I keep some quick detailer and microfibre cloths in the car to deal with any bird poo that gets deposited on my car. You still need to get it off the paintwork sharp-ish to stop it etching the paint, but by soaking the poo with QD and when softened, wiping it off carefully, it's not left to bake on the paintwork to do it's damage.
When I had my mk6 GTD, it got dive-bombed in a restaurant car park on a warm sunny by what must have been a flying elephant. By the time I came out, the elephant poo had baked on hard and was more than my QD and microfibres would've been able to handle. I washed it off as soon as I got home and the paintwork was badly etched

. Fortunately, a bit of effort with my DA polisher sorted it.
Not cheap, but my DA was one of the best investments I've made for keeping swirls and etching at bay on my car. My brother was really impressed recently when I sorted out some etching on his car that was caused by water dripping from a concrete multi-story roof. Looked as if it was beyond correction, but the DA soon had it sorted!