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.
