The timeless tale of monarch butterfly migration

By Michele S. Byers

Do you ever read through old newspapers and notice that sometimes the topic and perspective are still pretty current and fresh? So much has changed in the world in recent decades, but our fascination with nature is timeless. Please enjoy the following column written 34 years ago by Dave Moore, the former executive director of the New Jersey Conservation Foundation, with a few edits to reflect more recent research and understanding:

Ever notice those bright orange and black butterflies that fly purposefully through our yards and sometimes cluster overnight in trees? They are monarch butterflies, and their flight is purposeful: They are migrating south for the winter.

The monarch butterfly migrates all the way to the mountains of central Mexico, often from as far as New Jersey, New England or nearby Canada. This is one of the most amazing migration stories in nature; one in which the route has been partially realized by naturalists for a long time, but fully understood only a decade ago with the discovery of the long-sought wintering place of the monarchs.

Researchers are still adding to the story. For example, it was at first thought that the same butterflies returned to New Jersey a year after their southward migration. It’s now realized that it’s the grandchildren – or even the great-great-great-great grandchildren – who come back to the northeast.

Science is still a long way from learning how the butterflies have managed to arrive at the same small area of Mexico over millions of years. But they have, and during their migrations they even congregate on certain trees at specific locations, year after year.  These way-points in themselves are popular tourist attractions, as is the Mexican destination.

One butterfly tree of which I am aware stands in Island Beach State Park near Barnegat Lighthouse, and is decorated by thousands of monarchs each autumn. When science finally solves the riddle of the monarch’s migration, I suppose a little more magic will have gone out of our lives.

But the danger of lost magic is greater for another reason, and not just in terms of monarch migrations. Can you imagine a world without our common songbirds, or minus many of the larger birds that annually make long round trips south and north?

While we protect them up here, their habitats are being bulldozed and burned away in South America as many countries destroy forests to make way for new development.

The monarchs are lucky; Mexico has set aside their wintering place for tourist and scientific reasons. Not so with the birds.

There are so many plants and animals we know nothing about that are becoming extinct before we can really study them. Fewer than a tenth of the plants, insects and animals on earth have been identified. The rate of extinction is speeding up due to people’s blind exploitation of the environment.

We must do much more to protect reserves where plants and animals can survive in the hope of someday revealing exciting secrets for medicines and foods to help us survive. We must also do a better job of regulating our own chemicals so they don’t do us and other life forms in.

Bugs and weeds don’t attract as much attention as whales and pandas, but they are equally important in the scheme of things.

Monarch butterflies feed only on milkweed, for example. If we lose the milkweed, we lose the butterfly. And by the way, monarchs have the ability to turn milkweed juice into a toxic substance that has taught predators to avoid them. Other butterflies have learned to mimic monarchs to get the same protection.

With all this loss of life-forms, and with our growing interest in genetic engineering, genetic diversity becomes more important, even as it’s being threatened. That means we must protect natural areas worldwide, protect native plants and animals, and learn more about the effects of our pesticides and other chemicals before it’s too late.

You have read about possible links between the herbicide Agent Orange and cancer. Agent Orange contains 2,4-D, a common herbicide. Recent studies point toward a connection between 2,4-D and three cancers in humans, including Hodgkin’s disease.

Given that everything is connected to everything else, we need to proceed carefully. Not only do we not know who lives in the world with us, but we don’t even know what the majority of chemical substances we manufacture are doing to them or us.

Back to Michele: Since Dave’s nature column was written in September 1986, more research has been done on monarch butterfly migration, as well as on the harmful impacts of many chemical herbicides and pesticides, not just Agent Orange.

The annual journey of monarch butterflies still amazes. In Cape May, the New Jersey Audubon Society now monitors monarch butterflies each fall as they congregate on the peninsula in preparation for their flight across the Delaware Bay. If you get a chance this fall, be sure to visit to see migrating birds and butterflies.

Michele S. Byers is the executive director of the New Jersey Conservation Foundation, Far Hills. She may be reached at [email protected]