Rain Barrel Waterer System

[WonkierZulu]

You can try abs plumbing it is thicker than pvc. Might not prevent all freezing but should help with the frequency.

 

[U_Stormcrow]

You can try abs plumbing it is thicker than pvc. Might not prevent all freezing but should help with the frequency.

Unless you have direct sunlight and high temps - ABS will warp under those conditions faster than PVC will.
If the &*%$#! birds wouldn't peck at it, and eventually destroy it, I'd say use PEX and wrap it in pipe foam to protect against UV - it will take a 100 freeze cycles or more without failure - but your pipe foam won't last a week, and isn't good eats for your bird. Running PEX inside a PVC sleeve (for mechanical and UV protection) becomes increasing difficult the moment you add a T or a elbow - its beyond the skillset of the average homeowner, and a PITA for the rest of us.

 

[WonkierZulu]

Built an abs system myself works pretty good no issues. Painted the water reservoir side white. The rest don't get exposed too uv. No piping should be exposed to direct sunlight to be honest including pvc. Abs has a wider temperature range than pvc. Abs I belive is more expensive also. Pex is a decent solution but can get expensive with fittings. As for the freezing probably circulate the water like you mentioned or get a water warmer made for pools.