How would a roughly medieval military be changed by flying couriers?

Question

Aial is one of the most renown and sought after couriers in the world, that partly has to do with his work morale and partly with the fact that he's an aarakocra (I have to change that name because it's stupid), a humanoid avian creature with six limbs (a pair of wings in addition to the arms).

Aarakocra are primarily gliders and are quite good at it, in fact, they can easily commute between the farthest points of a Westeros-sized continent (though don't expect them to carry around heavy cargo, that's for Sam Porter Bridges).

After takeoff, they can flap their wings for 90 seconds (should be enough to attain a workable altitude) before having to rest, which they can do in the air. They can also basically ignore geographical barriers. As for their safety, they're out of range for anything short of a 14.5mm anti-aircraft gun when in cruising altitude.

Naturally, this would make them perfect to carry messages between armies. The only things you have to watch out for is that:

1. Aarakocra are low in number, most prefer to stay up in their villages.
2. Aarakocra prefer not to fight their own kind and you can't make them, since they have a good leverage on you (you can't police them when they fly and it's up to their goodwill whom they deliver the VERY IMPORTANT MESSAGES to).

I wonder how the addition of aarakocra couriers would change how a medieval campaign is conducted (when they're employed on both sides) on the strategic level?

Answer 1

Thats a CRAZY high climb rate!

Your bird-dudes are flying above the range of a 14.5mm aircraft cannon, which has a maximum engagement cieling of 4,000 meters. These creatures can sustain muscle powered flight for 90 seconds, during which period they are reaching this altitude. This means they are going to be climbing at 44 meters per second, giving them a climb rate of about 8,800 feet per minute. For reference, this is almost the same climb rate as the F-86 Sabre jet fighter.

I'd probably tone that down just a weeeee bit. Perhaps their flight method is more akin to an albatross or a condore where they slowly circle riding thermals to gain altitude, then glide from there. Because otherwise you have bird people with the functional climb and speed capabilities of 1960's era jet aircraft.

That aside, Heres how to use them:

Messengers

Commanders can now command units much farther afield than they normally could. A commander now no longer has to keep his entire army within riding distance. He can, using these swift couriers, divide his force up among multiple strategic positions, and use them to attack or react much more fluidly. Real Medieval commanders could not conduct strategic small unit manuevering. The best they could do was to send out small raiding and harassment parties and trust thier commanders to do the best. This was unpredictable, and if unlucky, a loss or critical info might not reach him until it was too late to utilize said info. Now, commanders do not have to worry about this and can conduct highly mobile, decentralized strategic actions.

Observers

Part of that reaction speed means that he can know the disposition of enemy forces well before hand and plan his responses in advance. Instead of having to wait until they are right on top of him to eye them up, he can set ambushes, destroy infrastructure in front of them like bridges, or close mountain passes. This means a commanders ability to manipulate the conflict enables him to better set the pace of the conflict and attempt to funnel the enemy into a position of his choosing.

Propaganda

Perhaps a commander could sow dischord in enemy rear areas by dropping propaganda leaflets on enemy cities and villaiges. Tell them thier armies have been crushed, or thier charismatic leader has fallen. Panic the public with conflicting reports and false narratives.

Strategic Arson

Fire was a real threat for medieval cities. You could use a few dozen of these bird men to fly in under cover of darkness, start a bunch of fires, then fly away. With luck and skill these fires may rage out of control and cause incredible economic and infrastructural damage to an enemy's rear areas. This forces the enemy to use forces he might otherwise have been able to commit to battle for defending his own assets. Additionally, damage like this is going to make a war far more expensive, and further diminish the number of assets that he could bring to bear on the front.

Counter Intelligence

Dress up some of your bird-men to look like some of the enemy's bird-men and have them carry messeges disguised as official orders to enemy commanders. Order units into ambushes, or give them orders to move to some location in the middle of nowhere where they miss a battle, or even, if you are insaneley lucky, convince them a nearby unit has been discovered to be traitors and to attack them.

Answer 2

In some ways they would be more useful than carrier pigeons as they would be able to deliver messages to a wide variety of locations. However if carrier pigeons exist and are used in your world they would greatly reduce the importance of these creatures.

Answer 3

For a strategic purpose the use case is obvious. Use them as a means of transport for field commanders, prioritize on intercepting them, shooting them down. I fundamentally think this is not that interesting, and that you would have arrived at that yourself.

I think the more interesting use case is tactical. There are 2 primary use-cases here.

1) The Balloon Corps of the Union army during the Civil War fulfilled the vital purpose of information gathering, map making, and recon.

2) Intrinsic Artillery Observation - the forerunner of modern US Army aviation is built from this purpose. Cannonade, Catapults, trebuchets, while individually inaccurate still, could be provided much more accurate targeting information for groupings. This might heavily incentive the use of artillery and archery, both to take out enemy infantry and discourage flyers.

I think personally carrying heavily cargo or munitions is a waste, and is likely to be very ineffective at their carrying capacity, unless they turn into Kamikaze units.