Guest essay by Kip Hansen
The marvelous Monarch Butterfly is an icon of biological mystery. When I was born, circa 1950, monarchs were known to fly north into southern Texas every spring by the millions. In the Fall, tourists would go to Cape May, New Jersey, timing their visits to watch the beauty and pageantry of the Monarch Migration south again as they are funneled down the southern New Jersey peninsula from New England and points north, headed south to an unknown destination, believed to be somewhere in Mexico.
It wasn’t until 1975, long after I had passed through university, that the location of the monarch overwintering site in the central mountains of Mexico was discovered. For 40 years, Dr. Fred Urquhart had searched for the monarch’s overwintering site…finally discovering the location in the fall of 1975. Urquhart wrote of his discovery in National Geographic magazine, which had funded his search, in the August 1976 issue. He did not, however, reveal the actual location of the butterfly colonies at that time, not even to other scientists.
As this image at the start of this essay shows monarch butterflies begin to move south every August (the orange arrows).
“Unlike most other insects in temperate climates, Monarch butterflies cannot survive a long cold winter. Instead, they spend the winter in roosting spots. Monarchs west of the Rocky Mountains travel to small groves of trees along the California coast. Those east of the Rocky Mountains fly farther south to the forests high in the mountains of Mexico. The monarch’s migration is driven by seasonal changes. Daylength and temperature changes influence the movement of the Monarch.
In all the world, no butterflies migrate like the Monarchs of North America. They travel much farther than all other tropical butterflies, up to three thousand miles. They are the only butterflies to make such a long, two way migration every year. Amazingly, they fly in masses to the same winter roosts, often to the exact same trees. Their migration is more the type we expect from birds or whales. However, unlike birds and whales, individuals only make the round-trip once. It is their children’s grandchildren [or great-grandchildren and even great-great-grandchildren] that return south the following fall.” [ link ]
Migrating Monarch populations have been in trouble since the turn of the century as measured by the area occupied at their overwintering site in Mexico — and secondarily at their West Coast overwintering sites on the coast of California.
These two graphs end in 2013 – five years ago – and it looks pretty grim.
So, are monarch butterflies endangered, as so many activist organizations and their press releases claim, threatened with extinction? Have they been more than decimated by pesticides? Are they doomed by climate change?
SPOILER ALERT: Clicking this link will give you the answer! (opens in a new tab)
Those of you not suffering from the desperate need for immediate gratification can read on . . . . . the story of the monarchs is fascinating.
Let’s give that overall population statistic another more-up-to-date look to include this winter’s stats from Mexico:
This population (above) represents 99% of the North American migrating population. As we can see in this graphic, the lowest point was in the winter of 2013-2014 — this winter, 2018-2019, shows an almost ten-fold increase from that time. The Western Migration population (not shown), however, is at an all-time low this winter, as bad as that sounds, the Western migrating population (west of the Rocky Mountains) only comprises 1% of the overall population of migrating monarchs in the United States.
What’s that in numbers?
“Researchers have estimated that there are approximately 21.1 million butterflies per hectare, although this number most certainly varies with the time of the winter as the colonies contract, expand, and move. It also varies with the density and size of the trees in the colony. Based on this estimate the largest population of monarchs occurred in 1996-1997 when the colonies covered over 18 hectares and contained an estimated 380 million butterflies. To date the lowest population recorded was in 2013-2014 with 0.67 hectares and approximately 14 million monarchs.” [ link ]
Using Lincoln Brower’s formula for the current 2018-2019 winter gives us an estimated 127,655,000 monarchs hugging the oyamel firs in Mexico this year. Yes, that’s 127 million.
A million of anything is a lot — click this link to see an image (in a new tab) of a million dots, one of which is red.
Students of Population Dynamics should find the graph above instructive. The population of migrating monarchs is not part of a predator-prey dynamic but rather a carrying capacity dynamic (in which the carrying capacity of the environment is the limiting factor to population numbers). The non-linearity of the population dynamic is evident in the numbers, with typical boom-and-bust behavior, on top of what appears to be a steady decline — which, when the information to follow here is taken into account, appears to be driven by a change in carrying capacity of the monarch’s North American range.
Are the Monarch’s Endangered by Climate Change? No.
Naturally, the claims of pending doom for the monarchs includes a very large Climate Change factor. Nearly every article on monarchs includes that they must be threatened by climate change, either in the present or certainly in the future. Many of these claims use the RCP8.5 to claim that monarchs will be forced further north in range, looking for milkweed, increasing the length of their migration. Another angle is that tropical milkweeds, which grow year around in the south of North America, will become more toxic with increasing temperatures harming the monarch caterpillar stage which feeds excusively on milkweed leaves and these imported, invasive tropical milkweeds have a higher toxicity which was shown to increase when grown under higher temperatures. However, neither of these two hypotheses are well supported by evidence, rather they are fears for the future.
Once the monarchs migrate north to Texas and beyond, they breed and grow throughout the entire northern range, following the blooming of milkweed, many of which grow and bloom all summer. Monarchs that overwintered in Mexico breed in Texas as soon as they find milkweed plants on which to lay their eggs. These butterflies then die, but their off-spring keep moving north, breeding generation after generation of new monarchs, each generation staying put if milkweed and nectar-flowers are available, or moving north to follow the seasons. Monarchs, unlike many bird species, do not have a specific destination to which they head for breeding purposes…they breed all along the way. Some keep moving — some settle in where they find themselves, as long as conditions are favorable. There is no reason to believe that they will not continue to do so, adapting their migration [or even abandoning the migration as some non-migrating populations have] as the climate changes
The other Climate Change worry is that “the number and intensity of storms will increase”. That is supposition and has not been found in the data to date. But, because butterflies are fragile, the Monarch Migration can and has been adversely affected by weather:
2002: “Between 12-16 January 2002, a severe winter storm hit the monarch sanctuary region deep in central Mexico. Mexico’s over-wintering sites harbor all of eastern North America’s migratory monarch breeding stock. Dr. Lincoln Brower and colleagues released mortality estimates. Based on data collected from the two largest sanctuaries, over 75% of the population was killed by this single storm.” [ The next overwintering season saw Monarch numbers only down by 20% — an astonishing recovery from a 75% mortality event! ]
2010 and 2016: “Storms earlier this year (2016) blew down more than a hundred acres of forests where migrating monarch butterflies spend the winter in central Mexico, killing more than 7% of the monarchs, according to conservationists.”
“Rain, cold and high winds from the storms caused the loss of 133 acres (54 hectares) of pine and fir trees in the forests west of Mexico City, more than four times the amount lost to illegal logging this year. It was the biggest storm-related loss since the winter of 2009-10, when unusually heavy rainstorms and mudslides caused the destruction of 262 acres (106 hectares) of trees.”
“This year’s storm also appears to have frozen or killed about 6.2m [million] butterflies, almost 7.4% of the estimated 84m butterflies that wintered in Mexico, said Alejandro Del Mazo, the attorney general for environmental protection.”
2016 (recount): “Approximately 30-38 percent of the monarch butterflies (Danaus plexippus) in the Sierra Chincua and Cerro Pelón overwintering colonies died in the storm, says a team led by Lincoln Brower, Ph.D., research professor of biology at Sweet Briar College, far more than the estimated 7 percent mortality rate cited in initial media reports after the storm that struck between March 7 and March 11, 2016.”
Hurricanes coming ashore in Texas in late-September and October would affect the migration as it heads for Mexico. Only one hurricane since 1980 fills this niche: “October 20–24, 2015 – Hurricane Patricia’s remnants bring heavy rain to Texas. The maximum rainfall total is reported to be 20.87 in (530 mm) in Corsicana. This rain causes the flooding and closure of Interstate 45 in that area.” It does not seem to have affected the migration in 2015-2016 as that year’s overwintering population was actually 3 times larger than the preceding year.
But in the end, we have this cheering news:
“Even so, most monarch scientists don’t believe monarchs will become extinct.”
“The migration won’t last forever. The monarchs will,” said migration expert Andy Davis, Assistant Research Scientist at the Odum School of Ecology at the University of Georgia and editor of the journal, Animal Migration. “The monarchs will adapt just like they have in every other population around the world,” he said.”
Wait a minute! What does he mean when he says “The migration won’t last forever. The monarchs will.”?
The venerable National Geographic reports:
“Are Monarch Butterflies Endangered?
“The short answer is no. Monarch butterflies are actually quite common across the world, with populations occurring as far away as North Africa and New Zealand.”
“However, the subspecies known as Danaus plexippus plexippus is the only one that performs the great North American migration—and these butterflies are increasingly under threat.”
The Smithsonian Institute reports:
“Monarch Butterflies: ORDER: Lepidoptera | FAMILY: Nymphalidae | GENUS: Danaus | SPECIES: plexippus
Status: Widespread common butterfly, best known as migrant.”
Many areas in the southern United States support year-round populations of Monarch Butterflies, particularly southern Florida. There are some year-round local populations in southern California, where there are also some western monarchs which migrate to Mexico instead of the California coast. “In the Americas, the monarch ranges from southern Canada through northern South America. It has also been found in Bermuda, Cook Islands, Hawaii, Cuba, and other Caribbean islands, the Solomons, New Caledonia, New Zealand, Papua New Guinea, Australia, the Azores, the Canary Islands, Gibraltar, the Philippines, and North Africa. It appears in the UK in some years as an accidental migrant.” [ link ]
It is the Monarch Migration, as a phenomena, that is possibly endangered. And it would be sad to see such a fantastic, unexpected, mysterious phenomena disappear. No one knows how the super-generation of monarchs knows to fly south and manages to find the same little patch of firs in far off Mexico.
California Monarchs overwintering on eucalyptus. [photo credit – charles the moderator]
What do experts really think is causing the decline in migrating monarchs?
Monarch populations are limited by the carrying-capacity of their range — this means that the major factor limiting numbers is the availability of the necessary breeding plant (milkweed species) and adequate food sources — nectar filled flowers.
That said, there are lots of nectar filled flowers in the North American environment but not so with milkweed. Milkweed is a common weed that loves disturbed soils — plowed fields, roadside ditches, hedgerows, highway verges. It used to be a major competitor in the corn belt’s millions of acres of corn and soy beans. What happened to all that milkweed?
Public enemy #1: Round-up. A herbicide that just works as designed — it kills plants that are not genetically engineered to withstand it.
Newly introduced “round-up ready” corn and soy beans now allow the between-the-rows milkweed to be killed without damaging the intended crop. In 2018, 94% of soybeans, 91% of cotton and 90% of corn planted in the US was an herbicide-resistant strain. All of that acreage used to be prime milkweed habitat, growing between rows and on the edges of farm fields. Almost all of that historically available milkweed has been lost.
This represents a case where an agricultural practice change brought about by a technological advance in biology has had the intended effect — fewer weeds competing with crops boosting crop yields — but which has been accompanied by an unintended effect — the loss of milkweeds subsequently suppressing populations of Monarchs.
This loss is seen not only in the corn, cotton and soy fields, but on the roadsides and waste land where weeds are being mowed or treated with herbicides. In my area, the land alongside railroad tracks sports wild native milkweed, but just as it begins to mature, it is mowed down. The same is happening all over America – plants that we consider as weeds are being eliminated.
Monarchs need milkweed to reproduce, they lay eggs only on milkweed and the young caterpillars eat only milkweed. More specifically, they need native milkweeds, not the often prettier non-native tropical milkweeds sold to gardeners.
Loss of native milkweed in the North American breeding grounds — Texas to the Great Lakes — is the primary factor that has limited monarch populations and is believed to be the major factor leading to their steady decline since the turn of the century.
There are lots of groups that are promoting milkweed planting (remember to insist on native milkweeds) and butterfly-friendly home gardens that provide ready sources of nectar for the monarchs and other butterflies. An internet search for butterfly-friendly gardens and milkweed sources will point you to the right places. (Many of the links in this essay go to monarch-specific sites that contain information.)
The other limiting factor is loss of overwintering habitat in Mexico due to illegal logging. To correct this, the government there has created a Monarch Butterfly Biosphere Reserve. There are ongoing reports of continuing illegal logging in the oyamel fir forests of central Mexico, inside the reserve. There have been damaging storms since the turn of the century (detailed above) [and in all probability there have always been storms] that have felled trees there and caused mudslides. But as we see in the population graphs above, monarch populations seem to be able to bounce back.
Note that there are some myths and superstitions about the oyamel — one is that monarchs return to the “same tree” each year, which is utter nonsense. It is not the same butterfly that left which is returning but a great-great-grandchild. But it may be true that the monarch swarms do tend to form on some of the trees used in previous years — whatever it is that attracts them to a specific tree may well attract them again — they may leave a scent marker on trees when they use them — research continues on this fascinating subject.
Take Home Messages:
- Monarch butterflies represent a nearly unique phenomena in their North American migration behavior — a beautiful thing to observe — and well worth conserving.
- Our North American Migratory Monarchs face challenges in our modern world — loss of available milkweed being the primary problem.
- You can help. You can plant native milkweeds (many of which are gorgeous) and butterfly-friendly flowers in your yards and gardens. You can encourage local authorities to leave milkweed patches unmowed on public land. You can participate in Monarch Citizen Science programs all across the US: Monarch Joint Venture, US Forest Service, the Monarch Larva Monitoring Project, Journey North’s monarch migration tracking program, and several opportunities for large and small project with Monarch Watch. The Xerces Society itself has programs and links to other monarch programs, including sources of milkweed seeds.
- Monarchs are not threatened by climate change — but can be adversely affected by weather phenomena. It is beyond our capability to control the weather, but we can support monarchs and add to their resilience by protecting their overwintering sites (well underway) and act to increase available milkweed in their breeding ranges.
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Author’s Comment Policy:
An interesting topic and yet another example of something good that is not really threatened by climate change. (That’s a long list…)
Every year in the summers I tend to stop and search milkweed patches for monarch eggs and caterpillars — or even signs that they have been there. I haven’t had much luck in my part of NY State, though an acquaintance living on the shores of the Hudson River nearby had great success this last summer with milkweeds she planted in her yard.
I’d love to read you stories of Monarchs and other Nature related experiences.
Beginning your comment with “Kip…” will let me know that you are ‘talking’ specifically to me.
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Monarchs were in plentiful supply here in northern Michigan last year. Every year is different, of course, but last year was an increase
Big T ==> Thanks for the local Michigan report! (When you say Upper Michigan, do you mean the Upper Peninsula?)
Vermonters also reported a big population increase.
He said “northern.” If he meant the upper peninsula he probably would have said so, e.g. U.P.
The Wanderer or Monarch Butterfly is also found in Australia where the species also makes limited migratory movements in the cooler areas. It has been in Australia since about 1871. Wanderer or Monarch Butteflies live in Australian urban areas, where its food plants (like milkweeds) are found.
The Wanderer Butterfly is found in eastern and southern Australia, in Queensland, New South Wales, Victoria and South Australia. They are commonly seen in Sydney during summer, usually flying close to ground level. They are fast. They have been recorded at speeds of up to 40 km per hour. The population only became established when its food plants, including poisonous milkweed, were also introduced.
In summer, Wanderers are found throughout their range along the east coast of Australia from Queensland to South Australia, and also in south-west Western Australia. Interestingly, they have also been found in isolated parts of the Northern Territory, which is wet and tropical. Their adult life is about a month to six weeks in summer. They often move to unoccupied areas to find new plants on which to lay eggs. They take nectar from flowers to maintain their energy levels as they go.
As winter approaches, the butterflies leave the inland areas as temperatures drop and migrate towards the coast, which not far away. The Monarchs or Wanderers evidently known exactly what is good for them. For Wanderers near the ideal climate of the coast north of the Richmond River in New South Wales, breeding can continue for most of the year with one generation immediately following another. Further south, adults that develop in autumn do not breed immediately, as in America. They remain in a non-breeding state throughout winter, some of them staying in the same district for several months. Again the butterflies show immediate and intelligent adaptation to the climate and the region.
In cooler areas, these non-breeding adults may gather together and hang from the branches of trees in large clusters of thousands of butterflies, just as they do in Mexico. The same trees are used for this year after year. The clusters are at first made up mainly of males. The females arrive a week or so later. During the warmth of the day the butterflies fly around the trees, but with the afternoon drop in temperature they settle to reform clusters. Cluster sites are known in the Sydney Basin and Hunter Valley, as well in the Mt Lofty Ranges, near Adelaide.
The clusters appear in about April and remain over winter until about August or September, when the butterflies disperse after mating. The females are the first to leave, moving off to lay the first eggs of the new season on fresh spring growth. Succeeding generations extend the range across the country until the full summer range of the species is again occupied.
Wanderer Butterfly caterpillars are most often found on their preferred food plants, which are from the milkweed family (Asclepiadaceae). These plants have a milky sap, from which the caterpillars derive distasteful toxins that deter predators from eating them. The caterpillars’ bright colouration is a warning to these predators that they are potentially toxic. The predators usually take the message.
The poison from the plants is carried through the various stages of the Wanderer Butterfly’s life cycle, making them unpalatable and causing many predators, including large birds, to be violently ill.
Some predators in Australia appear to be unaffected by the Wanderer Butterfly’s poison and birds such as the Pied Currawong (Strepera graculina) and the Black-faced Cuckoo-shrike (Coracina novaehollandiae) have been seen feeding on it.
wimmera in Vic this year had more than ive ever seen in my yard, in the hottests days too
when i was watering they all came out to drink, but damned if we have anything looking like milkweed here.
they were in the tomato plants and on the red gum trees, and amongst the leaflitter mostly.
the heat burned most flowers off and nectar on gums hasnt been all that good either.
oz ==> Thanks for the report from the Australian state of Victoria! Your ABC carried a piece that tells the story of Monarchs in Oz.
https://www.abc.net.au/radionational/programs/offtrack/flying-weeds:-how-the-monarch-butterfly-colonised-australia/6768228
Butterfly “Puddlers” are a nice addition to your garden — it is simply a shallow dish (flowerpot saucer, old birdbath) with some sand and stones. Add a bit of .water, but not covering all the sand or stones completely. Place in garden. There are kits for sale online.
Oz – former milkweeds (Asclepias species) now put in the genus Gomphocarpus seem to be the most common hosts in SE Queensland. They are usually called Balloon Cotton Bush or some variant of that or Giant Milkweed. The flowers (mostly white) and seed pods show their relationship to milkweeds, but they grow taller and bushier and would not be thought a milkweed on first glance. You may have those around.
Nicholas William Tesdorf ==> Thanks for that very thorough update on Australian Monarchs (aka Wanderer butterflies). The details and differences are extremey interesting.
Thanks Kip for bringing back happy memories of a weekend trip to Palm Springs, just over ten years ago. They were coming through there all that weekend. If I had to estimate the numbers, I would have guessed (probably incorrectly) at tens of millions just for that locale. It was amazing.
Phil ==> Absolutely amazing to see millions of butterflies streaming out of what appears to be an empty desert….saw it once as a boy. Thanks for sharing.
Thank you for this marvelous article. It’s timely and provides answers to some questions that have long plagued me.
John ==> You are welcome. I’ll admit to leaving this topic researched but not written for a couple of months but it would not leave me be, hounded me to be written.
A number of state environmental agencies along with their respective soil conservation services may want plant milk weed as part of the trees to tribs programs. This would help reduce their exposure to herbicides like Round Up.
Spuds ==> In fact, some of the programs linked in the essay do encourage public works departments to leave milkweed unmowed — and there are programs that grow milkweed to be introduced into habitat recovery sites.
Central California’s Trees to Tribs progrsam would be a good fit. (Oddly, I couldn’t find a link on a quick search. Can you supply one?)
Kip, here’s to you –
https://www.google.com/search?q=programs+that+grow+milkweed+to+be+introduced+into+habitat+recovery+sites&oq=programs+that+grow+milkweed+to+be+introduced+into+habitat+recovery+sites&aqs=chrome.
Johann ==> Thanks for the link to a G search of programs to reintroduce milkweed!
Appreciate!
Lots of monarchs here in northeastern Illinois and, as far as I know, lots to the west, also. There are many, many open grasslands as part of the forest preserves acreage that promote the growth and distribution of native milkweed plants. There is also an announcement in local papers about monarch migration starting, usually some time in late August or September when the milkweed has begun to go to seed.
I have lots of photos of them. That, and dragonflies.
Sara ==> Thanks for the Illinois Report!
If you email me your best monarch photo, I’ll add it to the essay. ( kip at the domain i4 decimal net )
Try this one if you want Kip. Checked my photo files, it’s the only way I keep my life memories in some kind of sequential order. March 2005, Palm Desert, California.
Although this one doesn’t showcase the fact, I had my real photography equipment with me that weekend and got some amazing photographs of other wildlife – mountain lions and a roadrunner chomping down a live lizard. Maybe later ….
Oooops:
http://oi68.tinypic.com/1ckr4.jpg
Phil ==> The photo you sent is of a Painted Lady butterfly — one often confused with the Monarch as it shares the same colors. It is also one that is very easy to raise at home — a great project for kids.
There is another butterfly that mimics the Monarch — the Viceroy Butterfly.
Wow strange, because it was amongst the thousands flying through Palm Desert when I was there, although the others were flying and this one was resting. Didn’t have the genetics to keep up perhaps?
Phil in CA – Painted Ladies are famous migrators too, but don’t seem to have the cachet of Monarchs.
This one hits home.
When I bought my SW Wisconsin dairy farm back in 1985, our alfalpha fields were bailed in 60# squares, loaded into the milking barn rafters. Three times per year. I still have the square baling hooks and a ‘hay fort’ my long since grown kids helped made up there.
Since about 2000 we switched to half ton round hay bales. Those are enclosed in plastic and never brought into the old hay barns. Just higher HP tractors and newer baling technology.
Rud ==> My maternal grandfather was a german Wisconsin dairy farmer. Of course, he had to have a day job as a mechanic as well to make ends meet. I have fond memories of being five years old through a Wisconsin summer.
Have you got native self-seeding milkweed around the property….I remember it on my grandfathers pastures. Cows wouldn’t eat it.
The Pennsylvania dairy farm I helped at baled #90 pound square bales when we first started helping in the early 1970s.
The farmer, Bob, had a Norwegian farm laborer, Hans, who one handedly threw bales up onto the flat bed, alternating arms.
He was so fast that two and three of us softies stacking bales couldn’t keep up.
I worked a full time job, so my efforts were weekends, occasional evenings and special needs. One of my brothers took full time employment before and after school on the farm.
Hans moved on and my Brother ended up being the one throwing #90 bales up onto the hay cart. Wrestling him was always a foregone conclusion.
A few years later and Bob was having too hard a time finding workers willing to hump #90 bales. He installed equipment for #60 and I believe #40 pound bales.
Bob passed on before the large round bales became ‘the’ method. His widow sold the farm to developers and moved to warmer winters.
When you’re a kid, milkweed pods are really cool. They make a great pretend hand grenade and if you catch one ready to seed and pop it open, you have a squadron of paratroopers descending from the sky. And Monarch butterflies are so ubiquitous that you just take it for granted that you can spot one whenever you care to look.
You can even break off an egg deposit, watch the caterpillar munch around, and then form a chrysalis which, with that rare bit of luck, you can catch the butterfly emerging. We’d usually have a chrysalis in a jar every year I was in grade school. Never did catch a butterfly emerging at school, though.
I did notice the decline in milkweed and was disappointed that my son did not get to see much of the life cycle of a Monarch, as was just so easy to do when I was a kid in the ’50s-’60s.
I’m thinking of putting in some milkweed. I have a great, out-of-the-way plot where it would be perfect for the Mrs. and me to watch the Monarchs and a good spot for the Monarchs.
P.S. What’s up with grasshoppers and praying mantises? Hardly any grasshoppers around for bass fishing anymore and precious few mantises to bring insect snacks to. I don’t miss the bag worms, though. Not many of them, either.
H.R. ==> I share those memories. Many of the more decorative native milkweeds can be planted in your flower garden where they will add beauty and interest. You can cut the seed pods off before they burst if your neighbors don’t want milkweed everywhere. Remember to plant butterfly food flowers in among the milkweeds to attract the monarchs and feed them while they lay eggs (hopefully) on your milkweed.
Screw the neighbors, Kip. Any milkweed in their yard just means more Monarchs. 😜
(Old cemetery catercorner to our property and the most likely place for any seeds to go. I’m not expecting a lot of complaints from “the neighbors.”)
Re: Grasshoppers and Mantids. Here in Terrell, TX we had a veritable PLAGUE of mantids last year (those and black widow spiders. Yikes!).
We haven’t had hopper/locusts in 4 years-I imagine this is because we have had some really bitter cold those past 4 winters. And now, because this winter has been closer to normal (warmer) I wonder if we’ll see our greedy friends reappear this summer.
Hint to fishermen: When hoppers are scarce for your bass fishing, try crawdads. Our bass love crawdads, (even fake ones, our color choice is black) I just wish the bass would jump out of the pond and devour the crawdads that tunnel on our property. Their ‘volcanoes’ are a very unsightly addition to my front yard.
Barbee ==> I’ll have to look into it. Some of these insects can be cyclical, like the famous seven-year locust.
I was also born in 1950 in San Francisco. I remember the clouds of monarchs flying through the area on their migratory path. Trees would be completely covered with them, and they would then cover the sidewalk, cars, or building faces.
My father’s family used to own 200,000 hectares right where that spot on the map is at. It was an old Spanish land grant. The land was mainly timber land, and minerals such as silver. The government took it away in the land reforms in the latter part of the 1950s. I remember my father and his brothers getting together to see what could be done to save the land grant. Eventually, the government gave around half of that back to the family. The other half was supposed to become an Indian reservation, but that never panned out. Around that time and over several decades afterwards the timber was stolen off of the land, and in surrounding forest lands. Good old Mexican corruption.
goldminor ==> Great story about the Spanish Land Grant!
The Western Monarchs are funneled down the northern peninsula past Marin and cross the entrance to SF Bay alongside the Golden Gate Bridge. a similar thing happens in southern New Jersey. Thanks for sharing.
Thanks for your article, I really enjoyed it! I am lucky enough to live in Texas and frequently travel the East/West highways of I-80 and I-20 near Terrell and Forney.
Each year, I delight in the the ability to witness the flight of 100’s and 1000’s of butterflies crossing these highways. (But I do have a pang of regret when one it struck by my car).
They are lively creatures who are always welcome to snack on my garden’s flowers. And no, I have not noticed a recent decline of monarchs but maybe an increase of other species. Perhaps that is because I live in a rural ag. area where cows, sheep, horses, goats, donkeys, chickens and pigs are pasture raised….maybe herbicides and pesticides are not used here as much as they are in a suburban housing. I HAVE tried to grow milkweed and failed. The ONLY one that readily grows is called Bull’s Balls. (I kid you not!) This plant grows wild in the cattle pasture, it’s low growing and unattractive. I cannot imagine this plant ever growing large enough to support even a single butterfly larva to adulthood.
Good luck growing your milkweed-I’ll enjoy your efforts and feed the migrating adults.
Barbee ==> Marvelous — there are hints and tips on growing milkweed from seed here. or get pre-started plants here.
Not everyone needs to plant milkweed — a butterfly garden is a supermarket for hungry butterflies of all stripes.
Keep up the good work!
Btw… milkweed can cause cardiac arrest for warm blooded animals. That’s why birds avoid them.
The problem for these watermelons incessantly bashing the horrors of man made climate change is sooner or later your arch nemesis will turn it back on you with a dose of sublime irony-
https://www.msn.com/en-au/video/news/science-may-be-the-last-hope-for-chocolate-which-experts-say-could-be-extinct-by-2050/vi-BBTyN9P
Now they wouldn’t be deliberately pushing the buttons of chocaholics for their own vested self interest would they?
Consider the Monarchs that populate the Hawaiian Islands. They seem to have adapted quite nicely, and, of course don’t migrate. I have seen them in various stages of development at/near Kanehoe.
https://hawaiinaturejournal.weebly.com/hawaii-plants-and-animals-in-the-backyard-and-beyond/a-merry-monarch-monarch-butterfly
G P Hanner ==> Exactly — monarchs adapt to year-around residence when biological conditions allow — nectar plants for food and milkweed plants for the larval stages. Thanks for the link to the photo of a monarch in Hawaii sipping nectar from tropical milkweed flowers — photo taken by Jeanne Lindgren.
Q: And why is there so much “Roundup Ready” corn being planted in the United States?
A: A major reason is misguided “climate change mitigation” schemes, to substitute biofuels for fossil fuels.
Here in the United States nearly half of our $14.5 billion corn crop is used to make ethanol, for fuel, to “fight climate change.” That’s about 50 million acres of Roundup-Ready monoculture corn, which is more than the COMBINED land area of MD, VT, NH, MA, NJ, HI, CT, DE & RI. In Brazil, they’re cutting down large areas of the Amazon rain forest, to grow sugarcane, to make motor fuel. Likewise, great swaths of Africa and Asia are being converted to monoculture palm oil plantations, displacing subsistence farmers and wildlife habitats, to make biodiesel — all to “fight climate change.”
An enormous amount of wildlife habitat and food are being sacrifice to feed the piggy:
As usual, the climate change is harmless, but the “mitigation” is anything but.
Dave ==> It was and is a wonky idea to make fuel out of food.
OT however, BP has just announced this;
“Renewables will be the main source of global energy by 2040, BP says”
https://www.smh.com.au/business/the-economy/renewables-will-be-the-main-source-of-global-energy-by-2040-bp-says-20190215-p50xzs.html
Yes I spotted that one but meanwhile folks as you were and keep on pumping our dirt busting fuel particularly for South Australia’s 9 emergency diesel generators presumably-
https://www.bp.com/en_au/australia/products-services/fuels/bp-ultimate-fuels.html
Nothing like having the Ultimate on tap when you run out of sun and wind.
Thank you KIp for this story.
Many decades ago, our group took a ferry to Amherst Island in Lake Ontario, west of Kingston.
We rode to the western tip of the island, and everything was still. Suddenly the sky was orange, as millions of Monarchs erupted from low bushes, almost blocking the Sun, and disappeared to the northwest – Magic!
ALLAN MACRAE ==> Thanks for prompting such a such a beautiful mental image!
I’ve long wondered how damaging the slicer dicer wind turbines are for Monarchs. Anyone know?
Dennis ==> I suspect (no data really) that Monarchs and other butterflies fly too slowly to interact with wind farm props.
If anyone reading has any information on this, please comment in reply.
I would say the autos destroy millions more butterflies of all species the do wind turbines
Big T thanks, I’m inclined to agree, but we need transportation vehicles whereas wind turbines are worth-less-than-nothing-junk so it would be a helpful addition to the growing list of wind turbine negatives to find that turbines kill monarchs. That would really resonate here in Cali!
Kip thanks but I’m still suspect and inclined to believe that wind turbines vs Monarchs has been looked it and quickly found to be bad news for butterflies and subsequently never pursued.
Dennis ==> Maybe you can find something on this — there are a lot of anti-wind-power groups in the US and Europe — someone may have been prowling around at the base of wind towers seeing what else, besides bats and birds, have been being killed. If you find anything, send it to me.
A) Milkweeds are common.
B) Farmers have long tilled or even pulled by hand any milkweeds found growing in their fields and pastures.
Blaming a herbicide ignores generations of farming practices.
Why such attention to certain plants?
1) They’re poisonous to livestock whether fresh or dried. Their smashed puld can contaminate edible fodder going into storage.
2) One milkweed plant can infest many acres with their seeds!
C) My wife and I plant a number of wildlife friendly plants, including flowers specifically for feeding butterflies.
* i) I far prefer fruit bearing crops that support wildlife, than food barren plants like the flowering cherries rampant in Washington DC.
D) I’ve already received this year’s Asclepias seeds for seeding around my property. Something, I consider important since so few areas are as barren of wildlife supporting food plants as suburban and urban areas are.
* i) Demonizing farms and farmers for practices they’ve long maintained overlooks the many square miles of paved urban areas, herbicide and insecticide treated food poor lawns and high speed traffic catching butterflies on their grills.
* ii) I purchased my Asclepias from Eden Brothers, who sell seed in quantities from packets to pounds.
I far prefer fruit bearing crops that support wildlife, than food barren plants like the flowering cherries rampant in Washington DC.
Thanks for pointing this out. Many of the big-store/nursery gaudy stuff have flowers that don’t even have nectar, let alone make edible (for wildlife) fruit.
ATheoK ==> The situation with milkweed and round-up is that once the crops are up and running (past the weeding stage) milkweed would grow between the rows — when you’ve got acres of corn, you don’t go in and hand pull these milkweeds. It is the ability of farmers now to knock down this milkweed with Round-up after the main crop has established itself that causes the deficit of milkweed.
My grandfathers farm in Wisconsin always had lots of milkweed in the among the corn for this reason back in the 1950s.
This is not blaming a herbicide, it is pointing out the unintended consequence of a change in farming practice.
Not so sure RoundUp is to blame: milkweed grows 3 ft tall; corn goes 6-10 ft– not much light penetrates between the rows after mid-July, and certainly not much flying room for the Monarch even if the weed is there. OTOH, milkweed really likes the roads side habitat where it grows in colonies which are regularly mowed by county DOTs now….No mention in the article of habitat loss in Mexico as forests have been cut to make room for new Avocado groves…Here in The Driftless Area of WI where I let many acres surrounding the house grow as natural meadow, I sit on my porch and butterfly watch like some people bird watch around their feeders. Danaus has a regular, constant presence here.
Forgot to add: habitat fragmentation is just as bad as habitat loss– it doesn’t do much good for one guy to plant milkweed in his suburban/urban yard if the next milkweed plant is 5 miles away. A concerted effort & wide-spread planting program is needed.
guidoLaMoto ==> In this specific case, scattered milkweed is fine, the monarchs find it anyway — they do not depend on milkweed for nectar asbutterflies, only for laying eggs, which they will only do on milkweed leaves.
The recommended thing is to plant native milkweeds in among nectar providing flowers in a consolidated butterfly garden — the nectar-providing flowers attract the monarchs to feed, then they find the milkweed to lay eggs.
guidoLaMoto => In Mexico the Monarchs only need a specific forest to remain uncut and undisturbed — the oyamel firs which are now in an official preserve.
They still do see some illegal logging despite efforts to curb it. — and have storms every few years that blow down trees and heavy rains that cause mudslides.
guidoLaMoto ==> It is not the chemical herbicide Round-up itself that is to blame, but the change in agricultural practice to GMO crops (corn, soy, and cotton) which are sprayed to limit weeds between rows, which has caused a huge reduction in the number of milkweed plants available to the Monarchs for egg laying.
I enjoyed your article, but disagree with your (and many others) contention GM corn/beans caused milkweed to disappear in corn/bean plantings. My husband grew corn on this west central WI dairy farm until the late 1980s, switching to growing all forage because he could often buy corn cheaper than cost of production. I cultivated corn, he sprayed with Atrazine mixed with other chemicals. I can tell you in the 1980s there was no milkweed growing in corn fields. I’ve checked with other farmers in the area and they agree that by the late 1980s (before the introduction of Roundup Ready seed) milkweed had been eradicated in most row crop fields. But, there used to be a lot of fence rows separating fields. Those 4′ wide areas usually contained a lot of milkweed plants. As livestock left farms and crop equipment got bigger the fences were removed.
But, this was also 20 years before large scale subdivisions invaded our township. It used to be ditches were mowed only in fall, and maybe 4′ wide along the road. The new people got upset when they got stuck on snow drifted roads so now ditches are mowed one pass (about 5′) in June, and mowed 2-3 passes(about 12′) in late fall. This mowing has definitely reduced milkweed plant populations.
And the subdivisions have not been monarch friendly, although a few people are changing their landscaping.
I’ve been able to maintain about a100-foot long, ditch-width patch of milkweed in front of the farm by putting plastic fence posts about a foot off the road to form a temporary fence, that so far, has been respected by the country worker mowing ditches. But milkweed is toxic to sheep, so in pastures it’s a dilemma balancing the need of Monarch with my responsibilities as a shepherd.
I came across an early 1900s (I believe it was around 1906) newspaper article reporting area farmers signing up for an on-farm weed control demonstration. The demo was put on by the University of Wisconsin and showcased the use of equipment designed to spray herbicide. Unfortunately the article didn’t identify the herbicide. The war on milkweed, and other perceived weeds, has been going on for a very long time.
gail –> Thanks for the complete first-hand report on your experience with corn/milkweed and herbicides. Everyone’s personal experience varies. The round-up/milkweed connection is the accepted wisdom of monarch experts and based on a series of studies done at many mid-western universities — which doesn’t make it true with a capital T, but part of the proof of that pudding is that extensive milkweed planting projects seems to be bring Eastern Monarch numbers back up over the last five years.
Words you never want to hear from a girl with a Balisong..
“Ahh, you buterfly!”
What a wonderful article! I see Monarchs on my farmette every year, and I have un-mowed land to plant native milkweeds on, which I am now going to do this year, thanks to Kip.
Patrick ==> Great idea! There are also packages of “butterfly friendly meadow weeds” available, so that your milkweed patch also has beautiful flowers and food for the butterflies.
I live in western NewYork and last summer was full of Monarchs. Milk weed does grow like a weed here alongside corn fields and in the ditches. All small family dairy farms around me who fertilize naturally.
Jeff ==> Good to have a positive report from western New York, thank you! It was a good year for monarchs in the northeast, Vermonters reported a bumper crop as well — and the census in Mexico at the overwintering sites bore this out with a great increase in Monarchs there.
Nice article Kip. I’ve noticed a decline in the number of monarchs passing through Northwestern Vermont in the Autumn. I’ve been thinking that may be due in part to a decline in agriculture and return to woodland in this part of the world. In general, butterflies seem to be fairly uncommon around here although there are a few around in the Summer.
There isn’t a lot of milkweed around here although I can recall seeing a plant every now and then. I can’t recall ever seeing a monarch caterpillar in Vermont. Which might be because I rarely see the butterflies in the Spring or Summer. Might plant a little milkweed. Anyone have any thoughts on where to get seeds? There seem to be a number of mail order sources. Any does and don’ts? Introducing non-native species to an area isn’t always a good idea.
Don ==> The Xerces Society has a milkweed seed finder page and the National Wildlife Foundation has page for native milkweed links.
@Don K You need to cold stratify the seeds, either plant them (outside) in the fall and let nature do it, or use your refrigerator for about a month.
Steve R ==> That is correct for most native milkweeds and why I linked to site pages that given instruction on planting and growing native milkweeds.
The tropical milkweeds do not need a winter and grow year around, raising fears that their abundance in the Us south (Gulf Coast and Florida) will tempt lots of monarchs to give up the migration.
They are common in Christchurch in New Zealand’s South Island, but they do not migrate. They fly even in winter on sunny days, so they have adapted to colder climates (Christchurch is NZ’s warmest and driest city in summer and its coldest in winter.) Animals and plants are generally very adaptable and have coped with massive climate changes in the past. There is one species of Talitrid landhopper that occupies the tops of mountains and hills in isolated alpine patches. It is cold adapted so when the climate ameliorated after the 20 or so Ice Ages ceased “recently”, it found nice cool refugia by climbing up the mountains. There it waits, no doubt hoping for another ice age when it will be able to come down from its places of coolasafety and conquer the plains once more! I wonder what it thinks of Climate Change? It probably would think: “Climate is always changing.”
Dr. Duncan ==> Well, thank you for making my day — any day I learn something new is a Good Day!
I had no idea that Talitrid landhopper were related to the sand flea!
And thank you for confirming that there are non[migrating Monarchs in New Zealand!
Thanks, informative and very interesting.
vukcevic ==> You’re welcome. The whole idea of migrating butterflies is just so fascinatingly odd….
Kip,
Thank you for your most interesting article. I would like to add some comments.
The adult monarch butterfly lives 2-6 weeks. It has an exception in the Methuselah generation designed for wintering, that can live 8-9 months. They can do that because they stop developing their reproductive organs (diapause). The phenomenon depends also on shorter days and lower temperatures and in the northern part of North America happens around the end of August.
The Methuselah adults that live in areas where wintering is not possible are the ones that migrate over long distances. They might know that they have to migrate by latitude (solar elevation angle).
Monarch butterflies were at some time blown over the Atlantic by winds, establishing colonies in Madeira, Azores, and Canary Islands. From there they have founded colonies in Portugal, Morocco, Spain, and Southern England.
In Southeastern Spain there are two milkweeds that support the local population, Asclepias curassavica from the American tropics, known here as Spanish flag for its flowers outer red/inner yellow pattern, and Asclepias fruticosa from Africa. Both are invasive species introduced by humans.
This migration of the North American Monarch Danaus plexippus across the Atlantic was natural, while the spread across the Pacific has been done by humans.
The Monarch butterfly is an amazing example of migration in more than one sense. It is also migrating across the World. There is no reason why it should not continue spreading towards the Eastern Mediterranean.
Javier ==> Thanks for the complete report from Iberia!
Monarchs have been known to appear in the UK as well, though they do not have a permanent breeding population there.
Hi Javier,
No one really knows, of course, but there is a reasonable hypothesis that Monarchs ‘naturally’ colonised Australia from an introduced population in New Caledonia via a cyclone in 1871 when Monarchs suddenly started appearing up and down the east coast of Australia. They are thought to have been introduced to New Caledonia. Whatever, their conquering of the Pacific required human introduction of exotic milkweeds first. Both Asclepias curassavica, which we call Bloodflower, and Gomphocarpus fruticosus (it has been moved from Asclepias) are common hosts here in Queensland and the latter is an important host in New Zealand.
Cheers,
I suspect that Milkweed will soon be declared an Invasive Weed here as their prevalence has gone from invisible to very obvious and distinctive.
Doug Huffman ==> Where are you writing from, Doug? With milkweeds becoming so prevalent I would expect you would be seeing Monarchs if you are living within the monarch’s range.
Kip
Great article. I am a retired primary school teacher who raised Monarchs in my classroom each September for 30 years. I live in Ontario, Canada and recently published a book entitled “When a Butterfly Speaks…Whispered Life Lessons “. It contains 111 stories of Monarch Magic blending science and spirituality. I just finished writing the Sequel. I enjoyed reading your well written article. My book is available on Amazon under Barbara J. Hacking
Kip
Loved your article!
I am a retired primary school teacher who raised Monarchs in my classroom each September for 30 years. When I retired in 2012, the Monarchs were almost non-existent here in Ontario, Canada. That year the Mexican population was very low and it was even lower the following year. I am so happy to see more Monarchs here this year. I will be visiting The magical Monarch mountains next week and look forward to the spectacular sights that await. I published a book in October called “When a Butterfly Speaks… Whispered Life Lessons “. I have learned so much from these wondrous insects. I just finished writing the Sequel this week. With the return of the Monarchs came these stories of science and spirituality. My first book is available on Amazon under Barbara J. Hacking. Thanks for making people aware! Remember to plant milkweed for their young.
Barbara ==> Thank you for the contribution you have made to the lives of so many children over the years!
And thanks for the Ontario up-date! Please do a report on your trip to Mexico to see the Monarchs — either as a submitted story here at WUWT or you can send it to me ( kip at the domain i4 dot net ), with photos please!
Barbara’s book is available here.
I most certainly will. This is my 4th year in a row visiting the Monarch sanctuaries. I first visiting them in 2005 with the Monarch Teacher Network. It was life changing for me. I will be posting photos on my Facebook page called “When a Butterfly Speaks “ its’s the next best thing to bring there.
Barb ==> If send me a bit of a report, I will turn it into a follow-up essay to this one, with permission to use photos.
Hi Kip, is your contact info
Kip@i4.net.
Or kip@domaini4.net.
Can you post videos? If so I have one that got 750,000 hits in the first week on Facebook.
Barb ==> Sorry to be obscure. Hiding the email address from web bots …. (have to remind myself that not everyone knows details and jargon of the web).
kip@i4.net will get to me.
Look forward to your report on your trip!
I do live in the UP of Michigan, in Iron Mountain. Last summer I found 2 young caterpillars on my milkweed. I took them indoors and put them in a small animal plastic box. Fed them, watched them grow and finally form a chrysalis. After about 2 weeks the chrysalis started turning from light green to a transparent stage. You could actually see the butterfly in the chrysalis. Beautiful. I watched diligently ever day and was able to see the butterfly emerge. It is truly an amazing thing to see them transform from a caterpillar to a butterfly. I was able to release them and watch them fly away. Hopefully, they made it to Mexico.
Barb P ==> Thanks for sharing your success with monarch caterpillars going through their mind-boggling transformation into butterflies.
And for the Monarch Update from the UP of Michigan!
Here in the Fingers Lakes area of NY State, we have noticed an uptick in the quantity of Monarchs in the last year or two. A few years back, the local Conservation Groups went all in, supplying milkweed seeds for anyone who wanted them.
We live on a 600+ acre ‘preserve’, and the milkweed is left alone…no herbicides or mowing of the plant is allowed. We have extensive flower beds on our little section, and this year will plant more Monarch-friendly flowers.
The numbers last year were nearer my memory of the amount always found here…and with a higher understanding of their life cycle, I can’t help but feel a bit sad when one impacts the vehicle on a highway.
bullfrex ==> Thanks for the encouraging report from New York state’s Finger Lake region — a beautiful part of the country (and geologically interesting).
Your local sample is in agreement with the official census of overwintering Monarchs in Mexico this year.
There is a lot of value-added in keeping some tracks of land undeveloped and un-farmed.
I can’t help but feel a bit sad when one impacts the vehicle on a highway.
I’m a bit sad when I see on my butterfly bush a pile of monarch wings right under a praying mantis…..
beng135 ==> Mantises have to eat too. Did you know that larger mantises have been known to capture, kill, and eat hummingbirds?
See https://www.cbc.ca/news/technology/hummingbirds-beware-praying-mantis-killers-1.4203443
I’ve seen them still passing thru in early Oct here in west MD, and worry that those might get caught by sudden cold & fail to make it.
beng135 ==> Yes, I think you are right, October is a little late for Maryland. There is hope, they could have been heading for southern Florida.
Many stretches of highway in Ohio are adopted by civic groups for litter cleanup. Maybe they should dig up the part of the periphery and plant milkweed.
Tom ==> There are various movements to plant hiway verges with native wildflowers, including milkweeds, some started in the late-1980s.
The Xerces Society might be able to help local efforts.
Here is another interesting part of the Monarch migration story: we are not sure whether some portion regularly migrate across the Gulf of Mexico.
They are seen on oil rigs, etc., but it is not clear whether Monarchs began this practice only after the oil rigs became present, and we are not sure if there is some portion that would begin the trip across the Gulf, unknowingly taking a wrong path and only surviving occasionally by luck and happenstance.
Hypothetically, a cross-Gulf migration could be a major part of their migration. We just don’t know. However, if it were, we would most likely have a lot of anecdotes from oil rig workers, like the many anecdotes here from many places, of a regularly occurring great parade of Monarchs transiting the Gulf.
TheLastDemocrat ==> A Gulf of Mexico route would be interesting. Monarchs are known to try to stay over land as much as possible — which accounts for the “funnel effect” seen north of San Franciso and in southern New Jersey at Cape May. I suspect that those seen on Gulf oil rigs are the occasional individual being blown off course — but keep your eyes and ears tuned for news on the idea — you may be onto something.
Here (in NE Colo.) migrating monarchs become obvious for several weeks each fall (Octoberish). You can usually spot one within seconds (often by its shadow, if you’re not looking horizontally/up) once the temp exceeds “overnight estivation level.” In this irrigated-farming-intensive area of the S. Platte River valley (100 mi NE of Denver), milkweed is far from obviously common…and ditto for monarchs every season but fall. Nature is amazing. (Go, little monarch, go!!!)
Bob W. ==> In the Fall you are probably seeing the southbound migration wherein Monarch are funneled by things like rivers and hills to fly in a common pathway — thus they become very apparent. One butterfly is easy to miss, but hundreds really make an impression.
Kip – “Roger your surmise,” wrt “probably seeing the southbound migration…” South is Very Definitely their overall flight direction. On days with “obvious southerly winds” they hug the ground (as in, attempt to remain within the boundary layer); other days, not so much. Watching them flutter their way south across the treeless section immediately south of our place, with knowledge of what they/nature are seeking to accomplish, makes it hard to NOT anthropomorphize and wish them well! (Go, little monarch, go!!!)
Unrelated to butterfly migration per se, in this neck of the woods (so to speak), daytime breezes (often, winds) are the norm. As a kid I ignorantly supposed butterflies were lucky to be able to occasionally/accidentally land on a flower and eat…hence the frequent moniker “flutter-by.” Ha ha ha! How utterly uninformed of me! Whatever they have inside their little head and bodies in the way of brains/ganglions/intelligence, they’re superbly capable of such things as: object detection/discrimination; directed/purposeful flight; in-flight decision-making. A few minutes of open-minded observation should be sufficient to convince any adult of such – perhaps little-known – things.
Thanks for an (ahem!) uplifting essay!
BobW ==> You’re welcome…and thanks for participating in the discussion. When readers truly participate, share their personal knowledge or experiences, contribute links to further information on the topic — then like a incoming tide, it raises all our knowledge boats.
One other observation…monarchs routinely soar – i.e. climb w/o flapping – on convective days…using the same (circling) technique to climb as do (lots of!) feathered critters and man-piloted sailplanes. Obviously (?) the physical scale of the actual physical atmospheric phenomena each critter (butterfly/bird/human) uses would prove “different” were the atmosphere visible, but there’s no question the basic driver is convective lift on many a day.
I’ve also watched monarchs “climb straight ahead” (w/o flapping) when they might well choose-to circle. Sailplane pilots often use the same technique as a means of “not stopping to thermal” (“stopping” in the speed-made-good-over-the-ground sense) when the thermal is perceived either weaker than one likely to be encountered ahead, or, the lift is believed/known to have a “larger than typical” horizontal extent, or, as a means of avoiding climbing into controlled airspace by flying/sinking faster and further increasing their speed-made-good-over-the-ground. My surmise is monarchs are “smart enough to understand” both the benefits of resting (by not flapping), and those of increasing their speed-made-good by climbing straight ahead w/o flapping. (Go, little monarch, go!!!)
Bob W.==> How do they fit all that knowledge into their little barely-multi-celled brains?
You can plant native milkweeds (many of which are gorgeous) and butterfly-friendly flowers in your yards and gardens
Good idea, as my gardening skills lead to weeds in my yard anyway.
😉
PaulH ==> That’s the spirit! If ya gonna get weeds anyway, you might as well make them useful weeds.
Actually many of the milkweeds are absolutely gorgeous in bloom, and neighbors may compliment you on the pretty flower garden.
My dear departed father had what we called a “black thumb” — everything he planted died within days…..even as children we took the family gardening tasks away from him so that something would live. My Dad could even kill the weeds!
Kip, I am visited by many Monarchs each summer in central New Brunswick, Canada. I have lilac bushes which they seem to love, especially my Preston Lilacs, which bloom later than my other lilacs.
John ==> Thanks for feeding the Monarchs in New Brunswick! What months do you have lilac blooms?
Kip, these creatures are even more remarkable thsn your fine essay reveals. I noticed on your map of the flyways you missed the important Great Lakes flyway from Ontario across Lake Erie. They fly westward along the north shore of Lake Ontario to Point Pelee the southernmost tip of Canada (same latitude as N Califotnia!) where in late August they festoon the trees and shrubs awaiting a northerly wind of sufficient strength to help carry them across the 35km lake width safely. There are several monarch festivals in towns on the Bruce Peninsula. Anyway, when the right wind strength arrives they lif off in clouds to set off on their journey. How these novice migrants know the right wind strength is another marvel to ponder.
https://journeynorth.org/monarch/fall2016/03/monarch-butterfly-migration090116.html
Gary P ==> Thanks for the tip on the Monarch festivals there at Point Pelee.
There is an eyewitness account on journeynorth here.
Kip,
I live in the Birmingham area of Alabama. The migration passes through our area the first week in September and the first week of April. I harvest the eggs from the plants (both native and tropical milkweed)and allow them to hatch in plastic containers. I have found that leaving them on the plant allows the caterpillar to be eaten by ants. I feed them in the containers and they form their chrysalis on the lid. I then hang the lid in a butterfly net and release them in my yard. I also share them with school and civic tours. I have about a 90 percent success rate for each egg I harvest. My mother does the same thing in her retirement home. She keeps her plants on her balcony. Between the 2 of us, we release several hundred butterflies each migration.
Holly ==> Thanks for sharing your experience in rearing Monarchs in Alabama.
If you see this, please share with readers your favorite web page explaining the ins and outs of rearing the Monarchs from eggs.
The author is misinformed. The Europe/Africa migration of the Painted Lady butterfly is by far the longest in the world.
Kenneth ==> You are referring to the text in the first block quote: “In all the world, no butterflies migrate like the Monarchs of North America. They travel much farther than all other tropical butterflies, up to three thousand miles.”
The reason I put quote marks on sentences is to indicate that I am quoting some other source (not my own opinion or words, but those of someone else). The link is provided.
It is true, however, that there is beginning to be evidence of an even longer migration between Europe and tropical Africa of the Painted Lady butterfly. The question is not settled yet, but at least one study claims to have evidence that some Painted Ladies make the reverse trip [pdf] from tropical Africa back to southern Europe. The study authors state “While it was demonstrated that this species massively migrates from Europe to the Afrotropics during the autumn, the existence of a reverse migration from the Afrotropics to Europe in the early spring remains hypothetical.”
I volunteer at a wildlife rehab center in Houston, TX. Every fall I repair or replace the wings of a number of monarchs. It is a joy to see them continue heading south afterwards…
Brian ==> How do you replace a monarchs wing? Have you tagged any repaired monarchs and found out how far they make it?
North America readers can get a general idea of what native milkweeds species may grow best in their area here under the Subordinate Taxa tab at the USDA:
https://plants.usda.gov/core/profile?symbol=ASCLE
Not all native milkweeds are equally good food for Monarchs, so you should do some more research before planting. In Australia, milkweeds and cotton bush are all weeds and Monarchs thrive on them.
DaveW ==> What a terrific resource! Combined with the links to sites that sell or provide various native milkweeds, reads can find exactly which sub-species are truly native to their region!
Thanks!
Hi Kip,
Very nice job on the write-up. I can’t help but wonder, though, what Eastern US populations of Monarchs were like before European settlement and land clearing. I imagine native milkweeds were far less common when Eastern North America was mostly covered with forest. One would also think that the demographics and migration patterns we see today may have been quite different during the Little Ice Age. I think it is quite likely that the current Monarch migration patterns may be of recent origin and strongly influenced by human land use changes. Ironic, then, that more recent changes are disrupting the pattern, which may not be at all ‘natural’.
DaveW ==> A very thoughtful comment. If you are truly interested, you might write to Andy Davis, Assistant Research Scientist at the Odum School of Ecology at the University of Georgia and editor of the journal, Animal Migration.
Animal Migration just had a recent issue focusing on the monarch migration.
Sailing is a humbling experience – ask any sailor. Point in case, 15-20 miles out in the middle of Georgian Bay, close-reaching at 6.6-6.8 knots in 15-18 knots of wind apparent, being passed by a solitary Monarch butterfly doing an estimated 7.5 knots! And knowing that it is not looking to land for a rest.
b_C ==> Thanks for sharing the story — about Monarchs and sailing1
(You may not know that I have spent 1/2 of my adult life living aboard and abroad on ships and boats, with a 12 year stint recently on our sailing cat in the Norther Caribbean.)
Kip ==> Alberg 37: love burying those toerails though!
b_C ==> Nice boats…what rig do you have. (Don’t those Albergs come both ketch-rigged and sloop rigged?)
Our Solaris 42 cat (built in Southhampton, UK) is ketch-rigged and originally intended as a trans-oceanic sailor — whereas we have used it only for near-shore work coming and going to the Caribbean and up and down the US East Coast. When our youngest son went to get his Captian’s License, he alread had 35,000 miles under his belt.
Kip ===> Came in yawl and sloop rigs. Mine’s cutter rigged sloop, but removed staysail stay – mostly singlehand. Envy your cruising grounds. Been to the Bahamas and has done a complete Down East loop – St. Lawrence, Maritimes, NE states, Hudson, etc.
Kip ===> Came in both yawl and sloop rigs. Mine’s cutter rigged sloop, but removed staysail stay – mostly singlehand. Envy your cruising grounds. Been to the Bahamas and has done a complete Down East loop – St. Lawrence, Maritimes, NE states, Hudson, etc.
In December 1982, my now wife & I visited Hearst Castle in San Simeon, CA. We ate lunch at the little park at the foot of the hill, which overlooked the ocean. There were tens of thousands of monarchs flying around and perched in the trees. It was a magical moment, which we still reminisce about.
Stevecsd ==> Lovely experience.
Some readers might not know that Hearst Castle is located just inland from San Simeon, California, which is on the coastal hiway (Route 1) that leads from San Luis Obispo (at the south end) through the Big Sur area up to Monterey and Santa Cruz (at the north end). There are overwintering sites for Monarchs all along this coast — Pismo Beach is one of the southern most sites (and easily accessed therefore much studied). Monarchs overwinter in Santa Cruz (at the north end) as well.
Kip – I turned 1/2 ace of my northern Illinois property to a prairie 10 years ago. Milkweed moved in on its own about six years ago and has increased every year since- even spreading to nearby fields. Monarchs have no trouble finding me. I appreciate your no nonsense article on this fascinating creature.
Bob Bailey ==> Terrific idea! Its people like you that can make a difference in a problem that may seem unsolvable. If they could, the Monarchs would send you a Thank You card!
Dog gone it!
https://youtu.be/3sDCipU5pzE
clipe ==> Need a TRIGGER WARNING on that YouTube –not to be viewed by small, impressionable children.
PS: I once had pigs that would do the same to my little Button Quail if they wandered into the pig pen.