Natural History

I know of a pet store that sells canaries.

They sell only one variety– the red factors.

Red factors are a colorbred canary, which means they have not been selected for their song. They have been bred for their coloration.

The wild-type Canary has yellow coloration, although it is not as clearly yellow as some domestic variants. They come in several other colors, which all appeared as mutations in exactly the same way other domestic animals have developed them.

However, this red coloration did not appear as a mutation.

It came from an outside source.

That outside source is the Venezuelan red siskin (Carduelis cucullata).

A yellow canary–either a Border or German roller– was bred to a red siskin.

And that introduced the red coloration into a line of birds that were bred back to canaries.

This coloration is genetic, but it has be fed a certain diet to develop the  really vivid color.

But there are those who will argue that these red canaries are not really canaries.

Why?

Because they have a red siskin ancestor somewhere in their family tree.

Wow.

The birds act like canaries, breed with canaries, and look like canaries. Except for their coloration, they don’t have anything about them that suggests another species.

This whole debate has a parallel in another avian species.

Domestic chickens are mostly derived from red jungle fowl. They are considered conspecific with red jungle fowl.

But recent research indicates that the yellow-skinned gene in the domestic chicken comes from gray jungle fowl.

I would contend that the domestic chicken is the same species as the red jungle fowl, but the fact that it may have some genes from another species doesn’t change its exact taxonomy.

Another example of this sort of thing are the domestic goat breeds that have markhor in them.

Just because an organism has some genes that came from another species does not make them unique species.

There are wolves in Minnesota that have coyote MtDNA haplotypes. They often pair off with wolves that have normal wolf MtDNA haplotypes. They recognize each other as being the same species. The fact that some wolves have coyotes as the basis for matriline does not mean that they are not wolves.

The red factor canaries and these other examples point to a more fluid concept of species.

Species can hybridize.  Gene flows exist between related species.

This has happened in the wild. (It may have even happened with us).

This is one part of evolution that we have not looked at closely.  We like to think of species as being fully formed and totally distinct. Sharp edges. No blurring.

But that’s not the way life is.

Life is blurry, and edges become softer and more nebulous.

That is what makes all of this so interesting.

So are red factor canaries canaries?

Yes.

Blood purity is not something that exists in nature. And we’ve been using hybrids to improve all sorts of domesticated species that this argument isn’t really worth making.