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At least 127 records · Page 7Linked to original sources
PubMed2005

Simultaneous liquid chromatographic determination of doxorubicin and its major metabolite doxorubicinol in parrot plasma.

A new microscale method is reported for the determination of doxorubicin and its active metabolite, doxorubicinol, in parrot plasma. Sample workup involved acetonitrile protein precipitation, ethyl acetate extraction, followed by back extraction into HCl. Separations were achieved on a phenyl-hexyl column at 30 degrees C using acetonitrile (17%, v/v) in 0.01 M orthophosphoric acid (83%, v/v) delivered via a linear flow program. Fluorometric detection wavelengths were 235 nm (excitation) and 550 nm (emission). Calibration plots were linear (r2>0.999), and recoveries were 71-87% from 20 to 400 ng/mL. Assay imprecision was <or=8.5% and inaccuracy was <or=6.3%. The limit of quantification was 25 ng/mL.

Animals↗
PubMed2001

Distribution of iron in the parrot brain: conserved (pallidal) and derived (nigral) labeling patterns.

The distribution of iron in the brain of a vocal learning parrot, the budgerigar (Melopsittacus undulatus), was examined using iron histochemistry. In mammals, iron is a highly specific stain for the dorsal and ventral pallidal subdivision as well as specific cell groups in the brainstem, including the substantia nigra pars reticulata [Neuroscience 11 (1984) 595-603]. The purpose of this study was to compare the distribution of iron in the mammalian and avian brain focusing on pallidal and nigral cell groups. The results show that in the avian brain, iron stains oligodendrocytes, neurons and the neuropil. Cell staining changes dramatically along the rostrocaudal axis, with neuronal labeling confined to regions caudal to the thalamus and oligodendrocyte labeling denser in regions rostral to the dorsal thalamus. Many sensory forebrain regions contain appreciable iron labeling, including telencephalic vocal control nuclei. The dorsal and ventral subdivision of the avian pallidum, along with the basal ganglia component of the vocal control circuit, the magnicellular nucleus of the lobus parolfactorius, stain heavily for iron. Several brainstem regions, including nucleus rotundus, the medial spiriform nucleus (SpM), the principle nucleus of the trigeminal nerve, nucleus laminaris and scattered cell groups throughout the isthmus and pontine reticular formation stain intensely for iron. Within SpM neuronal labeling is more intense in the medial division while oligodendrocyte labeling is more intense in the lateral division. surprisingly no nigral iron staining was observed. Our results imply that iron is a conserved marker for the pallidum in birds and mammals, but that patterns of nigral staining have diverged in birds and mammals. Differences in iron staining patterns between birds and mammals may also reflect the relatively greater importance of the collothalamic visual pathways, pretectal-cerebellar pathways and specialized vocal learning circuitry in avian sensory and motor processing.

Animals↗
PubMed1977

Histochemical study of the distribution of a few enzymes in the digestive system of Indian parrot.

Acid-and alkaline phosphatase, 5-nucleotidase and lipase have been localized histochemically in the gizzard, intestine liver and pancreas of Indian parrot, Psittacula krameri. In the gizzard and intestine, the mucosal epithelial cells are the main sites for the enzyme production. The tubular glands of the gizzard show intense reaction for all the enzymes tested. The hepatic sinusoid cells of the liver and the acinii of pancreas give positive reaction. Like pancreas, the intestine has also been found responsible for the production and secretion of lipase. Functional significance of phosphatases in the tissues tested has been discussed.

Acid Phosphatase↗
PubMed1991

Parrot psychology and behavior problems.

Behavior modification training, like veterinary medicine, is an exacting science, requiring a knowledge of not only wild avian behavior, but of child and adult human behavior as well. It is important to note that absolutely any changes in a bird's or its owner's environment may trigger a vast assortment undesirable behaviors. Some behavior problems are simple, but most have multiple causes and each of those causes must be determined and corrected before a high rate of success is evident. As in veterinary medicine, some birds respond to general "shotgun" techniques; however, parrots are intelligent and complex creatures. They consider themselves an integral part of their human "flock" and respond as such. Most commonly seen negative behaviors can be altered, at least to some extent, and, in most cases, they can be alleviated completely. Yelling at the bird, striking it, or any other type of confrontational behavior modification technique is virtually useless and can actually worsen most situations. A high percentage of success involves extensive history taking, an understanding of human and wild animal flock behavior, and the time to create a complete program for each individual and its owner.

Animals↗
PubMedDate not supplied

Postnatal development of lateralized motor preference in the African grey parrot (Psittacus erithacus).

The parrot appears to provide a potentially unique animal model of handedness in humans, but few (if any) observational studies of early postnatal development of postural/motor asymmetries have been published. We studied three African Grey hatchlings, raised without human physical contact, for the first 5 months of life. All three animals failed to show consistent postural and/or motor asymmetries until the end of the 4 postnatal week. These results appear to be comparable to data from prior studies with human infants. Delayed development of lateral motor and/or postural preferences may represent an evolutionarily adaptive strategy for altricial animals.

Animals↗
PubMed1991

Acquisition of a relative class concept by an African gray parrot (Psittacus erithacus): discriminations based on relative size.

We report that an African gray parrot (Psittacus erithacus), Alex, responds to stimuli on a relative basis. Previous laboratory studies with artificial stimuli (such as pure tones) suggest that birds make relational responses as a secondary strategy, only after they have acquired information about the absolute values of the stimuli. Alex, however, after learning to respond to a small set of exemplars on the basis of relative size, transferred this behavior to novel situations that did not provide specific information about the absolute values of the stimuli. He responded to vocal questions about which was the larger or smaller exemplar by vocally labeling its color or material, and he responded "none" if the exemplars did not differ in size. His overall accuracy was 78.7%.

Animals↗
PubMed1992

Proficient performance of a conjunctive, recursive task by an African gray parrot (Psittacus erithacus).

The comprehension skills of an African gray parrot (Psittacus erithacus), Alex, were tested on a taks that included a conjunctive condition. For each trial, Alex was shown different collections of 7 items, each collection chosen from among 100 objects of various combinations of shapes, colors, and materials, and he was asked to provide (vocally) information about the specific instance of one category of an item that was uniquely defined by the conjunction of two other categories (e.g., "What color is the [object defined by shape and material]?"). Other objects exemplified one, but not both, of these defining categories. Alex responded with an accuracy of 76.5%, which indicated that he understood all the elements in the question, including the conjunctive condition, and that he used these elements to guide his search for the one object in the collection that provided the requested information.

Animal Communication↗
PubMed2000

Vocal learning in the Grey parrot (Psittacus erithacus): effects of species identity and number of trainers.

Grey parrots (Psittacus erithacus) learn referential English labels when they view and interact with 2 humans who model vocal labeling and who demonstrate referentiality and functionality of a label (I.M. Pepperberg, 1990a). To test if both trainers are necessary, the authors contrasted 2-trainer modeling with training by 1 human who presented targeted labels to a bird in concert with appropriate items, who asked questions, and who would reward attempts at the label with the item. The bird was also tutored by either 1 or 2 interactive humans in conjunction with a conspecific who already used referential labels. Referential labels were learned from multiple live tutors but not a single trainer. Presence of a conspecific enhanced learning compared with single-trainer sessions but did not affect acquisition in 2-human sessions. Specific aspects of paired tutoring seem critical for acquiring referential vocal labels.

Animals↗
PubMed2005

Number comprehension by a grey parrot (Psittacus erithacus), including a zero-like concept.

A Grey parrot (Psittacus erithacus) that was able to quantify 6 item sets (including subsets of heterogeneous groups, e.g., blue blocks within groupings of blue and green blocks and balls) using English labels (I. M. Pepperberg, 1994a) was tested on comprehension of these labels, which is crucial for numerical competence (K. C. Fuson, 1988; see also record 1987-98811-000). He was, without training, asked "What color/object [number]?" for collections of various simultaneously presented quantities (e.g., subsets of 4, 5, and 6 blocks of 3 different colors; subsets of 2, 4, and 6 keys, corks, and sticks). Accuracy was greater than 80% and was unaffected by array quantity, mass, or contour. His results demonstrated numerical comprehension competence comparable to that of chimpanzees and very young children. He also demonstrated knowledge of absence of quantity, using "none" to designate zero.

Animals↗
PubMed2006

Grey Parrot (Psittacus erithacus) numerical abilities: addition and further experiments on a zero-like concept.

A Grey parrot (Psittacus erithacus), able to quantify 6 or fewer item sets (including heterogeneous subsets) by using English labels (I. M. Pepperberg, 1994), was tested on addition of quantities involving 0-6. He was, without explicit training, asked, "How many total X?" for 2 sequentially presented collections (e.g., of variously sized jelly beans or nuts) and required to answer with a vocal English number label. His accuracy suggested (a) that his addition abilities are comparable to those of nonhuman primates and young children, (b) some limits as to his correlation of "none" and the concept of zero, and (c) a possible counting-like strategy for the quantity 5.

Animals↗
PubMed2000

[Representation of the nerves of the wing of psittacines (Amazon, gray parrot} using a digital photographic technique].

In four blue-fronted Amazon and five African grey parrots, the nerves innervating the muscles of the wings were carefully dissected and described. The preparation steps were recorded with a digital camera. This technique has now advanced so far that the image quality is almost the same as that of a normal camera. The pictures are stored in a computer. They can be enhanced and published via the Internet.

Africa↗
PubMed2000

Screening the foods of an endangered parrot, the kakapo (Strigops habroptilus), for oestrogenic activity using a recombinant yeast bioassay.

In recent years the possibility of environmental oestrogens affecting the reproduction of vertebrates has become an issue of both public and scientific interest. Although the significance of such chemicals remains controversial there is clear evidence that, in some contexts, environmental oestrogens can influence the fertility of vertebrates. Highly endangered species represent a situation in which even modest reductions in the fertility of key individuals may have implications for the survival of the entire species. This paper reports the screening of both natural and supplementary foods of the kakapo (Strigops habroptilus), a critically endangered New Zealand nocturnal parrot, for oestrogenic activity using a recombinant yeast based bioassay. Low levels of oestrogenic activity were detected in one of the 'chick-raising' foods, but no oestrogenic activity was detected in the adult supplementary foods. The oestrogenicity of a range of phytochemicals possibly associated with the kakapo natural diet was also examined. Two such phytochemicals, podocarpic acid and its reduced derivative podocarpinol, showed weak oestrogenic activity (approximately 10(-6) and 10(-4) of the activity of 17-beta-oestradiol, respectively).

Abietanes↗
PubMed1975

Psittacine herpesvirus infection resembling pacheco's parrot disease.

Herpesvirus was detected by electron microscopy in hepatocytes of psittacine birds that died at a Florida aviary. The virus was identified in hepatocytes of chick embryos and budgerigars that were given injections of liver suspensions from naturally infected psittacines. Infected hepatocytes had prominent intranuclear inclusions that contained naked nucleocapsids. Both naked and enveloped virions were seen in the cytoplasm of hepatocytes, and enveloped nucleocapsids occasionally were seen in the perinuclear cisternae and extracellularly. The experimental and spontaneous disease mimicked a condition in parrots described previously by Pacheco. The viral agent was classified as Herpesvirus on the bases of the character of the intranuclear inclusions, the size and conformation of the agent as determined by electron microscopy and filtration, and the sensitivity of the agent to ether.

Animals↗
PubMed2001

Ultraviolet vision, fluorescence and mate choice in a parrot, the budgerigar Melopsittacus undulatus.

As in many parrots, the plumage of the budgerigar Melopsittacus undulatus reflects near-ultraviolet (UVA) wavelengths (300-400 nm) and exhibits UVA-induced fluorescence. However, there have, to our knowledge, been no tests of whether the yellow fluorescence observed under intense UVA illumination has any role in signalling. Four experiments were carried out on wild-type budgerigars, where the presence and absence of UV reflectance and fluorescence were manipulated using filters. Few studies have attempted to separate the contribution of UV reflectance to plumage hue as opposed to brightness or distinguish between a role in sexual as opposed to social preferences. However, our first experiments show that not only do females consistently prefer UV-reflecting males, but also that the observed preferences are due to removal of UV affecting the perceived hue rather than brightness. Furthermore, we found no effect of the light environment on male response to females, suggesting that the female preferences relate to plumage colour per se. Whilst UV reflectance appears important in heterosexual choice by females, it has no detectable influence on same-sex association preferences. The results from the second series of experiments suggest that enhancement of the budgerigar's yellow coloration through fluorescence has no effect on male attractiveness. However, the fluorescent plumage may play a role in signalling by virtue of the fact that it absorbs UVA and so increases contrast with nearby UV-reflecting plumage. Our study provides convincing evidence that UV reflectances can play a role in mate choice in non-passerines, but no evidence that the yellow fluorescence observed under UVA illumination is itself important as a signal.

Animals↗
PubMed1991

Intramuscular and oral disposition of enrofloxacin in African grey parrots following single and multiple doses.

The intramuscular (IM) and oral (PO) disposition of enrofloxacin, a new fluoroquinolone antimicrobial drug, were evaluated in African grey parrots. Peak enrofloxacin concentration, mean (+/- SEM), at 1 h following a 15-mg/kg IM dose was 3.87 (+/- 0.27) micrograms/ml and declined with a mean residence time of 3.05 h. Peak enrofloxacin plasma concentrations at 2 to 4 h following oral doses of 3, 15, and 30 mg/kg were 0.31 (+/- 0.11), 1.12 (+/- 0.11), and 1.69 (+/- 0.23) micrograms/ml, respectively, and declined with a mean residence time of 3.44-5.28 h. The relative bioavailability of the 15-mg/kg oral dose was 48%. An equipotent metabolite, ciprofloxacin, was detected in plasma at concentrations ranging from 3 to 78% of those of enrofloxacin. Enrofloxacin concentrations and area under the curve were significantly lower, the mean residence time significantly shorter and the ciprofloxacin/enrofloxacin ratios higher, following 10 days of oral treatment at 30 mg/kg every 12 h. Following 10 days of treatment, no significant biochemical changes were noted; however, polydipsia and polyuria occurred in treated birds, but resolved quickly upon discontinuation of enrofloxacin administration. These studies indicate that a rational starting dose for enrofloxacin in psittacines (7.5-30 mg/kg BID) should be higher than those in other domestic animals.

Administration, Oral↗
PubMed2005

Vocal dialects, sex-biased dispersal, and microsatellite population structure in the parrot Amazona auropalliata.

Geographic variation in microsatellite allele frequencies was assessed at nine sites in two regional vocal dialects of the parrot Amazona auropalliata (yellow-naped amazon) to test for correspondence between dialects and population structure. There was no relationship between the genetic distances between individuals and their dialect membership. High rates of gene flow were estimated between vocal dialects based on genetic differentiation. In addition, 5.5% of pairs of individuals compared across the dialect boundary were estimated to be related at the level of half siblings, indicating that dispersal is ongoing. The number of effective migrants per generation between dialects estimated with the microsatellite data was roughly one-seventh the number estimated with mitochondrial control region sequence data from the same individuals, suggesting that gene flow may be female-biased. Together, these results suggest that the observed mosaic pattern of geographic variation in vocalizations is maintained by learning of local call types by immigrant birds after dispersal. We found no evidence that ongoing habitat fragmentation has contributed to cryptic population structure.

Animals↗
PubMed1992

[Is there an internal tongue musculature in parrots?].

The result of this study shows that the tongue of the parrot has voluntary muscle that runs dorsally to the apex of the tongue. This musculature can be regarded as evidence that a reduced internal musculature exists.

Animals↗
PubMed2003

Acute beak and feather disease in juvenile African Grey parrots--an uncommon presentation of a common disease.

Psittacine Beak and Feather Disease is commonly diagnosed all over the world as a viral disease of psittacine birds that primarily results in abnormalities of the feathers and beak. The clinical presentation of this disease varies between species and age groups, but in the majority of cases the course of the disease is chronic. This case report documents an acute form of the disease in African Grey parrots (Psittacus erithacus erithacus) that resulted in death without lesions in the feathers and beak.

Acute Disease↗