Bird’s eye view: More thoughts on the London Fancy

Everyone seems to have their own thoughts on the London Fancy, and most of them have been aired in Cage and Aviary Birds several times over the last 100 years, but occasionally the magazine publishes an article that covers new ground and contributes to our knowledge.  Andy Early’s article More thoughts on the London Fancy (C&AB 25 November 2015*) is a case in point.

The subject of the article (that the London Fancy was derived from a fertile hybrid) is not new, but his observations on two cross-breeding experiments are.  The word ‘experiment’ covers a wide range of activities, from a  scientific research project, to simply messing about.  Andy’s experiments were neither; they were a classic example of an informed amateur with an enquiring mind following his own line of investigation.

Firstly he tested the American goldfinch (Spinus tristis) x canary cross, which many people consider a strong candidate in the ancestry of the London Fancy.  The S. tristis male does indeed resemble the London Fancy in having a bright yellow body with black wings, but there are many dissimilarities too.  Firstly, it is only the male in nuptial plumage that bears this likeness; secondly he has a black cap and a white rump; and thirdly, he has white bars on the wings.  There are exceptions though, and anyone who has watched the video recommended by Riziero Russo  (which you can find here) will see an American Goldfinch with a clear cap feeding at the bird table!

Andy obtained three hens from this cross from a friend, but was disappointed with both their drab appearance and their failure to breed.  He concluded “I think I can say with a fair degree of certainty that the London Fancy didn’t originate from an American goldfinch x canary cross”.

Am goldfinch x canary hen

I disagree.  We know from the experiments undertaken by Hans Duncker when he created the red canary by crossing the red siskin (S. cucullatus) with yellow canaries, that it was only the F1 males that proved fertile, and even their fertility rate was low.  This is an example of Haldane’s rule which Prof. Tim Birkhead summarised succinctly as “among hybrids, if you are the sex with different sex chromosomes you are more likely to be infertile or dead”**.   In birds, it is the hen that has different sex chromosomes, and female hybrids are therefore invariably sterile.  Had Andy undertaken his experiment with male American goldfinch x canary hybrids, he might have obtained very different results.

Secondly, Andy experimented by crossing the Lizard canary with the Jaspe, a variety of colour canary that Andy states originated from a Magellan siskin (Carduelis magellanica) x canary cross. However, the Jaspe’s ancestry is more complicated than that.  According to an article by Jean-Paul Glemet, translated by Geoff Walker, in C&AB in 2012, this variety originated from a European siskin (S. spinus) x canary cross, from which breeders produced a double factor pastel mutation.  The offspring were then crossed with the Magellan siskin and the red siskin.  The Jaspe isn’t just a hybrid, it is a multi-hybrid from four different species and possesses the pastel mutation!

Jaspe x Lizard F3 cross

The Jaspe x Lizard matings were repeated for three generations, but the offspring were disappointing: the pastel genes diluted the black melanins to a grey colour.  The melanin markings on the body became paler with each generation, but so did the melanins in the flight and tail feathers.  Hardly the outcome anyone trying to re-create the London Fancy would want.  One of the F3 youngsters was a Lizard canary look-alike, but had dark wing and tail feathers, which raises the intriguing possibility that the spangled gene and the pastel gene are located on the same allele.

With the benefit of hindsight, it would be easy to say that these results were predictable, but you don’t really know until you try.  Andy not only tried, but also published his findings, which is to be applauded.

Andy concluded his article with the statement that “I’m now convinced that the London Fancy is not produced from any hybrid”.  Again I have to disagree.  In retrospect, Andy was fighting against the odds with too few birds and too many genetic variables.  It is hardly surprising that his experiments didn’t achieve what he had hoped.  That doesn’t disprove the hypothesis though.  Who knows what might have happened if Andy had been able to obtain a Magellan siskin and paired it directly to a Lizard canary?

The fertile hybrid theory will continue to be debated for years to come.  There are many crosses between the canary and other serins, siskins and carduelines that are known to produce fertile hybrids, as Danielle Sugliani pointed out here.  We may never find the answer, but at least Andy is asking questions and putting them to the test.  Imagine how much we would have learned if everyone who had tested their theory of the London Fancy had published the results.

Footnote:

*  The original article can be obtained here.

**  The Red Canary by Tim Birkhead, 2003, p156.

Photo credits:

American goldfinch: Mdf, Magellan siskin: Dario Sanches.

American goldfinch x canary hen and the Jaspe x Lizard F3 offspring: Andy Early.

2 thoughts on “Bird’s eye view: More thoughts on the London Fancy

  1. just a small remark :
    the term pastel in siskin finches is wrongly used as it is a different mutation as pastel in canaries :
    – pastel in siskin finches is an autosomal recessive mutation that is called “dilute”
    – pastel in canaries is a sex-linked recessive mutation

  2. erratum
    – pastel in siskin finches is an autosomal dominant mutation called dilute (not recessive as previously mentioned)
    sorry –

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