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Saturday 19 November 2011

How canarys differ

Lizard
Today a huge variety of recognisably different breeds of canary exist. As with the domestic dog, the difference from the wild ancestor can be extreme, and selective breeding is still altering them further from the wild type. So how do the different breeds differ?


Song

Timbrado
The original canaries were kept for their song, and all male canaries still sing of course. However, only a few of the canary breeds are actually specifically bred for song type and quality. In Europe, the three commonest types are the Roller, the Waterslager, and the Spanish Timbrado. Each of these has a different song type, a modification of the original wild song.

Song canaries compete at special shows. The birds compete on points awarded against various components , called ‘tours’ of their song. To hear some of these, this website allows you to hear them: http://www.germanroller.com/roller_canary_jukebox.html

One feature of the song varieties is that they are quick studies. It is important that the different breeds are not kept in earshot of each other, as they will imitate each others songs. As part of their training, they are placed where they can hear good examples of the breed type song from either a champion or (especially these days) a recording of one. The young birds hear these when they leave the nest and the song they hear becomes a model for their own.

Size

Yorkshire
The original wild Canary is a small bird, and some canary breeds are still tiny and active. Very popular in the UK at the moment is the Fife, which is minute. By contrast, the Yorkshire is a very large breed, almost 15cm long, and also has a distinctive upright stance. Most other varieties are somewhere in between.

Posture

Swiss Frill
Some canary breeds are bred for their distinctive body shape, especially as they sit on their perch. Not especially popular these days, and to me they do look rather strange, although they can all get around perfectly well. Several of these type canaries also have frilled body feathers, resulting in a very distinctive bird.

Colour

The original wild canary had four different pigments in its feathers. Three different forms of melanin (eumelanin black, eumelanin brown, and phaomelanin) contributed to various black and brown shades in the plumage. In addition, a yellow lipochrome pigment, containing carotenoids derived from the diet, was present in each feather.

In the development of the various breeds, variations in the distribution, presence, and concentration of each of these pigments causes the differences in the colour and markings of each bird. A lot of genetic understanding is required by breeders of exhibition birds, as the genes containing each of these traits may be dominant, co-dominant, or recessive. They may also sometimes be sex-linked, which means that the genes concerned appear on the chromosomes controlling gender. In birds, the male has an identical pair of Z chromosomes, whereas the females have a Z and a W chromosome. This means that a recessive gene on the Z chromosome will appear in all females, but the trait will only be manifest in a male if it is inherited from both parents.

The wild canary is a yellow-ground bird, but white canarys exist. These lack the ability to express the lipochrome pigment, giving a bird which is variously light brown, grey, bluish, or pure white depending on what melanins are expressed.

Feather

Gloster
As mentioned above, some canary breeds have frilled feathers, a result of changes in the orientation in the feather tracts as the feathers emerge from the skin. The other main breed difference is in the crested varieties, of which the commonest is the Gloster. In crested canaries the crest-bearing birds have the feathers on the top of the head radiating from a central point, rather than pointing backwards from the beak. The crested gene is an autosomal dominant, and if a bird carries the gene it is always expressed in the appearance of the bird. However, if two crested birds are bred together (the crest can appear in male or female), any eggs inheriting a double dose of the crested gene die before hatching. For this reason crested varieties come in two recognised forms, crested and non-crested.

The other feature of canaries is that in the course of domestication two distinct forms of body feather became established in all breeds. One type is called variously ‘buff’, ‘frosted’ or ‘non-intensive’. Birds carrying this body feather type appear larger and rounder, but also paler, than birds with the other type of feather (called ‘yellow’, ‘non-frosted’, or ‘non-intensive’), which is narrower, with no white edge, and has a higher pigment concentration. Similar variation exists in other domesticated cage birds, and I presume similar variation also exists in wild birds, at least the finches.


Feather types
 The body feather types are present in most breeds, and the skill of an exhibitor lies in selecting pairings that combine the two types. Pairing two ‘yellow’ type canaries together eventually results in offspring with strong colour but which appear undersize and with a thin appearance, whereas pairing ‘buff’ type birds together results in birds which are large, pale, and loose-feathered.

All this was the state of play up to the 20th century. At this point, experimenters began trying to see if they could expand the palette of colours possible in the canary. The chosen additional colour was red, and how red canaries became possible is the subject of my next post.

Images from:

http://www.redbarnwings.com/
http://www.animalworld.com/

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