by Roque Díez

Song canary breeders may feel fortunate. Since quite a long time have been opened very interesting research lines related to the complex physical system of song in birds considering both its aspects neuronal and motor (physical). Canary is the most frecuently used species in these studies for different reasons. First because it is an easy to handle species as it was tamed centuries ago, but also because of its complex song, learning features and neurophysical mechanisms involved in these processes. There's another feature in canaries that has recently interested researchers and promoted new studies: the selective breeding of song canaries towards different song types has developed several song breeds with remarkable differences in song vocalization but also in the performance of the central and peripherial nervous system and even in the learning process of song.

Among these studies I have found two specially interesting: "Sex-linked inheritance of hearing and song in the Belgian Waterslager canary" (Wright,  Brittan-Powell, Dooling and Mundinger 2004) and "Bilateral Song Production in Domestic Canaries" (Suthers,Vallet, Tanvez and Kreutzer 2004). Both works develop very interesting subjects for canary song fanciers and among these they study the peculiarities of Waterslager song compared to those breeds whose song is close to wild canary´s, for instance Spanish Timbrado. The most remarkable differences found in those song types are:

- Waterslager breed shows a strong tendency to use the left side of the syrinx in the sound production, reaching even the 90% of the total. The canaries with wild canary like song use both sides equally or slightly more the right side.
- Wild canary like song reaches frecuencies over 7khz while Waterslager´s goes mainly under 4khz.
- The energy deployed in low frecuencies, under 2khz, is far greater in Waterslager song
- The breathing between syllables sung is done in Waterslager by the right side of the syrinx almost exclusively while canaries with wild like song breath simultaneously by both sides in most cases
- Waterslager breed shows severe hearing malfunction to the point that its sensitivity to frecuencies over 2Khz is 40db lesser than common canaries. This abnormality causes alterations in the learning of song and focus its development in low frecuencies.

It seems obvious that both song types are after different goals and to achieve them the breeders have selected distinctive physical and neural traits which are incompatible. This should be enough advise against any kind of crossbreeding but, moreover, the above mentioned researches show that the articulatory and auditive features studied in the Belgian breed are recessive and sex linked regarding its heredity. This means that many Waterslager's genetic characteristics remain latent in crossbreedings with wild like song breeds and are shown in the phenotype mainly by means of inbreeding. That´s to say, these mixed birds may have a song close to Timbrado but are carriers of Waterslager song. Avoiding inbreeding as a way to hide these recessive characters, as some breeders do, just leads to an irresponsible genetic pollution of Timbrado that would risk the future of the breed if spread out.

Sonogram of Waterslager song, focused on high energy low frecuencies. 

Sonogram of Spanish Timbrado with wide range of frecuencies reaching over 7Khz and a moderate energy in the deep ones.   

Sonogram of wild canary which pitch features are identical to Timbrado

Miguel Angel Obeso miguelobeso@hotmail.com