Today’s Wonder of the Day was inspired by Wonder Friend. Wonder Friend Wonders, “Why Would You Take a Canary Into a Coal Mine?” Thanks for WONDERing with us, Wonder Friend!

Today, we’re venturing out of Wonderopolis and into one of the deepest, darkest places in the world. We’re visiting a coal mine! We just need a few supplies before setting out. Pull on a pair of boots, grab a pair of gloves, and fasten your miner’s hat. Of course, we’ll need at least one more thing—do you know where we can find a canary?

Does that sound strange? A canary in a coal mine? It may not be the first thing you think of when you imagine entering a mine today. But there was a time when coal miners wouldn’t set foot in a coal mine without a canary present.

How did canaries help coal miners? They protected them from a danger that lurks in the mines—carbon monoxide (CO). This is an odorless, toxic gas. CO can cause dizziness, loss of consciousness, and even death in humans and animals.

What made canaries so well-suited to protect miners from carbon monoxide? Their breath is more rapid than that of most humans, causing them to take in more air. If poisonous gas was in the air, canaries would breathe in twice as much of it, causing them to become sick before the miners did. If a miner saw that a canary was acting strangely or lost consciousness, they knew to leave the mine at once.

The practice of bringing canaries into coal mines began in 1911 and took off quickly. In many cases, miners came to see the canaries as both protectors and pets. As such, they came up with ways to protect their companions, as well. One example is a device designed to resuscitate canaries who lost consciousness due to poisonous gas. When activated, it provided the birds with increased oxygen, often saving their lives.

Canaries weren’t the only animals to help protect miners from poisonous gases. Mice also did the job for a time until miners realized canaries gave an earlier warning. Today, animals have been replaced by digital CO detectors that warn miners of danger.

Use of canaries in coal mines ended in 1986. However, you may still hear people use the phrase “canary in a coal mine” today. It’s an idiom that describes something that may be a warning sign of trouble or danger to come.

Can you think of any examples of a “canary in a coal mine”? Spend some time today talking with a friend or family member about this saying and the history behind it. 

Standards: C3.D2.His.2, CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.SL.1, CCRA.SL.2, CCRA.W.4,

Wonder What's Next?

We think tomorrow's Wonder of the Day will really inSPIRE you!