The Spangle: 2011 Update
Surprisingly no new budgerigar mutations have appeared since the spangle around about 1974 and the saddleback in 1975. Or at least that is what I wrote 14 years ago. In fact, other new mutations have occurred. The blackface appeared in 1992 and the anthracite in 1998. It would be great if a way could be found to bring these varieties into Australia as they look interesting.
Surprisingly, a spangle variation referred to as the melanistic spangle has also appeared. These come out of the nest looking like normals except for their tails, which are yellow (green series) or white (blue series). During successive moults their wing patterns take on spangle characteristics. More information about the melanistic form can be found on the Budgerigar World website http://www.budgerigarworld.com in an article written by Jeff Attwood after he first saw them in Queensland in 1991. The double factor form has clear wings like the conventional spangle double factor but with body colour.
The original spangles were first bred in Victoria. Their ancestry has not been established since they came from colony breeding. The mutation is characterised by the wing pattern which resembles a similar mutation in poultry. I remember seeing spangles among my grandfather’s bantams back in the 1950’s. Since its origin in 1974 the spangle budgerigar has undergone rapid improvement with some incredible representatives appearing at national shows in both single and double factor forms. This seems to have occurred to some extent at the expense of the sharp spangle wing markings in the single factor form that were so striking when the mutation first appeared.
The spangle is often regarded as a dominant mutation, but this is not the case. There are three discrete phenotypes depending upon the presence in a budgerigar of none, one or two spangle mutations. The spangle mutation is in fact partially (or semi-) dominant since the single factor and double factor expressions of the gene are very different. Differences between single factor and double factor expression also exist for the dominant pied, English yellowface, Australian yellowface and anthracite mutations.
The Standard for the spangle (single factor) describes a fine black marking near (not at) the edge of each wing covert and flight feather. The black marking on the covert is in the same position as in the normal budgerigar, but narrower, and the edging which is grey in normals is white in the spangle. The fine black markings are generally lost in opaline spangles which can display a beautiful marbled effect on their wings. The sharp markings in cinnamon normal spangles can be barely visible and at a distance these birds resemble incredible clearwings. Hence the opaline and cinnamon variations of the spangle (single factor) generally score poorly for markings on the showbench. Since markings represent only 15% of the score when judged, opaline spangles in particular remain very competitive with the normal spangle.
Selection of genetic modifiers to enhance the quality of wing markings in the normal spangle could theoretically be achieved in three ways. One way would be by crossing the better marked spangles with normals that have been bred from well marked spangles. The second way would be by intercrossing two well marked spangles to achieve the same aim (as well as giving us a few double factor spangles). Finally, the double factor spangles produced from two well marked spangle parents can be crossed to normals bred from well marked spangles, or to an outcross. All offspring would be spangles, hence this might represent the most efficient use of an outcross to the spangle line.
The spangle mutation reduces the amount of melanin. The original spangles had clear centred target shaped spots due to partial loss of melanin, but such spots are not so common nowadays. Loss of melanin usually manifests as cresent shaped spots. Perhaps outcrossing to birds with large round spots could help restore the target shaped spots? One bad fault in spangles due to reduced melanin is patchy body colour on the rump. Perhaps this could be reduced by avoidance of such birds in the breeding program for single factor spangles; however, they would probably be useful outcrosses for double factor spangles, depending upon their other attributes, since double factor spangles need only exhibit ground colour.
One statement I remember reading in relation to spangles is that the quality of normals is enhanced by breeding through a spangle. I can’t think of any genetic basis for this, so I would suggest that this is yet another of the many myths associated with the breeding of budgerigars. A spangle would only improve type in normals if the spangle was a better bird than its normal partner in the first place!
The Standard for the double factor spangle describes a bird with no markings, the outcome of further reduction of melanin associated with a second spangle mutation (double factor) in the one bird. The body colour needs to be an even shade of ground colour (yellow in the green series and white in the blue series). This bird frequently has a fault (in terms of exhibition but not necessarily in terms of pleasing visual appearance) which is a collar of body colour suffusion (green in the yellow bird and blue or grey in the white bird). This can be rectified by breeding double factor spangles on a cinnamon and/or opaline background, both of which negatively modify colour suffusion. Presumably breeding programs for the white double factor spangle avoid the dark factor and incorporate the grey factor to reduce blue suffusion? I would be interested to find out, from anyone who knows, what effect the dark factor has on colour intensity in the yellow bird, and how grey green and dark green compare with each other as a genetic background for quality of yellow colour.
Finally, if spangle AOSV is introduced into show schedules with the aim of protecting wing markings in spangle ASC classes, in which class would the yellowfaced spangle with normal wing markings be exhibited?