canaries in a coal mine
Early danger detectors
Canaries in a coal mine refers to early warning signs of danger or trouble.
The phrase comes from the historical practice of bringing canaries into mines; the birds would die from toxic gases before levels became lethal to humans, alerting miners to evacuate.
Today it's used metaphorically for anything that signals approaching problems: Declining bee populations are canaries in a coal mine for environmental collapse.
The singular form canary in a coal mine is equally common.
- red flagsIndicators something's wrong
- harbingersSignals of what's ahead
- mining safetyProtecting underground workers
- miner's lampPortable underground illumination device
- fragilityEase of breaking
tipping points · tip of the iceberg · carbon monoxide · toxic fumes · cautionary tales · environmental health · forewarnings · smoke signals · omens · precursors · sacrificial · coal mining · occupational health · early warning systems · species extinction · bellwether · ventilation systems · warning signs
canaries in a coal mineautopsy
Medical examination after death
postmortem · hindsight · aftermath · damage assessment · too little too late
canaries in a coal minesilent killer
Asymptomatic lethal condition
boiling frog · death by a thousand cuts · hidden danger · ticking time bomb