The news two weeks ago about the declining numbers of monarch butterflies at a key butterfly preserve in Mexico gives one pause for concern. Reports from the Monarch Butterfly Biosphere Reserve, a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage site, indicate that these beautiful creatures occupied 59% less land in December 2012 than the previous year, their colonies covering the smallest area recorded in 20 years. The area covered by monarch colonies has dwindled from 44.9 acres in 1997 to a mere 2.9 acres this winter. A major reason cited for this decline is loss of habitat due to climate change (drought) and illegal logging in the Mexican forest, not to mention the powerful pesticides and herbicides (in widespread use in U.S. agriculture) designed to poison plant life (weeds) and insects (even the good ones).

Birds may be in trouble, too. Just this month, The American Bird Conservancy (ABC) issued a report calling for the discontinued use—until an independent review can be done—on a class of neurotoxic pesticides called neonicotinoids (“neonics” for short) pending an independent review of their effect on birds, invertebrates and other wildlife. In January this year, the European Food Safety Authority identified neonics as being an “unacceptable” danger to bees.

Still another report on CBS Evening News last week addressed the loss of wetland habitat due to widespread and prolonged drought along the Central Migration Flyway used by geese, ducks and other birds. Continued loss of wetlands will lead to serious population declines, said research scientist Denis Dean of the University of Texas at Dallas, who was interviewed for the report. Dean, who studies wildlife environments, warned that if the situation reaches a tipping point where the birds are no longer able to continue their migration due to lack of water and habitat, there will be mass die-offs. “I wouldn’t say we are there, because clearly we haven’t seen the mass die-offs,” Dean said, “but I think we’re getting close in many cases.”

Reports like these remind us of canaries in the coal mines, caged sentinels taken underground by miners to detect toxic gases, primarily carbon monoxide, in time to warn the miners of life-threatening danger. Canaries, butterflies, amphibians, bats and bees, to name just a few, are sentinels warning us of dangers ahead if we continue to damage our planet. Like coal miners of the past, we ignore these warnings at our own peril.

Many scientists who study these matters worry that the earth is in the midst of a sixth mass extinction (www.nytimes.com/interactive/2012/06/01/opinion/sunday/are-we-in-the-midst-of-a-sixth-mass-extinction.html?emc=eta1&_r=0), there having been five previous ones in the past 540 million years (The last mass extinction wiped out the dinosaurs around 65 million years ago). Currently, nearly 20,000 species of animals and plants worldwide are on a high-risk list for extinction, recorded on the so-called Red List of the International Union for Conservation of Nature (IUCN). Over the last several years, the IUCN has been working to establish a new Red List for ecosystems as well.

The symbiosis of species and ecosystems is irrefutable. Each species, no matter how small, plays an important role in an ecosystem, and the diversity of ecosystems is important, too, rendering critical services to humans and other living creatures allowing us to survive. Wetlands cleanse streams, forests absorb carbon dioxide, ice and snow from mountain glaciers bring fresh water to populations and farms downstream. From trees and plants to birds and bats, from fish and animals to insects and pollinators, from parasites and fungi to the tiniest micro-organisms, all are interdependent, part of the web of life.

Without the diversity nature provides, the stability to ecosystems is threatened. All species, humans included, depend on healthy ecosystems for clean air to breathe and clean water to drink. We depend on a hospitable climate to grow food to eat and for materials to build shelter. In short, we rely on nature and on Mother Earth to provide the basic conditions for survival.

What does our future hold if environmental degradation continues unchecked? Our destiny, the destiny of our children and grandchildren awaits. What are we thinking as we let the environment deteriorate around us—as we ignore the warning signs of canaries?