David Suzuki: Help ensure the monarch butterfly's survival

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      What weighs less than a paperclip, tastes terrible, and can travel thousands of kilometres without a map? Hint: this delicate critter is tawny-orange with black veins and white spots and has been mysteriously absent from Canada this summer.

      It’s the monarch butterfly. Each year, eastern populations of these amazing frequent flyers flit between forests in central Mexico and southern Ontario.

      It’s the only North American butterfly known to migrate and, most surprisingly, no single butterfly makes the return trip. In spring the butterflies depart from Mexico for states like Texas, where they breed and die. The offspring continue northward, repeating the reproductive cycle three or four times before arriving in Ontario.

      Toward the end of summer, a generation of super-monarchs is born that survives for seven or eight months and makes the incredible journey south. Even though they’ve never been to Mexico’s volcanic mountains, the butterflies use an internal compass and landscape to guide them to the forests where their ancestors hibernated the previous winter.

      Unfortunately, the past year has been bad for monarchs. Historically, about 350 million overwinter in Mexico, so densely covering the coniferous branches that they bow under the weight. This past winter scientists estimated only 60 million made ita decline of more than 80 percent.

      Why are monarch populations at a 20-year low? Although the Mexican government has halted industrial logging in their winter home, serious threats remain, including illegal logging. Scientists say the main threats, though, are record-setting heat waves (which reduce reproductive success) and pervasive use of genetically modified crops.

      One of the most important reproductive areas for the monarch is the U.S. Midwest, which has historically been blanketed with milkweed. This plant contains small amounts of cardenolide, a foul-tasting substance that can be toxic in large quantities. The monarch caterpillar eats only milkweed for this reason. Predators dislike the cardenolide stored in the monarch’s body, so they learn to steer clear of flittering things with orange and black wings. 

      Despite the conversion of much of the arable land in the Midwest to agriculture during the past couple of centuries, milkweed continued to grow along edges and between rows of crops—feeding millions of monarch caterpillars. 

      Over the past decade, about 150 million hectares of farmland in the region—an area about the size of Saskatchewan—have been planted with soybean and corn genetically modified to tolerate herbicides, known as “Roundup Ready” crops. Instead of tilling fields, farmers spray herbicides that kill all plants but the crop. This has wiped out much of the milkweed.

      With a decline of monarchs in Mexico and pervasive threats during migration, it wasn’t entirely surprising that they arrived in Canada six weeks later than normal this summer in unprecedented low numbers. Point Pelee National Park in Leamington, Ontario, even cancelled its annual monarch count because of lack of butterflies.

      While the future of the monarch looks bleak, we can all help ensure its survival.

      At home you can create a butterfly garden to provide habitat and food for monarchs and other pollinators. Plant milkweed and nectar-producing native flowers, like wild bergamot, New England aster and black-eyed Susans—especially ones with yellow, pink, orange and purple flowers. Adding these plants to gardens, balconies, parks and green spaces – and encouraging local schools, businesses and institutions to do the same—will help bees and butterflies stay healthy and well-fed.

      Want to go bigger than making your yard or park a butterfly haven? Check out the David Suzuki Foundation’s Homegrown National Park project in Toronto. It aims to create a butterfly corridor through the heart of the city by encouraging residents, businesses and institutions to add more green to yards, balconies, rooftops, streets, alleys, and parks.

      In the project’s first year, pollinator gardens were planted in more than a dozen locations along the Homegrown National Park corridor, including a network of “canoe gardens” in local parks and bee-and-butterfly gardens in schoolyards, health facilities and front- and backyards. Momentum is building for even grander green interventions next year.

      So, while the monarchs have already begun their journey south, I encourage you to start preparing for next year’s butterflies. Head to your local nursery and get your milkweed on. And do what you can to bring nature to your neighbourhood.

      With contributions from David Suzuki Foundation communications specialist Jode Roberts. Learn more at www.davidsuzuki.org.



      Paul Cherubini

      Oct 15, 2013 at 8:19pm

      Milkweed needs to be planted on a landscape scale in the roadside ditches that border the GMO crops in the Midwest to have a mathematically significant beneficial impact on monarch numbers. Planting in home gardens will add a far too small amount of milkweed to have a mathematically significant impact

      sam conroy

      Oct 16, 2013 at 1:42am

      What a wonderful way to engage community groups in supporting our butterflies and other pollinators. the Homegrown National Patk Projecf is soooo do-able! Let's challenge ohr neighbourhoods to grown butterfly gardebs on every street and to set aside wildflower meadows in every park, parkette and green space!!

      Benjamin Vogt

      Oct 16, 2013 at 11:02am

      I thought sulphurs and red admirals migrated, too. Aren't those butterflies?

      Beatriz Moisset

      Oct 17, 2013 at 1:36pm

      "According to some recent studies, most of the monarchs in Canada and the East Coast (fourth and fifth generations) are descended from the ones born in the Corn Belt (second and third generations). It seems that the weakest link in the chain is the Midwest where herbicide resistant crops plus herbicides are decimating the common milkweed. Trying to strengthen the other links may be futile.
      Our milkweeds and nectar plants, here in the East, are bereft of monarch butterflies. The same thing applies to the Oyamel forests of Mexico where overwintering monarchs used only a small fraction of the available habitat last year.
      If we want to save the monarchs, we need, most of all, to stop using herbicides in our breadbasket, which until recently was also the monarch's breadbasket."

      Lois Lockhart

      Apr 9, 2015 at 3:35pm

      Where can I buy or otherwise procure milkweed seed? And does anyone have up to date info on sitings of Monarchs on Vancouver Island. I see some UBC info that sitings are not common but have been seen at Tofino and Victoria. I'd like to get aboard this project. Thanks.