Earth Day is just around the corner, on April 22. This will be the 50th Earth Day. The first one in 1970 was a seminal event in the growth of the environmental movement.

The impetus for the creation of Earth Day was manifold. Smog had become oppressive in southern California. River pollution was causing fish kills. The Cuyahoga River southeast of Cleveland had caught on fire. The Cuyahoga was chronically polluted and the 1969 river fire was actually the thirteenth since 1868 but the 1969 fire made national headlines. In 1969, a massive oil spill occurred off the coast of Santa Barbara, California.

In  1962, Rachel Carson published her book, “Silent Spring,” alerting the world to the impact that DDT and other pesticides were having on birds and other wildlife.  The Breeding Bird Survey was launched in 1966 as a way to document the decline of our birds. Ospreys, peregrine falcons and bald eagle populations were plummeting. In the 1960s, Louisiana, the Pelican State, experienced a dramatic decline and ultimately elimination of brown pelicans. State wildlife officials brought in young brown pelicans from Florida and introduced them onto Queen Bess Island in Louisiana in 1968. These birds imprinted on the island and produced 11 nests in 1971, the first successful pelican nests in Louisiana since 1961.

In the 1960s, Louisiana experienced a dramatic decline and ultimately elimination of brown pelicans in the state as result of DDT poisoning. State wildlife officials brought in young brown pelicans from Florida and introduced them onto Queen Bess Island, pictured here. Louisiana Department of Wildlife and Fisheries photo via AP

These birds were all negatively affected by DDT. This synthetic insecticide was effective against mosquitoes but the compound was ingested by many terrestrial, freshwater and marine organisms. DDT also biomagnifies; it becomes more and more concentrated as one moves up the food web. Small fish to big fish to pelicans.

In birds, DDT interfered with normal calcium metabolism. The result was that female birds laid eggs with thin shells, causing incubating birds to crush their eggs.  DDT was banned in 1972; today, brown pelicans are thriving as well as other large predatory birds that were nearly destroyed by DDT.

By 1970, these environmental insults collectively were too much to bear. On the first Earth Day, events were held at 2,000 U.S. colleges and universities, thousands of primary and secondary schools as well as many cities and towns. Over 20 million Americans participated. In New York City, Mayor John Lindsay shut down Fifth Avenue for Earth Day participants and made Central Park available for talks and other activities. In Philadelphia, Maine’s Edmund Muskie was the keynote speaker.

Now, Earth Day is celebrated in over 190 countries. The scope of Earth Day is a testament to the power of the environmental movement.

Like most aspects of our lives, the coronavirus pandemic has cast a pall over Earth Day celebrations. There will be no parades, no group demonstrations, no talks. But we can reflect on the need to continue our efforts to protect the planet and redouble our efforts to make our individual footprints smaller.

The focus of this year’s Earth Day is climate change. We need to work to reduce the emission of greenhouse gases and promote renewable energy sources. Just like with effort to prevent the spread of coronavirus, we are all in this together.

As important as the creation of Earth Day was, effective conservation programs preceded it. One of the most important dates back over a century. In 1918, the Migratory Bird Treaty Act (MBTA) was signed into law.

Birds were being persecuted by overhunting of species like the passenger pigeon and the slaughter of egrets for their plumes to decorate women’s hats. Two constituencies found common ground: hunters who were concerned about overexploitation of game birds and naturalists concerned about birds in general.

The treaty was signed between the U.S. and Great Britain (acting on behalf of Canada). It prohibits the hunting, killing, capture or selling of any migratory bird listed in the treaty. The treaty lists over 800 species so virtually all North American birds are listed. Without a permit or waiver, even the collection of feathers, nests, eggs or dead birds is prohibited. The treaty has teeth and has withstood many court challenges.

Herb Wilson taught ornithology and other biology courses at Colby College. He welcomes reader comments and questions at whwilson@colby.edu