Moonsville's Million Pigeons

[Prompt: A systm to send messages between distant places]
"It's always raining in Moonsville." Yeah? More accurate opener might be "It's always guano in Moonsville." It's a good thing there are entire families of organisms evolved just for the eating-columba-shit niche, or the valley would be drowning in it. With a literal million pigeons inhabiting Moonsville, there's gonna be a lotta white leave-behinds. But we love them. We can't fault the pigeons just living their lives. Everyone poops. AND, out of the club of Moonsvillians Who Poop, pigeons are definitely among the most useful and versatile. They never lost their abilities of navigation and memory, and some even have the vocal mimicry to rival a corvid. Plus, they're delightfully friendly, and gorgeous to boot. (DON'T @ me!!) As a result, these blue-gray beauties are the perfect candidates for facilitating communication between all sorts of people at a variety of distances. They're still mainly stationed in Moonsville, taking messages back and forth across the Crake, but we've started sending tentatives out to Solenopolis and some of the friendlier willowing outposts.
There are several different ways we can us pigeons to send a message. Yeah, you've got the classic "wrap a scroll around the ankle," but that's about as reliable as a message in a bottle. Our solution may be ancient, but that doesn't mean we have to be passive about it! We've found the best results come from combining the birds with magic. Modifying Message for touch range: get a peck on the cheek, bam now there's a letter in your head. I, personally, am partial to casting Magic Mouth directly on the pigeon, to hilarious visual effect.
Now our sights are on extending our communication network into the lake. Can't leave the merguys out! The question is how. Maybe ducks?