I haven’t had much time in between working on my three books this year to post many original blogs, but I just couldn’t pass this up. One of the most important things I do during textbook revisions is fact check everything. Very often, “truisms” like contagious yawning suddenly become controversial, so revising is much more than just adding new stuff. You have to give everything another look.

Today, I was reviewing literature on the mimicry of the viceroy butterfly and the “truism” that the viceroy copies the appearance of the monarch in order to escape predation. Because the monarch retains cardiac glycosides from the milkweed it ingests, most birds get sick after eating them and subsequently leave them alone.  It’s an interesting example, I think, of classical conditioning. The truism about the viceroy’s mimicry of the monarch, though, seems not as clear cut as it used to be, so I ended up reading quite a bit about butterflies.

My search for truth led me to a rather grim 1964 article in the Journal of the Lepidopterists’ Society by Bruce Petersen, “Monarch butterflies are eaten by birds,” in which butterflies with their wings trimmed off were left to the birds. The article was quite descriptive, and I quote: “The last one to be eaten had been lying dead on the patio for four days.” In a table listing the tragic fates of the butterflies, the author apologizes for the smaller numbers at the beginning of the study: “It was difficult to catch enough butterflies at first.” Given the reverence with which the monarchs are held here in San Luis Obispo (their display in the eucalyptus trees of Morro Bay are splendid), the idea of the poor things hopping around as bird food was kind of tough.

Just when I was recovering from reading that article, my search returned the following headline: The Case of the Barfing Blue Jay. As much as I love Sherlock, I think this headline might give Dr. Watson’s blog a run for its money. Even better, the Science Friday episode from 2013 featured….you got it…..a photo of a barfing blue jay, provided by Lincoln Brower of Sweet Briar College in Virginia. I just had to share.

Only true diehard taste aversion experimenters like myself would probably know that the poor blue jay had one advantage over our lab rats. They can’t barf. So when they’re given lithium chloride in taste aversion experiments, they get very sick indeed. Just to make sure this memory of the past also holds up to current knowledge, I ran another search, only to find message boards where people were arguing about whether rats burp (no), vomit (no), or fart (yes), leading to efforts to kill them with Coca Cola.

So textbook writing is nothing if not downright bizarre at times. But you do end up learning some really interesting things!


chloe4178 · November 7, 2017 at 4:33 pm

This blog post definitely raised a topic I would have never put thought into. Looking at how different species react to what they ingest and how that differs to humans is very interesting. I think looking at the smallest reasons behind why certain occurrences happen and questioning everything is always necessary. Reading about you delve deep into the questions of these butterflies, is an awesome example of understanding their actions and how that effects the whole eco-system as a whole.

emilyknighton · November 13, 2017 at 10:24 pm

I remember learning about mimicry in butterflies as a protective adaptation, but I had never really thought much about the taste aversion experienced by the predators until taking your biopsychology course. I love learning about the parts of biology that remind me how related our species is to others. So imagining blue jays having strong memories and haunting dislikes for certain foods they’ve eaten as similar to my own experiences with bad foods is both humbling and amazing. And since I’ve never thought too hard about this shared experience, I definitely haven’t given those who research the topic enough credit. How does one even begin to design an experiment to test such intricate natural patterns? Or even notice that the patterns are there in the first place? The more I hear about research that is happening and what intricacies of nature have been studied already, the more excited I get about where science will take us in our future understanding.

egonz124 · December 1, 2017 at 12:21 am

Something that stood out to me that might be so obvious it might be overlooked is that butterflies are probably the largest insect that I can think of that fly. Having this aerodynamic advantage is no doubt a blessing and a curse so I wonder if the ability to retain cardiac glycoside provides a defense against birds. If the birds didn’t experience the taste aversion, then there would be negative consequence.

monjazeb · February 13, 2018 at 10:37 am

It is interesting to read about how different species ingest prey and how their bodies respond/react to their ingestions. As a biology major, I have had to think about the dietary habits and consumption of organisms and how organisms differ from each other in this way, so I can understand how this interesting aspect can be a means of classification.

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