. Chest X-ray film revealed a consolidation in the right lower lung. One month before admission he had purchased 2 parakeets (chick) and one parakeet died. On learning of his history of contact with the chick, psittacosis was suspected. After administration of fixation (CF) antibody titer against chlamydia rose to 1:128 and IgA titer against Chlamydia psittaci by microimmunofluorescence antibody technique (MAF) rose to 1:128 in 21 days after admission. The second case, the wife of the first, a 53-year-old woman had a fever and a cough about two weeks before the admission of the first case. At the time of her husband was admitted, she attended the outpatient department. The chest CT X-ray film showed a ground glass appearance in both lower lung fields. The third case, the daughter of the first, didn't have any signs. Chest X-ray film was normal. But IgM titer against Chlamydia psittaci by MAF rose to 1:16 and IgA titer against Chlamydia psittaci by MAF rose to 1:128. This case was considered as inapparent infection.

Adult↗
PubMed1988

Production and partial characterization of monoclonal antibodies to four Chlamydia psittaci isolates.

Monoclonal antibodies (MAbs) were produced to four Chlamydia psittaci isolates: NJ1 and TT3 from turkeys, VS1 from a parakeet, and B577 from an ovine abortion. MAbs were tested for reactivity with each isolate by the indirect immunofluorescent antibody technique and for neutralization by an inclusion reduction neutralization technique in tissue culture. Two genus-specific and 14 serovar-specific MAbs were produced. Genus-specific MAbs reacted with all avian and mammalian isolates; however, each failed to neutralize its homologous chlamydial isolate. Turkey isolates NJ1 and TT3 were antigenically similar; serovar-specific MAbs produced to each reacted equally with both isolates yet showed little or no reaction with other serovars. Serovar-specific MAbs to the parakeet and abortion isolates were distinct; no cross-reactions were seen with other serovars. None of the serovar-specific MAbs reacted with an ovine arthritis isolate. Of the 14 serovar-specific MAbs, 13 partially neutralized homologous strains with or without the addition of complement. Because of the high specificity, the serovar-specific MAbs used with the immunofluorescence technique provided a rapid and precise method to identify three serovars of C. psittaci.

Antibodies, Bacterial↗
PubMed1981

Topographic atlas of somatostatin-containing neurons system in the avian brain in relation to catecholamine-containing neurons system. I. Telencephalon and diencephalon.

The morphological organization of the somatostatin (SRIF)-positive neurons in the forebrain (telencephalon and diencephalon) of the warbling grass parakeet (Melopsittacus undulatus) was studied using the indirect immunohistochemical technique of Coons and co-workers ('58). In the telencephalon, a number of SRIF-positive neurons was detected in the lobus paraolfactorius, hippocampus, and paleostriatum. Furthermore, scattered SRIF-labeled cells were noticed in the area corticoidea dorsolateralis and area temporoparieto-occipitalis. A moderate density of immunoreactive fibers was found in the above areas. In addition, although the septal areas was devoid of SRIF-positive neurons, this area contained a moderate occurred in the following hypothalamic areas: (1) nucleus medialis hypothalami posterior, (2) lateral hypothalamus, and (3) mammillary nucleus. The bird hypothalamus also received a strikingly massive SRIF innervation. The heaviest concentration of SRIF-labeled fibers was detected in the medial eminence. Many SRIF-labeled fibers were also observed in other hypothalamic regions. Their locations roughly corresponded in many cases to the areas in which SRIF-positive neurons were disclosed. The overall distribution of the catecholamine system (CA) of the avian forebrain is also represented by means of histofluorescent technique. A possible interaction between SRIF and CA neurons systems is briefly discussed.

Animals↗
PubMed1983

Saprophytic fungi isolated from the hair of domestic and laboratory animals with suspected dermatophytosis.

Hair samples from domestic and laboratory animals with suspected dermatophytosis were examined for the presence of saprophytic fungi. A nutritionally poor base medium, developed by the author, was used in the isolation and identification of the saprophytes. Three hundred and ninety-four specimens were examined of which 246 were from dogs, 75 from cats, 30 from horses, 19 from cows, 12 from guinea pigs, 5 from rats, 2 from parakeets, 2 from chinchillas and one each from a goat, a mink and a lesser panda (Ailurus fulgens). Moulds classified in 32 genera were isolated. The commonest in order of frequency were members of the genera Penicillium, Cladosporium, Aspergillus, Mucor, Aureobasidium, Alternaria, Scopulariopsis, Trichoderma and Trichothecium. The yeasts that were isolated were not identified. Aureobasidium pullulans was isolated significantly more often (chi 2 test p less than 0.025) from the dog samples than those from cats, Cladosporium spp. in the samples from dogs than horses, Mucor spp. from the cow samples than horses, Penicillium spp. from the dog samples than those of cats or horses. Skin infections caused by any of the contaminants were not encountered.

Animals↗
PubMed1988

Sleep patterns in the bird Aratinga canicularis.

Behavioral and electrophysiological features of sleep and wakefulness were studied in chronically implanted adult parakeets, Aratinga canicularis. Four states of vigilance were observed: (1) Wakefulness. It is divided into active and passive. During this state there are generalized motor manifestations which are more frequent and intense in active wakefulness. Cerebral activity is fast and of low amplitude. (2) Drowsiness. Motor activity is notably lower. Blinkings become progressively less frequent. Electroencephalographic patterns are constituted by waves of variable amplitude and frequency. It constitutes 40.7% of the nychthemeral cycle. (3) Slow Wave Sleep (SWS). Animals remain immobile with eyes closed and eye movements are at their lowest frequency. Cerebral activity is slow and of high amplitude. It constitutes 14.7% of the nychthemeral cycle. No sleep spindles are present. (4) Paradoxical sleep (PS). The bird's head tends to drop due to additional muscular relaxation; its eyes remain closed but there are bursts of ocular movements. The EEG is similar to that of wakefulness. This state lasts 7.14 sec on average and occupies 1.98% of the nychthemeral cycle. It is always preceded by SWS. The absence of sleep spindles could be due to the differences in cerebral development compared with mammals.

Animals↗
PubMed1986

Hematological changes produced by lindane (gamma-HCH) in six species of birds.

Hematological changes were studied after oral administration of lindane (gamma-hexachlorocyclohexane) at 5 mg/kg body weight twice in 1 week in 6 species of agriculturally important birds: house sparrow, baya weaver bird, common myna, rose-ringed parakeet, blue rock pigeon and domestic duck. Lindane induced anemia in the birds as judged by reduced RBC count, hematocrit and hemoglobin content with corresponding changes in MCV, MCH and MCHC. Bleeding and clotting time were markedly prolonged. Splenic cell counts were decreased with marginal increase of splenic weight in most of the lindane fed birds. Total leucocyte counts were increased while the differential counts of WBC show marked heterophilia and eosinophilia with a decrease in monocyte, lymphocyte and basophil numbers. Domestic duck appears to be somewhat resistant compared to the wild birds studied. Besides anemia the results suggest both immunosuppression and stress effects and indicate that early hematological changes induced by lindane may serve as an initial warning for pesticide toxicity.

Animals↗
PubMed1979

Frequency selectivity in bird and man: a comparison among critical ratios, critical bands and psychophysical tuning curves.

The relative frequency selectivity of the internal auditory filters, as measured by critical bands or critical ratios, and psychophysical tuning curves, was compared in an avian species (parakeet) and human listeners. The results indicate that the critical band predicts the frequency selectivity of psychophysical tuning curves and vice versa. These findings suggest that there are similar mechanisms which contribute to the frequency selectivity measured by these two procedures and that these mechanisms operate in both the human and avian ear.

Adult↗
PubMed2004

Vocal-tract filtering by lingual articulation in a parrot.

Human speech and bird vocalization are complex communicative behaviors with notable similarities in development and underlying mechanisms. However, there is an important difference between humans and birds in the way vocal complexity is generally produced. Human speech originates from independent modulatory actions of a sound source, e.g., the vibrating vocal folds, and an acoustic filter, formed by the resonances of the vocal tract (formants). Modulation in bird vocalization, in contrast, is thought to originate predominantly from the sound source, whereas the role of the resonance filter is only subsidiary in emphasizing the complex time-frequency patterns of the source (e.g., but see ). However, it has been suggested that, analogous to human speech production, tongue movements observed in parrot vocalizations modulate formant characteristics independently from the vocal source. As yet, direct evidence of such a causal relationship is lacking. In five Monk parakeets, Myiopsitta monachus, we replaced the vocal source, the syrinx, with a small speaker that generated a broad-band sound, and we measured the effects of tongue placement on the sound emitted from the beak. The results show that tongue movements cause significant frequency changes in two formants and cause amplitude changes in all four formants present between 0.5 and 10 kHz. We suggest that lingual articulation may thus in part explain the well-known ability of parrots to mimic human speech, and, even more intriguingly, may also underlie a speech-like formant system in natural parrot vocalizations.

Acoustics↗
PubMed1998

The molecular basis for UV vision in birds: spectral characteristics, cDNA sequence and retinal localization of the UV-sensitive visual pigment of the budgerigar (Melopsittacus undulatus).

Microspectrophotometric (msp) studies have shown that the colour-vision system of many bird species is based on four pigments with absorption peaks in the red, green, blue and UV regions of the spectrum. The existence of a fourth pigment (UV) is the major difference between the trichromacy of humans and the tetrachromacy of such birds, and recent studies have shown that it may play a determining role in such diverse aspects of behaviour as mate selection and detection of food. Avian visual pigments are composed of an opsin protein covalently bound via a Schiff-base linkage to the chromophore 11-cis-retinal. Here we report the cDNA sequence of a UV opsin isolated from an avian species, Melopsittacus undulatus (budgerigar or small parakeet). This sequence has been expressed using the recombinant baculovirus system; the pigment generated from the expressed protein on addition of 11-cis-retinal yielded an absorption spectrum typical of a UV photopigment, with lambdamax 365+/-3 nm. This is the first UV opsin from an avian species to be sequenced and expressed in a heterologous system. In situ hybridization of this sequence to budgerigar retinas selectively labelled a sub-set of UV cones, representing approx. 9% of the total cone population, that are distributed in a semi-regular pattern across the entire retina.

Amino Acid Sequence↗
PubMed2000

The sensitivities of various erythrocytes in a haemagglutination assay for the detection of psittacine beak and feather disease virus.

The erythrocytes of various species were tested in psittacine beak and feather disease (PBFD) virus haemagglutination (HA) and haemagglutination inhibition assays to determine which are suitable for use in these assays. HA activity was observed for erythrocytes of the salmon-crested cockatoo, the sulphur-crested cockatoo, the umbrella cockatoo, the goffin's cockatoo and the cockatiel, with differences amongst individuals within species, but not for erythrocytes of humans, the pig, the guinea pig, the chicken, the goose, the rose-ringed parakeet or the budgerigar. Anti-PBFD virus rabbit sera inhibited the virus-induced agglutination of erythrocytes, confirming the specificity of HA activity. This suggests that selection of suitable psittacine species as well as suitable individuals within a species is necessary when obtaining erythrocytes for the PBFD virus HA assay.

Animals↗
PubMed1983

[Retention of indoles in the pineal organ of the bird (Melopsittacus undulatus, Shaw) during its preparation for radioautographic study].

Since high-resolution radioautography (dipping technique) might be very useful for the study of indole metabolism in the pineal cells, the retention of [3H]-indoles has to be examined during the preparation of specimens for electron microscopy (EM). The pineal organ of the parakeet (Melopsittacus undulatus) was used in the present work. 1) Indole metabolism: following uptake of [3H]-5-hydroxytryptophan ([3H]-HW) in vivo and [3H]-5-hydroxytryptamine ([3H]-HT) in vitro in similar seasonal and nycthemeral conditions--all the known pineal indolic metabolites were recovered by thin layer chromatography. [3H]-5-methoxyindoles were also formed from [3H]-melatonin ([3H]-aMT). 2) The radioactivity of fluids used in the processing of pineal organs in EM was determined by liquid scintillation counting: (a) no exogenous [3H]-indoles could be revealed in EM solutions after [3H]-HW in vivo uptake. (b) 8.8 to 13.4% of [3H]-indoles were washed out by glutaraldehyde after [3H]-HT in vitro uptake. (c) most of the 5-methoxyindoles after in vitro uptake of [3H]-aMT were lost in glutaraldehyde. Our chromatography procedures did not permit the identification of [3H]-indoles extracted by the glutaraldehyde fixative. In previous experiments, [3H]-HW and [3H]-HT uptake showed the presence of selective radioautographic reactions in the cells of the receptor line; however, silver grains were scarce and diffusely distributed in the pineal parenchyma after [3H]-aMT uptake.

5-Hydroxytryptophan↗
PubMed1979

Temporal summation of pure tones in birds.

Two parakeets and two field sparrows were trained by a method of avoidance conditioning to respond to pure tones. Absolute thresholds were obtained for 10 durations of a 2.86-kHz tone. The temporal integration function for these four birds can best be described by a time constant pi of 230 ms. These data are similar to those reported for a number of other species.

Animals↗
PubMed1999

Genomic relatedness of Chlamydia isolates determined by amplified fragment length polymorphism analysis.

The genomic relatedness of 19 Chlamydia pneumoniae isolates (17 from respiratory origin and 2 from atherosclerotic origin), 21 Chlamydia trachomatis isolates (all serovars from the human biovar, an isolate from the mouse biovar, and a porcine isolate), 6 Chlamydia psittaci isolates (5 avian isolates and 1 feline isolate), and 1 Chlamydia pecorum isolate was studied by analyzing genomic amplified fragment length polymorphism (AFLP) fingerprints. The AFLP procedure was adapted from a previously developed method for characterization of clinical C. trachomatis isolates. The fingerprints of all C. pneumoniae isolates were nearly identical, clustering together at a Dice similarity of 92.6% (+/- 1.6% standard deviation). The fingerprints of the C. trachomatis isolates of human, mouse, and swine origin were clearly distinct from each other. The fingerprints of the isolates from the human biovar could be divided into at least 12 different types when the presence or absence of specific bands was taken into account. The C. psittaci fingerprints could be divided into a parakeet, a pigeon, and a feline type. The fingerprint of C. pecorum was clearly distinct from all others. Cluster analysis of selected isolates from all species revealed groups other than those based on sequence data from single genes (in particular, omp1 and rRNA genes) but was in agreement with available DNA-DNA hybridization data. In conclusion, cluster analysis of AFLP fingerprints of representatives of all species provided suggestions for a grouping of chlamydiae based on the analysis of the whole genome. Furthermore, genomic AFLP analysis showed that the genome of C. pneumoniae is highly conserved and that no differences exist between isolates of respiratory and atherosclerotic origins.

Animals↗