The susceptibility of budgerigars (Melopsittacus undulatus) to graded doses of Toxoplasma gondii oocysts was studied. Sixteen budgerigars were divided into 4 groups (A-D) of 4 each. Birds in groups A-C were fed 100,000, 1,000, or 100 infective oocysts of the VEG strain of T. gondii, respectively. Budgerigars in group D were not fed oocysts and served as controls. All 4 birds in group A died (or...

In the Budgerigar Melopsittacus undulatus, the significance of a conspecific alarm call was investigated in two seasons, winter and spring. Two qualitatively different behavioral responses were displayed by the receivers in reply to playbacks: call(s) and/or taking flight(s). The comparative analysis of the number of birds responding to the alarm and to the control signals revealed two major fa...

Postmitotic hair-cell regeneration in the inner ear of birds provides an opportunity to study the effect of renewed auditory input on auditory perception, vocal production, and vocal learning in a vertebrate. We used behavioral conditioning to test both perception and vocal production in a small Australian parrot, the budgerigar. Results show that both auditory perception and vocal production a...

The agglutination of avian red cells, particularly pigeon and budgerigar cells, by sera from patients who had been exposed to birds and had respiratory symptoms, as well as from healthy bird fanciers, has been used to detect the presence of avian specific antibody. Agglutination tests performed by standard techniques using bird erythrocytes can be read within 45 minutes. One hundred and sixty-f...

The three avian polyomaviruses budgerigar fledgling disease virus types 1 to 3 (BFDV-1 to -3) contain genomes of identical size, 4981 bp. With differences of up to only 15 bp between the three genomes, these viruses show distinct tropism for cultured cells of various avian species: infection of chicken embryo (CE) cells with BFDV-1 and -2 results in virus propagation, whereas BFDV-3 is not repl...

False positive raised complement fixation titres to egg-grown virus preparations were found in six pigeon fanciers suffering from extrinsic allergic alveolitis but not in six similar budgerigar fanciers. The raised titres in the pigeon fanciers fell fourfold over a short interval in the absence of avian exposure and were attributable to antibodies directed against antigens from hen's egg in whi...