Search

Morphology, habitat and various selective pressures (e.g. social and sexual selection) can influence the evolution of acoustic signals, but the relative importance of their effects is not well understood. The order Psittaciformes (parrots, sensu lato) is a large clade of very vocal and often gregarious species for which large-scale comparative studies of vocalizations are lacking. We measured acoustic traits (duration, sound frequency, frequency bandwidth and sound entropy) of the predominant call type for200 parrot species to test: (1) for associations with body size; (2) the acoustic adaptation hypothesis (AAH) (predicting differences between forest and open-habitat species); (3) the social complexity hypothesis (predicting more complex calls in gregarious species) and (4) influences of sexual selection (predicting correlated evolution with colour ornamentation). Larger species had on average longer calls, lower sound frequency and wider frequency bandwidth. These associations with body size are all predicted by physical principles of sound production. We found no evidence for the acoustic adaptation and social complexity hypotheses, but perhaps social complexity is associated with vocal traits not studied here, such as call repertoire sizes. More sexually dichromatic species had on average simpler calls (shorter, with lower entropy and narrower frequency bandwidth) indicating an influence of sexual selection, namely an evolutionary negative correlation between colour ornamentation and elaborate acoustic signals, as predicted by the transference hypothesis. Our study is the first large-scale attempt at understanding acoustic diversity across the Psittaciformes, and indicates that body size and sexual selection influenced the evolution of species differences in vocal signals.

Parrot embryos carry peculiar appendages at their developing beak that have been described as pseudoteeth. To better characterize the pattern of development responsible for the emergence of these dental appendages, we examined parrot embryos combining conventional histology and microtomography approaches. Using immunohistochemistry, we observed the epithelial and mesenchymal expression of several proteins involved in tooth development in mammals. Parrot pseudoteeth arose by epithelial and mesenchymal evagination, and their early development was similar to the ontogeny of scales and feathers. There was no enamel tissue, and the evaginations were surrounded by the rhamphotheca. In adults, the rhamphotheca covers entirely the appendages, now represented by bone evaginations, which were more numerous in the lower than in the upper beak, being similar to the osseous teeth of the fossil Pelagornithidae. These embryonic pseudoteeth resembled reptile's first-generation teeth and dental appendages of chicken talpid

Objective To report the temporal and spatial distribution of rainbow lorikeets presenting with lorikeet paralysis syndrome (LPS) and their clinicopathologic and pathologic findings, exposure to toxins, and response to treatment. Methods Records of lorikeets admitted in 2017 and 2018 to facilities in south‐east Queensland (QLD) were reviewed and LPS and non‐LPS cases were mapped and their distribution compared. Plasma biochemistries and complete blood counts were done on 20 representative lorikeets from south‐east QLD and Grafton, New South Wales (NSW). Tissues from 28 lorikeets were examined histologically. Samples were tested for pesticides (n = 19), toxic elements (n = 23), botulism (n = 15) and alcohol (n = 5). Results LPS occurred in warmer months. Affected lorikeets were found across south‐east QLD. Hotspots were identified in Brisbane and the Sunshine Coast. Lorikeets had a heterophilic leucocytosis, elevated muscle enzymes, uric acid and sodium and chloride. Specific lesions were not found. Exposure to cadmium was common in LPS and non‐LPS lorikeets. Treated lorikeets had a 60–93% See Table 2 depending on severity of signs. Clinical significance The primary differential diagnosis for lorikeets presenting with lower motor neuron signs during spring, summer and autumn in northern NSW and south‐east Queensland should be LPS. With supportive care, prognosis is fair to good.

The genetic structure of animal populations has considerable behavioural, ecological and evolutionary implications and may arise from various demographic traits. Here, we use observational field data and molecular genetics to determine the genetic structure of an invasive population of monk parakeets, Myiopsitta monachus, at a range of spatial scales, and investigate the demographic processes that generate the observed structure. Monk parakeets construct large nests that can house several pairs occupying separate chambers; these nests are often aggregated within nesting trees. We determined patterns of relatedness within compound nests, within nesting trees and between trees. Spatial autocorrelation analyses of pairwise genetic relatedness revealed fine-scale genetic structure with relatives of both sexes spatially clustered within, but not beyond, nesting trees. In addition, males were more related to males sharing their compound nests than to other males occupying the same nesting tree. By contrast, males and females within compound nests were not significantly more closely related than elsewhere in the same tree, and we found no evidence for inbreeding. Adults showed high breeding site fidelity between years despite considerable disturbance of nest sites. Natal dispersal was female-biased, but dispersal distances were relatively short with some natal philopatry observed in both sexes. Sibling coalitions, typically of males, were observed amongst both philopatric and dispersing birds. Our results show significant clustering of kin within compound nests and nesting trees resulting from limited and coordinated natal dispersal, with subsequent breeding site fidelity. The resulting genetic structure has implications for social behaviour in this unusual parrot species.

Background Lipid accumulation disorders, such as atherosclerosis and hepatic lipidosis, are common in psittacine birds and associated with various dyslipidemias. Gel-permeation high-performance liquid chromatography (GP-HPLC) is a reference method for advanced lipoprotein profiling based on particle size separation, followed by an analysis of lipid contents. Objectives The objectives were to (a) characterize Quaker parrot lipoproteins using a commercial GP-HPLC method (Liposearch panel), and (b) obtain preliminary information on the reliability of the Friedewald formula for low-density lipoprotein-cholesterol (LDL-C) measurements. Methods Plasma samples were collected from 12 fasted healthy Quaker parrots. Cholesterol concentrations, triglyceride concentrations, particle sizes, and particle numbers were determined by GP-HPLC for four classes and 20 sub-fractions of lipoproteins. The LDL-C concentrations obtained using the Friedewald formula and direct measurements were compared with Bland-Altman plots. Alternate formulas were determined using multiple linear regression. Results High-density lipoprotein (HDL) was the predominant lipoprotein in Quaker parrots, and most particles were of medium-to-small sizes belonging to two sub-fractions (average size, 10.6 nm). LDL was the second most common lipoprotein and included large-to-small particles belonging to three sub-fractions (average size, 24.9 nm). Very-low-density lipoproteins (VLDL) and portomicrons were present in low concentrations. The Friedewald formula underestimated LDL-C concentrations with a significant bias of 0.44 mmol/L. An alternate formula was proposed: LDL-C = 0.75*Non-HDL-C. Conclusions GP-HPLC allowed unprecedented characterization of plasma lipoproteins in Quaker parrots. Characterizing psittacine lipoprotein is useful for validation and interpretation of routine clinical tests as well as for use in epidemiologic and experimental research on psittacine lipid accumulation disorders.

Parrots are often referenced in discussions of social and cognitive complexity, yet relatively little is known of their social organisation in the wild. In particular, the presence of long-lasting social ties has been highlighted as a hallmark of social complexity, however the presence of such ties can be masked in fission-fusion systems like that exhibited by most parrot species. Social network analysis has the potential to elucidate such multi-level dynamics. While most parrot species are tropical canopy dwellers, a subset have successfully colonised urban habitats, where they are often the focus of much public interest. Our study takes advantage of this to use citizen-science to collect observations of wing-tagged sulphur-crested cockatoos in central Sydney and record their social associations over multiple years. Using a specifically designed mobile phone application "Wingtags", we collected over >27,000 citizen-science reports of wing-tagged cockatoos, and built social networks from spatial-temporal co-occurrences in observations for 130 tagged birds. To validate this novel methodology, we GPS-tagged a subset of wing-tagged birds and compared networks built from both data collection methods. We then examined correlates of social network structure before exploring the temporal dynamics of network structure and social associations. Social networks constructed from GPS data and citizen science data were highly correlated, suggesting that this novel methodology is robust. Network structure exhibited little seasonal variability and was largely driven by roost site choice; however, individuals also showed a surprising degree of mixing between roosts in their foraging associations. Finally, within this larger fission-fusion system, individuals tended to maintain specific social ties for long periods of time. There was an effect of age on these temporal dynamics, with aging individuals increasing both social stability and longevity of associations. Our findings highlight the utility of citizen-science to measure social networks in urban species, and add to the evidence that long-lasting social associations can persist in fission-fusion social systems such as those observed in wild sulphur-crested cockatoos.

Life history theory predicts that physiological and behavioral responsiveness to stress should be delayed in development until the benefits of heightened reactivity outweigh the costs of potentially chronic glucocorticoid levels. Birds often acquire stress-responsiveness at locomotor independence, however, both stress-responsiveness and locomotor ability are delayed in birds with altricial developmental strategies. Parrots (Psittacidae) are extremely altricial, but it is not known whether they also postpone physiological responsiveness to stress until locomotor independence. We quantified individual variation in baseline and stress-induced plasma corticosterone (CORT) concentrations, the main avian glucocorticoid, in wild green-rumped parrotlets (Forpus passerinus) of Venezuela at four stages of nestling development. Parrotlet neonates are very underdeveloped and compete for parental care among extreme sibling size hierarchies, a competitive scenario that might benefit from early hypothalamic-pituitary-adrenal (HPA) functionality. Nestlings that underwent a standardized restraint stress-treatment showed higher average CORT concentrations compared to baseline in all age groups sampled, and exhibited no evidence of age-related changes in the stress response. This is 2 weeks before locomotor independence and earlier than previously documented for altricial species. Results suggest that precocity of HPA function may be advantageous to growth and survivorship in extremely altricial birds.

Sperm competition is an important component of post‐copulatory sexual selection that has shaped the evolution of sperm morphology. Previous studies have reported that sperm competition has a concurrently directional and stabilizing effect on sperm size. For example, bird species that show higher levels of extrapair paternity and larger testes (proxies for the intensity of sperm competition) have longer sperm and lower coefficients of variation in sperm length, both within and between males. For this reason, these sperm traits have been proposed as indexes to estimate the level of sperm competition in species for which other measures are not available. The relationship between sperm competition and sperm morphology has been explored mostly for bird species that breed in temperate zones, with the main focus on passerine birds. We measured sperm morphology in 62 parrot species that breed mainly in the tropics and related variation in sperm length to life‐history traits potentially indicative of the level of sperm competition. We showed that sperm length negatively correlated with the within‐male coefficient of variation in sperm length and positively with testes mass. We also showed that sperm is longer in sexually dichromatic and in gregarious species. Our results support the general validity of the hypothesis that sperm competition drives variation in sperm morphology. Our analyses suggest that post‐copulatory sexual selection is also important in tropical species, with more intense sperm competition among sexually dichromatic species and among species that breed at higher densities., Sperm competition has shaped the evolution of sperm morphology among different taxa, and we now provide evidence of this effect among parrots. Parrot species that breed close together and are sexually dichromatic have longer sperm.

Author(s): Ribot, Raoul FH; Berg, Mathew L; Schubert, Emanuel; Endler, John A; Bennett, Andrew TD

Sex-biased mortality can lead to altered adult sex ratios (ASRs), which may in turn lead to harassment and lower fitness of the rarer sex and changes in the mating system. Female critically endangered swift parrots (Lathamus discolor) suffer high predation while nesting due to an introduced mammalian predator, the sugar glider (Petaurus breviceps). High predation on females is causing severe population decline alongside strongly biased adult sex ratios (≥73% male). Our 6-year study showed that 50.5% of critically endangered swift parrot nests had shared paternity although the birds remained socially monogamous. Shared paternity increased significantly with the local rate of predation on breeding females, suggesting that rates of shared paternity increased when the ASR became more biased. Nests that were not predated produced fewer fledglings as the local ASR became more male-biased possibly due to higher interference during nesting from unpaired males. Population viability analyses showed that part of the predicted decline in the swift parrot population is due to reduced reproductive success when paternity is shared. The models predicted that the population would decline by 89.4% over three generations if the birds maintained the lowest observed rate of shared paternity. This compares with predicted population reductions of 92.1-94.9% under higher rates of shared paternity. We conclude that biases in the ASR, in this case caused by sex-specific predation from an introduced predator, can lead to changes in the mating system and negative impacts on both individual fitness and long-term population viability.

Self-control is critical for both humans and nonhuman animals because it underlies complex cognitive abilities, such as decision-making and future planning, enabling goal-directed behavior. For instance, it is positively associated with social competence and life success measures in humans. We present the first review of delay of gratification as a measure of self-control in nonhuman primates, corvids (crow family) and psittacines (parrot order): disparate groups that show comparable advanced cognitive abilities and similar socio-ecological factors. We compare delay of gratification performance and identify key issues and outstanding areas for future research, including finding the best measures and drivers of delayed gratification. Our review therefore contributes to our understanding of both delayed gratification as a measure of self-control and of complex cognition in animals. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Psychology > Comparative Psychology.

Self‐control is critical for both humans and nonhuman animals because it underlies complex cognitive abilities, such as decision‐making and future planning, enabling goal‐directed behavior. For instance, it is positively associated with social competence and life success measures in humans. We present the first review of delay of gratification as a measure of self‐control in nonhuman primates, corvids (crow family) and psittacines (parrot order): disparate groups that show comparable advanced cognitive abilities and similar socio‐ecological factors. We compare delay of gratification performance and identify key issues and outstanding areas for future research, including finding the best measures and drivers of delayed gratification. Our review therefore contributes to our understanding of both delayed gratification as a measure of self‐control and of complex cognition in animals. This article is categorized under:Cognitive Biology > Evolutionary Roots of CognitionPsychology > Comparative Psychology, Examples of delayed gratification tasks. (a) Exchange task with a corvid: subject can choose to swap a token (e.g., bottle top) for a reward after a delay; (b) Intertemporal choice: monkey can select the immediately available reward or wait for the delayed reward from a rotating tray.

Meloxicam is a nonsteroidal anti-inflammatory drug commonly used in avian species. In this study, the pharmacokinetic parameters for meloxicam were determined following single intravenous (i.v.), intramuscular (i.m.) and oral (p.o.) administrations of the drug (1 mg/kg·b.w.) in adult African grey parrots (Psittacus erithacus; n = 6). Serial plasma samples were collected and meloxicam concentrations were determined using a validated high-performance liquid chromatography assay. A noncompartmental pharmacokinetic analysis was performed. No undesirable side effects were observed during the study. After i.v. administration, the volume of distribution, clearance and elimination half-life were 90.6 ± 4.1 mL/kg, 2.18 ± 0.25 mL/h/kg and 31.4 ± 4.6 h, respectively. The peak mean ± SD plasma concentration was 8.32 ± 0.95 μg/mL at 30 min after i.m. administration. Oral administration resulted in a slower absorption (tmax = 13.2 ± 3.5 h; Cmax = 4.69 ± 0.75 μg/mL) and a lower bioavailability (38.1 ± 3.6%) than for i.m. (78.4 ± 5.5%) route. At 24 h, concentrations were 5.90 ± 0.28 μg/mL for i.v., 4.59 ± 0.36 μg/mL for i.m. and 3.21 ± 0.34 μg/mL for p.o. administrations and were higher than those published for Hispaniolan Amazon parrots at 12 h with predicted analgesic effects.

Objective This study investigated the prevalence of psittacine beak and feather disease virus (BFDV), avian polyomavirus (APV) and psittacine adenovirus (PsAdV) in captive psittacine birds around Port Phillip Bay, Victoria, Australia. Methods Samples of fresh droppings were collected from 118 psittacine birds (109 clinically normal and 9 with feather abnormalities) from 11 avaries in different locations and were used for detection of BFDV, APV and PsAdV using PCR. Results BFDV, APV and PsAdV were detected in 31%, 13% and 4%, respectively, of the specimens tested. One budgerigar was found to be co-infected with BFDV and PsAdV. At least one sample tested positive for BFDV at each location. Conclusion This is the first report of the prevalence of BFDV, APV and PsAdV in Victoria and provides a foundation for future studies examining the influence of these viruses on the health of aviary birds in Victoria.

Psittaciformes are a very diverse group of non-passerine birds, with advanced cognitive abilities and highly developed locomotor and feeding behaviours. Using computed tomography and three-dimensional (3D) visualization software, the endocasts of 14 extant Neotropical parrots were reconstructed, with the aim of analysing, comparing and exploring the morphology of the brain within the clade. A 3D geomorphometric analysis was performed, and the encephalization quotient (EQ) was calculated. Brain morphology character states were traced onto a Psittaciformes tree in order to facilitate interpretation of morphological traits in a phylogenetic context. Our results indicate that: (i) there are two conspicuously distinct brain morphologies, one considered walnut type (quadrangular and wider than long) and the other rounded (narrower and rostrally tapered); (ii) Psittaciformes possess a noticeable notch between hemisphaeria that divides the bulbus olfactorius; (iii) the plesiomorphic and most frequently observed characteristics of Neotropical parrots are a rostrally tapered telencephalon in dorsal view, distinctly enlarged dorsal expansion of the eminentia sagittalis and conspicuous fissura mediana; (iv) there is a positive correlation between body mass and brain volume; (v) psittacids are characterized by high EQ values that suggest high brain volumes in relation to their body masses; and (vi) the endocranial morphology of the Psittaciformes as a whole is distinctive relative to other birds. This new knowledge of brain morphology offers much potential for further insight in paleoneurological, phylogenetic and evolutionary studies., Facultad de Ciencias Naturales y Museo

Summary 1. Unlike philopatric migrants, the ecology of nomadic migrants is less well understood. This life-history strategy reflects responses to spatiotemporal variation in resource availability and the need to find resource rich patches to initiate breeding. The fitness consequences of movements between regions of patchily distributed resources can provide insight into ecology of all migrants and their responses to global change. 2. We link broad-scale data on spatiotemporal fluctuation in food availability to data on settlement patterns and fitness outcomes for a nomadic migrant, the endangered swift parrot Lathamus discolor. We test several predictions to determine whether facultative movements are adaptive for individual swift parrots in an environment where resources are patchily distributed over time and space. 3. Variation in the availability of swift parrot food resources across our study period was dramatic. As a consequence, swift parrots moved to breed wherever food was most abundant and did not resettle nesting regions in successive years when food availability declined. By moving, swift parrots exploited a variable food resource and reproduced successfully. 4. Exploiting the richest patches allowed swift parrots to maintain stable fitness outcomes between discrete breeding events at different locations. Unlike sedentary species that often produce few or lower quality offspring when food is scarce, nomadic migration buffered swift parrots against extreme environmental variation. 5. We provide the first detailed evidence that facultative movements and nomadic migration are adaptive for individuals in unpredictable environments. Our data support the widely held assumption that nomadic migration allows animals to escape resource limitation.

Inferring past demography is a central question in evolutionary and conservation biology. It is, however, sometimes challenging to infer the processes that shaped the current patterns of genetic variation in endangered species. Population substructuring can occur as a result of survival in several isolated refugia and subsequent recolonization processes or via genetic drift following a population decline. The kea (Nestor notabilis) is an endemic parrot widely distributed in the mountains of the South Island of New Zealand that has gone through a major human-induced population decline during the 1860s-1970s. The aims of this study were to understand the glacial and postglacial history of kea and to determine whether the recent population decline played a role in the shaping of the current genetic variation. We examined the distribution of genetic variation, differentiation and admixture in kea using 17 microsatellites and the mitochondrial control region. Mitochondrial data showed a shallow phylogeny and a genetic distinction between the North and South of the range consistent with the three genetic clusters identified with microsatellite data. Both marker types indicated an increase in genetic isolation by geographic distance. Approximate Bayesian Computation supported a scenario of postglacial divergence from a single ancestral glacial refugium, suggesting that the contemporary genetic structure has resulted from recolonization processes rather than from a recent population decline. The recent evolutionary origin of this genetic structure suggests that each genetic cluster does not need to be considered as independent conservation units.

Monk parrots (Myiopsitta monachus) are susceptible to atherosclerosis, a progressive disease characterized by the formation of plaques in the arteries accompanied by underlying chronic inflammation. The family of n-3 fatty acids, especially eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have consistently been shown to reduce atherosclerotic risk factors in humans and other mammals. Some avian species have been observed to convert α-linolenic acid (18:3n-3, ALA) to EPA and DHA (Htin et al. in Arch Geflugelk 71:258-266, 2007; Petzinger et al. in J Anim Physiol Anim Nutr, 2013). Therefore, the metabolic effects of including flaxseed oil, as a source of ALA, in the diet at three different levels (low, medium, and high) on the lipid metabolism of Monk parrots was evaluated through measuring plasma total cholesterol (TC), free cholesterol (FC), triacylglycerols (TAG), and phospholipid fatty acids. Feed intake, body weight, and body condition score were also assessed. Thus the dose and possible saturation response of increasing dietary ALA at constant linoleic acid (18:2n-6, LNA) concentration on lipid metabolism in Monk parrots (M. monachus) was evaluated. Calculated esterified cholesterol in addition to plasma TC, FC, and TAG were unaltered by increasing dietary ALA. The high ALA group had elevated levels of plasma phospholipid ALA, EPA, and docosapentaenoic acid (DPAn-3, 22:5n-3). The medium and high ALA groups had suppressed plasma phospholipid 20:2n-6 and adrenic acid (22:4n-6, ADA) compared to the low ALA group. When the present data were combined with data from a previous study (Petzinger et al. in J Anim Physiol Anim Nutr, 2013) a dose response to dietary ALA was observed when LNA was constant. Plasma phospholipid ALA, EPA, DPAn-3, DHA, and total n-3 were positively correlated while 20:2n-6, di-homo-gamma-linoleic acid (20:3n-6Δ7), arachidonic acid (20:4n-6), ADA, and total n-6 were inversely correlated with dietary en% ALA.

The effect of α-linolenic acid from a flaxseed (FLX)-enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty-four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at -5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n-3 (α-linolenic acid), 20:5n-3 (eicosapentaenoic acid) and 22:6n-3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n-6 (arachidonic acid). By day 70, the high-density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α-linolenic acid to the long-chain omega-3 derivatives including docosahexaenoic acid and reduce 20:4n-6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time.

The temporal origins of the extraordinary biodiversity of the Neotropical region are highly debated. Recent empirical work has found support for alternative models on the tempo of speciation in Neotropical species further fuelling the debate. However, relationships within many Neotropical lineages are poorly understood, and it is unclear how this uncertainty impacts inferences on the evolution of taxa in the region. We examined the robustness of diversification patterns in the avian genus Forpus by testing whether the use of different units of biodiversity (i.e. biological species and statistically inferred species) impacted diversification rates and inferences regarding important biogeographic breaks in the genus. We found that the best-fit model of diversification for the biological species data set was a declining rate of diversification; whereas a model of constant diversification was the best-fit model for statistically inferred species or subspecies. Moreover, the relative importance of different landscape features in delimiting genetic structure across the landscape varied across data sets with differing units of biodiversity. Patterns based on divergence times among biological species indicated old speciation events across major geographic and river barriers. In contrast, data sets more inclusive of the diversity in Forpus illustrate the role of both old divergence across major landscape features and more recent divergences that are possibly attributed to Pleistocene climatic changes. Overall, these results indicate that conflicting models on the temporal origins of Neotropical birds may be attributable to sampling biases.

A feeding trial was performed to study the influence of particle size in extruded parrot pellets on apparent digestibility and excreta consistency and pH. Two test diets were alternately provided to eight African grey parrots according to a 2 x 2 cross-over design. Both diets were similar in nutrient content and ingredient composition but differed in particle size of the composing particles of individual pellets. Apparent digestibility of macronutrients was studied using the total collection method. Next, the appearance of the excreta was studied by calculation of weight-surface ratio of individual excrements as an objective measurement of consistency. Last, excreta pH was measured directly on fresh excrements and on homogenized 10% excreta solutions. Neither apparent digestibility coefficients nor excreta pH values were significantly different in parrots fed the two diets. However, excreta consistency was significantly (p < 0.05) more solid when fed the coarse diet than when fed with the finely ground diet. The results of this study suggest that excreta consistency can be improved through larger particle size, without adverse effects on nutritive value of the diet.

Although knowledge of the nutrient requirements of pet birds has increased a lot over the last few years, basic data on food and water intake and the energy requirements of nectarivorous species, such as lorikeets, are scarce. Thus, the aim of this study was to try to generate some of these data for lorikeets kept at maintenance. Determination of the daily maintenance energy requirement enables calculation of the daily ration and thus, the appropriate nutrient concentrations in order to maintain body weight. Investigations were carried out with six Goldie's lorikeets (GL; Trichoglossus goldiei: 40-50 g BW; 1-4 years) and six rainbow lorikeets (RL; Trichoglossus haematodus haematodus: 120-140 g BW; 1-12 years). Three of the most commonly used diets/foods (commercial 'lory soup'/apples/pollen: crude ash - 52.9/17.8/18.8; crude protein - 178/32.5/191; crude fat - 52.8/0.89/73.1; crude fibre - 17.9/40.5/30.4; starch - 139/not detectable/127; sugar - 522/859/418 g/kg DM; ME - 13.9/14.6/10.9 MJ/kg DM) were individually offered ad libitum. The measured dry matter (DM) intake (g/100 g BW) corresponded well to the values reported for granivorous bird species of similar body mass. Both lorikeet species achieved an apparent digestibility of organic matter of more than 90% for apples, approximately 82% for 'lory soup' and approximately 55% for pollen. The water content of the food affected the DM content of the excreta; 8% when fed 'lory soup', 2% for apples and approximately 30% when fed pollen. Regression analysis of body weight change relative to energy intake demonstrated constant body mass (assuming no change in body composition) when the daily energy intakes were 860 (GL) or 650 (RL) kJ ME/kg BW(0.75).

Proventricular dilatation disease is a viral disease seen as a segmental neuropathy in parrots. It has always been believed to be a disease exotic to Australia, with the only reported case being a legally imported Green Wing Macaw (Ara chloroptera) in 1993. This paper reports a cluster of cases seen in south-east Queensland in 2005 to 2006. Clinical signs, autopsy findings and histopathological findings are described. No pattern or common source for these cases could be identified. The implications for Australian aviculture and avifauna are discussed.

The effects of providing ultraviolet (uv) radiation (285 to 315 nm, ultraviolet B) on calcium metabolism in two groups of 20 healthy grey parrots (Psittacus e erithacus) fed either a seed or pellet-based diet were investigated. There was a significant increase in the concentration of ionised calcium in the plasma of both groups, independent of the calcium and vitamin D(3) content of the diets fed, and a significant increase in the plasma concentration of 25-hydroxycholecalciferol in only the seed-fed group. In a separate study there were no significant increases in plasma ionised calcium or 25-hydroxycholecalciferol between March and August in a group of 28 South American parrots (Pionus species) exposed to unfiltered natural sunlight.

Parrots have developed unique jaw muscles in their evolutionary history. The M. pseudomasseter, which completely covers the lateral side of the jugal bar, is regarded as a jaw muscle unique to parrots. In a previous study, I presented a hypothesis on the relevance of modifications in the regulation of cranial neural crest cell (NCC) development to the generation of this novel jaw muscle based on histological analyses (Tokita [2004] J Morphol 259:69–81). In the present study, I investigated distribution and migration patterns of cranial neural crest cells (NCCs) through parrot embryogenesis with immunohistochemical techniques to further understand the role of cranial NCCs in the evolution of the M. pseudomasseter, and to provide new information on the relative plasticity in cranial NCC migration at early stages of avian development. The basic nature of cranial NCC development was mostly conserved between chick and parrot. In both, cranial NCCs migrated from the dorsal tip of the neural tube in a ventral direction. Three major populations were identified in their cranial NCCs. Migration pathways of these cells were almost identical between chick and parrot. The principal difference was seen in the relative timing of cranial NCC migration. In the parrot, cranial NCC migration into the first pharyngeal arch was more advanced than in the chick at early stages of development. Such a temporal shift in cranial NCC migration might influence architectural patterning of parrot jaw muscles that generates new muscle like M. pseudomasseter. J. Morphol. © 2005 Wiley-Liss, Inc.

The purpose of this study was to determine whether Japanese quail (Coturnix japonica) would serve as a pharmacokinetic animal model for two small companion parrots: cockatiels (Nymphicus hollandicus) and Poicephalus parrots. Oxytetracycline (OTC) was the pharmacologic agent chosen for this study as it is eliminated primarily by renal glomerular filtration and undergoes minimal metabolism. A single intravenous injection of 20 mg/kg oxytetracycline hydrochloride was administered to the three study groups and blood samples were obtained at 5, 10, 15, and 30 min post-OTC injection as well as 1, 2, 4, 8, 12 and 24 h post-OTC injection. Quantification of plasma OTC was accomplished using a standardized microbial inhibition assay. Naïve-pooled data (NPD) analysis of the plasma concentration-time profile of OTC best fit a two-compartment open model for all three avian species. Noncompartmental analysis of the mean data yielded the following parameters for quail, cockatiels and Poicephalus parrots respectively: lambda(z) = 3.14, 4.57, 3.71 h; AUC = 38.9, 42.7, 49.6 microg x h/mL; and Cl = 514, 468, 403 mL/h/kg. Based on the similarity of these pharmacokinetic parameters, it appears that quail could be used as a model species to predict the appropriate OTC dosing regimen for small psittacine birds. A bootstrap procedure was also applied to these sparse data sets for both compartmental and noncompartmental analysis. The bootstrap procedure allowed for the calculation of variability of parameters; however, the estimates of the parameters were very similar to those calculated using the NPD and the data mean values.

In this paper, an overview is given of the composition of 30 commercially available parrot seed mixtures. As parrots dehull the seeds, the analysis of the total seed mixture tends to differ from that of the ingested feed. Statistical evaluation and comparison of the dehulled seeds vs. the whole seeds indicates that most parrot species are fed a diet rich in fat (31.7 +/- 13.1% crude fat) and energy (22.4 +/- 2.9 MJ ME/kg). As the analysis of the total seed mixtures underestimates fat and energy content of the ingested feed, it is suggested that researchers, bird nutritionists and bird food producers should calculate diets based on the analysis of the dehulled seeds. Finally, the calculated data were compared with the composition of formulated pelleted/extruded diets on the market. These data indicate that the energy density of most diets (15.6 +/- 1.4 MJ ME/kg) is far below the energy density of common seed mixtures.

The aim of this study was to establish reference values for the assessment of cardiac function in birds by measuring structures in the heart of healthy psittacine birds; 60 grey parrots, 10 Amazon parrots, 10 cockatoos and 10 Senegal parrots were anaesthetised with isoflurane and examined echocardiographically. The heart was visualised in two planes (vertical and horizontal views). Depending on the quality of the images, several dimensions of the heart could be measured and various parameters calculated. On the basis of these values, it was possible to establish reference values for each parrot genus. Some relative parameters showed no significant difference between the genera, independent of the bird's size.

A clutch of five dusky parrots (Pionus fuscus) was observed from hatching to fully grown. They were examined radiographically from 16 to 45 days of age, a few days before the cessation of bone growth, and the development of their feathers and their behaviour were also studied. It was observed that when growing birds were removed from the nest and placed singly on a flat surface they would stand up and walk about until restrained; normally these birds would move very little and lie in an intertwined huddle that supported their relatively weak growing skeletons. At 50 days old they would climb to the nest entrance, retreating if scared. From day 51 the parrots flapped their wings vigorously inside the nest box, and they emerged at 53 days old when nearly all their large feathers had finished growing. These findings may help to explain the high rate of juvenile osteodystrophy in hand-reared parrots; premature exercise could lead to pathological deformity of the long bones, especially the major weight-bearing bone, the tibiotarsus.

Hydrocephalus was diagnosed in a juvenile African Grey parrot by high-field strength (4.7-Tesla) magnetic resonance imaging (MRI). Excellent anatomic detail was achieved, and there was severe dilation of all ventricles. Relative obstruction was localized to the level of or beyond the outflow of the fourth ventricle. There have been several reports of hydrocephalus diagnosed postmortem in psittacines (i.e., hook-billed parrots), however, this is the first report of an antemortem diagnosis in a psittacine using high-field strength MRI.

Vocal imitation is a complex form of imitative learning that is well developed only in humans, dolphins, and birds. Among birds, only some species are able to imitate sounds in adulthood. Of these, the budgerigar (Melopsittacus undulatus) has been studied in most detail. Previous studies suggested that the vocal motor system in budgerigars receives auditory information from the lateral frontal neostriatum (NFl). In the present study, we confirm this hypothesis by showing that infusions of the GABA agonist muscimol into NFl reduce the strength of auditory responses in a telencephalic vocal motor nucleus, the central nucleus of the lateral neostriatum (NLc). To test whether the auditory information conveyed from NFl to NLc plays a role in vocal imitation, we lesioned parts of NFl and the overlying ventral hyperstriatum (HVl) in seven adult male budgerigars and then examined whether the lesioned males would imitate the calls of females with whom they were paired. We found that, compared to sham-lesioned controls, the lesioned birds were significantly impaired in their imitation of female calls. Yet, the lesioned males were clearly not deaf (e.g., their previously learned calls did not degrade as they do after deafening). Therefore, the data suggest that NFl/HVl lesions impair vocal imitation by reducing the amount of auditory information that reaches the vocal motor system. Interestingly, the females that were paired with lesioned males displayed more vocal plasticity than the females in the control group, and some even imitated their male's prepairing calls.

ObjectiveTo describe a syndrome of wasting, diarrhoea and mortality in Australian king parrots (Alisterus scapularis). DesignField observations and laboratory examinations. Procedure Pathological examinations were performed on 50 Australian king parrots with wasting and diarrhoea. Wet preparations of intestinal contents were examined by light microscopy. Tannins were extracted from acorns (Quercussp) and tested for toxicity in mice. Clinicalsigns and epidemiology A syndrome of wasting, diarrhoea and mortality was observed in wild juvenile Australian king parrots in eastern Australia from 1984 to 2000. Sporadic cases and outbreaks of disease occurred from May to September in New South Wales, the Australian Capital Territory and Victoria. Outbreaks in the Australian Capital Territory in 1990 and 1991 were associated with parrots congregating to feed on acorns. Most affected birds failed to respond to treatment with dimetridazole and died 1 to 14 days after hospitalisation. Selected cases recovered following treatment with metronidazole. PathologyAffected birds were emaciated, with faecal matting of feathers around the cloaca and yellow-green fluid, foamy intestinal contents. Abundant motile Spironucleus trophozoites were observed in wet preparations of faeces of clinically affected birds and intestinal contents of birds examined within 1 h of death. Protozoa were detected histologically in crypts of Lieberkuhn in the intestine in association with exudation of mucus (catarrhal enteritis) or lymphoplasmacytic enteritis. ToxicologyTannin extracts from acorns induced periacinar hepatic necrosis in mice. ConclusionWasting, diarrhoea and mortality in wild juvenile Australian king parrots were associated with Spironucleuslike protozoa in the intestine. Acorns were not considered to be the cause of the syndrome.

A new species, Sarcocystis lindsayi n. sp., is proposed for a parasite resembling Sarcocystis falcatula. It was obtained from the lungs and muscles of budgerigars (Melopsittacus undulatus) fed sporocysts from a naturally-infected South American opossum, Didelphis albiventris, from Jaboticabal, Brazil. Sarcocysts of S. lindsayi n. sp. in budgerigars are microscopic, up to 600 microm long and up to 50 microm wide. The cyst wall is up to 2 microm thick. Ultrastructurally, the sarcocyst wall consists of numerous slender villar protrusions (up to 2.0 microm long and up to 0.3 microm wide), each with a stylet at its tip. Schizonts in cell culture divide by endopolygeny leaving a residual body. Sporocysts are approximately 12 x 7 microm. The parasite is genetically distinct from other organisms that also cycle between opossums and avian species and resemble S. falcatula. Diagnostic genetic variation has been observed in the nuclear large subunit ribosomal RNA gene, the internal transcribed spacer (ITS-1), and each of two other genetic loci. Although the structure of the sarcocyst wall may not provide sufficient grounds for differential diagnosis, several other attributes including schizont morphology and genetic variation at each of these genetic loci permit identification of S. lindsayi n. sp.. Natural intermediate hosts for S. lindsayi n. sp. are not known, and fuller characterization of these and other Sarcocystis species would benefit from experimental avian hosts that are more permissive to the maturation of sarcocysts.

Background: Chicken serum albumin (α-livetin) has been implicated as the causative allergen of the bird-egg syndrome. However, the clinical relevance of sensitization to this allergen has not been confirmed by specific challenge tests and environmental sampling. We investigated whether chicken albumin can be detected in air samples collected in a home with birds, and whether sensitization to this protein may cause respiratory and food allergy symptoms. The heat resistance of chicken albumin and the possible cross-reactivity with conalbumin were also investigated. Methods: We studied eight patients with food allergy to egg yolk who also suffered from respiratory symptoms (rhinitis and/or asthma) caused by exposure to birds. Sensitization to egg yolk and bird antigens was investigated by skin and serologic tests. Hypersensitivity to chicken albumin was confirmed by specific bronchial, conjunctival, and oral provocation tests. Results: All patients had positive skin tests and serum IgE against egg yolk, chicken serum, chicken meat, bird feathers, and chicken albumin. The presence of airborne chicken albumin in the domestic environment was confirmed. Specific bronchial challenge to chicken albumin elicited early asthmatic responses in six patients with asthma. An oral challenge with chicken albumin provoked digestive and systemic allergic symptoms in the two patients challenged. IgE reactivity to chicken albumin was reduced by 88% after heating at 90°C for 30 min. ELISA inhibition demonstrated only partial cross-reactivity between chicken albumin and conalbumin. Conclusions: Chicken albumin (Gal d 5) is a partially heat-labile allergen that may cause both respiratory and food-allergy symptoms in patients with the bird-egg syndrome.

Summary When newly emerged females of the mosquito Culex nigripalpus Theobald (Diptera: Culicidae) take a sugar meal, they develop both a propensity to seek a host and resting-stage ovarian follicles. As follicle growth is indicative of Juvenile Hormone (JH) activity, we searched for possible roles of JH in the behavioural shift from nectar to blood-host odour preference by Cx. nigripalpus after emergence, using an olfactometer-choice assay. Topically applied or injected methoprene (a JH analogue) resulted in a behavioural shift and follicular growth in unfed females that increased with increasing dosages. Topical methoprene 500 ng and 4 μg resulted in a switch to bird-odour preference. JH III injection resulted in a lesser shift from honey responses to bird responses. Methoprene application caused no detectable changes in glycogen, total sugars or total lipid when assayed 24 h after treatment. Additionally, as male accessory glands (MAG) have been shown to synthesize JH, we implanted intact paired MAGs from either conspecific or Aedes aegypti (L.) donors, or injected 1/3 gland pair equivalents of conspecific MAG homogenate into unfed newly emerged females. All MAG treatments failed to induce behavioural or ovarian modifications. Ovariectomy had no effect on the sugar-induced shift from nectar to host preference in the olfactometer. Thus JH, but not MAG, mimicked the effects of a sugar meal by causing both follicular growth and the shift to preference for a host.

A nestling Derbyan parrot (Psittacula derbiana) was presented with unusual subcutaneous swellings of the thigh regions, and poor growth. Histological examination revealed actinomycetous bacteria associated with multifocal systemic granulomas. The clinical and pathological findings of the case are presented, and some relevant aspects of actinomycetous bacterial infections in mammals and birds are discussed. Although granulomatous disease is encountered at times in avian species, the actinomycetous bacteria (Nocardia and Actinomyces spp.) have rarely been reported in association with multifocal granulomatous disease in birds.

This paper concerns a disease affecting a group of African grey parrots, which involves intranuclear inclusion bodies composed of filamentous material. The disease was characterized by either sudden death or death within 2-3 days from onset of non-specific symptoms. At necropsy, gross lesions included enlarged liver, mild hepatic congestion and focal necrosis. Samples from five birds were fixed in 10% formol and routinely processed for light and electron microscopy. In four birds, numerous hepatocytes displayed an enlarged nucleus, with peripheral margination of chromatin; the nucleus was partially or wholly filled by a basophilic inclusion body. In the remaining bird, inclusion bodies were acidophilic and completely filled the nucleus; nuclear enlargement was less evident than in the other birds. At ultrastructural examination, and in both types of IIB, nuclei contained looped filaments but no evidence of viral structures. However, virion-like structures were observed in the cytoplasm of some hepatocytes.

An approximately eight-year-old female grey parrot (Psittacus erithacus erithacus) was presented with a two months history of blindness. The radiographic examination showed a dilatation of the proventriculus, ventriculus and gut. Ophthalmoscopy and electroretinography revealed degeneration of the retina. A proventricular dilatation disease was suspected. The bird was euthanased because of deteriorating condition and poor prognosis. The pathological examination showed an atrophy of the ventricular muscles and lymphoplasmacytic infiltrates of the myenteric plexus of the proventriculus, ventriculus and gut as well as moderate lymphoplasmacytic infiltrates of the cerebrum with moderate neuronophagia. Lymphoplasmacytic infiltrates in the retina, indicating proventricular dilatation disease, and subsequent retinal degeneration were found. A potential common aetiology for proventricular dilatation disease and blindness is discussed.

To measure the prevalence of megabacteria in budgerigar-breeding colonies and to evaluate possible methods to reduce the prevalence.A monitoring study over several years.Two budgerigar (Melopsittacus undulatus) colonies with over 300 birds each.The prevalence of megabacteria in the faeces in two budgerigar breeding colonies, colony 1 and 2, was determined by faecal examination of each bird. Following an initial survey (1990), most of the birds that were scored 2+ or more were culled and a management practice was implemented to discriminate against positive birds. Consecutive yearly surveys (1991, 1992) were conducted on the young birds bred in these colonies. The prevalence of megabacteria in colony 2 was also evaluated in 1994 and 1996 after all the birds were treated with amphotericin B administered in drinking water.The prevalence of megabacteria in the two colonies was significantly (P0.001) different. Overall the prevalence of megabacteria adjusted for colony differences was significantly higher (P0.025) in males compared to females. Age was not an influencing factor. After the initial survey, the prevalence in the offspring did not significantly (P0.05) decrease in the following two annual breeding seasons but by inference it did significantly decrease after amphotericin B treatment.The practice of culling most birds with more megabacteria in faeces and discriminating against positive birds when selecting birds for breeding or culling birds on show quality does not decrease megabacteria prevalence in the offspring. However, a reduction in prevalence does occur with administration of amphotericin B. Birds may have amphotericin B-resistant organisms and these birds need to be identified and culled.

Ninety-seven environmental and four clinical isolates of Cryptococcus neoformans from several localities in extreme southern Italy were serotyped. All proved to be Cr. neoformans var. neoformans serotype A. The homogeneity of the serotypes suggests that geographical climatological conditions may play a role in Cr. neoformans serotype diffusion. It was furthermore revealed that, unlike the data reported for the serotypes of Cr. neoformans in mainland Italy, Cr. neoformans serotype D was not present in the examined sites in extreme southern Italy.