Have you ever seen one of these? It’s a Monarch Butterfly. Every spring, millions fly from Mexico and southern California to other parts of the US and southern Canada. And every autumn, they fly back. On the first of November, called the Day of the Dead, people celebrate the return of the monarchs to the mountainous fir forests of Central Mexico.
But their numbers are dropping. In 1997, there were 150 million. Last year there were only 60 million. One problem is the gradual sterilization of American farmlands thanks to powerful herbicides like Roundup. Monarch butterfly larvae eat a plant called milkweed. But the amount of this plant in Iowa, for example, has dropped between 60% and 90% over the last decade.
And this year was much worse for the monarchs. They came late to Mexico… and I think only 3 million have been seen so far! That’s a stunning decrease!
Some blame the intense drought that hit the US in recent years—the sort of drought we can expect to become more frequent as global warming proceeds.
Earlier this year, Michael Risnit wrote this in USA Today:
Illegal logging in the Mexican forests where they spend the winter, new climate patterns and the disappearance of milkweed—the only plant on which monarchs lay their eggs and on which their caterpillars feed—are being blamed for their shrinking numbers.
Brooke Beebe, former director of the Native Plant Center at Westchester Community College in Valhalla, N.Y., collects monarch eggs, raises them from caterpillar to butterfly and releases them.
“I do that when they’re here. They’re not here,” she said.
The alarm over disappearing monarchs intensified this spring when conservation organizations reported that the amount of Mexican forest the butterflies occupied was at its lowest in 20 years. The World Wildlife Fund, in partnership with a Mexican wireless company and Mexico’s National Commission of Protected Areas, found nine hibernating colonies occupied almost 3 acres during the 2012-13 winter, a 59% decrease from the previous winter.
Because the insects can’t be counted individually, the colonies’ total size is used. Almost 20 years ago, the colonies covered about 45 acres. A couple of acres contains millions of monarchs.
“The monarch population is pretty strong, except it’s not as strong as it used to be and we find out it keeps getting smaller and smaller,” said Travis Brady, the education director at the Greenburgh Nature Center here.
Monarchs arrived at the nature center later this year and in fewer numbers, Brady said.
The nature center’s butterfly house this summer was aflutter with red admirals, giant swallowtails, painted ladies and monarchs, among others. But the last were difficult to obtain because collectors supplying the center had trouble finding monarch eggs in the wild, he said.
No one is suggesting monarchs will become extinct. The concern is whether the annual migration will remain sustainable, said Jeffrey Glassberg, the North American Butterfly Association’s president.
The record low shouldn’t set off a panic, said Marianna T. Wright, executive director of the National Butterfly Center in Texas, a project of the butterfly association.
“It should certainly get some attention,” she said. “I do think the disappearance of milkweed nationwide needs to be addressed. If you want to have monarchs, you have to have milkweed.”
Milkweed is often not part of suburban landscape, succumbing to lawn mowers and weed whackers, monarch advocates point out. Without it, monarch eggs aren’t laid and monarch caterpillars can’t feed and develop into winged adults.
“Many people know milkweed, and many people like it,” said Brady at the nature center. “And a lot of people actively try to destroy it. The health of the monarch population is solely dependent on the milkweed plant.”
The widespread use of herbicide-resistant corn and soybeans, which has resulted in the loss of more than 80 million acres of monarch habitat in recent years, also threatens the plant, according to the website Monarch Watch. In spraying fields to eradicate unwanted plants, Midwest farmers also eliminate butterflies’ habitat.
The 2012 drought and wildfires in Texas also made butterfly life difficult. All monarchs heading to or from the eastern two-thirds of the country pass through the state.
So—check out Monarch Watch! Plant some milkweed and make your yard insect-friendly in other ways… like mine!
I may seem like a math nerd, but I’m out there every weekend gardening. My wife Lisa is the real driving force behind this operation, but I’ve learned to love working with plants, soil, and compost. The best thing we ever did is tear out the lawn. Lawns are boring, let native plants flourish! Even if you don’t like insects, birds eat them, and you’ve gotta like birds. Let the beauty of nature start right where you live.
What did Monarchs do during the ice age?
I suspect there are too few fossil butterflies to easily answer this question that way. But Monarch butterflies can easily fly 100 miles a day, and they are one of the few insects that can cross the Atlantic. In some years they have been seen in southwest Britain. They are becoming more common in Bermuda, due to increased use of milkweed as an ornamental plant in flower gardens. Monarch butterflies born in Bermuda remain year round due to the island’s mild climate!
They also reside in New Zealand. Over on Google+, Jeremy Webb notes that
So, I’d expect that if the climate changes slowly enough that milkweeds survive in large numbers, the Monarch Butterfly has a decent chance of going where the milkweeds are.
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Good news for poor milkweed.
No, bad news for the milkweed: we’re killing it off, so the food chain it supports may be collapsing. Please reread the article, or this:
Luckily, Dr. Taylor of Monarch Watch offers a way that scientists can address the problem: develop a Roundup-resistant strain of milkweed!
Or just stop expansion of farmland. Agriculture is far more damaging to the environment than any sane industrial practice can ever be, due to low flux density of its energy source which implies inefficient land use. The same is true for so called renewables for the same reason.
The main driver behind farmland expansion is the biofuel madness, it is time to put an end to it. No other industry can turn the entire countryside to utter wasteland devoid of all life in autumn (called ploughland). It is a temperate wet desert on a continental scale.
Only industrial wind farms can come in as close seconds with their extensive network of heavy duty service roads and unbelievably high level of low frequency (< 1 Hz) noise emission, which is not regulated in any way and can't even be measured with standard noise control equipment (one would need mirobarometers to do that).
Large solar photovoltaic arrays also interfere with wildlife by competing for a diluted energy source. They do not make sense anyway until an economic way to transient energy storage is found. Even then, they should be restricted to surfaces that are put to dual use like rooftops, parking lots and roads.
If CO₂ emission is a problem indeed, there is no other alternative than to go entirely nuclear with breeder reactors, possibly Thorium based ones. Passive cooling and elimination of long half life isotopes from waste is a must.
Berényi wrote:
Right, the big problem is how vast agricultural lands reduce biodiversity, and how some ‘improvements’ in agricultural practices, like the use of Roundup, only intensify that trend. For example, in Europe the population of many bird species has crashed over the last few decades:
• R.J. Fuller et al, Population declines and range contractions among lowland farmland birds in Britain, Conservation Biology 9 (1995) 1425–1441.
I’ve read that the reduction of hedgerows is part of the problem there—eliminating the place where birds and other species can live.
So, rebel biotechnologists developing Roundup-resistant strains of milkweed is a fun romantic idea, but the serious business is 1) finding farm practices that are efficient yet don’t damage biodiversity as much as currently popular ones, 2) stopping the insane government subsidies of biofuels, especially corn-based ethanol in the US.
I don’t know how damaging wind and solar plants are; stuff can grow around wind turbines. But I agree completely that we need to push for thorium reactors.
Several things…
Dawson College in Montreal, where I teach, is involved in a program called Monarchs Without Borders, run by the Jardin Botanique de Montreal — it gets people involved in raising and tagging caterpillars/butterflies. Great idea and program
http://espacepourlavie.ca/en/monarchs-without-borders-monarch-raising-kit
Participants who tag successfully are in fact contributing to research run out of the U of Kansas by Chip Taylor — see http://www.monarchwatch.org/
Re: “reduction of hedgerows” — do you have a source on that? I too recall reading something somewhere on this topic. In my rural childhood (in southern Ontario) all the fields were 5-10 acre units marked off by thick hedgerows of that harboured all kinds of trees, plants, birds & critters. With the vanishing of the smaller family farms and the elimination of garden crops by (you said it) corn, the hedgerows disappeared. Easier driving the big combine; too bad the top soil blows away faster.
Another factor in reduced bird populations is apparently cutting for hay multiple times over the growing season versus once or twice as was once the case. Where ground nesting species once had a chance to reproduce before the mid-to-late summer haying, now the bigger fields are cut early and often, 4 or 5 times, by rotary mowers. They skip the baling and blow it right into trucks to be hauled off to the feedlots.
Always enjoy dropping in on your blog John! Sustainability needs a healthy, expanding population of math nerds…
Monarch decline is certainly good news.
We are bad news, but that’s hardly news really. Also I don’t see any general population numbers for milkweed in the article, only information that it is much less prevalent on farmland but it doesn’t follow that its total population experienced as sharp a decline as that of butterflies.
For years I have been finding eggs on milkweed in my yard and “raising” the caterpillars in a tank on my porch until the butterflies are ready to be released. This summer I sadly had less than a quarter of my normal number of monarchs and attributed it to the post-Sandy ecosystem disruption in my Jersey shore area. I see the reason is much broader and more disturbing.
Reblogged this on 4writersandreaders and commented:
Learn about our Amazing Monarchs! ~ Bette A. Stevens http://www.4writersandreaders.com
I hate this. We used to have so many of them cover over our area and we had only a handful this year. What a tragedy. They are such awesome butterflies and the journey they make twice a year is of epic proportions. So sad. Natalie :(
I hate it too. Vote for politicians who care about the environment, help lobbies who pressure the politicians to do the right things, and tear out your lawn and grow plants that birds and insects like—those are some of the main things we can do.
Ian McKenzie—I’m glad you enjoy this blog! And I’m glad to hear about Monarchs Without Borders. Cutting for hay multiple times a year… that’s the kind of thing that could have a huge effect. How come they can do it now? Do they get the hay to grow faster, or just cut it more often?
As for the elimination of hedgerows causing a collapse of bird populations, I’ve mainly heard about that in Britain and Europe.
• Robin McKie, How EU farming policies led to a collapse in Europe’s bird population, The Guardian, 26 May 2012.
These grim statistics are for the whole European Union. The article writes:
The article is based on data from the Pan-European Common Bird Monitoring Scheme, and their website has more on bird populations. But for more on hedgerows we have to look elsewhere, like this:
• S. A. Hinsley and P. E. Bellamy, The influence of hedge structure, management and landscape context on the value of hedgerows to birds: a review, Journal of Environmental Management 60 (2000), 33–49.
In England, where there’s a lot of popular support for wildlife, people are trying to reverse the decline of bird populations:
• Fiona Harvey, UK’s wild bird population continues to decline, The Guardian, 17 October 2013.
Yes, I am grateful to have seen many. But recently I have not seen any.
Our house is alone in the woods within hearing distance of Lake Michigan. One spring day we went outside to sit together in the sun. There, were dozens and dozens of them flying above us in a patch of sunlight streaming through the trees.
And they were dancing with each other– in pairs! I watched one couple, which after a while flew apart. One of them flew to the siding on our house, moved its wings slowly after coming to a rest, and then bathed there in the sun. I watched it for a while. Suddenly it cocked its wings. Why? It’s partner was flying straight toward it, out of the trees, from its own resting place in the woods. In response it lept from the siding into the air and flew straight toward its onrushing partner. They came ever so close to each other, and then danced away, together, above us in the sun.
It is the tragedy of the commons. Nobody wants to see things like this destroyed. But something that nobody wants to see happen is nonetheless happening.
IMHO this is the consciousness of prosperity, manifesting prosperity, and nothing else– specifically, being unconscious of the dignity that this kind of prosperity can take from others, and being unconscious of the peace that can exist inside a human heart, just from living on the planet Earth.
(My apologies for waxing poetic. You started it.)
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I saw them in Mexico this time last year! They’re beautiful. A few words here http://millynomad.wordpress.com/2013/11/29/a-million-butterflies/
I saw a Monarch in my back yard yesterday! Some of them winter in California.