Did my baby pigeon die from getting the wrong food?
Pigeons do NOT need live food. The pet store gave you the wrong stuff. You were doing just fine. If it ever happens again that you need to rear a pigeon like this, simply get either some chicken mash or some game bird pellets and grind them up in a blender with water to make a slurry. Feed him that. Your bird will grow well. I’ve done it for years and raised hundreds of pigeons of many breeds. For future use, I’m listing some emergency feeding of pigeon below. I’d suggest earmarking them for reference or downloading and saving the info for next time.