Thursday, June 4, 2009

Death of a Tiger Swallowtail Butterfly

June 4, 2009

Our mama Hemingway cat, Polly (short for polydactyly), is venturing out away from her litter of kittens more now. The other day, I was outside and was intently watching the year's first Tiger Swallowtail Butterfly flitting past, when Polly flashed up and swept it out of midair. It really took me by surprise. All I could think of was the long migration that Monarch butterflies make every year, and what a shame it would have been for something so frail and delicate and slow moving to have made it all the way up to Northern Wisconsin only to become a slaughtered plaything for our cat. Even if it didn't migrate, it had made it through our Northern Wisconsin winters only to be snuffed out the first chance it had to bask in the warmth of the sun.

Eastern Tiger Swallowtail butterfly
Jerry A. Payne / USDA ARS

I had no idea whether the swallowtail makes migrations, so I started searching for information on it just to satisfy my curiosity and learned some pretty fascinating things.

First of all, the swallowtail that I saw could have been one of two possible species: the Eastern Tiger Swallowtail, Papilio glaucus, or the Canadian Tiger Swallowtail, Papilio canadensis.

OK. The genus name Papilio is Latin for butterfly, and papillon is French for butterfly. (Does anyone remember the old Steve McQueen and Dustin Hoffman movie entitled Papillon about the French penal colony on Devil's Island?) Anyway, in taxonomic science the genus name Papilio is now used only for the swallow-tailed butterflies.

Everybody can guess where the species name canadensis comes from, but according to most dictionaries, glaucus refers to a bluish-white coating. Well, that makes no sense. Alternatively, in Homer's Iliad, Glaucus was the name of a co-leader of the Lycian allies of the Trojans, and he foolishly exchanged his gold armor for the bronze armor of Diomedes. I guess that gets a little closer to the yellow color of the butterfly I know.

Then I found out something that I never knew before. All of the butterflies that are yellow are males. The females are usually dark blue and I would never have guessed that these are the same species.

Female eastern tiger swallowtail (black form)
photo by HaarFager on Wikipedia published under
terms of the GNU Free Documentation license Version 1.2 or later

OK. That's cool. I'll have to keep an eye out for that one. But we're back to glaucus referring to blue or yellow? I don't know.

How about Eastern versus Canadian? It turns out that until 1991, they were thought to be the same species, but two subspecies. With the advent of genetic technologies, scientists have determined that there are actually two different species that are "parapatric", which is a fancy way of saying that their geographic boundaries butt up next to each other, but don't overlap.

OK. So where is that boundary? I found a map that shows it right along the dotted line. Those numbers were collecting sites for P. canadensis (Stump AD, Sperling FAH, Crim A and Scriber JM. Great Lakes Entomologist, 2003:41-53.)

Well, heck then. That settles it, we live just a little bit south of the bottom of the 2 on the map. Polly must have nabbed a Canadian swallowtail.

But what if historically, the governments got our national boundaries all wrong? It looks to me like nature has drawn the line between Canada and the US with the butterfly population, and that line is to the south of us.

As of 1991, when this was discovered, maybe I became a Canadian. That might not be so bad, come to think of it.

Canadian banks didn't crash like the US ones did (

Deb and I are among the medically uninsured. Does this mean that we qualify for Canadian universal health care and cheaper pharmaceuticals? Did you know that contrary to what the US health and insurance industries would have you believe, the World Health Organization has ranked the US health system performance as 72nd in the world, and the Canadian health system as 35th (

Should we not need a passport to drive around Lake Superior on a vacation after all?

But wait a minute. The bottom line of that scientific study is that we should be using genetic techniques to watch for any shift northward of the P. glaucus species that could be caused by global warming.

Oh, oh. Is the naturally defined US-Canadian boundary creeping northwards? Should I be in a rush to make my butterfly natural history boundary plea for health care before it's too late?

Well, as of the night of June 3, 2009, we still have frost warnings. If I can't garden yet, there should be some bright side to living up here.

I don't think I need to be in any hurry to make my plea.

Quite yet anyway.

P.S. -- Sorry. Sometimes I just need to vent.


  1. Very the guys are yellow and the gals blue? I will remember that, thanks!

  2. Interesting post about butterflies and related info.

  3. I've seen Papillon! That's the only relevant information I have to this discourse. :)