Monarch butterflies migrate north

Berkshire naturalist Thom Smith reflects on monarch butterflies. Smith displayed photographs of monarchs in the June monthlong exhibit at the Lichtenstein Center for the Arts in Pittsfield and has watched them in Berkshire meadows for many years.

When I was a boy, about 7 or 8 years old, our family sometimes picnicked at a rest area along Route 7 in New Ashford. Behind  the picnic area back then lay a hillside meadow where I would chase butterflies and grasshoppers about for hours at a time. The hill is still there, but it is no longer a meadow. Today it is deep woodland of mature trees, with no open sunny places. The meadows where milkweed used to grow are gone. And the butterflies have gone too.

Monarch caterpillars only feed on milkweed, and it has grown scarce along the butterflies’ migration routes and in places where they breed.

In the U.S., Canada and Mexico, the monarch population is down more than 90 percent. University of Kansas insect ecologist Orley R. Taylor has been observing the fragile populations of monarch butterflies for decades, but he says he has never been more concerned about their future.

The Monarch Butterfly faces more threats than regrown forests and lack of food — consider deforestation, rampant use of herbicides and pesticides, climatic changes, droughts and floods, temperature extremes, and even uncontrolled Eco-Tourism.

Monarchs are uniquely vulnerable, partly because they travel. No other insect migrates 2,500 miles each year. The journey is hard in itself — even when all goes well, it is more than a butterfly can make in a lifetime. It takes five to generations for monarchs to make the trip from Mexico to North America.

The migration is so rare, scientists are still learning how the butterflies cross such distances, and new discoveries have refined the story until they have almost entirely re-written it.

The monarchs overwintering in the mountains of central Mexico mate before they begin the journey north. Their eggs hatch from in the spring in northern Mexico and the Southern U.S. As adults, this generation continue the journey north. A third and fourth continue across the country. So the butterflies in the Berkshires this summer are the great- and great-great grandchildren of the overwintering monarchs, and they lay eggs here and in the northern range of eastern monarchs in July and August.

These caterpillars spin chrysalides and emerge as butterflies in early autumn. And these butterflies do not reproduce. They spend their days drinking nectar and clustering together at night. And in September and October or early November the adults fly all the way back to central Mexico.

Weighing less than a tenth of an ounce, they migrate south to a unique forest habitat they have never seen. The butterflies depend for five months on this forest microclimate to survive the winter, and they return to small and specific regions every year to cluster and hibernate in oyamel fir trees.

In 1975 the U.S. scientific community finally tracked down these wintering sites. Until then, only local villagers and landowners had known them.

These sites are vulnerable now. Rampant illegal logging has cut into the trees. In response, over the course of 14 years, local people who love the butterflies have led international efforts to help them. Maraleen Manos-Jones, who coordinates Monarch Butterfly Tours to Mexico, and Jose Luis Alvarez, a forester in Minoachan who runs the nonprofit Forests for Monarchs, have stepped in with and more than 1,000 local families of mountain people to plant 6,000,000 trees in and around the monarch’s overwintering areas.

But often in America people fault others for environmental threats like these, when part of the problem lies here, in backyards and fields.

We learn in elementary school that animals need food, water, shelter, and space to live.

When the monarchs return north in the warm weather, they need milkweed and friendly habitats here, along their flights and in the fields where they spend the summer.

Historically, the U.S. Corn Belt has supported and fed the monarchs on their migrations. Before pesticides like Roundup, farmers controlled weeds by tilling fields and chopping them up and turning over the soil, but not destroying milkweed and other native plants. Now, increasingly, milkweed is disappearing across the midwest — and here too, as the forests logged a hundred years ago grow back.

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