About 150 species of butterflies have been documented in Ohio, but none are better known and more beloved than the iconic monarch. The large orange and black butterflies are conspicuous, easily recognized and have an amazing story.
Monarchs have tied their fortunes entirely to milkweeds, and that strategy has served them well for most of their existence. Like all species in the giant order lepidoptera (butterflies and moths), the monarch lifecycle is a perfect metamorphosis of four acts: egg, caterpillar, pupa, butterfly.
The brightly colored caterpillars have evolved the ability to assimilate toxic cardiac glycoside compounds within milkweeds. This in turn makes the caterpillars toxic, which thwarts many would-be predators, including birds, upping their odds of survival.
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Even without human interference, these insects need all the help that they can get. Eastern populations, such as in Ohio, engage in incredible end-of-season migrations to oyamel fir forests in central Mexico.
A monarch that was born in Columbus must travel about 1,800 miles to reach its wintering grounds. That’s in a straight line. In reality, the butterfly will fly much further as it will have to skirt around the Gulf of Mexico.
Remarkably, there is evidence suggesting that some monarchs cross the Gulf, having been seen on boats and oil rigs far out to sea.
Such a flight is fraught with peril, but nonetheless, butterflies appear on schedule in the oyamel fir forests, usually beginning to arrive around the Day of the Dead (Nov. 1).
The largest roosts on record occurred in the winter of 1996-97, when monarchs blanketed much of 45 acres of forest in their prime wintering locale. Such numbers are unimaginable and estimating individual numbers is impossible, hence the acreage measurement. Last winter, monarchs only utilized about 2.2 acres in the same area.
Cut to this year and a bleak forecast for wintering monarchs. Everyone that I’ve asked has seen far fewer monarchs than perhaps any other year, me included.
Despite routine far-flung travels, I’ve probably only seen a few dozen, the fewest I can ever recall. The World Wildlife Fund estimates a drop of 59% in the eastern population this year. There is also a western monarch population. Butterflies that breed west of the Rockies travel to wintering grounds in central and southern California. That population has declined about 95% from its known peak.
As is the case with most declining animals, habitat loss is a major issue. This is especially true in heavily agricultural regions like Ohio. Heavy use of herbicides and destruction of “weedy” edges and fencerows have caused milkweed declines.
Urban and suburban sprawl lays waste to massive swaths of former monarch habitats, and increased vehicle traffic spikes roadkill of low-flying butterflies.
People can help by planting milkweeds to host the butterflies, and many do. Even the smallest suburban lot can spawn butterflies.
Our metro parks certainly chip in. I visited Blendon Woods Metro Park on Oct. 6 and took the photo that accompanies this column. That monarch had just emerged from its chrysalis and was still drying its wings, prepping for the long flight ahead.
It was spawned from planted milkweeds, and senior naturalist Stephanie West oversees a monarch-rearing program that results in the production of scores of butterflies.
The disappearance of an organism as prolific as the monarch butterfly should be cause for alarm. Their loss is an environmental red flag, and a slap in the face as to how humans are treating the environment in which we all dwell.
On the rare occasions that I do see a monarch, I sometimes think of the passenger pigeon. It was once the most abundant bird in North America, numbering as many as 5 billion individuals. At its peak, no one would have thought such a prolific animal could ever be eliminated. But kill off the pigeon we did, through a variety of poor practices, and the last bird, Martha, died in the Cincinnati Zoo in 1914. No one alive today has seen a passenger pigeon.
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I wonder if the formerly abundant monarch is going the way of the passenger pigeon. It would be a shame for future generations to only know this marvelous insect from textbooks.
Naturalist Jim McCormac writes a column for The Dispatch on the first and third Sundays of the month. He also writes about nature at jim mccormac.blogspot.com .
This article originally appeared on The Columbus Dispatch: Nature: Monarch butterflies bring beauty to Columbus metro parks
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