Above: Canaries were once used to signal dangers to miners. - Image © Meletios Verras, iStockPhoto.com
The next time you're on your morning walk to school, take a moment to stop and listen to what’s going on around you. What do you hear? Cars driving down the road? Other kids walking past you?
One thing that might have slipped your mind is the vibrant chirping coming from birds. Birds and their beautiful songs have become such a normal part of our day that we sometimes forget that they're there.
But birds do more than just give you a nice tune to listen to in the morning. (Or create annoying noise if you like to sleep in!) Birds play a big role in our environment. Scientists are able to use birds as bioindicators. Bioindicators are species, groups of species or biological processes that scientists can study in order to learn about the surrounding environment.
A good bioindicator is one that is:
- widely studied;
- sensitive to what is disturbing or stressing the environment.
Some birds make good bioindicators. This means that scientists can study these birds to learn about the quality of the environment that these birds live in.
Did you know? Bioindicators include more than just living animals. Bioindicators can also be plants. Plants like lichens can indicate how much pollution is in the air.
Canary in a coal mine
Have you ever heard of the saying “canary in a coal mine?” This saying comes from the days when coal miners used canaries to indicate when toxic gas levels (like methane or carbon monoxide) in the coal mines were too high. Canaries are more sensitive to the toxic gases than humans. If the canary became sick or died, the workers knew it was time to exit the coal mine immediately. Even though these birds weren’t exactly used for scientific reasons, they were still important as bioindicators. They literally helped humans stay alive!
Birds and habitat restoration
Birds can also indicate when their environment is healthy and full of life! This is especially important when we want to know whether habitat restoration efforts are paying off.
For example, the Florida Everglades is a huge, rich wetland ecosystem. Humans have created canals and levees in the area for farming, water supplies, and flood control. This has been going on for over a century, and it has really changed the ecosystem.
Various projects in the area aim to restore the habitat and bring back original water flow. One result of this would be more shallow areas.
In a 2009 study, scientists showed how birds could indicate whether these restoration efforts were working. Egrets are birds that hunt in deep waters. If scientists saw egrets in the area, they knew that restoration efforts were not successful. Meanwhile, storks and ibises like to hunt in shallow waters. If scientists saw storks or ibises, they knew the water flow was low. That meant restoration efforts were successful.
As you can see, birds do more than just sit in trees and sing. They give us a heads-up when our environment is changing. They also give us an opportunity to find solutions to environmental problems before humans get affected. So next time you’re on your walk to school, take a moment to appreciate and listen to the birds chirping. They actually do a lot to protect us!
Let’s talk about it!!
- Do you have plants or pets in your home or neighbourhood? If so, what clues can they give you about conditions in your home or environment?
- In the Florida Everglades, scientists studied birds as bioindicators. But in the coal mines, everyday workers paid attention to the canaries. Should non-scientists be trained to pay attention to possible bioindicators in their environment? Or is this work best left to the scientists? Explain your answer.
Everglades: go with the flow (2017)
D. Allen, Geographical.
The Story of the Real Canary in the Coal Mine (2016)
K. Eschner, Smithsonian.
Bioindicators: Using Organisms to Measure Environmental Impacts (2010)
E.A. Holt & S.W. Miller, Nature Education Knowledge 3.
The White Ibis and Wood Stork as indicators for restoration of the everglades ecosystem (2009) P. Frederick, D.E. Gawlik, J.C. Ogden, M.I. Cook & M. Lusk, Ecological Indicators 9.
Link to abstract. Registration or subscription required to view full text.
What are Bioindicator Plants?
Penn State College of Agricultural Sciences.
Why is it Important to Restore the Everglades?
United States Environmental Protection Agency.