Last winter, monarch butterfly numbers soared, increasing by more than one-third in their overwintering habitat. Yet we are well into July, and while my milkweed garden has been abuzz with bees feasting on the nectar, there’s no sign of any monarchs or their caterpillars. I am probably not alone in my dismay, but hopefully butterfly enthusiasts won’t give up—at least I won’t.
According to MonarchWatch.org, storms this past winter took a toll on the population of overwintering butterflies in Mexico. It seems that Mother Nature did not want to cooperate this year with human efforts to help restore the ailing butterfly populations.
Despite such frustrations, private action to help save monarch butterflies is well worth it. These bright orange and black winged creatures are surely a marvel of nature. Over the summer in the United States and Canada, monarchs breed several generations on milkweed, with most butterflies living just a few weeks. But at the end of the summer, the last generation migrates all the way to Mexico where it overwinters and then flies back north in the spring to continue the cycle. Quite incredible!
Milkweed is essential for monarch butterflies because they depend on it to reproduce. The butterflies lay eggs on the milkweed, which hatch and grow into caterpillars that feed on this poisonous plant. The poisons in the milkweed make the caterpillars poisonous to many potential predators. While the adult butterflies can feed on other nectar-bearing plants, the caterpillars only eat milkweed.
In recent decades, monarch butterfly numbers have dwindled, raising concerns that the species could go extinct. The cause is not fully understood, but it is clear that habitat loss, particularly reduction of milkweed, is a significant challenge. In addition, inadequate access to other nectar producing plants also may play a role.
Some activist groups blame herbicides for monarch population declines because farmers use these products to eliminate milkweed plants, but it’s not the chemicals that are the problem. Farmers need to remove all kinds of weeds—with or without herbicides—so they can plant crops to feed people. And milkweed is poisonous and can kill livestock if they graze among it or if it gets into hay or other feed for the animals.
Accordingly, farmers do need to manage milkweed along with many other weeds, whether they do it manually or with herbicides. Herbicides not only make that process easier (reducing costs), these products also reduce the need to remove weeds by tilling, which means less erosion, reduced runoff, and less soil depletion. So overall, herbicides have environmentally beneficial effects.
Moreover, farmers are not the only ones who have removed milkweed from the environment. As cities, towns, and homeowners have chosen to landscape properties, many have grubbed up milkweed, which is also poisonous to humans and pets. If you get the “milk” from this plant in your eye, you could go blind temporarily.
A number of conservation groups and individuals around the nation are educating the public on the importance of milkweed and helpful nectar producing plants, and their efforts appear to be paying off. Cities and towns are making space for milkweed along highways where its blooms offer scenic views and its poisons pose low risk. Homeowners are planting it on private property as well, where they too can manage the risks. For example, my milkweed garden lies just outside my fence, out of reach of dogs.
Farmers are also making an effort to set aside space for nectar-bearing plants including milkweed, and ironically herbicides and other pesticides help make that possible by promoting high-yield agriculture. Farmers can produce more food per acre thanks to these technologies, which makes more land available for wildlife. For example, Cato Institute Scholar Indur Goklany’s research shows that if we did not have high-yield agriculture and we still farmed the way we did back in 1910, we’d have to plant more than three times the amount of land that we plant now to generate the same amount of food!
Voluntary effort appears to be helping. In March, The Christian Science Monitor reported: “This year’s overwintering population in Mexico was: “3.5 times greater than the previous season, which saw 2.8 acres of butterflies. This is also up from the record low of 1.66 acres in 2013.” However, the number of overwintering butterflies was still 32 percent below the “historic average,” the Monitor reported.
Unfortunately, Mother Nature did not cooperate this year, and she sent cold weather, storms, and hail to areas where butterflies were overwintering. But the damage would likely have been much worse if there were fewer butterflies and hopefully, they will rebound quickly, foraging in my yard and many privately provided habitats around the nation. Maybe even yours?