Losing a bird with no warning is rough. The usual suspects in Coturnix:
- Heat stress — quail handle cold better than heat; over ~95°F with no shade or airflow is dangerous.
- Injury — boinking (head trauma), getting caught in wire, or trampling in a panic.
- Predators/shock — even a predator that can’t get in can scare birds badly or cause a fatal flush.
- Disease — especially if droppings, appetite, or energy were “off” beforehand.
- Egg binding in hens (see the separate thread).
Prevention is mostly boring fundamentals: shade + airflow in heat, soft/low ceilings, secure cages, dry bedding, and quarantine for new birds. If you’re losing multiple birds, treat it as possible disease and separate/observe closely.
Keeper, not a vet — if you’re seeing repeat losses, loop in a poultry vet. Sorry for your loss if that’s why you’re here.