The canary was a type of bird commonly kept as a pet. Characterized by its yellow feathers, this bird was a member of the finch family. They were originally native to the Canary Islands on Earth.
In 2153, Jonathan Archer made an analogy in reference to s Sphere-Builder who was discovered in a transport pod as part of an experiment designed to monitor his exposure to normal space. This analogy was, quoting Archer, that "miners used to take canaries into the tunnels with them. If the canary didn't die, the miners knew the air would be safe to breathe, and they could proceed." (ENT: "Harbinger")
In 2365, Thadiun Okona joked, "Life is like loading twice your cargo weight onto your spacecraft. If it's canaries and you keep half of them flying all the time, you're alright." (TNG: "The Outrageous Okona")
In 2382, Jet Manhaver warned Brad Boimler that Commander Jack Ransom used junior officers as "canaries in coal mines" for dangerous situations. Later in front of a ski slope, Boimler told Ransom and Andy Billups, "This canary is about to fly," puzzling them. Billups then noted, "It's hard to think of an animal that's good at skiing." (LD: "The Best Exotic Nanite Hotel")