WWF-Canada Blog:

Monarch butterfly numbers drop by ‘ominous’ 59% – How you can help.

As late winter eases into early spring, I’ve been seeing waves of migratory birds in southern Ontario pushing northwards:  waterfowl, blackbirds, some birds of prey.  But one migrant, not a bird, but the Monarch Butterfly, is just now leaving its winter home in Mexico.  They leave occupying less area – under 3 acres – of oyamel fir forest in Mexico’s central highlands than ever before recorded.

Monarch sherry 1.5

Numbers fluctuate, but some 10-100 million Monarch Butterflies occur in the central and eastern portion of their North American range.  (A much smaller population lives from southwestern B.C. to California.)  Counting those butterflies is difficult – I have seen the fir trees in late February in Mexico, drooping to the ground with the weight of hundreds of thousands of butterflies, looking from a distance like shimmering orange snow on the fir boughs.

One way to estimate their numbers is to simply measure the area of forest in which trees are found with monarchs.  As the graph shows, where for years some 5-10 hectares of forest were occupied, this past winter only 1.19 ha hosted monarchs,  a startling drop of about 60% over the previous year.  The story was big news over the last week.

monarch numbers graph

There are multiple causes for the decline:  loss of the monarch’s only host plant, milkweed, from herbicide spraying of corn and soy farm fields in the U.S. and Canada; illegal logging in parts of the oyamel fir forest; heavy ecotourism in Mexico; probably climate change in the breeding and wintering grounds.

My earlier blog details the monarch’s life cycle and connection to Canadian scientists, as well as a wonderful documentary of their life and plights, Four Wings and a Prayer.

Though over a hundred species of migratory birds, along with whales, bats and marine turtles, share North American land- and sea-scapes for their breeding grounds and wintering areas, no species symbolizes the ecological connection among Canada, the U.S. and Mexico as vibrantly as the Monarch Butterfly.  It became a symbol for many things tri-national on this continent.   Just as the loss of the Giant Panda would be a tragedy for China (and WWF, given our panda logo!), so would conservation prospects be set back enormously in North America by loss of the migratory wonder of the Monarch Butterfly.

So, what can you do?

Two easy steps:  keep some milkweed in your backyard, cottage or farm and enjoy the butterflies whose host plant you maintain.  I do this and it’s fun to see Monarch females lay eggs there every year.  Second, participate in Earth Hour, turn out your lights, and vote by candlelight for society to tackle climate change, which threatens monarchs in their summer and wintering habitats.  And after you’ve done taken these two steps, tell your federal MP you’ve taken action and you expect the federal government to do so, too!

  • Joy says:

    I put wire plant supports around the young plants that spring up in the lawn because the Monarchs LOVE the tender little shoots for their eggs! My husband grumbles and mows around them! He’s a good man!

  • Louise Davis says:

    If we spent more time thinking about our actions, we probably wouldn’t be having this discussion.

    Since alot of companies are more concerned about building than keeping our Earth clean.

  • Louise Davis says:

    If we spent more time thinking of how our actions actually effect nature we probably wouldn’t be having this discussion.

    Since companies are more concerned about building than keeping our Earth healthy.

  • Jocelyn Rait says:

    Don’t forget that the monarchs also need late blooming flowers to sustain them, e.g. phlox, asclepias, bee balm, coneflower – and they love Jerusalem artichoke flowers. It is the caterpillars that eat the milkweed leaves, the butterflies consume nectar from flowers and need a good supply if they are to thrive. I live near Ottawa and we do usually see monarchs every year, but things do not sound good for this year.

  • Walter R. says:

    We live in east end of central Toronto and have several butterfly bushes in the yard as well as in the neighourhood which the monarch butterflies love and are such a joy to watch. Last fall I collected milkweed pods . I think I can plant the seeds any day now right in the back of the garden which is sheltered. and flower bed(formerly lawn) on the front of the house facing south. Crocuses are blooming and tulips are up. I’ll put some in pots indoors as well. I was surprised to see how many milkweeds are growing just in my neighbourhood in flowerbeds and boulevards.

  • Valerie says:

    When you plant milkweed be very careful where you put it. The roots spread far and wide so you will have milkweed popping up in your lawn. If this happens you CANNOT cut your grass because there will be eggs on the plants. Plant so that the roots can be contained in your garden and not spread to your lawn.

  • Caroline says:

    I grow Butterflyweed (monarch butterfly host plant) at the cottage but now will plant some in my garden at home too. The blossoms are a brillliant orange and really stand out so your garden will look great and you’ll help the monarchs.

  • Paul Morris says:

    We grow Butterfly, Common and Swamp Milkweed at Acorus Restoration Native Plant Nursery. They seem to like Swamp Milkweed the best!

  • Marg Davey says:

    If these stats are true, we all have to step up and plant milkweed for these beautiful delicate creatures! I’m so tired of people being so destructive to this beautiful planet and all of its inhabitants, we have a responsibility to protect and help bring their numbers back, so let’s all do it!

  • Sandy Thompson says:

    I am a Girl Guide Leader and we are studying Butterflies, especially the Monarch which is quite active in our Ontario gardens. They have been dwindling and I am so glad that someone has printing how we can help by planting the Milkweed. All of my girls will make this a prominent issue to plant this year if it will help. Anything else we can do for them?

  • Vicki Johnston says:

    I live in Edmonton Alberta and thought that this year I would plant a butterly garden. Is there any point to planting milkweed? Do the Monarchs ever come this way? Vicki Johnston

  • Tamara C. says:

    Asclepias is a perennial that survives our winters in Western Canada. Last year was the first and only time that our plants were covered with Monarchs. I was surprised to see them on the plants and we watched with interest as the chrysalides appeared. These plants are easy to grow from seed.

  • jo says:

    A tropical milkweed plant exists that goes in Canada in the summer but does not survive the winter – save the seeds from the pods and start the growth early in the spring inside then put them outside – this keeps the monarchs and the farmers happy – the monarchs have food – the farmers do have have to deal with the spread of milkweed – I live on a farm and when I tell my local farmer friends I am planting milkweed they nearly have a stroke – then I explain.

  • Nick Zeis says:

    I always have done my best to protect milkweed – several years ago a monarch caterpillar settled under my water hose “reel” to go into its pupal stage. I put a sign saying “monarch under construction” and checked every day until one day, it was gone – successfully changing into a monarch. Although I never actually saw the monarch – it was such a wonderful experience to know that my actions helped this wonderful species, even if only one at a time!!!

  • Barb W. says:

    The milkweed planting is important and the counts as well but if they don’t have a wintering ground none of these measures will matter. What is being DONE in Mexico to halt the decimation of their wintering ground AND to increase the size of the winter ground with new plantings? For those in Canada, did you know we have legislation that not only wants but INSISTS that farmers kill of all milkweed on their properties? It’s true. Milkweed is unfortunately the plant necessary for the Monarch but deadly to livestock so we have actual legislation permitting its lawful destruction. Creating pathways of milkweed across Canada and the USA and into Mexico is the only option while farmers are legally allowed to decimate the plant but if the Monarch’s wintering grounds are not protected and enlarged through new planting, generations to come may only be able to read what a Monarch Butterfly is. This can happen before I even have grandchildren so it’s quite a frightening prospect.

  • Margaret Munday says:

    I planted Asclepias a couple of years ago. It has pods in late summer that. I understood that it is a variety of milkweed. Is this true?I have seen a few Monarchs at the plant, but as far as a I can see no eggs have been layed.


  • We are planting lots of milkweed all over our properties this year and spending lots of time educating others about the risks GMOs [as we always do… it’s our job to explain organic things and sell things that are not genetically engineered]. We buy local, organic products and antique furniture [no new imported, freshly chopped down trees from anywhere for the love of life and oxygen and all things good… isn’t there enough stuff already made to go around?!] and we don’t ever intend on vacationing in Mexico… Is “Eco Tourism” really a big sham? Another marketing term? Oh my 😮 my vacation will be biking all over my province. I don’t need to fly to Mexico and support a place that maybe doesn’t care about the precious Monarchs… ? Canada would be strange without these butterflies…

  • Aidene says:

    Just to add I have watched this migration since 1976 and there has been a huge drop in numbers in this last few years. I am a gardener and have spent full days out in my garden watching them and both my husband and I were very sad to see the decline in numbers. Let us do all we can.

  • Aidene says:

    For many years I have watched the monarchs fly south and took many photos of them on my butterfly bush. My husband brought home some Milkweed seeds and we planted them years ago and up they come each year. My husband died in 2010 and I think I will be planting more Milkweed in memory of the wonderful love he had for wildlife and our monarchs. He used to spot all the different birds coming back in the spring and would point them out way before I saw them. He taught my Granddaughter and I to be unafraid of the bees by going up to them on the flowers and gently giving them a stroke probably not something one should do a lot but it cured us of our fear. So now I look forward to going out and see if I can find some of those Milkweed pods left with seeds. I have never found the Milkweed to be invasive but they are in soil which is directly under some fir trees and quite hard packed so perhaps not an easy place to spread. But as I said they come up every year with out fail.

  • Bob says:

    This is so sad- – when we lived in Scarborough – Eastern Toronto above the Scarborough bluffs we were on their flyway over the the bluffs and we always enjoyed their journeys south and back. Excessive milkweed was never a problem.

    There is no doubt in my mind that genetically modified plants that allow the use of – pesticides are at the root of this problem and that Monsanto is the culprit here.

    EPA is toothless these days and I am truly disappointed in Obama here as he appears to be disinterested in giving it a push forward.

    What we on the west cost of BC are noticing now is the discouraging drop in the number of honey and bumble bees – and I believe that they are suffering from the same problem.

    If our governments do not take action quickly we are sure to have a major problem that may be irreversible\.

  • pat says:

    I will look for milkweed pods and spread the seeds on the river bank. I know the plant. I also participate in Earthhour and encourage others to do so. Active member od WWF

  • I want to help out with protecting wildlife.

  • Yes planting milkweed could help, but lets get serious it is GMO’s and pesticides that are causing the decline. Obama signing the Monsanto Protection act now you can expect this declining number to grow.

  • Tracy says:

    I too will be planting milkweed in my garden with my girls this year! 🙂

  • Betsy says:

    You can purchase many kinds of milkweed and other butterfly friendly plant seeds here: http://www.butterflyencounters.com/milkweed.html

  • Sonja says:

    Check out http://www.richters.com for Milkweed Seed

  • Sonja says:

    We have 11 arces of hardwood bush and it’s always been a migration stop on the way south for Monarchs. We have also notice a large drop in their population over the past 5 years. Where once they covered whole branches and vines and circled overhead, they scarcely make a splendored show. It’s so sad. It has always been a highlight to the start of the fall season for us.

  • PATTY says:

    how do we save them

  • Steven Price says:

    Thanks for the comments and questions about where to get milkweed. Yes, Jerry, the Common Milkweed, widespread in central and eastern North America, can spread quickly. A few took hold in my yard and each year, I just limit them by easy weeding in the late spring to only 10-12 plants in my yard.

    Marge, Jaimie, Mary — the Common Milkweed is easy to find. Check out a pic on Wikipedia. Just this weekend, after a lot of snow over the winter, I still found pods in an empty lot with seeds in them. There are probably milkweed pods within 100 metres of every house in southern Canada!

    Also, Butterfly Milkweed, an orange-flowered milkweed of prairies and dry habitats, has become quite popular as an ornamental — this one you will find in better nurseries as a native plant for sale. And Swamp Milkweed is found along wet shores and other wetland habitats. But Common Milkweed is much more, well, common!


  • People who are looking for milkweed can check with their local native plant supplier: http://www.nanps.org/index.php/plant-sources/other-sources

    A great way to get the whole family, and community, happily involved is to raise monarch butterflies. I wrote a fun, short, easy to read book on the subject that is beautiful, and has received only superlative reviews from the most prestigious organizations. Available everywhere, including the library. How To Raise Monarch Butterflies A Step-by-Step Guide For Kids (Firefly Books, 2012)

    And, be sure to take everyone you know to see Flight of the Butterflies in 3D IMAX. You will all love it, and you will be helping to spread the word.

  • Mary Weisz says:

    Great article.I also admire and love Monarch butterflies.
    Where do you find or buy milkweed? Very informative website.
    Thanks Mary

  • Jerry says:

    I have a small yard, and Milkweed is extremely invasive, so think twice about that. I live right on the Monarch migration path on the East Coast US, and saw just as many Monarchs migrating south in each of the last 3 years. These estimates might be off. Maybe different gathering locations are not apparent? Maybe warming trends are keeping them from moving so far south.

  • Jaimie says:

    Where can you buy milkweed?

  • Marge Hughes says:

    I also love the Monarch butterfly… It Always amazes me how something that fragile can and does fly from Canada to Mexico and return, thru’ All kinds of weather or prey on them… Simply amazing!!
    But I need to know, please… Where does one find Milkweed these days to plant??? Everyone is doing away with “weeds” these days… So where???
    Thanking you, in advance,
    Marge Hughes

  • M.Knerr says:

    We will be planting milkweed at our home and school gardens this year! We love monarchs!!

  • David Pritchard says:

    No mention of the problem with GMO corn? http://www.nature.com/nature/journal/v399/n6733/abs/399214a0.html

  • steffiblack says:

    Thanks for this informative article – I will be sure to plant milkweed in my backyard and participate in Earth Hour too.

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