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  • Andy Davis

I am officially challenging the IUCN listing of North American monarchs

UPDATE (Sept. 28, 2023) - The Standards and Petitions Committee of the IUCN issued their ruling on this petition, and, they decided to take North American monarchs out of their "Endangered" category. Based on their own analyses, they believed listing them as "Vulnerable" would be better suited. I still disagree, so stay tuned for more developments, I guess.

The full decision is online here -

The rest of this blog was written when I was in the middle of the petition process in early 2023, and it is still a good read to understand the issues and the nuts and bolts of my petition.


Hello blog readers,

Yes, you heard me right. I am making an official challenge to the 2022 decision to put the North American monarch on the IUCN redlist as an endangered species. I think this should never have happened, and, that there were some serious problems with the way this was done. If my challenge is "accepted" by the IUCN, it means that it is possible that the entire listing could change, possibly later this year. Today, I'm going to tell you all about this process, including my rationale for doing this (teaser - I'm not alone).

First, let's go back to the summer of 2022, when there was a whirlwind of opposing monarch-related stories. Longtime blog readers will recall that up until then I had been working with a team of entomologists to study the conservation status of the monarch breeding population, and early that summer, our team finally published the results of that work. It showed how the North American breeding population appears to be stable, based on long-term surveys of butterflies (see the blog here). The headlines thereafter read "Monarchs in North America are thriving!". Then one month later, another news story broke, about the publication of the decision by the "IUCN" to list monarchs in North America as endangered. Then the news stories changed to "Monarchs in North America are in grave danger!" Crazy right?

I put the IUCN in quotes above to highlight something that I don't think people appreciated. The IUCN in Switzerland didn't really make this decision - a small group of US-based monarch scientists did, who were led by Anna Walker, an insect conservationist based in New Mexico. This team, which included Karen Oberhauser, Emma Pelton, John Pleasants and Wayne Thogmartin, put together a document that made the case that the migratory subspecies of monarchs (Danaus plexippus plexippus) in North America should be listed as endangered, based on some criteria laid out by the IUCN. A person from the IUCN then looked at the document and approved it. I simplified this greatly, but my point is that the IUCN had little involvement, other than to state the rules for how to assess the species in question. The team of people I mentioned are the ones who spearheaded this effort.

The IUCN's "rules" for listing a species as endangered are that the species in question must be currently declining, and must have declined by at least 50%. There are a bunch of other criteria but that is the main one. If you read through the actual listing document (which is online, here), you can see that the researchers made the case that since the monarch winter colonies in the east and west had declined by this much or more since the 1990s, then this qualifies the North American population for the endangered status. Again, I simplified this. The actual document was a hefty read, and there were some statistics involved.

Here is the part that a lot of folks don't know - the IUCN also has some rules regarding challenges to their listings, and this is where I come in. They have a standing rule that states that any party can challenge an existing listing decision, at any time, and this process involves a series of steps and criteria, which is laid out on their website. First, the challenging party must hold 4 weeks of discussions with the listing party to attempt to resolve the issue. We have done this. Last fall, I met (via zoom) with the lead author, plus someone from the IUCN, for that 4 week period, and we ultimately failed to resolve the issue.

These zoom discussions actually culminated in one fateful zoom meeting in December, in which multiple other monarch scientists and experts were invited to participate. This ended up being a very diverse pool of people from three countries, and representing a wide range of expertise and backgrounds. I managed to get a screenshot during the meeting, below. We didn't advertise this to the public, or even record it! That's right, We had a secret meeting of top monarch scientists, and there is no recording. How many people here would have wished to be a fly on that wall, I wonder!

I recall this meeting lasted an entire afternoon. There was lots of arguing over whether the listing decision was sound. There were people arguing for and against. I was not the only one who was against this, in fact. In the end, the issue was not resolved still, so, we went to the next step, which is for the original challenging party (me) to submit a preliminary "petition" to the IUCN, which I did in January of this year. This petition outlined the main argument(s) for why the listing needs to be challenged. I'll come back to this. That document went to a special committee within the IUCN which specifically handles these, called the Standards and Petitions Committee. Anyway, my petition was examined, and accepted as valid this spring. That simply means they thought it had enough merit that they wanted to hear more. This then triggered the NEXT step, which was for me to submit another document that provided further justification for the petition. This document is now submitted. I know, this sounds exhausting.

Next, the original listing party (Walker's team) now has to submit a justification document for their original assessment, and this is where things stand now. Once all of these documents are submitted, they all go back to this petition committee, who will review them and then decide if the entire petition is justified, or should be thrown out. That should happen sometime this fall. I should mention that in my challenge, I have argued that the monarchs should not be considered "Endangered," but in fact listed as "Least Concern." So this means that it is possible that monarchs will come off the endangered species list completely later this year. That would be a huge deal.

Actually, if you go to the IUCN website right now, you can find a page where they list all of the past and current "petitions", and you can see the monarch petition is listed. So I guess this means that if anyone asks, it is most accurate to say the monarch IUCN listing is "currently being petitioned."

OK, so that's the nuts and bolts of how the IUCN petition works, now let me tell you what my petition argued.

First, I need to show you something, which is a graph of monarch abundance at the eastern and western winter colonies, combined. This graph is basically a copy of the same graph we've all seen ad nauseum from any news piece or article about the winter colonies, and, it is the same data that the Walker et al. team used in their assessment. Note that even though the western colonies have been added to this graph, keep in mind that they only represent a tiny fraction of the overall North American population. So that's why this graph looks a lot like the one we've all seen of the "eastern" cohort. In other words, the western colonies don't really add much to this graph. Notice also that I've added a line that denotes the last ten years of data. And see that if you just look at these latest numbers, and ignore all else, then you can see that the colonies are no longer getting smaller, but are basically more or less stable in size now. This is a very important point to consider going forward.

I pointed this out to you because if you read the actual IUCN instructions for listing a species as "endangered," they are quite clear that the population in question must be currently declining, as in, showing evidence of decline within the last ten years. They are quite explicit on this point. I know that the entire graph shows that the colonies were declining at one point, but, the IUCN wants these listings to be based on the current state of the population, not what has happened in the past. They are very, very clear on this. That's because these listings are supposed to represent a species' current risk of going extinct. This graph above shows that with the current trend at the winter colonies, the population is not currently heading toward extinction. If anything, the colonies are trending upward now.

This right here, is the basis of my petition. I have argued that the original listing authors did not follow the terms of the IUCN listing procedures, and, (according to the IUCN's own interpretation) that the migratory North American monarchs should be listed as "Least Concern." In other words, there is no concern now that the winter colonies are continuing to shrink. But, this is not what the Walker et al. assessment concluded. They used the entire winter colony dataset, going back to the 1990s, and they basically drew a straight line downward along the graph. In know that it sounds logical to do it that way, but, this is NOT what the IUCN wants assessors to do. Again, they are very, very clear on this. Actually it is a bit of a mystery how this assessment document got accepted in the first place, given this egregious error.

OK, so I mentioned earlier that I'm not alone in my objection to this listing, which is true. In fact, I'm not alone in my view that the listing was based on an incorrect analysis of the data. Two of the scientists who were at the December zoom meeting in fact felt so strongly that the data were improperly analyzed that they went right home and conducted their own statistical analysis of the data, and they used the proper IUCN procedures and statistics. Their effort showed just what I stated above, that if you just look at the last ten years of colony data, they do NOT show evidence of decline, and therefore the original assessment was incorrect. That's not all - these scientists actually submitted their findings as a manuscript to a scientific journal immediately after the December meeting, and their paper had already been peer-reviewed and accepted, and, it is now online at the journal! See for yourself - I'm putting a link here that will take you directly to it.

That's right, there is a scientific paper online right now (even before the petition process is complete) that argues that the monarch listing is not correct. I'm not sure if that will sway the committee or not, but it certainly helps the case. Actually, I really don't know how this will all fall out. I do know that the IUCN Petition committee is going to have its hands full with all of this. Especially once the media gets involved.

OK, so lastly, you might be wondering why am I doing all of this? If you think about it, this IUCN listing is really just a symbolic thing, because that group really has no official jurisdiction. And you might be asking, doesn't it help to have the monarchs listed as endangered, even if it is a bit of a white lie, because it gets lots and lots of people trying to help them? There are basically two reasons for my petition, below.

Firstly, it's the scientific principle of it. The winter colony data are very, very misleading when considered alone, but yet the assessing team only used these data to draw their conclusion that the entire population is near extinction. This is just not the case, and so the narrative that this listing created is not based on the actual science. That's a fancy way to say that it is a lie. The scientist in me just couldn't stand by watching this all happen.

Second, this "monarchs are in trouble" narrative is actually causing some significant harm to the population (tragically), and this is my attempt to tamp this down. Yes, it may have gotten some people to plant milkweed, which is an important host for other insects, but, this same narrative has also spurred people to plant lots of non-native milkweed in their yards, or to raise even more monarchs in their kitchens, in misguided efforts to "save the monarchs." If you've been following the science and this blog, then you know that both of these activities are really, really causing harm to the monarch migration, ironically. So basically, my other reason for doing this is to save the monarch migration, believe it or not! Having the monarchs be listed as "least concern" by the IUCN will signal to people that they will be better off if we leave them alone.

OK that's all for now. I'll certainly update this post as this all progresses.


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The science of monarch butterflies

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