The Sun Compass

Male monarch butterfly (photo by Marcy Cunkelman)
Monarch butterfly, 2008 (photo by Marcy Cunkelman)

25 September 2013

A week ago I saw my first and only monarch butterfly of 2013.  Their sudden disappearance is both troubling and saddening.  It’s now possible to imagine a world without monarch butterflies.  We are nearly there.

Last winter’s monarch survey in Mexico showed their population was down 59%, a record low.  There have always been population fluctuations but the trend has been running low and lower since 2004.  Scientists believe that agricultural pesticides and herbicides have reduced available poison-free habitat for butterflies (similar to the bees’ problem), so this spring monarch enthusiasts encouraged people to grow safe-haven milkweed for the butterflies.  It wasn’t enough.

Each species has an intrinsic value.  If, or when, the eastern monarch butterfly goes extinct we will lose its pollination contribution, milkweed symbiosis, beauty, and the amazing adaptations that allow multiple generations to migrate from Mexico to Canada and back.

One of the adaptations that will disappear is this:  Monarch butterflies have a sun compass in their antennae.

Their antennae have light sensors that track the amount of light each day.  According to a study in 2009 by Merlin, Gegear and Reppert, this circadian clock “provides the internal timing device that allows the butterflies to correct their flight orientation, relative to skylight parameters, and maintain a southerly flight bearing, as the sun moves across the sky during the day.”  Migratory monarchs without antennae fly in aimless directions.  Monarchs with antennae always orient southwest.

The monarch’s sun compass was discovered only a few years ago.  Now there are almost no monarch butterflies to study.  The world will be a poorer place without them.

Click here for more information on the monarch’s amazing sun compass.

(photo credits: monarch by Marcy Cunkelman, 2008)

21 thoughts on “The Sun Compass

  1. Well, I’ve seen 2, both migrating downriver in the past two weeks. So don’t give up hope of seeing some more, Kate.

    Still, it’s very sad to see this happening, and we can only hope they can recover.

    Scott Shalaway said on his show last Sunday that the wintering habitat in Mexico is down to 3 acres, which is another contributing factor. Double whammy!

  2. I was puzzled at why I only saw one monarch this year (NH) – now I know. I was once lucky to find myself in the middle of a migration – we were in a field and suddenly were surrounded by hundreds of monarchs, some near the ground all the way up to tiny specs in the sky. I’ve always wished for it to happen again.

  3. I always look for them migrating in August and September. This year I’ve seen just a hand full. Not as many as in past years now that I think about it.

    One of the concerns I have that I’ve seen the last few years is that I see a lot more weed killer being used along the roads sides to minimize overgrowth. I’m not sure why municipalities seem to be doing this more and I’m not sure the logic of it. It is unsightly seeing dead vegetation along the road side and it makes for more erosion or cause even landslides. How this killing of road side vegetation effects birds and other animals, butterflies and the like, I doubt has been studied much. Not good, and not to smart.


  4. Amazing information… and sad news.

    It makes me wonder what knowledge we could have had, if other now-extinct species had survived. Too big of a loss for me to get my arms around. 🙁

  5. PPG in Monroeville does a Monarch count and tagging, I’ll find out what their numbers are like.

    But I’ve been seeing them, or their mimics, out here. I saw 2 or 3 yesterday at ABQ Biopark.

  6. Kate and Marcy — is there any way to help fight the loss of our beautiful monarchs? It’s so sad. I can’t imagine a world without them.

    1. I’m afraid the problem is really huge and has to do with the systemic poisons now bred into our crops which take up so much land area. For instance, ethanol corn can be poisoned more than normal because no one is going to eat it. These are changes that have been happening since 2003 so I think we are seeing the results now.

      Marcy has some suggestions, I’m sure. Stay tuned.

  7. About a month ago I found 6 very large monarch caterpillars crawling on a swamp milkweed. A few days later when I checked the same plant, they had all left, which was good because a few days later I walked by and saw that someone had weed-whacked the area, and that particular plant was gone. Fortunately, there are a few other swamp milkweed plants nearby on a steep slope that have been left undisturbed, but it is a shame that even just one of them was cut down, because the seed pods were ruined. It makes no sense at all; there was no reason to weed-whack that plant! I hope those caterpillars found a safe place.

    Another troubling thing I’ve noticed this summer (in the area where I live) is the number of milkweeds that still have all of their leaves intact. I would prefer to see them eaten by monarch caterpillars. I’m trying to get milkweeds to grow in my backyard, where at least I know they won’t be sprayed or cut down, although it won’t do much good unless a monarch finds them and lays her eggs. I really do hope that more people will realize what’s happening and try to help the monarchs.

  8. Still busy in the kitchen canning and dehydrating…but I have seen a few migrating monarchs here in the yard…I forgot to order tags, so I didn’t tag any….I will comment later..there is lots we can do to HELP our monarchs and other pollinators…

  9. I have two swamp milkweed plants, growing in large pots on either side of my front door (Yes they can grow very well in containers!). At the end of July, I observed one Monarch through the picture window, gracefully descending upon the milkweed; I sat on the couch and held my breath, while it spent a great deal of time there. After she had left, I got my wish…4 eggs!

    I brought them inside and reared them, which was a new and AMAZING experience for me. Two made it to beautiful and seemingly perfect adulthood, male and female, which I released the day they eclosed during the first week of September. One caterpillar died very young, and the other had all the classic signs of OE, a protozoan disease unique to Monarchs, and had to be euthanized because of severe deformities. This disease is more common in the Western population, so this was concerning.

    I felt so incredibly blessed to have the opportunity to have raised these wondrous creatures; once I got word from the Monarch Larval Monitoring Project ( as to what a poor year it has been for the species, I truly am in awe recounting the experience.

    I already have milkweed seeds waiting to be planted…and as I type, the milkweed in the picture window is covered with honeybees and bumblebees. Please plant milkweed; I can attest, even a few plants make a meaningful difference!

  10. Saw three here in East Central Ohio…unfortunately the third was one I hit while going down the road…Vehicles take their toll as well…just look in the radiator of your vehicle…

  11. I harvested seeds from my swamp milkweed, as well as a couple of seed pods from Common Milkweed (Asclepias syriaca) and Butterfly Weed (Asclepias tuberosa) from roadside plants I have found. My mother found some Poke Milkweed (Asclepias quadrifolia) plants and harvested the pods from them; this species has lovely white, pendulous flowers and is one of the few species happy in part (as opposed to full) sun.

    I plan on planting the seeds where they are to grow in November/after the first freeze, covering lightly with soil, then mulching very lightly (remove mulch in spring). Since these are native plants, they need a few months of cold temperatures to break dormancy. If not planted this fall, they will need to spend some time in the refrigerator until spring to simulate natural temps.

    Some excellent online resources to purchase and learn about growing milkweed and other plants for the butterfly garden are:

    I strongly believe in collecting and preserving seeds from wild sourced, native plants in our area, but I am also excited to try some different species I purchased from these sources. Check them out! And if anyone would like some Swamp Milkweed seeds, I’d be happy to mail some…I have way more than I could ever hope to grow!

  12. Carolyn said it perfectly…collect the mature seeds and plant now(where you want them)… then you won’t have to worry about chilling and they will come up next year…I have seen the Poke Milkweed in WV but not here in PA…

    If you really would like to help, certify your yard as a Monarch Waystation(go to for more info)….I am#894…there are requirements you need to satisfy and a fee, but at least you will be especially helping the monarchs….but if you prefer not to do this, one of the first things to do is to NOT use chemicals…this not only harms the monarchs, but also the other pollinators in your yard and birds and other critters if they eat something that has been poisoned. Many babies have been poisoned by sprays and even over spraying up or down wind from you…I had that problem this year when chemicals were sprayed for weeds…lost ALL my monarchs and it was too late after I finally saw the dead vegetation….Killing weeds is not the easy way to get rid of them…too many complications.

    Planting milkweed (including all the varieties that Carolyn found), is the host plant for the monarch caterillars….but when the common milkweed is blooming, the scent is pleasing to all including all the pollinators, even birds and of course our noses…

    It was a very sad year for the monarchs, but lets hope the illegal logging in their winter sites decrease and the weather is not harmful (freezing and snow)….and the drought in the lower states of Texas and Arizona is not as bad as in the past few years. They have gotten rain and it’s greening up…

    Planting native fall blooms will be like “fast food” for the migrating monarchs. Goldenrod (there are varieties now that are not as aggressive) and Asters of all kinds, esp the purple New England Asters planted in a large mass will be a welcome site when flying over. (joe-pye-weed, ironweed even zinnias and other flowers are used.) Nothing is better than watching a high flying monarch circle over your flowers and come down for a drink of energy. They may even stay over for the night and leave in the morning or stick around for a couple of days. (And if you have tags, you can tag them and maybe you will get a report one of yours was found on the migration path.)

    So get those milkweed seeds in this fall, find some native seeds from friends (Me) and get those sprinkled over an area where you can watch for monarchs.

    (Carolyn if you have extra swamp seeds, I would like a few) Hope this helps…it’s not hard..

    1. Thanks, Marcy, for all your great advice. Sorry to hear about the spraying that killed your monarchs!

  13. Thanks to Marcy for highlighting the importance of NO chemicals in wildlife gardens of any kind. It is important to stress that even insecticides and herbicides labeled as “safer” or “environmentally friendly” should NOT be used…they don’t discriminate between which insects/plants they kill.

    As an organic/natural gardener, you have to forget the mentality of totally eradicating pests such as aphids or slugs. First and foremost, encourage natural predators, such as ladybugs, spiders, mantises, and birds. Aid heavily infested plants by handpicking pests, or spraying them gently with a stream from the water hose. And of course pull those weeds by hand like the olden days! Accept that these guys are unmistakably a part of the natural garden too, and will always be present to some degree!

    1. Carolyn, since email addresses aren’t visible in the comments I will send yours to Marcy, Libby & Lauren.

  14. Thanks, I will need to get your email address to contact you Carolyn.
    [see Note below]

    By the way, did you hear that tomorrows show (Sept 29th) will be Dr Scott Shalaway’s last live radio show? The radio station was donated to a Christian station, so he will record tomorrow’s show and it is supposed to air again on Oct 6th. I am having a listeners of Scotts show get-together on Oct 13th…can’t believe we have to go thru this again…hope he finds another station to pick up his program…we will all be in withdrawal.

    [Note from Kate St.John: eMail addresses published here *might* get a lot of spam so I have emailed all of you just now to share your addresses.]

  15. Ok, time to do something practical I think I’ll plant some milkweed seeds. I’ve noticed milkweed here seem to mostly grow on disturbed ground, so i’m going to look beyond our own yard and spread seed along the ditch the township cleared out this summer. Not a single monarch around here this summer.

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