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  • Andy Davis

Food for thought: are eastern monarchs better off because the location of the winter sites is known?

Hello everyone,

Today I have a thought-provoking, hypothetical question to address, which you saw in the title of this post. It's a what-if scenario, obviously, but certainly worthy of a deep dive, which is what I'll do today. And as always, I'll bring in some science to the discussion, and be candid and brutally objective, as is my way.

Let's start from the beginning. We all know where the wintering destination is for monarchs east of the Rockies, but did you know that the man who "found" these sites never intended to let the world know of their location? That's right, Fred Urquhart, who spent decades organizing his citizen-science monarch tagging program, meticulously mapping flight paths, until they led him to Mexico, never actually wanted people to know the location of these mountaintop sites. After he and his team made the historic discovery in 1975, they "publicly" announced this discovery in a scientific paper published in 1976 in the Journal of the Lepidopterists' Society (link here), plus in the famous National Geographic issue, pictured above. But, in both cases, he purposely left out the details of where exactly the sites were. He described the events leading up to the discovery, plus some natural history observations, but there were no actual details about a location. He thought the monarchs would be better off if people didn't know where they were! Did he have a point here? An argument could certainly be made, but let's keep going.

We really know where the sites are now because of Lincoln Brower. He had been studying monarchs leading up to that point, and it was he and Dr. Bill Calvert, who did some sleuthing to figure out the exact locations. From what I understand, they basically just laid out a map of Mexico and pieced together the probable spots based on some key bits of information Fred had given, like the altitude, and the general region of Mexico that was mentioned in one of the articles. Then, they (Bill, really) tracked down the real sites. This then led to a famous confrontation at the wintering sites, where Lincoln meets up with Fred, who was there tagging monarchs. Lincoln recounts this story in one of his (very elaborate) papers describing the monarch migration (link here). The bit about the meeting begins on page 333.

As I understand it, Lincoln felt that the location of the sites needed to be known, not only for scientific reasons, but in order to establish protections for them. And this here, is the other side of this coin. Did Lincoln have a point? I guess this is the heart of the hypothetical question I'm posing today. Should the location have been kept secret, or was it better (for the monarchs!) that the location was made public.

Note that I specifically said "for the monarchs", as in, are the monarchs better off now that we know about the location? I realize that these winter colonies are of importance for the local communities in terms of ecotourism and their local economies, but that's a different issue. It's true that those people benefit from the tourism, but do the monarchs? That's the question.

OK, so the first thing you're probably thinking is, that knowing where the wintering colonies are did lead to them being protected, as Lincoln had wanted. Indeed, in 1986 the Mexican government established the monarch wintering colonies and the surrounding forests as officially "protected" habitat. I understand that Lincoln was a big part of this effort. Buuut...this actually did very little to keep the forests from being cut down within the protected area. In a study published in 2002 (link), Lincoln and a team of scientists examined aerial photographs of the forests within this protected area over 30 years and saw that the forests were still being degraded well after the decree. Since then, other scientific studies have come out that have examined the degree of forest cover being lost over time (i.e. trees being cut down), and it does not look like the habitat is being "protected", or at least, not as much as we'd like. However, the latest paper I saw (led by Omar Vidal - link) did describe a more recent decrease in logging activity in the protected forest. Keep in mind this paper was published in 2014, nearly 30 years after the protection went in place.

So, did making the location of the sites known really lead to their protection? Objectively speaking, the answer seems to be a vague...maybe.

Next up, let's talk about the scientific value of these sites. Here, there is no question that our knowledge of monarchs and their amazing migration would not be where it is today if we didn't know where they are going for the winter. And, there have literally been hundreds of scientific studies done on monarch wintering biology over the years (I checked). So, there is no doubt that scientifically, this has been a good thing. But, that's not the real question, which recall, was: are the monarchs better off? In this case, are they better off because of all of this scientific research? Did any of that research actually lead to better "care" of them during this stage of their life cycle? Or really, did all of this research just help us (humans) to understand this stage better? Remember, I'm being brutally objective here. One could argue that very little of this research has actually benefited the wintering monarchs themselves.

One could argue that because of the annual efforts to gauge the size of the winter colonies (which showed declines over time), there is now a heightened interest in the protection of monarchs at all stages of their lives, as in, up here in the U.S. and Canada. That's certainly a good thing, right? In fact, the long-term declines in winter colony size is what has led to the petition to have the monarch listed as an endangered species in the U.S., and, it is already being listed in provinces in Canada. Being listed as endangered should help them right? Well... as I blogged about recently, this is probably going overboard, and will probably lead to public confusion and unnecessary regulations (the monarch population isn't really declining in Canada). Either way, this part may be a little tangential to the original question anyway, which was more about the actual wintering sites.

Let's turn this argument around and think about what would have happened if Fred Urquhart had had it his way, if the location had been kept hidden. What would have happened to the monarchs at the wintering colonies? Well for one, there would certainly be no intrusions of thousands of tourists each year into the colonies (to be fair, I know the local officials do keep people from going too close to the monarchs). In terms of the forest, the effect of thousands of people (and horses) going up and down a trail can be quite damaging for sure, so for this reason alone, it may have been better (for the forest) to not have people traipsing through. So there's that. I guess the real question is, would there be just as much logging, if not more, within those forests if no one was there to monitor it? We'll never know the answer here.

There's another way to think about this issue, and again, from the perspective of the monarchs. We need to ask ourselves - what is it that the monarchs really "need" during their wintering cycle, other than trees to hang in? The trees not only provide hanging surfaces, but also they act as a "blanket" as Lincoln would always say, that keeps the temperature within the colonies just right for conserving energy. But that's only if the forest is intact. Regardless, we know for sure these trees are the biggest "need" of the monarchs. (Interesting side note here - the monarchs that winter in California appear to be able to use other types of trees than those at the Mexican overwintering sites). But from the perspective of the monarchs, one could argue that besides the trees, the only real thing they need is to be left alone to sleep! I guess this is where Fred's argument comes in.

I personally think that even if Fred wanted it kept secret, someone, perhaps another scientist, would have done the same thing Lincoln did. After all, it didn't sound like Lincoln had to work very hard to figure it out after reading the articles. And, scientists are naturally curious people! So no matter what, the outcome we have now was probably inevitable.

I'll end this by reiterating - I know that we humans - scientists, citizens, tourists, etc, all benefit in some way from knowing where the winter colonies are. But do the monarchs care about us? What's in it for them if a scientist studies their wintering behavior?

What do you think? Are the monarchs better off because we know where they go in the winter? Put your thinking cap on...

That's all for now.


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The science of monarch butterflies

A blog about monarchs, written by a monarch scientist, for people who love monarchs

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