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I add the caveat that my research was conducted in Ontario Canada and is possibly most relative to the Canadian Monarch crisis, but I do believe that much of it applies to the whole migration corridor.
Firstly, I will state that there is NO shortage of milkweed plants in Canada; what there is is a shortage of seedling and regrowth milkweed. While it is generally accepted that the preferred milkweed for egg laying is young growth, from what I see no one has asked the question why? Fact is that milkweed, like most other vegetative plants, loses nutrition very quickly post-flowering, and by early seed set protein has already dropped by close to 50%, digestibility and relative feed value has dropped almost the same while fiber has increased. Post-flowering of established milkweed stands in Canada is precisely when Monarch caterpillars begin to hatch. While I have no evidence specific to Monarch butterflies and the caterpillars re their survival rate on low nutrition milkweeds, I (and you) do have evidence in droves of low survival rates of many other species on low nutrition diets, up to and including humans. IMO it would be insane not to presume that Monarchs would not also suffer from low survival rates given a diet lacking nutrition. Let's not be so naive as to believe that the reason Monarchs "prefer" seedling and regrowth milkweed is "cosmetic"; millions of years of evolution has taught them what is important - that is NUTRITION!
Where have all the milkweed seedlings gone?
Fact is that milkweed seed will not (or minimally) germinate on untilled soil but rather prefers tilled soil ie; cropland. Seedling milkweed did in fact grow abundantly in cropped land up until chemical ag came along. It is important that we not put all the blame on GM Roundup tolerant crops although it is these that have allowed the elimination of established milkweed in crop land. It is true that most all newer pre-emergent herbicides (non Roundup) also kill or prevent germination of milkweed seedlings in crops. While many studies indicate that up to 50% of milkweed has been eliminated they fail to mention (or look at) the fact that seedling milkweed has suffered almost complete elimination in most of Canada's Monarch breeding range. With Monarchs being given little choice they will lay eggs on mature milkweed plants, but what is the survival rate of the Monarch? I suspect it is very low. Further, in years of drought and heat such as 2013 existing milkweed stands will be even more mature earlier resulting in even lower survival rates. While I may be alone (but not wrong) in pointing this out, this is what we saw last year through the entire Monarch migration corridor - "the smoking gun" NUTRITION! or better said, lack of it. Plenty of milkweed! - just not vegetative or nutritious.
Where has all the "regrowth" milkweed gone? Twenty five years ago 2 crop haying was standard, hay fields were cut mid to late June and then again early fall allowing established milkweed to regrow post first cut and be in perfect vegetative state for Monarch egg laying, and caterpillar feeding. That has all changed now with the current standard 3 to 4 cuts per year, never allowing substantial milkweed plant growth. At the same time the hay acreage has decreased dramatically while grain crops have increased. Pasture fields were good sites for Monarch egg laying on regrowth milkweed that had been trampled by the grazing animals (and/or mowed by farmers late June) and regrown but pasturing animals in most of Canada is no longer practiced. These fields have been converted to cash grain cropping. Also disturbing is the current campaign to discourage roadway mowing. Road allowance mowing should instead be encouraged but at times that will assure not only regrowth milkweed but also nectar flower bloom timed with Monarch arrival (mowing typically mid to late June).
A bit about Wallace Springs and our findings this year
Wallace Springs is an operating ecologically based mixed farming operation in the heart of CAFO farming country (Perth County Ontario) consisting of approx. 100 acres of conventional non GMO cropland and 50 acres of nature preserve (original hardwood bush, reforested coniferous, meadow, and riparian). While we discourage crop spraying, conventional herbicides are allowed to control weeds, in crop, excluding Roundup which is not used in crop as no GMO crops are allowed. Sadly, this said the result is virtually no seedling milkweed in the cropland while we do have a good population of established milkweed in all the cropland (over 5000 plants in the 100 acres of cropland and another 5000 + plants in the reserve and field margins).
This year in addition to distributing free milkweed seed across Canada and encouraging people to "Plant a Patch" we decided to plant our own patch even though we thought we had lots of milkweed. We planted a patch in May approx. 10' X 18' with approx 2000 seeds adjacent to the cropland..
What happened is best described as absolutely astounding. While I was unable to find any Monarch eggs or caterpillars on the farm's established unmowed milkweed our seedling patch had over 300 healthy thriving caterpillars in it. Equally good results were achieved on a small patch of regrowth milkweed in the garden. Interestingly this garden patch was right adjacent to an established patch beside the garden (in fact it most likely grew from the adjacent patch rhizomes) and there were absolutely no cats on the adjacent unmowed patch. One has to conclude that the issue is frankly a shortage of vegetative milkweed leading to the Monarch population crisis.
So, where to from here?
It is highly unlikely that chemical farming methods are going to change any time soon, but even accepting that much can be done without a signifigent cost impact:
1) Mow roadway and utility rights of ways and other uncropped open land in a timely fashion (mid to late June)
2) Encourage every farm to "Plant a Patch". Every farm has a 10' X 18' piece of lawn that could be planted to milkweed. What needs to be done is to somehow incentive this planting (maybe a seed/chemical co.). It costs so little, children (and a lot of adults) love it, it will not spread by rhizome if mowed around, it will not go to seed and spread if mowed in mid to late June after the first year and it is not ugly. I repeat, it is not ugly! Ontario farms alone could add 50 - 60 million Monarchs to the migration. Obviously adding farms across Canada and if 10% of town and city folk would plant a patch hundreds of millions of Monarchs could be added to the fall migration. Habitat it and they will come
3)While milkweed "fluffing" parties, seed bombing and scattering milkweed seed on vacant unworked (undisturbed soil) are all noble concepts, the results, in reality, are much less than what the participants imagine. These efforts could be redirected to "Adopting a Patch" of wild milkweed if your space does not permit "Planting a Patch". Mow it in mid to late June (whipper snippers; aka string/brush trimmers are great), enjoy the show and most importantly share it! Encourage your friends/associates to also help the Monarch where they can. One citizen "armed" with a whipper snipper for one morning could add 10's of thousands of Monarchs to the migration - IMAGINE what a small army of volunteers (or paid contractors) could do! We need a "National Mow the Milkweed Day" mid to late June! Remember - Do not mow all the milkweed, leave some to go to seed as mowed milkweed will not set seed in most of Canada.
4) As a Canadian who believes that the Monarch solution is jointly and equally shared by Mexico,
the US, and Canada I find it distressing that on many published Monarch migratory and breeding area images that Canada and Mexico are totally missing. Organizations advocating must be more inclusive if we in Canada and those in Mexico are to convince our friends and neighbours that their efforts are important. Misinformation and "drawing borders" that the Monarchs know nothing of helps no one and certainly not the Monarch. Our respective leaders "the three amigos" agreed back in February that the Monarch population issue was a tri lateral issue, now let's get the rest of us on board and start acting that way.
5) I know that my findings are correct but to convince others it will most likely be required that peer reviewed side by side studies be done. It will be necessary to study not only the nutritional requirements of Monarch caterpillars but also the survivability of malnourished cats through the life cycle of the resulting adult Monarch. The nutritional content of milkweed will need to be studied from full vegetative to full plant maturity. We are prepared to offer our space and milkweed population for those efforts.
Remember, the generation of Monarchs raised in Canada is the migrating generation, what they need to fuel their journey and survive the winter in Mexico is the best most highly nutritious diet Canada can muster - it's sad that we have reduced their diet to basically scraps. We can and must do better!
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| image via Canadian Soybean Council |
Fact is that milkweed seed will not (or minimally) germinate on untilled soil but rather prefers tilled soil ie; cropland. Seedling milkweed did in fact grow abundantly in cropped land up until chemical ag came along. It is important that we not put all the blame on GM Roundup tolerant crops although it is these that have allowed the elimination of established milkweed in crop land. It is true that most all newer pre-emergent herbicides (non Roundup) also kill or prevent germination of milkweed seedlings in crops. While many studies indicate that up to 50% of milkweed has been eliminated they fail to mention (or look at) the fact that seedling milkweed has suffered almost complete elimination in most of Canada's Monarch breeding range. With Monarchs being given little choice they will lay eggs on mature milkweed plants, but what is the survival rate of the Monarch? I suspect it is very low. Further, in years of drought and heat such as 2013 existing milkweed stands will be even more mature earlier resulting in even lower survival rates. While I may be alone (but not wrong) in pointing this out, this is what we saw last year through the entire Monarch migration corridor - "the smoking gun" NUTRITION! or better said, lack of it. Plenty of milkweed! - just not vegetative or nutritious.
Where has all the "regrowth" milkweed gone? Twenty five years ago 2 crop haying was standard, hay fields were cut mid to late June and then again early fall allowing established milkweed to regrow post first cut and be in perfect vegetative state for Monarch egg laying, and caterpillar feeding. That has all changed now with the current standard 3 to 4 cuts per year, never allowing substantial milkweed plant growth. At the same time the hay acreage has decreased dramatically while grain crops have increased. Pasture fields were good sites for Monarch egg laying on regrowth milkweed that had been trampled by the grazing animals (and/or mowed by farmers late June) and regrown but pasturing animals in most of Canada is no longer practiced. These fields have been converted to cash grain cropping. Also disturbing is the current campaign to discourage roadway mowing. Road allowance mowing should instead be encouraged but at times that will assure not only regrowth milkweed but also nectar flower bloom timed with Monarch arrival (mowing typically mid to late June).
A bit about Wallace Springs and our findings this year
 |
| Established patch of milkweed at Wallace Springs |
This year in addition to distributing free milkweed seed across Canada and encouraging people to "Plant a Patch" we decided to plant our own patch even though we thought we had lots of milkweed. We planted a patch in May approx. 10' X 18' with approx 2000 seeds adjacent to the cropland..
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| seedling milkweed patch at Wallace Springs |
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| Cats in the patch at Wallace Springs |
It is highly unlikely that chemical farming methods are going to change any time soon, but even accepting that much can be done without a signifigent cost impact:
1) Mow roadway and utility rights of ways and other uncropped open land in a timely fashion (mid to late June)
2) Encourage every farm to "Plant a Patch". Every farm has a 10' X 18' piece of lawn that could be planted to milkweed. What needs to be done is to somehow incentive this planting (maybe a seed/chemical co.). It costs so little, children (and a lot of adults) love it, it will not spread by rhizome if mowed around, it will not go to seed and spread if mowed in mid to late June after the first year and it is not ugly. I repeat, it is not ugly! Ontario farms alone could add 50 - 60 million Monarchs to the migration. Obviously adding farms across Canada and if 10% of town and city folk would plant a patch hundreds of millions of Monarchs could be added to the fall migration. Habitat it and they will come
3)While milkweed "fluffing" parties, seed bombing and scattering milkweed seed on vacant unworked (undisturbed soil) are all noble concepts, the results, in reality, are much less than what the participants imagine. These efforts could be redirected to "Adopting a Patch" of wild milkweed if your space does not permit "Planting a Patch". Mow it in mid to late June (whipper snippers; aka string/brush trimmers are great), enjoy the show and most importantly share it! Encourage your friends/associates to also help the Monarch where they can. One citizen "armed" with a whipper snipper for one morning could add 10's of thousands of Monarchs to the migration - IMAGINE what a small army of volunteers (or paid contractors) could do! We need a "National Mow the Milkweed Day" mid to late June! Remember - Do not mow all the milkweed, leave some to go to seed as mowed milkweed will not set seed in most of Canada.
4) As a Canadian who believes that the Monarch solution is jointly and equally shared by Mexico,
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| Spring and summer breeding areas in the milkweed/monarch corridor - Monarch watch.org |
5) I know that my findings are correct but to convince others it will most likely be required that peer reviewed side by side studies be done. It will be necessary to study not only the nutritional requirements of Monarch caterpillars but also the survivability of malnourished cats through the life cycle of the resulting adult Monarch. The nutritional content of milkweed will need to be studied from full vegetative to full plant maturity. We are prepared to offer our space and milkweed population for those efforts.
Remember, the generation of Monarchs raised in Canada is the migrating generation, what they need to fuel their journey and survive the winter in Mexico is the best most highly nutritious diet Canada can muster - it's sad that we have reduced their diet to basically scraps. We can and must do better!
