Swallowtail Weather

I tend to associate swallowtails with late June/early July, as Tiger Swallowtails were going gangbusters during this time on my first encounter with Michigan (2002).

This year, they've been a fizzle: a few sightings early in spring, and a mere handful at what I'd considered their peak season.  Even our annual jaunt to Lake Superior didn't net us many swallowtail sightings, and the last two years they made an obstacle course of every road we traveled north of Standish.

So, I was thrilled to see a large, dark form swooping around my workplace's front lot with that characteristic "heavy" swallowtail wingbeat.[*]  It came close to me repeatedly, once flying straight at me before veering off with a metre to spare.  It had definite tails, but otherwise its appearence was foreign to me.  It was dark, but lacked the brilliant colour pattern of a Black Swallowtail, and it was not iridescent like a Spicebush, much less a Pipevine.

I know those three 'guys' very well, and none of them checked out.  This butterfly was about the size of a Spicebush, and it had the "classic" rounded outline instead of the "long," angular wing-shape of a Black Swallowtail.  It was dark brown, not true black, and the colour outlining its hind-wings was yellow-orange.  There may have been some yellow on the forewings as well.

Hold on, you say.  There is a butterfly in the region with just those colours in that pattern, the Giant Swallowtail.  Nuh-uh.  I had a vivid encounter with those at Point Pelee last year, and that glass slipper won't fit.  One, those things are freaking huge, literally the size of a small bird.  I watched a Giant zoom through a glade containing a couple of Monarchs, and the Monarchs were rendered Dwarfs, or at least Peasants, by it.  Two, the Giant Swallowtail flies like a bird.  No leaden wings there.  Three, the Giant has pale underwings, and this mystery visitor did not.

I'm stumped, and while I love to see a new and unfamiliar lepidopteran, I don't want to be flummoxed by one.
    
A few minutes later, I saw a Tiger soaring over the road.  That makes it a very good day.     

* Compare a Tiger in flight to a Monarch sometime.  Even better, compare a Monarch with one of the dark swallowtails, like the Spicebush.  The swallowtails seem positively clumsy by comparison.