"For centuries (the arabs) had used carrier pigeons to convey messages from town to town. Every army on the march carried pigeons that had been raised in various Muslim cities and strongholds. They had been trained always to return to their nests of origin. It was therefore enough to scribble a message, roll it up, attach it to a pigeon's leg, and release the bird, which would then fly, much faster than the swiftest charger, to announce victory, defeat, or the death of a prince, to call for assistance or to encourage resistance among a beleaguered garrison"
"The Crusades Through Arab Eyes" - Alan Maalouf page 124
I don't suppoose any manufacturer in any scale makes figures to represent this important element of Muslim (and no doubt, other) armies. A camel carrying a couple of wicker baskets, another such basket on the ground, one man holding a pigeon securely while putting a message on his leg and another, with arms outstretched, releasing a pigeon with its wings already extended. Now that's a vignette that could be used for a whole range of armies over a very long time period. I'd buy it in 28mm like a shot.