InsectNet forum

Here is another lovely piece of unusual
appearance from my collection. This is an
example of a "transitional" form in our native
Tiger Swallowtail (P. glaucus). Field men who
run across these rarely encountered (females)
aptly call these "smokey" tigers or "smokies' for
short.

Females of P. glaucus typically have 2 color forms;
yellow ones and black ones (the further south you go).
However, ones such as this fall--between--the two typical
forms; having a light-black to greyish appearance with
yellow (trying) to break through in places.

These transitionals/intermediates are only rarely produced
in nature when the right environmental conditions alighn.
Some are more extreme than this example and these in general
are held in high regard by collectors fortunate enough to
encounter one of these rarities of nature.

Most field men barely ever encounter even one of these but,
a rare few may run across a few select examples over their years.

I have a good friend in central Illinois who has
had some remarkable good fortune over his years.
He is an avid field man and has run across (no less)
than 6 stunning "smokies" of varying intensities.

Four of them are present in the photo below.

Without doubt, my friends most extreme encounter
with a "smokey" tiger takes the form of the specimen
in the right half of the below photograph.

Tiger stripes AND yellow background "bleeding" through
the light black overall color. A true "one in a million"....

Here is a recently acquired "smokey" tiger
from Columbia, Missouri (Aug.02.2004). It
was wild-collected and is a marvelous example
of a late summer capture of one of these.

Better than the first one shown at the start
of this thread as the tiger stripes are more
pronounced !

Interesting, Columbia, Missouri is well south of the boundary w/ the all yellow female population.

Perlman and Perlman published in 2019 Holarctic Lepidoptera a two-paper series examining "mosaics" (their term) which includes "fletcheri" and "smokies". both can be found online.

Short story, many of these aberrations can be replicated with cold shock, and as I'd noted previously citing Scriber, once induced these genetic changes become hereditary. Perlman & Perlman cite that in some local populations up to 10% of the females exhibit some form of mosaic morphology (mosaicism??)

Both papers are loaded with photos, which will be interesting even to those not interested in the genetics or breeding tests.

I have read this paper as well. Some of what they called “aberrant” are probably what most of us just call normal variation. If you look very closely, a significant percentage of specimens will have some amount of aberrancy based on their criteria.

eurytides wrote: ↑Tue Mar 14, 2023 2:55 pm I have read this paper as well. Some of what they called “aberrant” are probably what most of us just call normal variation. If you look very closely, a significant percentage of specimens will have some amount of aberrancy based on their criteria.

True, the eastern Tigers are extremely variable, most variation being just extremes of what's already there. That said, Perlman & Perlman do picture some spectacular oddities.

If you take, for example, the morphology of Papilio appalachiensis, a "glaucus" that meets the discerning criteria isn't uncommon. That's part of why there's so much confusion; I've seen images of a number of "appalachiensis" that I suspect are not.

At the extreme is Ornithoptera victoriae, which has a number of named "morphs" or forms, which for the most part is rediculous because the species as a whole is extremely variable. In many cases, it would be easy to present a specimen that looks like a different ssp but is not. Even the morphs with extreme enhancement or absence of key patterns are quite common, they just don't seem to make it into books or online images.

Going back to Tigers and "normal variation" well just what is that? Given that the environment can cause permanent, hereditary changes in morphology, "normal variation" could be cited as just that, despite significant patterns and colors. It's not like Hesperidae in which all individuals of a species look the same, and in fact most species look the same (OK, cheap swipe at one of our friends.)

Well, “normal variation” is a subjective term. Just how common does something have to be for it to be considered normal? I have no idea. However, I have never seen a smokey tiger in real life, so that seems rare enough. Bleeding colors or slightly scalloped tiger stripes - half my specimens have some of that if you look carefully enough.

eurytides wrote: ↑Tue Mar 14, 2023 5:45 pm Well, “normal variation” is a subjective term. Just how common does something have to be for it to be considered normal? I have no idea. However, I have never seen a smokey tiger in real life, so that seems rare enough. Bleeding colors or slightly scalloped tiger stripes - half my specimens have some of that if you look carefully enough.

I have some disappointingly-not-so-smoky females. Some have a few insignificant dashes of yellow. My two most extremely marked smokies are beat to heck. But as I'd mentioned before (either in this thread or the other, which is similar) there are hotspots for smoky tigers.

And yes, scalloping, black bleed, high proportions of blue, etc. are all relatively common. Which is cool, because that's where a series really shines. I regret having ignored the Tigers for 40 years.

Here I offer yet another of my smokey tiger selection;
the third in my short series (of four) mid-late summer
examples.

This one is not quite as dark as the one pictured in my
previous post. It has much more (yellow) present in the
background color, bolder red spots and "slight" reddish
bleeds into the (yellow) hindwing spots, and a light
"dusting" of blue scales on the hindwings overall.

This one thus far is my favorite of the 3 posted to this
thread.

It was collected sometime between July 27 thru Aug.03
(1997) in the Missouri Ozarks.

Those female smokies, especially in good condition, are simply stunning! Thanks for posting Trehopr1.

John K.