Duplex syrinx and acoustic diversity in magpies

Thanks for posting this. I've casually wondered for a while now how one might go about synthesizing magpie songs, so it's nice to have so many specific frequencies, acoustic terms, and further resources all laid out here.

This is a nitpick beacause it's hardly the focus of the article, but I'm not sure if the warbling they describe is strictly an individual activity. During the laziest part of the day, after everybody has had plenty of grubs, you can see and hear them aimlessly dueting in their trees for hours.