Cacatua Galerita Research Articles

Recombinant expression of a truncated capsid protein of beak and feather disease virus and its application in serological tests

Beak and feather disease virus (BFDV) causes severe disease characterized by irreversible feather disorders and severe immunosuppression in many psittacine species. BFDV cannot be propagated in tissue or cell cultures, rendering virus propagation and thus diagnosis rather difficult. To develop reliable diagnostic methods, the region encoding the BFDV capsid protein C1 was cloned from an infected sulphur-crested cockatoo (Cacatua galerita). Phylogenetic analysis showed this gene had 76.3 to 83.2% amino acid identity to published sequences. No protein was detected after induction of full-length C1 expression in Escherichia coli. However, deletion of an amino-terminal arginine-rich sequence facilitated expression. C139–244-His, a polyhistidine-tailed variant of this protein, was purified and used for immunization of chickens. The immune sera detected C1 with an apparent molecular weight of 27 kDa in western blots of organ homogenates of BFDV-infected birds. Using C139–244-His as antigen, 11 psittacine sera were tested for the presence of BFDV-specific antibodies by enzyme-linked immunosorbent assay and immunoblotting. The results obtained correlated well with the BFDV-specific haemagglutination inhibition activity of the sera, suggesting C139–244-His has value as a recombinant antigen for BFDV-specific serological tests.

Overlap and competition for nest holes among eclectus parrots, palm cockatoos and sulphur-crested cockatoos

We examined the extent of overlap in the characteristics of nest holes used by eclectus parrots (Eclectus roratus), palm cockatoos (Probosciger aterrimus) and sulphur-crested cockatoos (Cacatua galerita) in patches of rainforest and woodland in and around Iron Range National Park, Cape York Peninsula, Australia. Eclectus parrots nested only in rainforest and palm cockatoos nested mostly in eucalypt woodland adjacent to rainforest. Sulphur-crested cockatoos nested in both habitats. Nest holes of eclectus parrots and rainforest sulphur-crested cockatoos were in trees of larger DBH (diameter at breast height) and higher off the ground than those of palm cockatoos and sulphur-crested cockatoos in woodland. Palm cockatoos differed from the other parrots in their use of deeper holes with entrances that faced skywards rather than sideways. Both palm cockatoos and woodland sulphur-crested cockatoos used nests with smaller entrances than eclectus parrots and rainforest sulphur-crested cockatoos. All species showed intraspecific competition for nest holes. Behavioural conflict was also common between sulphur-crested cockatoos and the other two species. Each year 9.7–25.8% of eclectus parrot nests were taken over either permanently or temporarily by sulphur-crested cockatoos. Only one palm cockatoo nest was taken over by sulphur-crested cockatoos. Nest-holes were destroyed by natural causes at similar rates in rainforest (3.8% per annum over 174 nest-years) and woodland (5.4% per annum over 93 nest-years). Four nest trees fell over, and the floor of the nest collapsed at a further four holes. Three woodland nest trees burnt down during dry-season fires (August–October). New eclectus parrot and rainforest sulphur-crested cockatoo holes originated from incipient hollows on the tree that were modified by the parrots. We discuss the intense competition between these large parrots in light of the apparent shortage of appropriate nest holes in Cape York rainforest and eucalypt woodland.

Chronology and spatial distribution of cockatoo damage to two sunflower hybrids in south-eastern Australia, and the influence of plant morphology on damage

Cockatoos ( Cacatua spp.) and other birds cause significant damage to sunflower ( Helianthus annuus L.) crops in NSW, Australia. Growing sunflower hybrids with pendulous heads has been suggested as a means of reducing damage. Also, the chronology of damage caused by cockatoos to sunflower heads and whole crops has not been well documented. The patterns and amount of damage caused by cockatoos to two sunflower hybrids, one representing the growth habit of commonly grown hybrids and the other being more pendulous, were studied in one growing season. The crop attracted a flock of galahs and sulphur-crested cockatoos that fed on the crop until after the normal harvest date. Two techniques for estimating damage to sunflower heads were highly correlated. No differences in the susceptibility of the two hybrids to cockatoo damage were observed. However, within the crop, heads that were taller or larger were more susceptible to damage while down-facing heads were less susceptible to damage. Early damage occurred near the margins but later the whole crop was damaged. This work supports previous suggestions that early harvesting, reducing the edge to area ratio of the crop, and planting of hybrids of uniform height and with down-facing heads might help reduce the damage to sunflowers caused by cockatoos.

Air Sac Functional Anatomy of the Sulphur-crested Cockatoo (Cacatua galerita) During Isoflurane Anesthesia

The air sac functional anatomy of sulphur-crested cockatoos (Cacatua galerita) during isoflurane anesthesia was studied by evaluation of respiratory casts of sulphur-crested cockatoos, blood gas analysis, and air sac gas analyses. The air sac anatomy of the sulphur-crested cockatoo was different from that described previously in nonpsittacine bird species, with more extensive cranial and caudal thoracic air sacs and smaller abdominal air sacs. Blood gas analysis results indicated arterial and venous hyperoxia as a result of using 100% O2 as the anesthetic carrier gas, the significance of which in birds is currently unclear. Cranial and caudal thoracic air sac oxygen and carbon dioxide partial pressures (Po2 and Pco2, respectively) were similar to those previously described in birds ventilated with 100% O2. Clavicular air sac Po2 and Pco2 were significantly lower than the cranial thoracic air sac, indicating significantly less ventilation of the clavicular air sac than of either the cranial or caudal air sacs.

Psittacine beak and feather disease in three captive sulphur-crested cockatoos (Cacatua galerita) in Thailand.

Three sulphur-crested cockatoos (Cacatua galerita) were diagnosed as psittacine beak and feather disease (PBFD). Histopathology of the feather pulp and follicles showed intracytoplasmic botryoid clusters or granular inclusion bodies in epithelial cells and macrophages. Electron microscopy revealed multiple cytoplasmic clusters of electron dense viral particles corresponding to the inclusions. PBFD virus (circovirus) DNA-specific product was detected from formalin-fixed paraffin-embedded feathers by nested polymerase chain reaction (PCR) method.

Comparison of Endotracheal, Caudal Thoracic Air Sac, and Clavicular Air Sac Administration of Isoflurane in Sulphur-Crested Cockatoos (Cacatua galerita)

Ten sulphur-crested cockatoos (Cacatua galerita) were anesthetized twice, 2 weeks apart, to evaluate the effects on respiratory function of endotracheal (ET), caudal thoracic (CT) air sac, and clavicular air sac administration of isoflurane anesthesia. Four administration methods were evaluated by administering anesthetic gases through either the ET tube or the air sac as an open or closed system. Respiratory function was monitored by arterial and venous blood gas determination, gas-in-gas determination of both ET tube and air sac gases, and spirometry. Both ET tube and CT air sac administration provided a reliable method of maintaining anesthesia and resulted in minimal alteration in respiratory function. Blood pH, partial pressure of carbon dioxide (Pco2), bicarbonate, total carbon dioxide, and base excess were not significantly altered by CT air sac administration. Increased partial pressure of oxygen and oxygen saturation were evidence of hyperoxia. CT air sac Pco2 decreased to 12.7 ± 7.9 mm Hg with CT administration, and this was sufficient to maintain spontaneous respiratory movements. Spirometry demonstrated maintenance of tidal and minute volumes with each administration method despite apparent reduction in visible respiratory movements. Clavicular air sac administration was not successful in providing ventilation or maintaining anesthesia. Despite the demonstrated ability to flush a bolus of gas through this air sac and out the ET tube, no spontaneous ventilation was detected in this air sac in either an open or closed system, preventing delivery of sufficient isoflurane to maintain anesthesia.

Intravenous Cisplatin Administration in Sulphur-Crested Cockatoos (Cacatua galerita): Clinical and Pathologic Observations

The prevalence of neoplasia in birds is generally low; however, in some species of companion and aviary birds, the incidence is high and neoplasia is a common cause of death. Surgical excision or limb amputation has been performed as the therapeutic plan. Chemotherapy in the treatment of avian neoplasia is largely empirical and poorly documented. For example, cisplatin has been used intralesionally in macaws (Ara species) with limited clinical success. Eight sulphur-crested cockatoos (Cacatua galerita), under general isoflurane anesthesia, were infused intravenously with cisplatin at 6.4 or 1.0 mg/kg over 1 hour and hydrated with lactated Ringer's solution for 1 hour before and 2 hours after cisplatin infusion. Birds were euthanatized 96 hours after infusion, except for 2 birds given the low cisplatin dose, which were euthanatized on day 35 after dosing. All birds tolerated the study procedure while under anesthesia. Blood pressure, heart rate, and respiratory rate did not change significantly. In the low-dose group, the mean cloacal temperature decreased significantly during the infusion period (P < .001) and then rose progressively to preinfusion values by 24 hours. Also in this group, the mean body weight tended to increase during the infusion period before significantly decreasing (P < .05) by 5% at 96 hours after dosing. At 24 hours after dosing, all birds were bright and eating. However, intermittent regurgitation and fecal changes (moist, dark green feces and yellow urates) occurred in 3 of 8 birds, especially those given the high dose. By 72 hours after dosing, droppings in the low-dose group were normal in appearance. One bird in the high-dose group died by 94 hours after dosing. Myelosuppression was not observed in any bird and at necropsy, no evidence of cisplatin toxicity was found except in 1 bird given the high cisplatin dose. On histology, this bird showed nephrotoxicity, and its serum uric acid levels and mean estimated white blood cell count increased significantly by 24 hours after dosing. This paper reports for the first time the effect of systemic cisplatin administration in birds and provides veterinarians data for formulating efficacious and safe protocols for platinum-containing compounds when treating neoplasia in parrots and other companion birds.

A class of chaotic bird calls?

Evidence is presented that the basic vocalized sound produced by some cockatoos, specifically the Australian sulfur-crested cockatoo (Cacatua galerita) and the gang-gang cockatoo (Callocephalon fimbriatum), has a chaotic acoustic structure rather than the harmonic structure characteristic of most birdsongs. These findings support those of Fee et al. [Nature (London) 395(3), 67-71 (1999)] on nonlinear period-doubling transitions in the song of the zebra finch (Taeniopygia guttata). It is suggested that syllables with chaotic structure may be a feature of the songs of many birds.

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

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

Platinum pharmacokinetics in sulphur-crested cockatoos (Cacatua galerita) following single-dose cisplatin infusion.

To determine the pharmacokinetics of platinum (Pt) in cockatoos. A pharmacokinetic study of Pt, following a single i.v. infusion of cisplatin, was done in six healthy sulphur-crested cockatoos (Cacatua galerita). Birds were hydrated for 1 h before and 2 h after a 1-h cisplatin infusion (1 mg/kg, i.v.). Serial blood samples were collected for 96 h after initiation of the infusion and urine was collected for 2 h during the hydration period after cisplatin administration. Tissue samples from 10 organs were obtained at necropsy, 96 h after cisplatin infusion. Total Pt and filterable Pt in plasma, urinary Pt and tissue Pt concentrations were assayed by inductively coupled plasma-mass spectrometry. A noncompartmental pharmacokinetic analysis was performed on the plasma and urine data. For total Pt and filterable Pt, the respective mean systemic clearances were 0.373 and 0.699 L/kg hourly, the steady state volumes of distribution were 4.19 and 0.356 L/kg, and the mean residence times were 111 and 0.512 h. Total plasma Pt displayed a bi-exponential decay profile with average half-lives of 0.398 and 79.0 h, while filterable Pt had a monoexponential decay with mean half-life of 0.413 h. The renal clearance during the 2-h postinfusion period was 0.167 L/kg hourly. The kidneys had the highest Pt accumulation (4.54 micrograms/g DM). Cisplatin infusion in cockatoos was well tolerated and Pt plasma concentrations were similar to those measured during treatment of solid tumours in human patients. Despite anatomical, physiological and biochemical differences among animal species, the pharmacokinetic disposition of Pt in the cockatoo shares some features with the kinetics reported previously in rodents, dogs and human beings.

Immune and pathophysiological responses to different strains of Giardia duodenalis in neonatal mice

Numerous studies have demonstrated various strain differences between Giardia isolates, but little is known about the immunology and pathogenesis of infections. This study aimed to compare host responses to strains of Giardi duodenalis differing in levels of virulence and pathogenicity and, by doing so, elucidate the mechanisms via which pathogenic strains establish infections. Marked differences were found in the infection dynamics, histopathological responses and serum antibody responses of neonatal mice infected with either G. duodenalis strain BRIS/83/HEPU/106 (isolated from a human) or BRIS/95/HEPU/2041 (isolated from a sulphur-crested cockatoo, Cacatua galerita). Infections with the bird strain were more intense (6.7-times greater) and persisted longer (by 14 days) than infections with the human strain. The bird strain was more pathogenic and caused greater pathophysiological alteration to the gut mucosa, including increased villous atrophy, hyperplasia of goblet cells and vacuolated epithelial cells. Mice infected with the bird strain produced less serum anti- Giardia IgA and IgM, but more total (non-specific) serum IgA than those infected with the human strain of Giardia. This suggests that avian G. duodenalis strains are infective for mammalian hosts and may contribute to zoonotic infections. Furthermore, infection of mice with BRIS/95/HEPU/2041 serves as a good experimental model to provide further insight into the mechanisms via which G. duodenalis causes disease.

Heterophilic leucocytosis and granulocytic hyperplasia associated with infection in a cockatoo

A female adult lesser sulphur-crested cockatoo (Cacatua sulphurea) presented with a traumatic foot lesion that was surgically debrided. The distal limb was immobilised, and the animal treated with antimicrobial drugs. Postoperatively, the bird initially appeared to recover well; however, depression and anorexia developed on day 3. A marked non-responsive anaemia with a severe leucocytosis and left shift were noted on blood examination. The patient was fed through tube-administration for four days. Death on day 5 was attributed to a traumatic oesophageal perforation. Postmortem examination suggested pulmonary collapse secondary to oesophageal rupture as the immediate cause of death. Microscopic bone marrow changes consisted of marked granulocytic hyperplasia with erythroid hypoplasia. These changes were attributed to chronically stimulated myelopoiesis in response to a persistent infection, likely from the distal limb site. This case illustrates the ability of a psittacine bird to mount a marked heterophilic leucocytosis.

Interspecific and Locational Differences in Heavy Metal Levels in Four Species of Birds Near Sydney, Australia

We examined the levels of cadmium, chromium, lead, manganese, mercury, and selenium in four species of birds near Sydney, New South Wales, Australia in January, 1996. Molted contour feathers were collected from silver gull, Larus novaehollandiae (Royal National Park and downtown Sydney), sulphur-crested cockatoo, Cacatua sulphurea (Blue Mountains, Royal National Park, and Sydney), Australian white ibis, Threskiornis molucca (Sydney), and rock dove Columba livia (Royal National Park and Sydney). We tested the null hypothesis that there were no species or locational differences in metal levels. There were significant species differences in all metals, with rock doves having the highest levels of cadmium, chromium, lead, and manganese, and silver gulls having the highest levels of mercury and selenium. Metal levels were generally low in cockatoos, and were lowest in those from the Royal National Park. For silver gulls, cadmium, lead, and chromium levels were highest at Sydney, and there were no locational differences in manganese, mercury, and selenium levels. For rock doves, cadmium, chromium and manganese were higher in Sydney, and there were no locational differences in lead, mercury, and selenium. Overall, cadmium and chromium levels were significantly higher in Sydney than in the Royal National Park for all species, and there were no locational differences in mercury levels. Although the levels of most metals in feathers from these Australian birds were within the ranges reported worldwide, lead levels in ibises and rock doves were among the highest reported worldwide, suggesting a cause for concern.

Virulent Avian Giardia duodenalis Pathogenic for Mice

Early in 1995, a sulphur-crested cockatoo captured in the wild died along with several other cage mates, apparently of an overwhelming, acute infection of Giardia. Trophozoites isolated from the dead bird and established in traditional Giardia axenic medium were infective to mice and established chronic infections associated with weight gain impairment. Genetically and morphologically, the Giardia isolated from the bird belonged to the duodenalis group. Here, Jacqui Upcroft, Ann McDonnell and Peter Upcroft present data on pathogenic avian Giardia with he potential to contaminate watersheds and discuss the implications.

A serologic survey for avian polyomavirus and Pacheco's disease virus in Australian cockatoos

Sera collected from wild and captive Australian cockatoos and other psittacine species (n = 411) were tested for antibodies to avian polyomavirus (APV) and Pacheco's disease virus (PDV). Of 144 wild sulphur‐crested cockatoos (Cacatua galerita) sampled at three regions in New South Wales (NSW) 96 (64.4%) birds had positive (≥ 1:32) neutralizing antibody titres to avian polyomavirus (range 1:32–1:2048). Two of 17 wild long‐billed corellas (Cacatua tenuirostris) were also APV‐antibody positive. However, no samples from 107 wild galahs (Eolophus roseicapillus) were positive for neutralizing antibody to APV. Sera were also collected from captive psittacine bird flocks from NSW, Tasmania, Victoria, and Western Australia. In a mixed aviary of cockatoos and lorikeets, APV antibody was detected in sera from sulphur‐crested cockatoos, Major Mitchell's cockatoos (Cacatua leadbeateri), a white‐tailed black cockatoo (Calyptorhynchus baudinii latirostris), a red‐tailed black cockatoo (Calyptorhynchus magnificus) a single galah, a rainbow lorikeet (Trichoglossus haematodus), and a scaley‐breasted lorikeet (Trichoglossus chlorolepidotus). All 411 wild and captive birds were negative for the presence of neutralizing antibody to PDV. These results indicate that wild sulphur‐crested cockatoos in NSW are enzootically infected with avian polyomavirus and that the sampled populations are free of Pacheco's disease.

Lethal Giardia from a wild-caught sulphur-crested cockatoo (Cacatua galerita) established in vitro chronically infects mice.

An axenic culture of Giardia was established from a sample of infected intestine obtained following autopsy of a sulphur-crested cockatoo (Cacatua galerita). The cockatoo recently captured in the wild and with good muscle tone died along with several other cage mates, apparently of an overwhelming, acute infection of Giardia. Trophozoites which established in the traditional, axenic Giardia medium (TYI-S-33 with supplementary bile) were morphologically identical to G. duodenalis. When outbred Quackenbush Swiss neonatal mice were infected with trophozoites a chronic infection was established and parasites were still present at 38 days post-inoculation. Weight gain by infected mice was reduced by 20%, thus mimicking failure-to-thrive syndrome in children, and maximum parasite load was more than 3-fold higher in comparison with other G. duodenalis strains. Analysis of the electrophoretic karyotype, rDNA and hybridization studies together with Giemsa- and trichrome-stained samples, and scanning electron microscopy indicated that the bird-derived Giardia belonged to the duodenalis group. This is the first report of infection of mammals with Giardia isolated from a bird. These data may have potentially serious implications for contamination of watersheds and establishment of zoonotic infections.

Roosting of the Sulphur-Crested Cockatoo Cacatua galerita

Sulphur-Crested Cockatoos Cacatua galerita may move considerable distances between night-time roosting sites and other areas where foraging takes place. Flocks may maintain a permanent roosting site and may occu- py it for many years (Lamm & Calaby 1970; Frith 1976; Taylor & COG 1992). In south-eastem Australia they roost in various trees including eucalypts, casuarinas, melaleucas and leptospermums (Lamm & Calaby 1970; Cooper 1975). We describe the night-time roosting be- haviour of C. galerita, the species of trees used and the characteristics of the remnant habitat patches occupied.

Synovial cell sarcoma in a sulphur‐crested cockatoo (Cacatua galerita)

A 13-year-old sulphur-crested cockatoo (Cacatua galerita) was presented with a mass surrounding the right elbow joint. Radiographs showed a soft tissue mass. The right wing was amputated. Histological examination of the mass revealed an incompletely lobulated tumour composed of strands of spindle-shaped cells and of epithelial cells resembling acini. On morphological grounds the tumour was classified to be a synovial cell sarcoma. After 6 months the bird was returned for examination because of lameness in the right leg. Radiographs showed osteolysis in the right tibiotarsal bone. Cytological investigation of a bone marrow biopsy revealed neoplasia. The bird was euthanized. Necropsy revealed metastases in many organs. This is believed to be the first reported case of synovial cell sarcoma in a bird.

Population sizes, status and habitat associations of the restricted-range bird species of Sumba, Indonesia

SummaryThe island of Sumba was visited in 1989 and 1992 with the aim of collecting data on its avifauna. The endemic and other restricted-range bird species are very poorly known and, potentially, at great risk from extinction due to habitat change. Using standardized methods, habitat and bird census data were collected in eight forest areas. Analysis of the habitat data shows that most of the restricted-range species are forest-dependent. The exception is Turnix everetti (Sumba Buttonquail), which is found in open grassland. Discriminant Function Analysis was used to define habitat associations in a more precise and objective way. The species with the most specific requirements are Ptilinopus dohertyi (Red-naped Fruit-dove) and Zoothera dohertyi (Chestnut-backed Thrush), which are associated with primary forest at high altitudes, and Cacatua sulphurea (Sulphur-crested Cockatoo) and Rhyticeros everetti (Sumba Hornbill), which prefer evergreen primary or mature secondary forest at low altitudes. The results of the bird censuses were combined with data on habitat cover from satellite photographs to produce estimates of total population sizes. Among the rarest and most endangered species on Sumba are three which are represented by endemic subspecies: C. sulphurea (estimated population 3,200 birds), Eclectus roratus (Eclectus Parrot) (1,900), Tanygnathus megalorynchos (Great-billed Parrot) (1,700). The rarest endemic species is R. everetti, with a population of approximately 6,500. It is suggested that the census method used – point counts With distance estimates to bird contacts – is the best compromise for multi-species surveys in tropical forests.

The haemagglutination spectrum of psittacine beak and feather disease virus

A simple method for concentrating psittacine beak and feather disease virus (PBFDV) from crude feather suspensions is described. The addition of 10% polyethylene glycol (MW 6000 to 9000) to feather suspensions facilitated the precipitation and pelleting of PBFDV by low speed centrifugation. Pellets were resuspended in one-twentieth of the original volume with caesium chloride (CsCl) buffer and subjected to isopycnic ultracentrifugation. Peak haemagglutination activity (HA) occurred at 1.35 g/ml in PBFDV CsCl gradients. CsCl purified virus agglutinated galah (Eolophus roseicapillus), eastern long-billed corella (Cacatua tenuirostris), sulphur-crested cockatoo (Cacatua galerita), Major Mitchell's cockatoo (Cacatua lead-beateri) and gang gang cockatoo (Callocephalon fimbriatum) erythrocytes, but not those of 19 other avian or five mammalian species. PBFDV agglutinated galah erythrocytes at 4 degrees C and 37 degrees C over a wide range of pH and no change in HA titre was observed when PBFDV was treated with chloroform. HA persisted in PBFDV suspensions heated to 80 degrees C for 30 min, but was not detected after incubation at higher temperatures. High HA titres were detected in the feathers, serum, liver and kidneys of PBFD-affected birds.