Media Amplification of Forister’s Feeble Butterfly Science and Climate Fearmongering

Guest post by Jim Steele,

Last week the Guardian proclaimed Butterfly Numbers Plummeting in US West as Climate Crisis Takes Toll. Numerous media outlets flooded the internet with similar versions in response to the research article Fewer Butterflies Seen by Community Scientists Across the Warming and Drying Landscapes of The American West  by lead author Dr. Matt Forister.  For the factors examined, their research found climate change had the greatest statistical effect associated with changing butterfly populations. Warmer summer temperatures however had a positive effect, while warmer autumn temperatures had a negative effect. Of course, in an age where chicken little catastrophes sell, only warming fall temperatures and butterfly extinctions could promote a profitable climate crisis. Worse, the public was misled to assume “all” western butterflies were declining.

For example, a  University of Arizona press release (home of Forister’s co-author) stated, “Western butterfly populations are declining at an estimated rate of 1.6% per year,….The report looks at more than 450 butterfly species.” However, the researchers only stated their databases “encompassed more than 450 species”. In reality their analyses addressed just 290 species of which only 182 or 40% of the 450 species exhibited declining populations. Another 106 species were stable or increasing, and 251 lacked sufficient data for analysis.

It’s expected that during any given decade various populations of a butterfly species will randomly increase in one area but decrease in another, but with no overall declines as recently reported for USA insects. So correctly, Forister et al. asked if a species’ population trend was restricted to a local area or widespread. To answer that they examined 3 independent datasets. The North American Butterfly Association (NABA) supplied their once‑a‑year butterfly counts, typically held around July 4th, of which only 72 different sites had the required 10+ years of data (average was 21 years) with which to determine a species’ abundance trend.  A second data set came from Dr. Art Shapiro’s northern California bi-weekly surveys but covered only 10 sites from the San Francisco Bay area to the Sierra Nevada crest at Donner Pass. A third database used iNaturalist’s citizen science data that only provided flashy optics suggesting  widespread coverage. Although iNaturalist is a great application that easily connects laypeople with experts for accurate identifications and determines the presence of a species in a given locale, it doesn’t provide trustworthy trend data. 

To argue for widespread declines, a species had to be declining in at least two of their three datasets. Comparing trends in the NABA & Shapiro datasets, only 104 species exhibited declines in both. In other words, only 23% of the ballyhooed 450 species showed a possible widespread decline. However, when interviewed by the Washington Post for the article Butterflies Are Vanishing Out West. Scientists Say Climate Change is to Blame,  Forister contrarily stated, “The influence of climate change is driving those declines, which makes sense because they’re so widespread

Despite the real number of examined species, National Geographic still trumpeted 450 Butterfly Species Rapidly Declining Due to Warmer Autumns In The Western U.S. while shamefully ignoring the positive summer warming. Indeed Forister had reported, “locations that have been warming in the fall months have seen fewer butterflies over time”, adding an unsupported hypothesis that “fall warming likely induces physiological stress on active and diapausing stages, reduces host plant vigor, or extends activity periods for natural enemies.” But most butterfly species are no longer flying or laying eggs or feeding during the autumn. Instead, they have snuggled into relative safety from environmental changes to overwinter until the next flush of new springtime vegetation.

The larvae (caterpillars) of some declining species feed on grasses (i.e. Eufala Skipper and Sachem skipper), or herbs (i.e. Cabbage White or Sara Orange-Tip). But most grasses and herbs are dead or dormant by the end of summer. Other larvae of declining species feed on the young leaves or needles produced by trees in the spring (like Propertius duskywing or Western pine elfin). Autumn warmth has no effect on the “vigor” of dead or dormant food plants. Autumn temperatures are simply not critically important. Natural enemies like parasitic wasps typically evolved similar sensitivities to the same environmental cues as their caterpillar hosts and insect eating birds begin migrating south in August. Claiming global warming somehow selectively hurts butterflies but helps their enemies is a totally unsupported claim hurled far too often by those fabricating a climate crisis.

Disturbingly, Forister et al. simultaneously downplayed known benefits of summer warming, suggesting it only increased ‘butterfly visibility’ stating, “warming in the summer influences adult activity times directly and hence increases the probability of detection”. But to power their flight, butterflies sunbathe to raise their body temperature above ambient air temperature. Increased activity is needed for mating and finding host plants. Greater summer warmth also enables faster larval growth, which in some species enables an increased number of generations each year enabling larger summer populations (i.e. Monarchs). In other species like Edith’s checkerspot the caterpillars seek hotter surfaces to grow fast enough each summer and reach a required size allowing overwinter survival. Warmer summers benefit many species in many ways.

To my knowledge not one media outlet reported the summer benefits or the most telling conclusion of Forister et al. “Although our analyses point to warming fall temperatures as an important factor in insect declines, we acknowledge the multifaceted nature of the problem and how muchremains to be understood about climate change interacting with habitat loss anddegradation.”

If Forister et al. were truly trying to decipher the causes for observed butterfly declines, they should have at least adhered to the most basic scientific principle of controlling for known confounding factors. To blame climate change, confounding effects must be removed. But they were not. Thus, declining trends could be completely caused by insecticides and land use. And Forister was well aware of such important factors.

In a 2010 paper co-authored with Dr. Shapiro he found, “most severe reductions at the lowest elevations, where habitat destruction is greatest.” In a 2014 paper Forister concluded  “Patterns of land use contributed to declines in species richness, but the net effect of a changing climate on butterfly richness was more difficult to discern.” In his 2016 paper he modelled negative effects of neonicotinoid insecticides. Listed as Forister’s 37th most declining species, the media highlighted the recent 99% decline of western Monarch butterflies. Yet the Monarch’s big killers are also land use change and herbicides, not climate change.

In the 1970s scientists discovered virtually all monarchs breeding east of the Rocky Mountains migrate to extremely small patches of high mountain forests in central Mexico. When that critical wintering habitat was logged, it opened the forest canopies removing its insulating effects. In January 2002, a storm brought cold rains followed by clear skies. Without the clouds’ greenhouse effect, or an insulating forest canopy, temperatures plummeted to 23°F (- 4°C). Millions of damp butterflies froze in place. Many millions more fell creating an eerie carpet of dead and dying butterflies several inches deep. Distraught researchers calculated 500 million butterflies died that winter, wiping out 80% of the entire eastern population. Similar cold events happened in 2004, 2010 and 2016.

In contrast, monarchs breeding west of the Rockies winter along the California coast to Baja where the ocean moderates temperatures and prevents freezing. Nonetheless those wintering populations also plummeted by 81% by 2014. Interestingly, tagging studies and genetics suggest California and Mexican wintering populations intermingle. Although it’s not clear if one wintering population contributes to the other, their abundance has fluctuated very similarly. In addition, a 1991 statewide study implicated land use as 38 overwintering sites in California were destroyed.

Herbicides severely reduced the monarch’s food plants, milkweeds. Adapted to colonizing open disturbed landscapes, milkweed species began invading the fertilized ground between rows of crops. As 1900s monarch populations boomed, farmers’ crops suffered. Milkweed competition reduced harvests of wheat and sorghum by 20% and most states declared milkweed a noxious weed. Attempts to eradicate milkweed by tilling only stimulated underground roots promoting more milkweed. The 1970s discovery that the herbicide glyphosate (i.e. Roundup) killed the whole plant, turned the tide against milkweed. When genetically modified herbicide‑resistant soybean and corn crops were developed in 1996, herbicide use dramatically increased, furthering the milkweeds rapid decline. That loss of milkweed now hinders monarch recovery. For monarch lovers, our best safeguard is planting more milkweed in our gardens. Likewise, we can plant butterfly friendly gardens for all species. On the bright side of climate change, warming could allow an added monarch generation.

Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus, authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism and a member of the CO2 Coalition

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Sweet Old Bob
March 10, 2021 6:26 pm

“For the factors examined, their research found climate change had the greatest statistical effect associated with changing butterfly populations. ”

I only see what I look for …

Ron Long
Reply to  Sweet Old Bob
March 11, 2021 1:59 am

Also, Sweet OB, “if it bleeds it leads” is the force behind virtually all information services. You simply cannot sell “everything is OK and plants and animals are adapting normally to the slightly changing climate”.

March 10, 2021 7:06 pm

Jim ==> Thanks for the pragmatic truth. Here in the Northeast US, the biggest milkweed loss is the mowing of roadsides and wasteland fields.

Reply to  Kip Hansen
March 10, 2021 10:53 pm

Hey Kip,

Indeed milkweeds are most common in disturbed habitat. Some of my favorite milkweed patches in the Sierra Nevada were disturbed roadsides, which occasionally get mowed. I wrote about monarchs and milkweed in more detail about a year ago.

Several milkweed species are adapted to colonize disturbed habitat. Some paleobotanists believe milkweed first expanded in to roadsides and ditches and eventually into crop rows. The great abundance of monarchs is likely a recent (last 200 years) result of European settlers clearing the land. In more natural habitat milkweed and monarch populations appeared to be stable. However on agricultural lands there was a boom and bust. Boomed as milkweed successfully colonized farmland followed by a bust as farmers eradicated it. Monarch populations followed suit

Reply to  Jim Steele
March 11, 2021 1:03 am

Could herds of millions of bison disturb a habitat ?

Reply to  Jim Steele
March 14, 2021 12:17 pm

Jim ==> Yes, I have been following the Monarch story for many years, and written about it here on occasion. I think there is an element of Chaotic Population Dynamics involved with the Monarchs overall — with the discovery of the Monarchs in Mexico in the 1970s catching them at a Boom period….

Reply to  Kip Hansen
March 12, 2021 10:19 am

Just my observations, tho perhaps milkweed numbers have declined, I still see plenty of patches in various disturbed areas in western MD — roadsides, borders between agricultural fields, forest edges, etc. I do see fewer milkweeds on my lot (and fewer goldenrods and asters) because of being crowded out/smothered by invasive grasses. What few are left, I dig some up and plant around the house where I can tend them — and they spread by roots.

Mike Dubrasich
March 10, 2021 7:24 pm

Monarch butterflies have four or more generations in one year. Most individual Monarch butterflies fly for only a few weeks and never migrate or hibernate. Those who do migrate may not always arrive at the same place previous generations landed.

Many myths abound about insects. For instance, honey bees do not communicate via dancing, despite what you may have been taught. What is true is that many insect populations increase and decrease in multi-year cycles. Weather may influence those cycles, but other factors are involved. You may be sure that an insect which ranges from the tropics to Canada is not affected by a 1° change in global average temperature.

Reply to  Mike Dubrasich
March 10, 2021 8:14 pm

Talking of myths, no species is an island.

Reply to  Loydo
March 10, 2021 9:05 pm

Talking of myths..

How about warming by atmospheric CO2.

Any evidence yet loy-dodo?

Reply to  Loydo
March 11, 2021 9:11 am

Talking of myths, there was the one about Loydo actually using a legitimate argument.

David A
Reply to  Loydo
March 12, 2021 3:45 am

Loydo strawman much? Show me where anyone asserted that.

March 10, 2021 7:25 pm

Here in Temple. TX where I have lived all of my 58 years I have seen a lot of land use changes. Farms and ranches and wild fields are now subdivisions. Also few homeowners plants flower and vegetable gardens like in the past. Also due to rising land prices lot sizes are smaller and houses are built closer together. Municipal codes also require fences to be 6 foot wooden ones rather than the 4 foot chain link fences that were once common place.
I can find milkweed on the more rural roads around Temple, but certainly won’t find any in any of these new subdivisions.
A few years ago I contacted a professor at Texas A&M University who studies Monarch butterflies. I commented on land use changes and asked if taller fences and closer structures impeded the migration of Monarch’s. He assured me that Monarch’s fly high enough for them not to be a factor.
What he did say was that large cities pose a barrier to Monarch’s. There is little food source and sometimes limited water for them and they often will fatigue and die before they can fly the long distance over cities.
He called cities, Green Deserts.

Mike Dubrasich
Reply to  Myron
March 10, 2021 11:11 pm

Land use changes over the last 58 years are significant, but not as significant as the changes over the last 500 years.

When examining environmental changes, people often look for “base line” conditions to compare to the present. Pre-Columbian conditions are best for that. Over the last 500 years so much has changed in land use, land stewardship, and the introduction of Old World species (aka the Columbian Exchange). Minor changes in “climate” are dwarfed by the major changes in a myriad of other factors. Conclusions drawn which ignore these major factors, 500 years worth, are weak and insufficient as a result.

Reply to  Myron
March 11, 2021 9:31 am

Indeed, Myron. Have seen this myself in SoCal. Vast acreage has been transformed into homes and tiny sterile patches of grass where once grew myriad species of plants.

David A
Reply to  Myron
March 12, 2021 3:47 am

One to add, millions of S California lawns have been removed for water savings.

Brian Jackson
March 10, 2021 7:33 pm

Mr Steele is numerically challenged.
He posts: ” In reality their analyses addressed just 290 species”
He then posts: “of which only 182 or 40% of the 450 species….”

And then he posts: ” Another 106 species were stable or increasing,….”

182 + 106 = 288 not 290.

Reply to  Brian Jackson
March 10, 2021 8:03 pm

Brian, indeed there was a mistake that I didnt catch until after I submitted the article. When sorting the data on XCEL an empty row caused some totals to be off by one. I apologize for my sloppiness

Nonetheless my mistake doesn’t change the paper’s extremely problematic issues. Its interesting that you are fine with the gross misrepresentation of 450 declining species, or the researchers’ unsupported claim that a little autumn warming is killing butterflies. Instead you try to insult me.

Makes me wonder in how many ways you might be “challenged”

Reply to  Brian Jackson
March 10, 2021 9:07 pm

Brianless one is a mathematical NON-ENTITY

Devoid of all rational or scientific thought processes.

These are only estimates.. brianless moron. !!

Reply to  Brian Jackson
March 10, 2021 10:09 pm

The fact that brianless whats to argue about a difference of 2 in a random collection of 450 species, is quite hilarious

…. and shows JUST HOW LITTLE he has to offer to any discussion.

Picking up on a very minor calculation error shows he has absolutely no other arguments about your comments about the LOUSY quality of this paper.

Last edited 1 month ago by fred250
March 10, 2021 7:52 pm

We can’t find any climate change, but we sure as heck can find the affects of climate change.

March 10, 2021 8:15 pm

Maybe it’s an exception, but in the upper midwest where I live, there is plenty of milkweed for the monarchs, in addition to other species they like, such as wild asters. They are NOT solely dependent on one species of plant. There are over 100 species of milkweed in North America alone, and this report shows a complete lack of information about that part, too.
I don’t see declines as much as changes from one year to the next: short on population numbers one year, extremely increased another, somewhere in between in another year. Also applies to the various swallowtails, admirals, checkerspots and fritillaries, as well as all those other species.
Focusing on one species is ridiculous, showing a vapid ignorance of that particular butterfly. Since there are three (3 – count ’em) species of monarchs, why is no one looking at the other two, but focusing ONLY on one species? That is nonsense. It’s apparent that the white ch and Jamaican monarch count for nothing in this spiel.
And since I have continuously photographed butterflies in the field for going on 18 years now, and have run into butterfly species that resemble the American monarch, e.g., the emperor, I find it necessary to ask why are the other species not being observed as well?

Reply to  Sara
March 10, 2021 10:18 pm

I wonder how much damage wind turdines to to butterflies.

I don’t suppose the leftists really care. !

Reply to  Sara
March 10, 2021 11:20 pm

Sara, the focus here on monarchs is in response to a recent study that got a lot of publicity and that the media discussed only one Danaus species, monarchs. The study did list another Danaus species the Queen, but it is not a monarch.

The criticized studies’ focus is not on just one species nor is my response. The monarch is simply one example of the declining species that the study implied was partly driven by warm autumns, while ignoring the really important factors of land use and chemicals

I am sure you see plenty of monarchs in the upper midwest as they migrate north each summer. Each generation increases the population 40 fold, with more southerly monarch having 4 generations and the most northerly having just one before returning mostly to Mexico. West of the Rockies they are less abundant.

The alarm about lost monarchs is based mostly on observed changes in the Mexican wintering populations. There, high concentrations make it easier to estimate abundance. In contrast studies in natural summer habitat do not notice any significant declines. There are major summer declines connected to agricultural changes. And again the point of this article is a simple refutation of Forister’s climate alarmism based on bad science which then the media is hyping.

monarch watch 2021.png
Reply to  Jim Steele
March 11, 2021 4:38 am

Forister’s climate alarmism is what I was referring to, NOT your article, Jim. The alarmism is ridiculous and smacks of desk jockeys who will look at one field of wildflowers, which they’d likely refer to as weeds, and draw a conclusion based on that, and we’ve seen that repeatedly. That the subject report doesn’t even refer to why milkweed, in all its various manifestations, is so important (egg-laying and baby food) to the monarchs says (to me) that they’re not interested in field work where they could define the increases and declines in population groups on a year-over-year basis.

Sorry I wasn’t more clear about this.
But I will repeat, if the monarchs, as a specific branch of Danaus are so important, then why weren’t THOSE people checking on those OTHER species, too? And why not address the decline in the luna moth population while they’re at it? That’s my oint.

I’ll try to be MUCH more clear next time. (Goes and sits in a corner.)

Reply to  Sara
March 11, 2021 4:39 am

“oint” meant “point”. Not enough caffeine….

Reply to  Sara
March 11, 2021 9:13 am

You’ve heard of spell check? I’m convinced that some computers come with a function that randomly misspells words just before you save the text.

Reply to  Sara
March 11, 2021 12:39 pm

Nah, Mark, that was just fat finger typing. 🙂

March 10, 2021 8:38 pm

Bad things happening because of “Climate change” = government funding.

March 10, 2021 9:49 pm

This article is about the “baby bust” – a sharp fall in birth rates caused by the current covid19 pandemic. But it also makes the point that climate doom-mongering about illusory future crises and extinctions is also depressing birth rates.

In the economic sphere climate catastrophism is thus achieving a degree of self-fulfilment by driving down birth rates.

But scaring people into stopping having children is no doubt intentional. Climate alarmism feeds on a bilious misanthropy.

Abolition Man
March 10, 2021 9:58 pm

Thanks, Jim!
I had been mostly planning to add hummingbird friendly plants to the garden this year, but your post reminds me that I need to provide for flutterbys as well! There is a lot of overlap but I’ll take a look at specific butterfly friendly plants, too.
I’m thinking of getting a second copy of your book to send to my little sister back in Commifornia! I want to try and talk her down off the alarmist ledge, and your and Michael Schellenberger’s books seem like the best place to start. Patrick Moore’s book, with it’s plug from President Trump, might not be productive unless I can wean her off regular TV viewing!

Doug Huffman
March 11, 2021 2:38 am

I expect milkweed to shortly be declared an invasive plant for the expanding patches. I have a big patch in my backyard, perhaps 100 plants, and most every late summer day I go up and practice seeing the caterpillars. I have no way to measure their breeding success.

Reply to  Doug Huffman
March 11, 2021 9:40 am

Doug, I sure would enjoy seeing your backyard. I would bring a chair with me to simply sit and watch.

March 11, 2021 3:13 am

swan bush is a favoured plant here in Aus and is a pretty garden addition easy to grow perennial. friend had a huge amount of the young aphidlike hatchlings earlier in the yr but extreme hot days knocked em rotten
however we do have a few caterpillars eating now;-)

March 11, 2021 4:04 am

The Guardian, for those who may be unaware, makes no real secret of its alarmist mission:

The Guardian has updated its ‘style’ guide to introduce terms that more accurately describe the environmental crises facing the world.

Instead of “climate change” the preferred terms are “climate emergency, crisis or breakdown” and “global heating” is favoured over “global warming”, although the original terms are not banned.

And my favourite…

“We want to ensure that we are being scientifically precise, while also communicating clearly with readers on this very important issue”

You can see why Griff buys into it.

Coeur de Lion
March 11, 2021 4:40 am

As regards the crisis’, surely USA is cooling, isn’t it? (recent notrickszone post).

Reply to  Coeur de Lion
March 11, 2021 6:56 am

This should not be a problem because Obama’s Climate Genius, John Holdren, said Global Warming brings Global Cooling — and the butterflies should be happy …

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