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At least 19 recordsLinked to original sources

Effects of mydriatic agents in cockatoos, African gray parrots, and Blue-fronted Amazon parrots.

OBJECTIVE: To compare, in psittacines, the mydriatic effects of several topically applied curariform, sympathomimetic, and parasympatholytic drugs with and without the addition of surface-acting penetrating agents. DESIGN: Prospective, randomized controlled trial. ANIMALS: 10 adult cockatoos (Cacatua sulphurea subspecies), 2 adult African gray parrots (Psittacus erithacus), and 3 adult Blue-fronted Amazon parrots (Amazona aestiva). PROCEDURE: Three curariform drugs (d-tubocurarine, pancuronium, and vecuronium bromide) and 2 autonomic drugs (atropine and phenylephrine hydrochloride) were evaluated. Drugs were tested with and without the addition of a surface-acting penetrating agent, either saponin or benzalkonium chloride. The agent that resulted in the most significant change in pupillary diameter with the fewest systemic side effects in the cockatoos then was evaluated for its effects in the African gray parrots and the Blue-fronted Amazon parrots. During each drug trial, 1 eye was randomly selected to receive the control drug (0.9% NaCl), and the opposite eye was selected to receive the test drug. Each pupil was videotaped 5 (cockatoos only), 15, 30, 45, 60, and 75 minutes after treatment. Pupil diameters were measured by use of a computerized image analysis system. Data for pupil size were analyzed by means of repeated measures ANOVA. RESULTS: Vecuronium without the addition of a surface-acting penetrating agent produced the most consistent and greatest pupillary dilatation in all 3 species with the fewest systemic side effects. CLINICAL IMPLICATIONS: Vecuronium is potentially a clinically useful, topical mydriatic agent for use in avian species. Documented differences in the prevalence of systemic side effects between species suggests that caution should be applied when applying this drug bilaterally.

Animals

Application of DNA fingerprinting to the recovery program of the endangered Puerto Rican parrot.

The Puerto Rican parrot was reduced to approximately 13 animals in 1975 and as a conservation measure, a captive population was established from a few founders taken from the wild between 1973 and 1983. The number of successful breeding pairs in captivity has been low, and the captive breeding program has not been as productive as that of the closely related Hispaniolan parrot. Therefore, a genetic study was initiated to examine the relative levels of relatedness of the captive founders using levels of bandsharing in DNA fingerprints. Unrelated captive founder Puerto Rican parrots had the same average level of bandsharing (0.41) as second-degree relatives of the Hispaniolan parrot (0.38, P > 0.05), with an inbreeding coefficient of 0.04. High levels of bandsharing (> 40%) between pairs of males and females correlated with reproductive failure, suggesting that inbreeding depression is partly responsible for the low number of breeding pairs. Consequently, DNA profiling can be used to guide the captive breeding program for the Puerto Rican parrot, and other endangered species, by identifying pairs of males and females with low levels of bandsharing.

Animals

[A comparison of parrot food commercially available in The Netherlands].

The composition of a number of parrot foods commercially available in the Netherlands was put to the test for the (partly hypothetical) needs of the larger psittacine birds such as African Grey parrots, Amazon parrots, macaws and cockatoos. These studies showed that the majority of the foods is multideficient. When the deficient foods are supplied to parrots without any additions, this will give rise to the appearance of disease. However, some of the products recently put on the market (Bogena and Kasper Fauna Food) comply better with the requirements of a 'complete parrot food'. As regards public enlightenment, food producers, petshops, consumer organisations and veterinarians are obviously responsible.

Animal Feed

Lexicon size and its relation to foot preference in the African grey parrot (Psittacus erithacus).

To study footedness in parrots, an international survey of parrot owners was conducted. Responses were obtained from 524 individuals, including 70 owners of African Grey parrots (all animals > or = 10 months old). All respondents were given a 10-item questionnaire and a standard method for testing foot preference in their pets, and they were asked to count the number of separate words in their pets' lexicons of human speech sounds. Right-footed African Greys (N = 36) had significantly larger lexicons than left-footed African Greys (N = 34; P = 0.01). This difference could not be accounted for by group differences in training efforts or socialization/housing with conspecifics. A non-significant trend in the same direction was found in a comparison sample of Amazon parrots, although these genera are less adept than African Greys at learning human speech sounds. Other investigators have provided convincing evidence of lateralization, in the avian brain, for the analysis and memory of differing types of stimuli. In addition, there appears to be preferential left hypserstriatal activation for long-term memory consolidation. Our results suggest a relationship between lateral asymmetry for motor preference and asymmetric CNS mediation of a 'higher cognitive' function (i.e. the categorization and long-term mnestic processing of human speech sound.

Animals

CT-assisted versus silicone rubber cast morphometry of the lower respiratory tract in healthy amazons (genus Amazona) and grey parrots (genus Psittacus).

The objective of this study was to examine the normal respiratory tract of grey parrots and amazons by using two different methods. The lower respiratory tract of five amazons and four grey parrots, all healthy, were investigated applying computerised tomography (CT). Volumes and densities of the body, the body cavities, the normal lungs, and the airsacs in the living animals were defined as reference values of healthy birds to give a basis for future CT-diagnosis of respiratory diseases and their precise locations in parrots. In a parallel study, the lung and air sac volumes of six amazons and two grey parrots were measured using silicone rubber casts produced after the method described by H.-R. Duncker. Values for identical respiratory structures gained by these different methods were compared.

Anatomy, Cross-Sectional

Development of Piagetian object permanence in a grey parrot (Psittacus erithacus).

The authors evaluated the ontogenetic performance of a grey parrot (Psittacus erithacus) on object permanence tasks designed for human infants. Testing began when the bird was 8 weeks old, prior to fledging and weaning. Because adult grey parrots understand complex invisible displacements (I. M. Pepperberg & F. A. Kozak, 1986), the authors continued weekly testing until the current subject completed all of I. C. Uzgiris and J. Hunt's (1975) Scale 1 tasks. Stage 6 object permanence with respect to these tasks emerged at 22 weeks, after the bird had fledged but before it was completely weaned. Although the parrot progressed more rapidly overall than other species that have been tested ontogenetically, the subject similarly exhibited a behavioral plateau part way through the study. Additional tests, administered at 8 and 12 months as well as to an adult grey parrot, demonstrated, respectively, that these birds have some representation of a hidden object and understand advanced invisible displacements.

Animals

Footedness in parrots: three centuries of research, theory, and mere surmise.

In contemporary debates about laterality in animals, the parrot (Psittaciformes) is often cited as an exemplar--possibly unique--of laterality in limb function at the population level comparable in kind and strength to handedness in man. This conclusion rests on just two reports (Friedman & Davis, 1938; Rogers, 1980) that most species of parrots are left-footed, that is, that they preferentially perch on the right foot and hold food with the left. In fact, speculation about and scientific study of laterality in parrots go well beyond these two investigations. The question itself dates from at least the 17th century, after which, beginning in the 1860s, it became the subject of broad interest and debate. In our own time, it also has continued to occupy the attention of at least a small number of ornithologists and field biologists whose work, like that of their predecessors, is not cited in the current neuropsychological literature on this topic. To fill out the historical as well as contemporary record for consideration by neuropsychologists today, these other observations and theoretical analyses are reviewed, and new questions about laterality in parrots raised by this work are presented.

Animals

Psittacine pox virus: virus isolation and identification, transmission, and cross-challenge studies in parrots and chickens.

An avian pox virus was isolated from Amazon parrots dying with severe diphtheritic oral, esophageal, and crop lesions. The virus was propagated on chorioallantoic membranes (CAM) of 10-day-old chicken embryos, and a homogenate of the infected CAM was rubbed vigorously onto the conjunctiva, oral mucosa, and defeathered follicles of two healthy Amazon parrots and three conures. All experimental birds developed cutaneous and ocular pox lesions, and one parrot developed oral pox lesions. Specific-pathogen-free chicks inoculated with the virus isolate developed skin lesions identical to those of the parrots. Chickens vaccinated with fowl and pigeon pox vaccines and inoculated with the psittacine isolate developed lesions typical of avian pox. Chickens vaccinated with the psittacine virus were susceptible to fowl and pigeon pox virus infection. This pox virus isolate may thus be regarded as a potential pathogen for chickens.

Animals

First molecular detection and partial ORF1 characterization of psittacine beak and feather disease virus (PBFDV) in domesticated parrots of Northern Vietnam.

Psittacine beak and feather disease virus (PBFDV), currently classified within the species Circovirus parrot, is an infectious agent in avian species, particularly psittacine birds. PBFDV is the causative agent of psittacine beak and feather disease (PBFD), leading to feather loss, deformed beaks and nails, immunosuppression, and high mortality. However, there is limited information on PBFDV in Vietnam, particularly in domesticated parrots. This study aims to detect and molecularly characterize PBFDV in psittacine birds in Northern Vietnam. Among the 193 psittacine birds tested by conventional PCR, 48 were PBFDV-positive, corresponding to a positivity rate of 24.87%. Based on partial ORF1 characterization, phylogenetic tree analysis of the ten PBFDV sequences showed that genotype I, which exhibits genetic diversity, is circulating in Vietnam. This study highlights the importance of genomic characterization of PBFDV in domesticated exotic psittacine birds in Vietnam. Together with the recent cases of PBFD in domestic parrots, further surveillance is needed to elucidate the host specificity, transmission, and pathophysiology of PBFDV.

Animals

Prophylactic antibiotics to prevent chest infections in children with neurological impairment: the PARROT RCT.

BACKGROUND: Improvements in neonatal and paediatric care in recent decades have increased the survival of children with non-progressive neurological impairment. Respiratory disease in children with neurological impairment is common, with symptoms difficult to manage and lower respiratory tract infection occurring frequently. To reduce these, prophylactic antibiotics are being increasingly used, but the type, duration and dose of antibiotics can vary considerably, and there is limited evidence about their effectiveness in children and young people. A joint United Kingdom and Australia multicentre, randomised, double-blind, placebo-controlled trial comparing 52 weeks of azithromycin to placebo in children and young people with neurological impairment at risk of lower respiratory tract infection (PARROT) was planned to address this gap. PARROT was a multicentre, parallel group, blinded, pragmatic randomised controlled trial of 52-week duration with a planned sample size of 500 (250 in each arm) participants with neurological impairment. The primary outcome was the proportion of children and young people hospitalised with lower respiratory tract infection over the 52-week period. RESULTS: In total, 90 children and young people (62 in Australia, 28 in the United Kingdom) aged 3-17 years, with a diagnosed non-progressive, non-neuromuscular neurological impairment, who had persistent respiratory symptoms were randomised (1 : 1) to receive azithromycin or placebo. Baseline demographic and clinical characteristics were relatively well balanced across the two treatment groups and countries. Overall, mean (standard deviation) age was 9.2 (4.4) years, with 64% of participants having cerebral palsy, 67% being non-ambulant and 54% being totally tube-fed. At baseline, mean (standard deviation) numbers of hospital admissions with lower respiratory tract infection in the preceding year were 1.8 (2.0)/year, and general practitioner attendances 3.3 (3.0)/year. The PARROT trial was closed early to recruitment due to challenges arising from the COVID-19 pandemic. Sixty-five (72%) participants (azithromycin n = 30, placebo n = 35) completed 52 weeks of treatment and were not withdrawn early from the trial. Regarding the primary outcome, 11 (36.7%) in the azithromycin group were hospitalised with lower respiratory tract infection and 9 (25.7%) in the placebo group [absolute risk reduction 0.11 (95% confidence interval -0.12 to 0.33), relative risk 1.43 (95% confidence interval 0.68 to 2.97)]. Analysis of secondary outcome data was limited by the number of missing data, but parent-reported quality of life for young person and parent, sleep amount/quality for young person and parent, and respiratory symptoms were similar between groups and countries. LIMITATIONS: As PARROT was stopped early and was consequently underpowered, it is not possible to say whether azithromycin prophylaxis is any more effective than placebo in reducing the proportion of children admitted to hospital with lower respiratory tract infection after a 52-week period. CONCLUSIONS AND FUTURE WORK: Although we cannot comment on the effectiveness of prophylactic antibiotics in this context, we can draw some useful conclusions from this trial. Thus, the importance placed by families on hospitalisation and its prevalence in both treatment groups, even during the pandemic, would suggest that this is an appropriate primary outcome measure for future trials in this high-risk group of children and young people. Furthermore, the high attrition rate and large numbers of missing data, specifically for questionnaire-based outcomes at later follow-up points, should encourage researchers to be mindful of minimising trial burden to families for any future trials wherever possible. FUNDING: This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number 16/17/01.

Humans

Spermatozoal ultrastructure in three species of parrots (aves, Psittaciformes) and its phylogenetic implications.

BACKGROUND: DNA-DNA hybridization studies suggest that Psittaciformes are highly, but not the most, derived nonpasserines. Multilocus protein electrophoresis indicates that cockatoos (Cacatuinae) form a monophyletic lineage distant from the other Australo-Papuan psittacids (Psittacinae). METHODS: Transmission electron microscope procedures are applied to the spermatozoa of three parrots, in the Cacatuninae and Psittacinae, to investigate these relationships. RESULTS: Psittaciform sperm have the following characteristics: (1) conical acrosome vesicle; rodlike perforatorium; cylindrical, highly condensed nucleus; proximal and distal centriole embedded in dense material; elongate periaxonemal mitochondrial midpiece, (2) nine dense peripheral axonemal fibers (coarse fibers), (3) no fibrous sheath around the axoneme, (4) mitochondria with linear cristae, lacking intra- (or inter-) mitochondrial dense bodies, (5) restriction of the endonuclear perforatorial canal to the anterior region of the nucleus, (6) a short distal centriole, and (7) nucleus abutting on but not penetrating the acrosome. CONCLUSIONS: (1) These features are tetrapod symplesiomorphies, (2) is an amniote synapomorphy; the fibers differ from those of reptiles in being uniform in size, (3) loss of the fibrous sheath is an apomorphy known elsewhere only in columbiforms, (4) are apomorphies relative to basal aminiotes (Chelonia, Sphenodon, and Crocodilia), (5) is an apomorphic condition shared with other nonpasserines (galliforms and the white-naped crane) and crocodilians, (6) the latter taxa differ from parrots in a plesiomorphic elongation of the distal centriole, and (7) is a unique apomorphy of parrot sperm relative to other nonpasserines and reptiles. The short midpiece of N. hollandicus distinguishes this cacatuine from the two psittacines.

Animals

Highly repeated DNA sequences in birds: the structure and evolution of an abundant, tandemly repeated 190-bp DNA fragment in parrots.

Up to 6.8% of the parrot (Psittaciformes) genome consists of a tandemly repeated, 190-bp sequence (P1) located in the centromere of many if not all chromosomes. Monomer repeats from 10 different psittacine species representing four subfamilies were isolated and cloned. The intraspecific sequence variation ranged from 1.5 to 7%. The interspecific sequence variation ranged from less than 3% between two species of cockatoos to approximately 45% between cockatoos and other parrots. The monomer sequences of all 10 parrot species contained several conserved (> 90%) sequence elements at identical locations within the repeat. A comparison with tandemly repeated DNA sequences in other avian species showed that several of these conserved elements were also present at similar locations within the 184-bp repeat of the Chilean flamingo (Phoenicopterus chilensis), suggesting a great antiquity of the repeat. One of the elements was also found in the tandemly repeated sequences of the crane (Gruidae) and falcon (Falconidae) families. The data were used for the construction of a partial most parsimonious relationship that supports a regional subdivision of the Psittaciformes.

Animals

Effect of avian-human joint attention on allospecific vocal learning by grey parrots (Psittacus erithacus).

The authors studied whether grey parrots (Psittacus erithacus) would learn referential English vocalizations if training lacked full social interaction with humans. In previous studies, grey parrots learned human vocalizations most readily when training simultaneously demonstrated the meaning (full reference) and function (full contextual applicability) of the utterance and actively engaged the subject in learning (full interaction). Those studies, however, did not contrast effects of limited and full interaction or examine how interaction affects contextual applicability. Because an important factor in child language acquisition is joint attention-the social interaction between caretaker and human infant concerning objects and actions in their environment-the authors contrasted training in which joint attention was present or absent (i.e., full vs. limited interaction) and found that 2 parrots did not learn in the absence of joint attention but did learn English labels when full interaction was present.

Adult

Cytochrome-b sequence variation among parrots.

The nucleotide sequence of a 307 bp fragment of the mitochondrial cytochrome-b gene was determined for 12 species of parrot, using the polymerase chain reaction and direct sequencing. Sequence divergence ranged from 26-54 differences in pairwise comparisons, with the majority of base substitutions occurring at third positions of codons. The transition:transversion ratio was determined to be higher (approximately 24.3:1) in recently divergent parrot lineages than has generally been observed in other groups. Strongly biased base composition, particularly at the third position of codons, is evident among the sequences. Phylogenetic relationships among more divergent taxa were estimated, using only transversion substitutions, while all the substitutions were useful for closely related taxa. The African genera Psittacus and Poicephalus are closely related, in contrast to the Australian genera Nymphicus, Purpureicephalus and Melopsittacus, which represent more divergent lineages. The cockatoos appear to represent an ancient lineage within the parrots.

Animals

A comparative study of human and parrot phonation: acoustic and articulatory correlates of vowels.

General acoustic and articulatory parallels between human and avian production of human vowels have been identified. A complete set of vowels from an African Grey parrot (Psittacus erithacus) and a limited set from a Yellow-naped Amazon parrot (Amazonica ochrocephala auropalliata) have been analyzed. Comparison of human and avian acoustic parameters demonstrated both differences (e.g., absolute values of first formant frequencies) and similarities (e.g., separation of vowels into back and front categories with respect to tongue placement) in acoustic properties of avian and human speech. Similarities and differences were also found in articulatory mechanisms: Parrots, for example, use their tongues in some but not all the ways used by humans to produce vowels. Because humans perceive and correctly label vowels produced by psittacids despite differences in avian and human articulatory and acoustic parameters, the findings (a) are consistent with research that demonstrates the flexibility of vowel perception by humans and (b) suggest that the perceptual discontinuities that are exploited by speech may be basic to vertebrates rather than to mammals.

Animals

Nocardiosis in two Pesquet's parrots (Psittrichas fulgidus).

Nocardiosis is described in two Pesquet's parrots (Psittrichas fulgidus). Granulomatous lesions containing numerous branching, filamentous, acid-fast, gram- and methenamine silver-positive organisms were observed in sections of lung from both parrots, suggesting an oral-respiratory portal of entry. Thyroid follicular hyperplasia and osteoporosis were observed in one parrot, suggesting the presence of an underlying nutritional or metabolic defect.

Animals

Haematological findings in healthy and sick African grey parrots (Psittacus erithacus).

Full blood counts and fibrinogen estimations were carried out on 11 clinically normal, adult African grey parrots. Reference values derived from these tests were used to identify abnormalities in the blood counts of 11 sick parrots thought to be suffering from bacterial infections. All sick birds showed higher than normal heterophil counts, paralleled in some cases by lymphocytosis, monocytosis, thrombocytosis and increased fibrinogen levels. Anaemia was present in two birds and several others showed minor red cell abnormalities. The findings indicate that clinical haematology can make a useful contribution to the differential diagnosis of infection in African grey parrots. The findings also suggest that the development of anaemia can be a significant complicating factor in infectious conditions in these birds.

Animals