The Mystery of the Missing Monarchs

MonarchYou may have seen the story in the Boston Globe on August 13 about how monarch butterflies have been hard to find at Mass Audubon’s Boston Nature Center. Monarchs may be our most popular and well-known insects, and this is the time of year when we should be seeing their familiar orange and black wings over gardens. But observers all across the state say they’re spotting very few of them.

Is this a sign that monarchs everywhere are in trouble? And if so, why? The answers to these questions aren’t as simple as you may think.

A Closer Look at Monarch Numbers
The number of monarch butterflies in Massachusetts fluctuates from year to year, and when the insects are scant here, they may be numerous elsewhere. We have to be careful about using our local sightings to talk about the overall health of the species.

However, we do know that observers in nearby areas, such as eastern Canada, Vermont, and New Jersey, are also reporting low monarch numbers this year—what we’re observing here may be part of a larger pattern.

Perhaps most alarmingly, the monarch population hit a record low at its overwintering sites in Mexico, down 59 percent from the previous year’s December count—and researchers have documented declines there in six out of the past seven years.

Threats to Monarchs
There are many reasons why monarch numbers may be dropping. Because they travel over such a wide area and spend time in different habitats, they’re vulnerable to environmental change all along their route. Here are some issues:

  1. Habitat destruction in Mexico, where monarchs winter, has historically represented a major threat.
  2. They’re sensitive to extreme weather; they don’t do well if it’s too hot or too cold, too dry or too wet.
  3. Monarchs are very specialized—they only lay eggs on milkweed. These plants have declined in the central and mid-western states’ expansive corn and soybean fields due to changes in farming practices, such as new developments in herbicides.

Learn More
Consider participating in one of our upcoming programs about monarchs and other butterflies. We’ve got butterfly walks for both kids and adults, where you’ll learn about their life histories and favorite plants, and hopefully glimpse some monarchs.

You can also participate in research programs at Ipswich River Wildlife Sanctuary in Topsfield, Allens Pond Wildlife Sanctuary in South Dartmouth, and Wachusett Meadow Wildlife Sanctuary in Princeton. You’ll learn how to “tag” monarch butterflies, applying tiny stickers to their wings as part of a continent-wide research effort to track their travels.

Have you seen any monarch butterflies this year? If so, tell us where and when in the comments.

69 thoughts on “The Mystery of the Missing Monarchs

  1. Bruce

    I live in Roanoke County Virginia and have house in Bedford County at a lake. In previous years saw many monarchs during summer and on fall migration everywhere. I would watch a trail of a hundred or more monarchs in one hour migrating across the lake. I have numerous milk weed plants that I have planted in past years to attract monarchs, which has happened for their eggs and caterpillars.
    I have not seen one monarch this year. At the same time I have seen numerous tiger swallowtail butterflies and other butterflies all summer.

    Truly a major problem possibly for the monarchs. Very sad if the monarchs are on a major decline.

  2. Susan Gionfriddo

    I live in Western Ma and have several butterfly bushes in my garden. Unlike most here, we have seen more Monarchs this year on the bushes then any other previous summers! They recently left due to the very cool weather that has recently arrived. Miss them already!

  3. Mahala Beams

    I live in a West Roxbury, Boston. Usually I see at least one monarch in the summer months, but have not in the summer of 2013. More disturbing, in our family vacation home in the hills of Chester, Vermont, where I usually see many monarchs, I have not seen one this summer. Commenting on this out loud in a local cafe, a local teacher piped in, saying she had not seen one this summer in the Chester area. I have planted milkweed in my garden in West Roxbury, and it is plentiful in the meadows around our Vermont place.

  4. Michael Bean

    Living in Idaho, with milkweed all over the property, monarch butterflies are usually here most of the summer, and leave during September when the weather starts cooling off. Not a single monarch or western swallowtail since 2011 have been sighted on our property.
    This is an agricultural area, but most of the land within a mile in any direction is alfalfa for hay, or pasture, and there’s a lot of undeveloped land surrounding those fields and pastures. Our local populations went from a noticeable decline 4 years ago, to almost no presence in the last 2 years.
    We still have a lot of healthy bees around the property, but all the butterflies that more than a 1 inch wingspan are nowhere to be found…

  5. Susan Madaus

    Finally saw the first Monarch of the year yesterday on my butterfly bush in Lexington, MA. It was a female (no wing spots) but she has not laid any eggs yet in my milkweed garden. The cloudy say prevented the sun from warming her wings to fly and she stayed close and spent the night in one of our trees. She’s back on the bush today. Hope she’s mated and will leave eggs on some milkweed to bring in to protect from the 90 degree day tomorrow. If she leaves eggs, it will take 4 days to hatch on the leaf (it’s stem is tucked into a tiny glass tube of water), 16 more to pupate (fed with fresh milkweed leaves), and another 8 to hatch and release. Have never raised them this late in the season. Fingers are crossed.

  6. Francie Von Mertens

    Your observation about the decline in milkweed in the central states was very mild, pointing to “new developments in herbicides.” The “new development” was approval in 1996 of crops genetically modified to survive spraying with the herbicide glyphosate. The central and Great Lakes states produce the majority of monarchs. Monarchs born there head east to MA and here to NH. That’s also the heart of corn/soybean intensive agriculture. Today some 90% of corn and soy crops are treated with glyphosate, killing milkweed as well as other “weeds” that pollinators nectar at. Recent push for biofuels led to a spike in corn prices, and millions of additional acres of corn were planted, including millions of acres taken out of the Conservation Reserve Program. More corn / more herbicides / less milkweed / fewer monarchs in the very essential epicenter of monarch production. Isotope studies can pinpoint which regional milkweed a monarch feeds on in caterpillar/larval stage. Central states is where most originate that overwinter in Mexico. Last year’s serious drought and heat wave also impacted monarchs. Their eggs don’t survive temps in high 90s. But crops genetically engineered to withstand spraying with glyphosate (known as “Roundup ready” crops) is the main challenge to monarchs here in the U.S. There is a lot of supportive data for that. I think it’s important that conservation groups get that information out to members/the public without any soft filters.

    1. Colleen Wade

      Francie, I couldn’t agree more! Monsanto, the friendly folks who gave us Agent Orange, are continuing to buy the government and now fill our land and bodies with GMOs. Unless we fight the chemical giants and monitor our elected officials, we will continue to see much of nature disappear…

  7. Kathleen Hansen

    I maintain butterfly gardens both in Chelsea. MA an Wells, ME. Butterflies of ALL varieties have been scare this year. It is more than depressing to not having them to enjoy and photograph. Last year in late September I noted on my Facebook page that I was caught in a blizzard of Monarchs at Parsons Beach, ME…wish I cold turn back the clock to that day. I would be more than happy to plant more Milkweed in both places with the hopes that next year will be better…

  8. leslie

    I thought I was the only one missing the Monarchs. There also seems to me a decline in swallowtail butterflies as I have only seen one, plus a number of other species seem to be missing. There are a numerous milkweed spots that I know of plus my own and not one Monarch!!

  9. Mary on Cape Cod

    Usually my butterfly bushes have many monach vists but this year I have seen only two monachs in my Harwich backyard.

  10. ian pepper

    saw a Monarch on August 22 in Ipswich, dear Bull Brook Reservoir, it looked large and healthy, I got a photo.

  11. Butterfly lover

    My property is a certified Monarch Waystation in the metro-west Boston area. I raise and tag Monarchs. Haven’t seen any Monarchs at all this year. This happened in 2009 but that was likely because the weather was constantly cool and wet that summer. This year, the weather has been okay, and there is plenty of good quality milkweed, but no Monarchs.

    Raising butterflies is very relaxing for me. Miss the Monarchs very much this year!

  12. Bill Rohan

    I saw my first monarch of the season at 5:48. PM (8/26/13) in Williamsburg on my buddleia bush.

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