Monarch displacements and orientation

Lost and found

In the spring of 2019, I cleaned out my office in Haworth Hall, the main biology building. It was an emotional trip through my 47-year career as a KU faculty member as I sorted through the artifacts that represented my academic and personal history. In the process, I made a number of discoveries that led to recovered memories but also engaged in a few searches for things long lost.

One priority involved the search for an unpublished manuscript that was written about 20 years ago by Sandra Perez and myself. I had been looking for that text since the data therein speaks to some of the recent discussions about monarch orientation. Unfortunately, the manuscript was a no show. Then Covid-19 paid us all a visit this spring, and I had to move my office from Monarch Watch to home. That required a bit of clean-up of the home office to make it more usable – and, you guessed it. I found the Perez/Taylor manuscript in an unmarked folder. I suspect many retired profs have unpublished texts. I have a bunch. Some should have been published and others not. The Perez/Taylor manuscript was reviewed and sent back for revisions. Unfortunately, I don’t have the reviews. For reasons I don’t recall, the revisions were never made and the manuscript wasn’t resubmitted.

The text described the results of two field experiments conducted in 1997 and 1998 involving orientation of displaced migratory monarchs. The results of the first test were clear and informative, but there was a problem with the second experiment due to the fact that it was shortened and possibly influenced at one location by an advancing hurricane. In other words, the two-site comparison we were counting on, that would have given power to the results, whatever they showed, was compromised. In the best of all possible worlds, to achieve the two-site results we wanted, a do over the next migratory season was required, but that wasn’t possible. Below is a link to the manuscript as I found it. It needs a rewrite and a little more context and if we were to do the same set of experiments again, we would do them a bit differently. I’m posting this to the Blog since the data from the first experiment is informative and that of the second is certainly suggestive though not entirely convincing. These experiments should be repeated on a larger scale, this time with more controls and radio tagged or simply tagged monarchs that have been weighed and measured. We hope someone will take up this challenge. At another level, this approach offers an opportunity to trace the physiological (biochemical and genetic) change from one entrained behavioral response to specific environmental cues to another set of cues or signals at new locations. What I’m suggesting is that displaced monarchs go through a reset process, not unlike jet lag in humans. However, unlike humans, in monarchs, the reset duration is temperature dependent.

Link to unpublished manuscript (PDF):
Monarch Butterfly (Danaus plexippus) Migratory Orientation: Regional Differences and Effects of Displacement
Sandra M. Perez and Orley R. Taylor