Proventricular impaction associated with nonsuppurative encephalomyelitis and ganglioneuritis in two Canada geese

Two wild Canada geese (Branta canadensis) in an extremely emaciated state and with severe proventricular food impaction also had a nonsuppurative encephalomyelitis and ganglioneuritis. The condition in these two birds was morphologically similar to psittacine proventricular dilatation, a recently identified disease of psittacine birds.     

Avian Bornavirus Associated with Fatal Disease in Psittacine Birds

Thanks to new technologies which enable rapid and unbiased screening for viral nucleic acids in clinical specimens, an impressive number of previously unknown viruses have recently been discovered. Two research groups independently identified a novel negative-strand RNA virus, now designated avian bornavirus (ABV), in parrots with proventricular dilatation disease (PDD), a severe lymphoplasmacytic ganglioneuritis of the gastrointestinal tract of psittacine birds that is frequently accompanied by encephalomyelitis. Since its discovery, ABV has been detected worldwide in many captive parrots and in one canary with PDD. ABV induced a PDD-like disease in experimentally infected cockatiels, strongly suggesting that ABV is highly pathogenic in psittacine birds. Until the discovery of ABV, the Bornaviridae family consisted of a single species, classical Borna disease virus (BDV), which is the causative agent of a progressive neurological disorder that affects primarily horses, sheep, and some other farm animals in central Europe. Although ABV and BDV share many biological features, there exist several interesting differences, which are discussed in this review.     

Characterization of Pasteurellaceae‐like bacteria isolated from clinically affected psittacine birds

Aims: The aim of the present investigation was to identify and characterize Pasteurella‐like isolates obtained from clinically affected psittacine birds. Methods and Results: A total of 37 isolates from psittacine birds tentatively classified with the family Pasteurellaceae were characterized phenotypically. The genetic relationship was investigated by sequencing of partial rpoB and 16S rRNA genes for selected isolates. The results obtained were compared with the data from 16 reference strains. Nine isolates were identified as Gallibacterium spp., 16 as Volucribacter spp. or Volucribacter‐like, while 11 isolates were classified as taxon 44 of Bisgaard. A single isolate was identified as Pasteurella multocida. Conclusions: Characterization of Pasteurellaceae by traditional methods is often inconclusive because of inconsistent reactions and phenotypic diversity. For the same reason, genotyping is essential to allow proper classification as demonstrated in the present study. Significance and Impact of the Study: Limited information exists on the isolation and significance of Pasteurellaceae associated with clinically affected psittacine birds showing signs of digestive and/or respiratory disorders. The present investigations demonstrated that these organisms are widely distributed among clinically affected birds, but isolation of these taxa cannot be unambiguously correlated with the symptoms observed.     

Duplex shuttle PCR for differential diagnosis of budgerigar fledgling disease and psittacine beak and feather disease

Two common viral diseases in psittacine birds including budgerigar fledgling disease (BFD), generally called avian polyomavirus (APV) infection, and psittacine beak and feather disease (PBFD) have similar clinical manifestations characterized by feather disorders. A duplex shuttle PCR was developed for detection of APV and PBFD virus (PBFDV). Two pairs of oligonucleotide primers were designed to amplify a 298-bp fragment of the t/T antigen region of APV genome and a 495-bp fragment of the capsid protein region encoded by open reading frame (ORF) C1 of PBFDV genome, respectively. In the present study, APV and PBFDV were detected simultaneously in one tube by duplex shuttle PCR using these two pairs of primers. The detection limits were 2 viral copies of APV and 3 viral copies of PBFDV. In the clinical application, we detected 16 APV-positive, 15 PBFDV-positive, and 3 mixed infected samples in 39 samples examined. Sequences of the amplified products were read. The t/T antigen region was conserved in the APV-positive samples as expected. ORF C1 of PBFDV genome showed diversity. Phylogenic analysis indicated that PBFDV ORF C1 consisted of 6 clusters which were related to subfamilies of psittacine birds. Our duplex shuttle PCR could be a useful method for differential diagnosis and molecular epidemiology of BFD and PBFD.     

A new eimerian species (Apicomplexa: Eimeriidae) from the blue-fronted Amazon parrot Amazona aestiva L. (Aves: Psittacidae) in Brazil

The Neotropical psittacine species Amazona aestiva, commonly known as the blue-fronted Amazon, is one of the most common and best-known psittacine birds kept as a pet worldwide. However, very little is known about the diseases or parasites of these birds. In this study, we describe a new species, Eimeria aestivae, associated with these parrots. The new species is characterized by: ovoid smooth oocysts (n = 60), 36.8 (33.2-41.5) × 23.7 (21.7-25.7) μm, length/width ratio = 1.55; polar granule present; ellipsoidal sporocysts (n = 25), 19.8 (17.5-21.6) × 9.3 (8.3-9.9) μm; Stieda, sub-Stieda body, and sporocyst residuum present. Sporozoites (n = 20), 2 per sporocyst, elongate and curved, 17.6 (15.8-19.2) × 3.8 (3.2-4.8) μm; each with 2 refractile bodies. The oocysts of the other 2 eimerian species described for Amazona are larger than those of the presented species, but they all seem to be closely related because of some similarities among them.     

Guidelines and ethical considerations for housing and management of psittacine birds used in research

The Psittaciformes are a large order of landbirds comprising over 350 species in about 83 genera. In 2009, 141 published studies implicated parrots as research subjects; in 31 of these studies, 483 individuals from 45 different species could be considered laboratory animals. Amazons and budgerigars were by far the most represented psittacine species. The laboratory research topics were categorized as either veterinary medicine and diagnostics (bacteriology, hematology, morphology, and reproduction; 45%) or behavioral and sensory studies (behavior, acoustics, and vision; 17%). Confinement of psittacine species for research purposes is a matter of concern as scientifically based species-specific housing guidelines are scarce. The aim of this article is to provide scientific information relevant to the laboratory confinement of Psittaciformes to promote the refinement of acquisition, housing, and maintenance practices of these birds as laboratory animals. We briefly discuss systematics, geographical distribution, legislation, and conservation status as background information on laboratory parrot confinement. The following section presents welfare concerns related to captive containment (including domestication status) and psittacine cognition. We then discuss considerations in the acquisition of laboratory parrots and review important management issues such as nutrition, zoonoses, housing, and environmental enrichment. The final section reviews indications of distress and compromised welfare.     

Evidence for the existence of two new members of the family Chlamydiaceae and proposal of Chlamydia avium sp. nov. and Chlamydia gallinacea sp. nov.

The family Chlamydiaceae with the recombined single genus Chlamydia currently comprises nine species, all of which are obligate intracellular organisms distinguished by a unique biphasic developmental cycle. Anecdotal evidence from epidemiological surveys in flocks of poultry, pigeons and psittacine birds have indicated the presence of non-classified chlamydial strains, some of which may act as pathogens. In the present study, phylogenetic analysis of ribosomal RNA and ompA genes, as well as multi-locus sequence analysis of 11 field isolates were conducted. All independent analyses assigned the strains into two different clades of monophyletic origin corresponding to pigeon and psittacine strains or poultry isolates, respectively. Comparative genome analysis involving the type strains of currently accepted Chlamydiaceae species and the designated type strains representing the two new clades confirmed that the latter could be classified into two different species as their average nucleotide identity (ANI) values were always below 94%, both with the closest relative species and between themselves.     

Immunotyping of Chlamydia psittaci by indirect immunofluorescence antibody test with monoclonal antibodies

Monoclonal antibodies against pigeon and budgerigar strains of Chlamydia psittaci were used to classify the immunotypes of C. psittaci strains by an indirect immunofluorescence antibody (IFA) test. Thirty-three C. psittaci strains from pigeons and 24 from budgerigars were divided into three immunotypes (P-I, P-II, and P-III) and (B-I, B-II, and B-III), respectively. Two strains from human psittacosis patients were identified as P-III and B-I, coinciding with the epidemiological evidence of each human infection. Two strains from psittacine birds, a parrot and a parakeet, were identical to the B-II immunotype. Other mammalian strains were quite distinct from avian strains in their IFA reaction with the monoclonal antibodies.     

Food sharing and affiliation: An experimental and longitudinal study in cockatiels (Nymphicus hollandicus)

Food sharing has attracted much attention because of its apparently altruistic nature and its link to prosociality. However, food sharing has been mostly studied in a reproductive context, during courtship and parental care, where the fitness benefits are obvious. We still lack a clear understanding of the functions of food sharing outside any reproductive context and within social groups of same‐aged peers. Previous studies suggest that cofeeding, the action to let another animal feed from the same monopolizable food source, may be used to build and strengthen bonds between individuals. This may be particularly crucial in social birds forming long‐term associations between mates or siblings such as psittacids and corvids. Here, we investigated food sharing and affiliative behaviors such as allopreening in a psittacine species, namely in a group of captive juvenile cockatiels (Nymphicus hollandicus) consisting of five siblings and five unrelated birds. Our main objective was to study the developmental pattern of food sharing over time and its implication in social bonding depending on kinship, affiliation, and sex. Studying cockatiels in this context is providing many new information since most of the studies on food sharing in birds focused on corvids. We found that, contrary to jackdaws, cockatiels continued to share food with multiple individuals, although the frequency of cofeeding as well as the number of cofeeding partners decreased over time. Cockatiels shared more food with their siblings than with other conspecifics but they were not more likely to do cofeeding with birds of the opposite sex. We also found evidence that young cockatiels exchanged more food with those from whom they received food (reciprocity) and, to a lesser extent, allopreening (interchange), than from other cockatiels. Our findings suggest that in cockatiels, food sharing within social groups serves the formation (and maintenance) of affiliative bonds, especially between siblings, rather than pair bonds, but might additionally be explained by reciprocity, interchange, and harassment avoidance.     

Eucalyptus pollen grain emptying by two Australian nectarivorous psittacines

The relative importance of pollen as a source of protein to vertebrates is controversial. In nectarivorous psittacine birds, field studies support its importance, but an experimental study in a nectarivorous parrot showed that less than 7% of pollen grains were emptied. We investigated pollen grain emptying by two nectarivorous Australian parrots, the Swift Parrot Lathamus discolor and the Musk Lorikeet Glossopsitta concinna . We used a controlled experiment, and examined pollen located at different levels through the alimentary tract of wild L. discolor . There was significant emptying of pollen grains (x¯=45.4%±1.91 s.e.) by all birds in the experimental trials. There was also a progressive increase in the percentage of pollen grains emptied at different sites along the alimentary tract in wild birds (crop x¯=24.2%±4.44 s.e., proventriculus x¯=34.0%±7.29 s.e., duodenum x¯=54.3%±5.42 s.e. and distal intestine x¯=64.2%±4.68 s.e.). The percentage of pollen grains emptied by captive L. discolor in the experimental trial (x¯=44.1%±2.77 s.e.) was not significantly different from that found in wild L. discolor (x¯=40.3%±4.25 s.e.). Both species of nectarivorous parrot were able to rapidly ingest large quantities of Eucalyptus pollen and appeared to empty the pollen grains efficiently. Eucalyptus pollen appears to be an important source of protein for these birds.     

Comparative study of long-term reduction of high-frequency song syllables in deafened zebra and Bengalese finches: implications for the role of auditory feedback in song maintenance

Auditory feedback is necessary for adult song maintenance in both oscines and psittacines. Although belonging to phylogenically separated orders, deafened adult oscine Bengalese finches and psittacine budgerigars exhibit similarities in certain aspects of song changes. An interesting question is whether these birds share common mechanisms for song maintenance. Therefore, it is important to compare the effects of deafening on adult song patterns among and within orders. Although zebra and Bengalese finches are closely related oscine species, few studies have performed direct, long-term, quantitative comparisons of their songs after deafening because suitable song characteristics have not been identified. Based on our previous findings for Bengalese finch songs, we analyzed zebra finch songs over 9 months after deafening, focusing on changes in the number of syllables categorized according to fundamental frequencies. Deafened zebra finches demonstrated a gradual but significant decrease in high-frequency syllables and a tendency to increase low-frequency syllables, similar to deafened Bengalese finches. Although this change took longer in zebra finches, the altered proportion of syllables eventually stabilized. Results indicated that adult songs show similar aspects after auditory deprivation, and that neural mechanisms involved in the maintenance of high-frequency song syllables, using auditory feedback, may be present in both finches despite species differences.     

Antibody selection for immunocytochemical characterization of the male reproductive system in Psittaciformes

The success of breeding programs is limited by the sparse knowledge about endocrine regulation and biochemical reactions in the psittacine male tract. The immunocytochemical analysis of parrots' testicular tissues provides an insight into their reproductive system but is often hampered by the lack of reliable antibodies. In the present study, we tested a large panel of antibodies raised against steroid receptors, steroidogenic enzymes, relaxin peptides including their receptors, and proliferation markers on paraffin sections of testicular tissue from eight psittacine genera representing three continents. All investigated species displayed the tested markers in somatic and germ cells of testis and epididymis, even though cell distribution was partly heterogenous and in species-specific patterns. The 17β-hydroxysteroid-dehydrogenase-2, 3β-hydroxysteroid-dehydrogenase, and smooth muscle actin allowed the cross-species differentiation between active and nonactive gonads. The remaining steroidogenic enzymes, steroid receptors, relaxin peptides, and Ki67 proved to be suitable to define reproductive activity depending on the parrot species. Adapting immunocytochemical methods to different psittacines was successful, though various cellular expression patterns do not allow the transfer of results among different parrot species. However, the availability of a reliable repertory of sexual markers is important to examine reproductive biology of psittacine birds.     

Encephalitozoon hellem in Two Eclectus Parrots (Eclectus roratus): Identification from Archival Tissues

ABSTRACT Members of the phylum Microspora are obligate, intracellular, single-celled parasites identified in a wide range of vertebrate and invertebrate hosts. Only a few cases of microsporidial infections have been documented in psittacine birds including peach-faced, masked, and Fischer's lovebirds ( Agapornis roseicollis, A. personata , and A. fischeri. respectively), budgerigars ( Melopsittacus undulatus ), and a double yellow-headed Amazon parrot ( Amazona ochrocephala ). Parasite identification has typically been limited to phylum or genus, and no avian species of microsporidia has clearly been described. In this report, microsporidia were identified in the kidney and intestine of a new host, the eclectus parrot ( Eclectus roratus ). Parasites were identified as Encephalitozoon hellem using morphologic, ultrastructural, and small subunit ribosomal RNA gene sequence data obtained from archived tissues. This parasite species was first identified in immunocompromised humans and may be a potential zoonotic pathogen. The epidemiology and prevalence of this parasite in humans and birds should be further explored.     

Psittacid herpesvirus 1 and infectious laryngotracheitis virus: Comparative genome sequence analysis of two avian alphaherpesviruses

Psittacid herpesvirus 1 (PsHV-1) is the causative agent of Pacheco's disease, an acute, highly contagious, and potentially lethal respiratory herpesvirus infection in psittacine birds, while infectious laryngotracheitis virus (ILTV) is a highly contagious and economically significant avian herpesvirus which is responsible for an acute respiratory disease limited to galliform birds. The complete genome sequence of PsHV-1 has been determined and compared to the ILTV sequence, assembled from published data. The PsHV-1 and ILTV genomes exhibit similar structural characteristics and are 163,025 bp and 148,665 bp in length, respectively. The PsHV-1 genome contains 73 predicted open reading frames (ORFs), while the ILTV genome contains 77 predicted ORFs. Both genomes contain an inversion in the unique long region similar to that observed in pseudorabies virus. PsHV-1 is closely related to ILTV, and it is proposed that it be assigned to the Iltovirus genus. These two avian herpesviruses represent a phylogenetically unique clade of alphaherpesviruses that are distinct from the Marek's disease-like viruses (Mardivirus). The determination of the complete genomic nucleotide sequences of PsHV-1 and ILTV provides a tool for further comparative and functional analysis of this unique class of avian alphaherpesviruses.     

A new species of <Emphasis Type="Italic">Pterothominx</Emphasis> Freitas, 1959 (Nematoda: Capillariidae) parasitising psittacine birds (Psittaciformes)

A new species, Pterothominx (Pterothominx) moraveci n. sp. (Trichinelloidea: Capillariidae) is described from an Australian parrot, Barnardius zonarius Shaw (Psittacidae: Psittaciformes), imported from Germany and kept in captivity in the Czech Republic. Males of the new taxon differ from all other species of the subgenus Pterothominx Freitas, 1959, which mainly parasitise galliform birds, in having a shorter spicule (0.925–1.338; mean 1.050 mm), a shorter body length and a different form of armed spicular sheath and bursa. Females differ in having the smallest eggs (40–50 × 20–25; mean 48 × 23 μm) and in other morphometrical characters. From the species P. (P.) totani (Linstow, 1875), which parasitises charadriiform birds, the new species differs in its smaller number of stichocytes (females 42–46, mean 44; versus 50–54), different form of the bursa and praebursal alae, and other characters. This is the only species of Pterothominx that parasitises psittacine birds.     

Vocal learning by greater spear-nosed bats.

Vocal learning is well known among passerine and psittacine birds, but most data on mammals are equivocal. Specific benefits of vocal learning are poorly understood for most species. One case where vocal learning should be favoured by selection is where calls indicate group membership and group mates are unrelated. Female greater spear-nosed bats, Phyllostomus hastatus, live in stable groups of unrelated bats and use loud, broadband calls to coordinate foraging movements of social group mates. Bats benefit from group foraging. Calls differ between female social groups and cave colonies, and playback experiments demonstrate that bats perceive these acoustic differences. Here I show that the group distinctive structure of calls arises through vocal learning. Females change call structure when group composition changes, resulting in increased similarity among new social group mates. Comparisons of transfers with age-matched half-sibs indicate that call changes are not simply due to maturation, the physical environment or heredity. These results suggest that studies testing vocal learning in mammals could profit by focusing on vocalizations that signify group membership.     

Gender effects on aggression, dominance rank, and affiliative behaviors in a flock of captive adult cockatiels (Nymphicus hollandicus)

Agonistic and affiliative behaviors and spatial positioning were studied in a small psittacine species, Nymphicus hollandicus. Subjects studied were flock-housed breeders including five hens and seven cocks. Fifteen-minute focal animal samples were collected for the entire flock in a randomly distributed order during mate selection and the onset of the breeding season. All agonistic behaviors were recorded, including the winner and loser of each interaction, along with allopreening and copulation behavior. Point samples were recorded every 60s to determine social spacing. Rates of aggression were significantly higher for male cockatiels than female cockatiels. Results based on dyadic agonistic interactions showed males to rank significantly higher in the social hierarchy than females. Associations within the flock were not random. Individual birds associated more with specific birds than would be predicted by chance. Analysis of spatial data revealed that there were both same-sex and opposite-sex preferred associations within the flock. Male cockatiels engaged in allopreening behavior with females significantly more than with other males. Observations of breeding and nesting behaviors revealed pairs, a triad, and extra-pair mating.     

Auditory feedback is necessary for long-term maintenance of high-frequency sound syllables in the song of adult male budgerigars (<Emphasis Type="Italic">Melopsittacus undulatus</Emphasis>)

Among avian species that communicate using vocalization, songbirds (oscine Passeriformes), hummingbirds (Trochiliformes), and parrots (Psittaciformes) are vocal learners. Early studies showed that songbirds require auditory feedback for song development in young and maintenance in adults. To determine whether auditory feedback is also necessary for adult song maintenance in non-passerine species, we deprived adult male budgerigars (Psittaciformes) of auditory input by surgical cochlear removal. Songs of the deafened birds changed within 6 months after auditory deprivation. In postoperative songs, high narrowband syllables, which comprised frequency-modulated narrowband elements with relatively high fundamental frequencies of 2–4 kHz, decreased significantly. High harmonic broadband syllables, with fundamental frequencies ≥2 kHz, also decreased. The altered proportions of syllables were subsequently retained, and maintained 12 months after deafening. The sequence linearity score, a parameter representing the stereotypy of the syllable sequence, was higher than that before deafening. The inter-syllable silence was prolonged. Little change was observed in the songs of intact and sham-operated birds. The significant decrease in high-frequency syllables and song alteration followed by stabilization resembled the results with songbirds, although song stabilization took a long time in budgerigars. Therefore, our results suggest that psittacine budgerigars and oscine songbirds require auditory feedback similarly for adult song maintenance.     

Handraising large parrots: Methodology and expected weight gains

Handraising psittacine chicks is gaining acceptance as a conservative tool, because it facilitates increased chick production through double-clutching. Techniques involving environment, banding, diet, hygiene, and veterinary care used in the handrearing nursery of Aviculture Institute/Behavioral Study of Brids, Inc. are reported here. The mortality rate has steadily decreased since the nursery was established in 1981, while the total number of chicks handreared has increased from 116 in that year to 300 in 1985. Weight gain data of healthy, handreared chicks from the 1984 and 1985 breeding seasons are presented, representing 21 species of large, Old and New World parrots. Weight gains improved to a plateau reached in 1984. Tables are provided that contain normal weight gain values useful for comparison and evaluation of growth progress of handraised parrot chicks.     

Psittacosis in Hamilton: A case report and epidemiological study

A case report of a patient severely ill with psittacosis is presented, together with an epidemiological study of his fellow workers. This study illustrates the contagiousness of the disease and indicates that it is probably more prevalent than clinical experience suggests. Only three of the 83 persons studied who were exposed became ill enough to seek medical attention. It is important that both the physician and the public be made aware of this disease so that definitive treatment can be instituted as early as possible. Tetracycline is the drug of choice. Since this infection is widespread among many varieties of birds, and is not confined to those of the parrot family, this disease must be considered in any patient with an atypical pneumonia, especially when there has been contact with a bird. Since there is not likely to be a reinstitution of the ban on the importation of psittacine birds as domestic pets, the only alternative means of controlling outbreaks of this disease is public and physician awareness. Since some outbreaks appear to be spread from man to man, sometimes with high mortality, it is important that any patient suspected of having this disease be kept in strict isolation.