Couriers. Before the Emergence, Betweeners didn’t use unsecured means of communication. Letters, messages, and communiques are still usually hand-delivered by heralds. Thus far, all of the heralds we’ve met in the Saga & Songs have been avian. (It’s a proud tradition.)

Is it important?” inquired Thrussel.
Wyn left off his fifth reread to blandly reply, “Most letters hand-delivered by heralds are. How did this even find me?”
“Discreet channels.”
“Am I found, then?”
“No, Wyn. We songbirds have our own way of making sure letters reach their intended recipients.” He touched Wyn’s arm. “It was passed from dove to ptarmigan to warbler before arriving in our vicinity. Someone remembered Lord Alderney having a little place by the name, and I offered to see it delivered. None the wiser.”
Hemmed in Silver (Songs of the Amaranthine, #5