Study of “genetic franken monarchs” provokes online ire and debate

A new study that suggests monarch butterflies fostered from the wild or cultivated by commercial breeders have trouble migrating and can exhibit unusual genetic traits hit the monarch butterfly community this week. The reaction has been intense.

“Boy, you gotta have thick skin to be part of this group!” said migration studies expert Andy Davis on the DPLEX, an email discussion group for about 800 monarch butterfly scientists, citizen scientists, hobbyists and others who follow monarch butterfly news and science. Davis edits the journal Animal Migration at the University of Georgia.

He was among the first and loudest voices to praise the paper on his MonarchScience blog. His June 24 post of 3,000+ words started with this scene setter: “Well folks, get ready…I’m about to blow your mind.”

Davis then unpacked the study, published in PNAS, detailing for the layperson how University of Chicago researchers studied commercially bred monarchs and those caught in the wild and fostered in a “common garden experience.” The research took place in July of 2016. The scientists reared offspring of both groups over two generations through the summer and autumn, then tested the creatures for their flight orientation skills, and later, examined their offspring’s genetic traits.

Monarch butterfly lays eggs at Shady Oak Butterfly Farm. Photo courtesy Edith Smith

The researchers were looking for displays of directional flight, a characteristic typical of migratory monarchs late in the season. Generally, in late summer and early fall, migrating monarchs orient themselves to fly south; nonmigratory monarchs do not display such behaviour. The PNAS paper showed that the commercially bred butterflies and also those caught in the wild and reared indoors in less natural conditions, often do NOT display directional flight behaviors.

Perhaps more disturbing, when the researchers examined the DNA of the commercially reared butterflies, they found that the commercially bred monarchs’ genomes beared little resemblance to those of wild monarchs. They exhibited different traits, “genetic franken-monarchs,” as Davis said.

The study’s lead author Ayse Tenger-Trolander did not dispute Davis’ description.

“It is a franken monarch genetically,” said the evolutionary biologist who led the study. “It’s distinct, and comes up as its own branch on the tree of monarch life,” she said.

Tenger-Trolander speculated that the aberration likely resulted NOT from inbreeding, but from repetitive breeding of creatures that have had no generational exposure to migration. “The monarchs have likely lost migratory traits simply because they and their ancestors (also bred in captivity) haven’t been exposed to migration in many, many generations,” said Tenger-Trolander. “Without that selective event, monarchs that would never have survived in nature are allowed to mate and produce offspring in captivity.”

Save the dates! October 12 – 22, 2019

However, Tenger-Trolander was careful to add that this study included a small sample from a single breeder. Future studies will likely include a more diverse mix of monarchs and breeders. The study also mentioned the many advantages of hobbyists fostering a few monarch butterflies. Rearing by summer hobbyists and schools groups, stated the paper, is a “net positive, especially in the link it creates between people and their natural environment.”

The paper also referenced the news that five butterflies tagged and released at our 2017 Monarch Butterfly and Pollinator Festival in San Antonio were recovered in Mexico in the spring of 2018. These butterflies were reared at Flutterby Gardens  butterfly farm in Florida, shipped to Texas, tagged and released at the San Antonio Festival, and recovered on the forest floor in the Mexican mountains. In 2019, three butterflies tagged and released at our 2018 Festival were recovered, for a total of eight commercially reared butterflies making it to Mexico. The 2019 Monarch Butterfly and Pollinator Festival is set for October 12 – 20 in San Antonio.

Conventional monarch butterfly science has held that butterflies raised in captivity without natural cues don’t have the Darwinian skill set to migrate.

Not surprisingly, the study provoked a heated online debate. As it moved through social and mainstream media, monarch butterfly fans challenged its claims, pushed back on its veracity and debated the very nature of scientific research. A post by Monarch Watch addressed the study and was shared on Facebook where it had more than 130 comments. Chip Taylor, founder of Monarch Watch, the citizen science tagging program at the University of Kansas at Lawrence, addressed the study’s claims.

“The system is resilient, complicated and still full of unexplained attributes–as well as unexplainable outcomes–e.g. indoor raised monarchs in Florida that were tagged and released in San Antonio with nine (not five as stated in the paper) recovered at the overwintering sites in Mexico,” wrote Taylor. “The article gives the impression that many of those who rear, tag and release get their stock from breeders. That’s not the case.”

When asked if she was surprised by the visceral reaction of the monarch community to the study, Tenger-Trolander, an evolutionary biologist at the University of Chicago, responded: “Yes, to a degree….I was hoping for a little more measured response.”

That said, Tenger-Trolander agreed that the study was imperfect and shared that she and colleagues are already strategizing on how to improve it.

One possibility is to replicate the experiment during monarch breeding and migration season along the migratory pathway, perhaps utilizing citizen scientists or universities in different locations. Training and uniformity of the experiment’s execution would be challenging, but doable. She added that any future study will likely focus on monarchs’ ability to see the sun and experience decreasing day length.

“But that’s the other question: is it one thing?” said Tenger-Trolander. “Is there some one environmental condition that’s kind of necessary and sufficient to cause migration…or is it a combination of everything? Like if you don’t get three of the five, you don’t do this behavior correctly, but if you get five out of five, you do.”

The president of the International Butterfly Breeders Association (IBBA) David Bohlken, called the study “extremely flawed.”

Bohlken and others were disappointed that the researchers refused to divulge the source of the butterflies. Tenger-Trolander, when pressed, said she didn’t want to thrown any one breeder “under the bus.”

“I can’t comment because I don’t know where the butterflies came from,” said Bohlken. When asked what best practices the IBBA recommends to its membership regarding how many generations of butterflies can be bred from an initial pair of “breeders,” as they’re known, before introducing new genetic material, Bohlken pleaded ignorance. “We preach hygiene to make sure monarchs are healthy…we do not get involved in genetics.”

Edith Smith, a commercial breeder at Shady Oak Butterfly Farm, one of the largest butterfly farms in the country, said she was most intrigued by the study’s claim that commercially bred monarchs have a separate set of genes, distinct from those in the wild.

Edith Smith at Shady Oak Butterfly Farm has mastered breeding the uncommon Blue Buckeye. Photo via Edith Smith, Shady Oak Butterfly Farm

Smith, who’s been breeding monarchs for decades and teaches classes to potential breeders at the Association for Butterflies, has experience in creating new strains of butterflies, such as her “Blue Buckeye.”

Years ago, whenever Smith noticed blue in the background of a Buckeye’s wings, she isolated the creature’s eggs for breeding. Over time, each generation of Junonia coenia produced a more pronounced iridescent blue in the background of the Buckeye’s wings.  Eventually, Buckeye butterflies emerged with the entire backdrop of their wings a metallic blue in place of the original brown coloration.

As for the controversial study, Tenger-Trolander sees the take-home as a call for more research. We simply don’t know enough about how monarchs develop into their migratory habits yet, she said. In the meantime, she offers this advice: “If you want to be careful and really want to help monarchs, just put them on your porch instead of your kitchen.”


TOP PHOTO: Monarch butterfly getting tested for directional flight. Photo courtesy Ayse Tenger-Trolander


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21 Responses

  1. Kris
    | Reply

    As noted in my previous comment, I was flummoxed by this paper and the woeful lack of scientific methodology. So I have been doing a bit of research on a possible motivation. I came across a great comment from Ricardo Ballardo on the website of the Phytophagy Lab at Cornell University. I am so intrigued by his question that I am quoting him in its entirety:

    “If the Monarch is added to the list of Endangered Wildlife as threatened what will that mean to the thousands of butterfly enthusiasts that ware currently raising the wild eggs to adults in their efforts to increase the population. If the monarch is listed will that make it a crime for these citizens to continue to raise and release these beautiful creatures? After all many of these enthusiasts have been working tirelessly for decades to help educate and increase the population and it seems that with a single stroke of a pen they could end up being in violation of the law and could be fined for trying to continue to help preserve these butterflies.”

    This is a very good question. And I do think this question actually meshes with concerns of some regarding the interference with natural selection. Still, one cannot address natural selection concerns with a seriously flawed study, even if the results agree with an agenda.

    I think we can all agree that Mankind has cut down forests for agriculture and housing, has used chemicals to prevent insects from eating our food supply, has released tachinid flies as beneficial insects to reduce the effects of crop-devastating caterpillars in the fields. Where we diverge is how to correct the damage to other species, or even should we. In my opinion – and clearly in many peoples’ opinion – the least we can do is create habitat – and yes, protected habitat – for the butterfly life cycle, especially as we saw their numbers dwindling perilously. Let’s prevent a species from becoming Endangered is our thinking, not react after the fact. Others also follow their conscience to a different conclusion: Scientists have the right answers and allowing a species’ numbers to dwindle in order to put that species on the Endangered list allows the scientists to be in charge of the solution.

    Each individual has the right to follow their own conscience. But no one has the right to put their finger on the scale, so to speak, in an attempt to influence an important decision. This is not about scientists vs hobbyists or vs commercial breeders. This is about everyone working together for the long-term health of these butterflies. And we can only be helpful to one another – and thus to the butterflies – by being honest with our methodology, observations and conclusions.

  2. Ruth Henriquez Lyon
    | Reply

    The study showing that hand rearing interferes with migration was definitely flawed, and I take it as preliminary. However, its faults do not negate the fact that there is another issue around hand rearing wild creatures in huge numbers, which is that you are interfering with natural selection, and in doing so you are increasing the potential for weakening genes that may be necessary for the health of the species as a whole.

    The Xerces Society came out against hand rearing monarchs before this latest study was even published: Xerces is a reputable organization dedicated to one thing: the health of invertebrate populations all over the planet.

    It is interesting to me how heated these discussions can become and I suspect that the most heat is generated by those who have a financial interest in or emotional attachment to hand rearing monarchs. Such motives can be problematic when trying to look at data with a neutral mindset, unless one is aware of their own bias and confronts it head on.

    And the notion of bias is key here: what would be the bias of scientists who are suggesting we step back from hand-rearing monarchs? Are they secretly trying to decrease the monarch population? Stop us from having fun with our monarch farms? I don’t think so. I think their bias is more about the established fact that when humans start tinkering with natural systems, they have a strong tendency to screw them up. This is a case where good intentions may be paving a road to a very bad place.

  3. Kris
    | Reply

    Another thought in addition to my previous post below:

    One of the main tenets of scientific thought is that every study is replicable. The original research was done in July 2016. The researchers could have repeated the study in July 2017 and 2018 with butterflies from different commercial breeders to see if the results were the same – or different. Also, when they discovered that caterpillars fostered to adulthood in indoor incubators lacked the ability to migrate, the researchers had ample time to replicate actual practices of summertime hobbyists. Why didn’t they?

    Instead of replicating the study with the appropriate changes – or handing it off to someone who could access funding – they chose to publish their findings as a “conclusion”. Why? Why not publish it an as interesting study in progress with the goal of inspiring further research?

    Ironically, the timing of the publication was during the best migratory season in 12 years. Even the butterflies themselves refuted this study. And in reality, theirs is the most important opinion of all.

  4. Kris
    | Reply

    The lack of scientific reasoning and methodology of the paper appalls me. My college-level statistics professor would be gleefully using this “study” as an example of what not to do. Where to even begin??

    First, the abstract should state upfront the sample size and further that this small sample was from only one breeder. This boggles the scientific mind. It is an interesting outcome, but the publication is way premature.

    A few thoughts: Some butterfly populations naturally became non-migratory after generations of not needing to migrate. Can butterfly mills change the genetics? Is it the same as it occurs in the wild? Or is it because the goal of these farms is to ship the tiny animals long distances. Farms need hardy stock, not stock that can navigate on their own. Do they inadvertently filter out an important genetic material? Also, what effect does flying the butterflies around the country have on their navigational system? If the researchers are studying butterflies that have been artificially removed from their habitat by hundreds or thousands of miles, is that a factor that should be studied? The wild monarchs in the study were from the local area, which meant that they didn’t have the same transporting experience as the commercially-raised butterflies. While I am not a big fan of commercial breeders, I am a fan of scientific methodology.

    Next, the study of fostering caterpillars. The researchers conclude, and I quote from their abstract “Here, we show that captive breeding, both commercially and by summertime hobbyists, causes migratory behavior to be lost.” In his blog, Andy Davis details the methodology for this conclusion: wild monarchs were raised inside, in incubators – and then failed to orient. This was in comparison to wild monarchs that were raised outside in protected insectiaries. Yep, like backyard hobbyists have artificial incubators. The researchers even observe that bringing pupae from the outdoor cages into the indoor incubator for finishing disrupted their orienting ability. Yes, researchers, something is wrong – and it is your methodology! You cannot accurately conclude that summertime hobbyists are contributing to the loss of migratory behavior. I would be laughing hysterically at their idiocy, if it weren’t published in PNAS, which many people hold in high regard. Newsflash: Caterpillars are fostered in homes with windows, or outside on the porch.

    But perhaps in this experiment you did actually imitate how commercial breeders raise butterflies. You took wild monarchs, raised the offspring in incubators – and they failed to orient. After multiple generations, perhaps their offspring will not orient either, even if raised outdoors in insectiaries. Hmm.

    Funny story: I started fostering monarch caterpillars/butterflies here in Southern California. The tachinid flies are horrible. So I raised the caterpillars indoors and then released the butterflies from the front porch in the spring – and off they flew. Well, I noticed they would always fly towards the road, and, being a nervous Nellie, I decided to release them from the back yard, and then from the side yard. Always flew towards the road. What direction was the road? I thought about it. Yup. North. This past January I released several butterflies during a nice warm stretch. Flew south. Hmm. Go figure. It didn’t seem to matter if I raised them indoors or on my porch. Or some of each, when the weather was awfully cold out there. They did always experience day and night, even inside, with natural daylight through the window. So that might be a clue.

    Well, that’s my “measured” response! I can certainly understand a “visceral” response: when something is clearly ridiculous we feel it. I’m still shaking my head. I have seen clearer, unbiased, scientific thought from high schoolers. My esteem for PNAS has plummeted, honestly.

    • Rob Wood
      | Reply

      In response to the question Kris quoted by Ricardo Ballardo (“If the Monarch is added to the list of Endangered Wildlife as threatened what will that mean to the thousands of butterfly enthusiasts that ware currently raising the wild eggs to adults in their efforts to increase the population…”)

      The petition to the U.S. Fish and Wildlife Service to list the monarch butterfly as threatened under the ESA contains a provision to allow a small number (less than 10 per year) to be taken by individuals and/or households with certain restrictions:

      (3) Paragraph (b)(1) will not apply to individuals engaged in scientific research on monarchs and/or their habitat that:
      (i) is beneficial to the conservation of the species or aimed at understanding monarch biology in ways that could benefit future monarch conservation;
      (ii) does not entail collection of the species for commercial display or commercial breeding;

      (4) Paragraph (b)(1) will not apply to individuals engaged in citizen monitoring designed to
      conserve monarchs or scientific research designed to conserve the species or better understand
      monarch biology that:
      (i) is overseen by a scientist, conservation organization, or other entity dedicated to the conservation of the species;
      (ii) does not require capture of members of the species for commercial display or commercial breeding;

      (5) Paragraph (b)(1) will not apply to conservation education activities that enhance the survival or propagation of the species, including but not limited to:
      (i) the rearing of monarchs in school classrooms provided that the monarchs are not provided by commercial suppliers;
      (ii) the rearing of monarchs at nature centers or other facilities designed to educate the public about the ecological role and conservation needs of the species provided that the monarchs are not provided by commercial suppliers;

      (6) Paragraph (b)(1) will not apply to the collection of wild members of the species and rearing of fewer than ten monarchs per year by any individual, household, or educational entity.

      Read the petition here:

      • Kris
        | Reply

        Thank you for the information, Rob, and for the link. If this petition is approved, I will not be able to contribute to the extent I have been, which is around 30-50 butterflies per year. I’m sure many hobbyists are in the same boat.
        By the way, I must correct my mistake with Ricardo’s last name; should be Bacallao. My apologies, Ricardo!
        Well, I hope the petition is not approved. Better if we all work together for a worthy cause.

        • Rob Wood
          | Reply

          Kris, but wouldn’t (4)(i) enable you to continue as you have been (raising 30-50 butterflies per year?)
          (i) is overseen by a scientist, conservation organization, or other entity dedicated to the conservation of the species;

          • Kris

            No, not overseen by a scientist, organization, entity, etc.

            I was at the Nursery today and it is fun to chat with others also buying milkweed. People buy it for their own gardens, some foster the caterpillars for the same reason I ended up fostering – the tachinid flies. But no, we are not overseen by anyone. Nor do I actually want to be. Too independent-minded, I suppose. 🙂

  5. Ann M Corrigan
    | Reply

    I will continue to raise Monarchs until it is proven to be detrimental to them.

  6. Craig Oveson
    | Reply

    Andy Davis and his wife Sonia Altizer were taught most everything they know about monarchs by Dr. Karen Oberhauser and she founded Monarch Joint Venture. On the 26th of June she gave her views about what We all do in response to the monarch fairy tale written about above. That is, we collect eggs and or caterpillars in the wild and raise them indoors during the migration to protect them from predators. I would assume she also meant wild catching a monarch and raising her eggs laid on milkweed in a hatchery indoors. She said. “The genetic aspects of the study were interesting and important, but the conclusion about risks of single-generation raising of wild-collected eggs and larvae has much less validity. In my opinion, what people are doing when they rear monarchs in this way has incredible educational, inspirational, and scientific importance. As Ilse Gebhart pointed out, we would not know what we know about monarch parasitoids without the citizen scientists who rear monarchs they collect as eggs and larvae. I would encourage everyone who does rear monarchs to report their findings to the Monarch Larva Monitoring Project (; look for Activity 3 in the monitoring section).” Please Plant pollinator gardens with a supplemental water source available to protect monarch and pollinator habitat during catastrophic drought conditions and collect eggs and caterpillars and bring them indoors to protect them from predators until in flight. If you’re a good catcher net a monarch you see laying eggs on your milkweed, bring her in and let her safely lay her eggs on a bouquet of rinsed milkweed stems in a vaselike container in a large netted popup hatchery, add fresh rinsed stems as needed, they ill firm a chrysalis on top thehatchery when they are ready and they will reach flight stage in about 10 days only to be released into nature to breed and add monarchs to the population and migration that would never have made it without your help. You can make a difference 🤠🤔😎

  7. Ricardo Bacallao
    | Reply

    I read the article and found it in my opinion to be a very self-serving study once again coming out of the academic community with conclusions based on a sample that is so small that it barely reaches the scale when you consider that the monarch population is in the millions. So I could publish a study with as much validity based on the over 500 reared monarchs that ware tagged and released and have had some found in the overwintering grounds and from that I can conclude that their study is just not worth the ink it took to publish it. Now I take the hundreds of thousands “hobbyists” who do the same and as a community have reared and released over a million butterflies and in the fall those are tagged and thousands have been found in the overwintering sites. But oh we don’t get paid to produce a study, there isn’t any monetary reward for us nor future grants or fancy papers for us. We first and foremost insist that people produce gardens filled with native milkweeds and native nectar plants at the very least. We promote educating each other and the communities around the world to helping by growing plants and the academia have the gall to slam us for being concerned and proactive citizens and conservationist. I say if you want to make a true study perhaps you better get in the field and do some raising for yourselves without any grant money like we the monarch hobbyists are doing.

  8. Craig Oveson
    | Reply

    As the articles all say, Monarchs raised over multiple generations indoors were sent to San Antonio by airplane from Florida by a commercial breeder tagged and released in October at least 2 years in a row. A substantial percentage were found in the overwintering sanctuaries in Mexico when compared to monarchs caught and tagged during the migration. Chip Taylor who founded the current tagging program over Twenty five years ago and analyses the data recently said 33.5 % of tagged monarchs found on dead monarchs at the overwintering sites in Mexico were captive reared. This proves Captive reared monarchs protected from predators indoors increases the monarch population and migration by making it to Mexico to overwinter because it is a proven fact most of them would not have survived their early stages of development in the wild. The above facts prove this. Karen Oberhauser former lead at .Monarch Joint Venture hailed this monarch fairy tale as a great study and it proved a lot of negatives about captive reared monarchs when on the contrary there is a lot of evidence captive reared monarchs are healthy and migrate to Mexico. She is the person who taught some of the people quoted in a number of these media articles including Sonia Altizer Andy Davis’s wife who now operate a monarch parasite lab at the University of Georgia. Andy Davis or no one else has anything to prove any negative effects on the monarch population by predator protected captive rearing and they themselves have admitted it by using pharses such as “we think” or “it could be”. In every publication I have ever read by any of them. These are lawyer reviewed articles riddled with disclaimers to avoid liability in case of lawsuits challenging their incomplete studies and incomplete research and uneducated “opinions. ” This was nothing more than another bogus study already proven to be false before anyone published any stories about it designed to influence uneducated new enthusiasts. Monarch butterfly enthusiasts who captive rear monarchs to protect them from predators in the wild are encouraged by monarch experts who are administrators and monitors of the hundreds of monarch enthusiasts Facebook groups and encourage new members who have been introduced to the plight of monarchs and pollinators in general to plant pollinator plants. The individuals mentioning negative unproven opinions disguised as studies in these articles in relation to predator protected rearing monarchs indoors and their supporters should be ignored. These individuals negatively affect the national movement by pollinator enthusiasts planting gardens and protected rearing butterflies. They add nothing of value to our positive pursuits by 100s of thousands of Americans using their time and their own hard earned money to improve our environment.

  9. Paul Cherubini
    | Reply

    20 years ago, the West’s largest commercial monarch breeder near Sacramento, Calif.
    inbred 6 generations of wild caught fall monarchs during the spring and summer. They were reared on tropical (currassavica) milkweed in air conditioned trailers that held a steady temperature of about 78 degrees. The trailers had windows so the caterpillars received natural lighting.

    After 6 generations of inbreeding and indoor captive rearing, a total of 5,343 of them were fedex’d for release to 4 locations in the Rocky Mountain states and 1 location in central California (Placerville) between mid-Sept and early Oct. Seven of the Rocky Mountain State released butterflies were resighted at overwintering sites in central Mexico and 4 were resighted at or near overwintering sites along the California coast. 20 of the Placerville, Calif. group were resighted alive along the Calif. coast nearly all while clustering at overwintering sites.

    These results showed neither 6 generations of inbreeding and captive rearing indoors, nor rearing on a non-native tropical milkweed caused fall migrants to lose their southward migration capability or the ability to locate overwintering sites. Map showing tag recovery results:

  10. Barbara Potter
    | Reply

    We can thank any or all of the consequences of hand rearing Monarchs to Monsanto. Think about it before you buy ANYTHING they manufacture

  11. Rob Wood
    | Reply

    Contemporary loss of migration: A flawed paper. Editorial by Rob Wood, Citizen Scientist

    Regarding the paper, “Contemporary loss of migration in monarch butterflies,” edited by Nancy A. Moran, University of Texas at Austin, Austin, TX, and approved April 17, 2019 (received for review March 21, 2019):

    I’ve had some to study it, and have found what I believe to be such serious flaws in the methodology, sample sizes, logic and background information that I question the value of the conclusions reached by the authors.

    1) False/misleading statement. “Here, we show that captive breeding, both commercially and by summertime hobbyists, causes migratory behavior to be lost.” The paper may show that under some circumstances – namely, the rearing practices of one, unnamed commercial breeder – it is possible to breed out the ability of monarchs to orient south, thus impairing their ability to migrate in the fall. It never tests or shows any data regarding captive breeding by “summertime hobbyists.” In another part of the paper, it admits to using a sample size that is too small to draw statistical data from, and it also admits that “…we assessed only one commercially bred lineage, and there is evidence that other commercially bred monarchs do migrate.”

    2) Conclusion not supported by evidence. “Furthermore, rearing wild-caught monarchs in an indoor environment mimicking natural migration-inducing conditions failed to elicit southward flight orientation.” The researchers failed to accurately mimic natural, migration-inducing conditions. Not only did the artificial lighting remain on/off for a set number of hours, there is no mention of variability in intensity or angle, and no mention of the Kelvin temperature. Was it full-spectrum lighting? Daylight color temperature at noon is 5600K, but sunlight color temperature can vary widely based on time of day and weather conditions. Since the researchers neglected to vary the intensity and color temperature of the lighting, the test results are inconclusive (to put it kindly). In addition, the ambient temperature in the chamber was constant (18 °C with a 14-h day) and (25 °C with a 16-h day). How could “summertime hobbyists” so rigidly maintain breeding conditions of that consistency, and even more importantly, why would they even try?

    3) False/misleading/sweeping generalization. “In fact, merely eclosing indoors after an otherwise complete lifecycle outdoors was enough to disrupt southern orientation.” This statement equates the conditions in a rigidly controlled “environmental chamber” with “indoors.” Since “indoors” is also coupled by the authors with “summertime hobbyists,” in order for this statement to be true, all “summertime hobbyists” must therefore breed monarch butterflies in “environmental chambers” with rigidly controlled lighting and ambient temperatures. The authors did not claim to have identified even one “summertime hobbyist” who breeds monarchs in this fashion.

    4) Background statement contrary to scientific evidence. “Over the past hundreds or thousands of years, NA monarchs dispersed out of North America at least three times, once south into Central and South America and the Caribbean, once west across the Pacific Islands and into Australia, and once east into southern Europe and North Africa. Each of these dispersal events produced populations that reproduce year-round and do not migrate.” As has been pointed out by Dr. David G. James, Associate Professor of Entomology and Director of WSU Monarch-tagging program, Department of Entomology, Washington State University who researched this subject extensively in the 1980s, Southern Australia and New Zealand populations migrate in the fall, and overwinter “exactly in the manner of Western USA populations.”

    5) Contradictory statement. “Recently, 720 monarchs that were raised by a different commercial breeder were tagged and released in San Antonio, TX, of which five were recovered at overwintering sites in Mexico. We do not know if different husbandry practices affect whether a captive population is likely to lose migration behavior or if some proportion of all commercial monarchs have the potential to orient and migrate successfully.” If this statement is true, then this statement, if it’s referring to all commercial breeders, is false: “…however, as a group, these commercial monarchs are not directional.”

    6) Conclusion not supported by evidence. “Commercial-lineage monarchs do not orient south but enter reproductive arrest.” The tests upon which the study depended only showed that some monarch butterflies did not orient south while attached to a flight simulator. Since the test subjects were euthanized after the experiments, there is no way to reliably discount the possibility that the monarchs, had they been released into a natural environment, might have ultimately oriented south.

    7) Undefined terms used to support conclusions. What is a “summertime hobbyist?” The paper seems to use this term interchangeably when referring both to (presumably) amateur captive breeders (“…captive breeding, both commercially and by summertime hobbyists”), and when referring to people who raise monarchs in their homes (“Summertime hobbyists raise monarchs in their homes throughout the summer and autumn and then release them…”) I suggest that “summertime hobbyist” is actually a pejorative term used by the authors to denigrate the very large (and growing) international community of citizen scientists who approach the business of captive raising/rearing (not breeding) very seriously. Amateur captive raisers (as opposed to professional breeders) have contributed, and continue to contribute, important data to the scientific monarch community. A fantastic example is the 17-year joint University of Minnesota/MLMP tachinid study, published in July of 2017, that relied entirely on citizen scientists to collect tachinid larvae from their own parasitized caterpillars, properly label them, allow the maggots to pupate and eclose, freeze the samples, and send them to the university’s lab for identification.

    Rob Wood, San Marcos, California

    • Rachel Larsen
      | Reply

      Ron thank you for coming to the defense of “summer captive breeders”. I live in Southern California and we have an over wintering static colony here. We are overrun with tach fly and Black Death and that brown football shaped parasite that deforms wings and causes the butterflies to be weak and not emerge from the chrysalis. The only defense is bringing the eggs in side and to also rinse everything in a bleach/water solution. I use tropical and native milkweed in my yard as an attractor and laying site. As well as a food source. I think the use of tropical milkweed has lessened the monarchs poisonous defense. It harbors the diseases on it better and the active nasty taste isn’t as prevalent in tropical milkweed, maybe?? I’m finding that when I release a healthy adult butterfly, it gets immediately attacked by a diseased male butterfly with the brown spores and therefore it’s offspring become diseased too. Hence why I put my hatched monarchs on nondescript plants when the are strong. And why I have started the disinfecting portion of egg and food retrieval. Also it helps to talk to plant nursery owners that you won’t accept plants treated with pesticides. They listen. We “backyard scientists” are smarter than most think. Also…all this “evidence” is based off of one report, just like that one “scientist” said autism is caused by vaccinations…. one Report…how is that a complete scientific report? Please explain the measles outbreaks since then sir? He fabricated it and now millions of keyboard jockeys think they are right to not vaccinate. Well now kids are dying for no reason bc of one false report. Again thank you for standing up for us.

      • Kris
        | Reply

        I certainly agree, Rachel. Us summer breeders who protect the species from predators, especially the tach fly, contribute greatly to the cause.

        And I have the same concerns as you regarding the tropical milkweed. I too have experienced diseased milkweed. I decided to rid my yard of all the red/orange-flowered tropical milkweed, as that seems to be the biggest disease-magnet. I now have only the yellow-flowered “Silky Gold”, in addition to narrow-leafed milkweed. Much, much better. Please shovel-prune your disease-magnets!

        And yes, you are spot on regarding varying levels of “poison”, depending on the milkweed. I have been reading about that very topic recently. There are many varieties of milkweed, with varying levels of the toxin, which allows the cats to fight off the maggots. I am hoping the researchers will figure out which milkweed is best.

        In the meantime, I am finding the best practice for fostering cats is to purchase a healthy milkweed, with no pesticides, from a trusted Nursery. (One Nursery I called used “organic” pesticide on all incoming plants, from tomato plants to milkweed. I tried to explain that the pesticide that kills tomato worm will also kill the butterfly caterpillars. Not sure he cared.)
        I thoroughly and gently wash off the plant, first setting aside any caterpillars that may be on it already. I use just plain water, which washes off any disease spores and any fly eggs, aphids, etc. This process does not dislodge monarch eggs. I then give the plant a nice drink of worm castings diluted in water. The plant is ready to be set outside for the female butterflies to lay her eggs on. I leave it outside for a few days, then put the entire plant in a protective enclosure designed to keep the flies out. This is either on the front porch or in a sunny bay window. The plant is still alive and needs sunlight, as do the caterpillars. I continue to water the plant; I also mist it every morning to mimic condensation that is formed on the outdoor plants. It doesn’t take long for the eggs to hatch. The caterpillars don’t like a direct water spray, so I am mindful of their locations during misting. The frass falls to the bottom of the enclosure, which collects in a tray and is used to fertilize my outside plants. As the cats get bigger, and eat more, I need to buy another plant. I don’t set it outside, simply transfer the cats to it. Eventually the cats travel to the top of the enclosure from the plant and form their chrysalid.
        I have a very good success rate with this methodology, pretty much 100%. Not so much with cats rescued from outside. I have observed the dreaded tach flies around the outdoor milkweed; they are the worst predator.

        Thank you to all the summertime hobbyists for your help and volunteerism!! I do also thank the scientists for their contributions as well. Figuring out which milkweed is best, as well as studying the predators such as the tach fly, helps us hobbyists help the butterflies.

  12. Craig Oveson
    | Reply

    Chip Taylor also said in his response To this butterfly tale 33.5% of tagged monarchs found dead on the sanctuaries floor were “captive reared”. Of course we have no idea how many captive reared monarchs return to the U S in the spring.

    The above story says and I quote, “The PNAS paper showed that the commercially bred butterflies and also those caught in the wild and reared indoors in less natural conditions, often do NOT display directional flight behaviors”. . Of course there is a “Disclaimer” word in this sentence. One word is “often”. How much is often ? One out of four times a monarch could fly North, South, East or West. How big was the study ? Maybe it flew east or west Then turned south or north and then in a few hours turned south. How about the ones caught in the wild, tagged, and released, did they all fly south when released. So because they congregate on a certain side of an enclosure oroves something

    A simple question in It’s own column on the form filled out when tagging monarchs; “Which way did the monarch fly when released until it was out of sight ?

    An analysis will prove monrchs fly in all directions after being tagged and released. Anyone who has ever tagged and released many monarchs knows this. It doesn’t mean they don’t start heading south at some point. Did the researchers release some and chase them for a few dozen miles and/or days. I didn’t think so. Maybe it takes a day or two or a few miles to have their directional compass kick in. Is that covered in the study ? Where’s the study ? Oh they want you to buy the study. If it’s going to be so controversial why not share it FREE ? Oh, I see, you folks do this for money and controversy sells better. Once a small enough GPS sending unit is developed that amonarch can fly with it attached we can get more statistics about this behavior. From what I have read that’s been put out about the study there’s no reliable proven evidence there’s anything in this report worth putting out to the public for consumption. As we all know there are always people who want to waste other peoples time with noncontroveshal controversy. Just because it is written doesn’t mean it deserves credibility.

  13. Ruth Henriquez Lyon
    | Reply

    I will certainly look for and read the follow-up studies. But for now, I’m stepping back from rearing caterpillars indoors. Even before the study came out, the Xerces Society recommended against hand raising cats. If you think about it, it makes sense. By raising cats indoors, you’re interfering with natural selection, the long-term results of which none of us can know.

    The recent history of our relationship with the natural world is one of humans causing problems, then taking actions to try to solve those problems, then realizing that the actions taken to solve the first set of problems cause yet other problems, thus necessitating more actions, and so on, ad infinitum. Maybe in this case the best thing to do is build habitat and encourage others to do the same, then step back and let Nature handle things on her own, without interference by well-meaning but clueless humans.

    • Rachel
      | Reply

      Then zoos doing captive rearing and breeding are also in trouble yeah? Those rhinos and their horns on the black market for Asian humans who need it for penis enlargement are just a product of natural selection?? It’s people who are misinformed about things like this that are doing the most damage. Ewe spiders are gross so I will spray my yard to get rid of them. Oh wait where are the butterflies?? I mowed down all their food sources so my yard looks nice and I don’t have a few spiders…. we are the problem. Not natural selection. Let’s keep killing everything with our hands and our poisons….🙄

  14. Kylee Baumle
    | Reply

    “But that’s the other question: is it one thing?” said Tenger-Trolander. “Is there some one environmental condition that’s kind of necessary and sufficient to cause migration…or is it a combination of everything? Like if you don’t get three of the five, you don’t do this behavior correctly, but if you get five out of five, you do.”

    I asked a similar question some time ago in the Dplex group. It’s been my understanding that it isn’t just one thing. But I also wonder the same thing as Tenger-Trolander: how many of the cues are necessary to trigger migration? Knowing how nature often has “safeguards” in place, I’m inclined to think that all of them aren’t necessary, but perhaps a majority of them are. But what ones? What’s the minimal or “magical” combination, if you will?

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