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  • Andy Davis

No, you didn't used to see more monarchs years ago

Hi blog readers,

For the thousandth time, I just encountered someone who told me this, or some version of this statement - "There used to be more monarchs, I remember seeing lots of them". I bet lots of people reading this even have this thought too. It is always an interesting conversation when this happens because when I hear this, I then politely tell people what the actual data on monarch abundance shows (they are not declining), and then they tell me the data must be wrong. Well folks, I'm here to tell you that your memories are wrong! That's right, and, I'm even going to tell you about some crazy science that proves it (hint, it involves Bugs Bunny!). So strap in....

Before going further, let's quickly recap what the science shows on monarch abundance in North America. Yes, I know there are declines at the wintering colonies, though analyses of actual counts of monarchs during the summer show no long-term declines over 30 years. The size of the monarch breeding range is currently the largest of any butterfly species in North America now too. And, even analysis of monarch DNA has recently shown how the population size now is not smaller than it was in the past, in fact if anything it is larger.

With all of this in mind then, how is it that a person can "remember" seeing more monarchs years ago? Based on the actual numbers, there clearly weren't more monarchs back then. So what gives? There really are two different answers to this, and people aren't going to like hearing either of them, because both involve admitting that their memories are wrong. That's a tough pill to swallow for some people. I'm not sure why this is (I have a hard time remembering what I ate for breakfast), but, people tend to get insulted by it for some reason.

The first answer is probably the simplest too. Those memories you had of "dozens of monarchs" in your yard, or field, or whatever, were probably from a time when the monarchs were migrating through that region in the fall. Lots of people have witnessed these "big days" as have I, many times. They are indeed quite memorable, since there are monarchs flying all around, whizzing by your face, etc. But somehow people believe that these big accumulations represent the size of the breeding numbers in that time. The thing is, monarchs NEVER have numbers like this in the summer, that is not their biology. Monarch males are territorial even, and will chase away others. So in any given day in the summer, you would be likely to only have one or 2 monarchs in your yard at any given time. And, actual counts of adult monarchs in the summer by trained professionals bear this out - they usually only count 1 or 2 monarchs per hour at sites in the summer. So based on their basic biology alone, it is unlikely that you remember there being "more" monarchs in the summertime.

OK, the second answer is going to sound weird at first - your memories could be tricking you. Or another way to put this is, that your memories could be fake! That's right. Believe it or not, there is a whole slew of actual scientific research on this too, i.e. on how "unreliable" people's memories are. You sometimes hear about this research in court cases. After hearing from many, many people over the years, where they tell me about their memories of monarchs, I started casually looking into this research more and more. And, the more I dig into it, the more I question all of these "memories" of more monarchs years ago.

It turns out that human memories are somewhat "flexible" or "malleable", which means they can be changed or modified subconsciously, like without you even knowing. And importantly, it looks like memories can even be implanted, so that the person really believes they remember something that didn't happen! There is actual research on this in the world of human psychology, and I've read it. In fact, I'll tell you about one very, very intwesting stowy about a wascally wabbit.

There was a study of human psychology done about 20 years ago by a group from Washington state, who were investigating the reliability of human memories. This study became rather famous, and you can easily find news stories online about this study too. In it, the researchers had "interviewed" 120 different people in a room (separately), and had told people this was for an advertising campaign for Disney World. Each of the subjects had been to Disney at some point in their life. Here the neat part - for some of the interviews, the researchers had casually placed a cardboard cutout of bugs bunny on the wall in the background, and for other interviews they had nothing. There was more to it but I'm simplifying. Then, during the interviews they asked the people if they remembered seeing Bugs Bunny at Disney World when they were younger. Keep in mind that Bugs is not a Disney character and this would not be true. About 30% of people who were in the "Bugs Bunny room" responded yes! Then when pressed for details on this, those people "remembered" shaking his hand, seeing him eat a carrot, and other details that simply were fake, but yet those people clearly remembered them. I'm putting a link to a youtube interview (the trailer, anyway) with the lead author next.

So basically, these researchers had shown that people's memories can be "implanted", especially if they see something that can trigger it. They had subtly exposed those interviewees to a picture of Bugs, which then created a false memory of meeting him. But to the people in the room, those memories seemed real! And, I bet if the researchers told them they weren't, the people probably got insulted too!

OK, let's get back to the monarchs. Lots of people seem to "believe" that there used to be more monarchs years ago, because they "remember" seeing them. But lately I've been wondering if these "memories" are real, or, are they "implanted" like in the Bugs Bunny study. I think it's the latter, and here is why - because many people have been exposed to a "Bugs Bunny-like", memory-altering trigger for years, which is the graph of "monarch abundance" from the Mexican (or Californian) wintering colonies, which I've pasted below.

This is a graph that has been reproduced and shown in news stories every year, and the stories are always the same - the monarchs are in trouble. How many times have we all seen this? Keep in mind that the graph is not wrong, mind you, since those counts in Mexico are real, but this graph is not at all representative of how many monarchs there are in the U.S. and Canada, despite what people think. And that's just it, people think it does represent their own "experiences" from their childhood. I think this graph is doing something similar to what Bugs Bunny did in the study - people look at this graph and it seems to create "memories" of seeing more monarchs when they were younger.

Or, maybe both answers here are correct - maybe people really do remember seeing dozens of monarchs on one glorious day when they were younger, but, that day was during the fall migration. And, then upon seeing this graph, those memories get modified and people then believe that there used to be dozens of monarchs in any given spot each day in the summer.

If you are one of these people, and you are still unconvinced, maybe try this - think back to that day you keep remembering of seeing "lots of monarchs" - can you really recall what the actual date was, like what time of year it was? Maybe also consider this - did you see any monarchs being territorial that day, or were there just lots of monarchs nectaring? If it was summertime, you would have seen territorial behavior, or maybe mating, stuff like that.

I'm guessing there will be people who, after reading this, will probably dig their heels in, and double-down on their memories being correct and the data must be wrong. If you find yourself doing this, maybe that's a sign that you should take a minute and think hard about your own memories. Or better yet, read about the Bugs Bunny research! I did, and it completely changed my mind (see what I did there?).



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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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