Well into the twentieth century, live canaries were taken to the working levels of underground coal mines to provide an early warning of dangerous conditions. Canaries quickly responded to high concentrations of carbon monoxide and methane in the mine. When the birds stopped singing, became lethargic, or fell off their perches, miners knew they had only minutes to get out of a toxic environment.
We may be ignoring a similar warning in our environmental system right now. Granted, we don’t live in a coal mine and our caged canaries are fine, but as we look out the window at the natural world, it is easy to see everything is not fine. It may be as simple as realizing that we are not seeing monarch butterflies in the fall when we expect them.
The population on the earth continues to grow. As the human species expands, our activities make it increasingly difficult for virtually all other species to live and reproduce. The Center for Biological Diversity concludes from fossil records over many millennia that there has been a background rate of extinction on the planet of one to five species per year. Recent data shows that we are now seeing a species loss at more than a thousand times the historical background rate.
Each species reacts to a changing environment differently. Some are lost because they get crowded out. People take over creature space and the creatures just disappear. For many species, the necessary habitat to live in and reproduce is lost and there is a slow and persistent decline in the population. Because of pollution and climate change, conditions are becoming too toxic for many species to survive.
Most of the increasing numbers of species that are going extinct are small, obscure, and not part of our lives. We don’t become concerned or we don’t even notice. Occasionally our awareness is jolted by a situation such as is occurring with the monarch butterfly.
Monarchs provide a familiar splash of color in our gardens as they make their migration through Iowa. However the monarch butterfly population is declining dramatically, a loss of over 90 percent in the past 20 years. There are several reasons for this, but a major factor has been the use of Roundup-type herbicides in Iowa agriculture. This has killed most of the native milkweed which is the primary food source for monarch butterflies.
Do we care? We can probably get along without monarch butterflies as we get along without other less visible species that are becoming extinct. But something tragic happens when we can no longer experience this simple beauty in our backyard. Continuing indifference will quickly lead us to a tipping point.
The monarch butterfly may be our canary in the coal mine. This may be a signal that our environment is becoming toxic and we have only a limited time to avoid the consequences.