A 1-year-old male canary (Serinus canaria, Jibber breed), with a protuberance on the left tibia was referred to the clinic. The bird was not able to use the affected foot to stand on its perch. Results of radiographs revealed a radio-opaque hard tissue mass. The canary was euthanatized and submitted for necropsy. On histopathologic examination, the mass was diagnosed as an ossifying fibroma tum...

The respective influence of testosterone and estradiol on the structure of the Common Canary Serinus canaria song was studied by experimentally controlling blood levels of steroid hormones in males and analyzing the consequent effects on acoustic parameters. A detailed acoustic analysis of the songs produced before and after hormonal manipulation revealed that testosterone and estradiol seem to...

Osteoma is an uncommon bone tumor in avian species and other animals. A 2-year-old male canary (Serinus canaria) with a history of an oval mass in the left wing for several months was examined. Radiographs showed a radio-opaque mass. Upon the bird's owner request, the canary was euthanatized and submitted for necropsy. The histopathologic examination revealed numerous trabeculae consisting of b...

We present a model of sound production in a songbird's vocal organ and find that much of the complexity of the song of the canary (Serinus canaria) can be produced from simple time variations in forcing functions. The starts, stops, and pauses between syllables, as well as variation in pitch and timbre are inherent in the mechanics and can often be expressed through smooth and simple variations...

Yolk sac infection (YSI) and dead-in-shell mortality caused by Enterobacteriaceae in birds are not a rare phenomenon, however there are only a few reports indicating the association between these conditions and Klebsiella spp. among canary chicks (Serinus canaria). There have been reports of high mortality among 1-3 day old canary chicks in an indoor flock of canaries. In order to study the cau...

Osteoma is an uncommon bone tumor in avian species and other animals. A 2-year-old male canary (Serinus canaria) with a history of an oval mass in the left wing for several months was examined. Radiographs showed a radio-opaque mass. Upon the bird’s owner request, the canary was euthanatized and submitted for necropsy. The histopathologic examination revealed numerous trabeculae consis...

New neurons are incorporated into the high vocal center (HVC), a nucleus of the adult canary (Serinus canaria) brain that plays a critical role in the acquisition and production of learned song. Recruitment of new neurons in the HVC is seasonally regulated and depends upon testosterone levels. We show here that brain-derived neurotrophic factor (BDNF) is present in the HVC of adult males but is...

Oocysts of Isospora serini and Isospora canaria, from the canary Serinus canarius, were broken, added to a cell suspension, fixed in Karnovsky's fluid, and studied in the electron microscope. The oocyst wall of each species had an electron-lucent inner layer, a more osmiophilic middle layer and an outer layer of electron-lucent (I. serini) or electron-dense material interspersed with some elect...

Animals that use vocal signals to communicate often compensate for interference and masking from background noise by raising the amplitude of their vocalisations. This response has been termed the Lombard effect. However, despite more than a century of research, little is known how quickly animals can adjust the amplitude of their vocalisations after the onset of noise. The ability to respond q...