Many people know the sweet song of the House Finch, the western bird that escaped a pet store on Long Island
and thence colonized the eastern U.S. Here is one of its country cousins, the Cassin's Finch.
This pretty red finch resides in the Interior West during the nesting season (summer).
Its closest relative, the Purple Finch, summers both west and east of the Cassin's. The songs of all four populations
are similar, but they can be distinguished by ear.
One of the specialties of the Cassin's Finch is mimicry. The two long pure tones (flat lines on the sonogram) at the
end of this bird's song are not typical of finches, and probably were appropriated from some other species in the neighborhood.
Later in the day, this bird was caught ending his song with a Mountain Chickadee song, and the notes above may also have
been copied from that species.
Like any meme, these notes have a phenotype, a sound in this case, and a "memotype" (analogous to a genotype), the library entry in
the brain of some carrier (or vehicle, to use Dawkins's term). Genes are transmitted directly from one body to another, the phenotype only
facilitating the success of that transfer. Memes, though, are more evanescent. The phenotype is the transmission agent, from one brain to
another, from one memome
to another, as it were. We know from the work of Rod Suthers that Northern Mockingbirds use the same articulatory gestures to make their borrowed sounds
as the species from which they borrowed them. Think of that: Brain -- syrinx -- sound -- ear -- brain -- syrinx -- sound.
The instructions for making the sound reside somehow in the sound itself. Reminds me of axe handles. "How we go on."