In response to today's "Scholars' Circle" on KPFK - Sunday, 09/04/2016 12 noon:

I wrote: Thanks for an XLNT program.

I believe we met years ago at Chapman University at the Yu Torture Memo presentations.

Regarding bird communication capability: I have informally studied crows and ravens for about three decades, and for several years I had a red-front Amazon parrot.  After several years during which my parrot had virtually no contact with any other parrots, I took him with me into a bird store, packed with dozens of parrots and other birds.  The instant that my parrot entered the store, he rendered a long and hugely complex sequence of calls and other sounds - none of which had ever been otherwise  rendered in my presence.  His focus was absolute during this ~15-second rendering, with his eyes bugging out in effort.  And he didn't repeat the rendering.  He had obviously said his piece, which sounded very doleful and heart rendering.  I'm sure he was relating his sad and lonely existence, enslaved to monstrously huge ground dwellers, without a flock, etc. 

I also tried that trick of slowing down recordings of my parrot. His strident  flocking cry  ~"Alright!  ALRIGHT!  ... HE-HAHHH rrrrrRRRRUP!!" rendered after capture on my Amiga computer and slowdown as this hauntingly  beautiful and melodic piece that a slow human would never hear.

I.e., there is evidence to suggest that "bird calls" may go beyond the signaling model altogether and constitute something approaching an actual language.  Crows and especially Ravens also have the ability to render very complex sound sequences, such as a crowd of kids playing.  They use their capabilities very rarely, which is a puzzle.  How did they evolve something so sophisticated and versatile that sees so little actual play?

According to Daniel Suarez, sf/tech-thriller fiction writer and researcher, as presented in his novel "Kill Decision," ravens have had a LONG history of collaborating with whoever is the local top predator - typically human or wolf .  The ravens would operate like drones, finding downed prey and leading the wolf pack or human band to it in exchange for a portion of the feast. 

Based on my own long term observations of urban crow families, I suggest that they played the same role in forest settings.  Don't get on the wrong side of a crow.  DON'T EVER touch a crow baby on its first day out of the nest.  If you do, be prepared to be mobbed every time any crow in the local area (10 miles) spots you - and they will - and they will pass it on for generations.  I.e., predators that mess with crow kids do not pass on their genes, as they never manage to get anywhere close to prey, what  with the incessant "CROW MOLESTOR" chorus following them everywhere.

I introduced myself to the crow family that I studied for about a decade by flashing the sun in their eyes with a CD.  This resulted in the crow daddy rendering sounds of disgust and despair that I had never heard before from any human or animal - but they were instantly recognizable...   After a few weeks of feeding the crows, one of the family followed me and dropped a shiny screw on the ground, waiting to see if I would pick it up.  When I did, the crow flew off, having fulfilled his contractual obligation.

Years later, I watched as a sea gull executed a hovering-in-place move.  Then one of the teenage crows who had been studying the gull swooped over to exactly that place in mid-air - and hovered.  Perhaps a first in crow aviation.

Crows also participate in various kinds of group behaviors, not just mobbing a predator.  For a while, the huge local master flock hung out right across from my home.  Each morning, I would hear the crow leader sounding off the day's flocking cry, which would then be repeated back verbatim by the several thousand crows in the flock.  They would do several repetitions before breaking up into local flocks and departing to their territories.

Check it out: http://www.armoudian.com/scholars-circle-bird-songs-new-form-of-corporate-lawlessness-september-4-2016/#respond

On another, possibly related front, there is the buzz about ultraviolet light communications between birds.  Apparently some birds not only see in the ultraviolet range, but can somehow control their own reflectance to use as a signaling or messaging system. 

Check it out: http://jeb.biologists.org/content/204/14/2499