Creating Boids Upright

I’m trying to use a boids system to make groups of little characters walk around on some terrain, but many of them start off upside-down. I’ve tried dropping them onto the terrain from above, and I’ve tried starting them off on the terrain itself. This is what I have so far:
Is there any way to affect the rotation at which the boids start out? If so, how? If not, are there any workarounds?

If it helps, here are the physics and render setting for the particle system:

So after being away from Blender for the weekend, I’ve come close to a solution:

The boids already start upright, so it’s more of a matter of keeping them upright. I’ve found the best way to help in this process is to start them close to the ground, to enable “rotation” in render settings, and to give them some time to align themselves.