Tiger tails, Red spots, and Blue highlights.

[trehopr1]

Here in the eastern half of North America we are fortunate
to have the marvelous Eastern Tiger Swallowtail (Papilio glaucus)
in our midst. The females are simply a delight to see and they
come in two color forms or "phases" - both light and dark.

I think anyone who has an appreciation for beauty in all its many
splendid forms would have to be somewhat awestruck to see one of
these "light phase" beauties up close in their garden.

These are large butterflies by American standards; considering
that most people only encounter the typical cabbage white's, Red
Admirals, or the occasional Monarch at the garden flowers. Seeing
one of these huge "flapping" yellow giants dancing about the flower
tops of ones garden is a camera moment to be sure.

Some notable and yet subtle highlights regarding the (light) females
pertains to things which only collectors can view amongst their prize
captures.

For example, take those magnificent "tails" which add a tapering
elegance to the hindwings. They really are not quite all the same.
Tiger tails do vary in their appearance. While there is a somewhat
"typical" length of tail on females of 9-10 mm; there are individuals
encountered with tails of a even more tapered and longer length. I
have 3 with tails measuring 15mm beyond the edge of the hindwing.

Below is a comparison photo:
Typical length tail (top specimen)
Extended length tail (bottom specimen)



Tiger tails also "occasionally" appear in a slightly abbreviated
"fat form" which reminds me somewhat of those grand Gloss
papilio species of the Indochina region.

Below is another comparison photo:
Typical length tail (top specimen)
Fat-tail appearance (bottom specimen)



A comparison of the three is in order -- below.



Another subtle and yet sometimes striking difference in appearance
arrives in the form of those "red spots" located at the top region of 
the hindwing.

Here one will witness a variety of red tones present along with
(or without) reduction of the size of those spots. My above photo
provides some degree of noticeable difference but, the photo below
illustrates a truly bold and outstanding individual.



Lastly, what discussion regarding subtleties (of this species)
would be complete without a mention of the glorious blue highlights
of which only females possess. Yes, here too we see variation in 
"spectacular" presence.

The blue coloration of these butterflies literally takes up the bottom
half of the hindwings. Upon close inspection it even "runs" or overlaps
into the yellow coloration of the hindwing AND starts running upward
into the black border of the forewing !

As well, this coloration on differing individuals varies in its intensity.
Some females really "pop" in their blue highlights whilst others appear
noticeably subdued in intensity.

Below again, I try to offer a comparison.



Unfortunately, all this beauty and glamour does come at a
personal cost. It's bad enough that these large bright yellow
butterflies cannot be missed in their presence; yet that bold
"flashing" blue only invites attention !!

As a collector and rabid enthusiast of this species I can attest
to the "difficulty" of truly acquiring good "wild collected" examples.

Simply put -- it's tough !

Bird attacks are particularly present on any more than a day or two old.

And yet, there's nothing quite like catching your own occasional
prizes to make for a wonderful outing and a well spent day in the life...

Hope that you have enjoyed this little discussion of mine
on one of my personal favorite homegrown butterflies !

[Adam Cotton]

Superb, thanks for posting notes on the variability of these wonderful butterflies.

Adam.

[exoticimports]

Caught my first ever dark female yesterday. Long elusive to me, I’ve seen many but had never been able to net one!

[gaspipe]

Great write up! Thanks

[exoticimports]

Just got back from the field. You southerners have it made. They were all over the thistles, sometimes three to a flower. It was stupefying.

[trehopr1]

The "dark phase" of P. glaucus females have a certain
attraction in their own right. Though, they lack the
bold yellow of the light phase they can be every bit
as large, possess those bright red spots, and still
have a "brilliance" of blue color on those hind wings.

Below, I offer up a recently captured example
featuring bold red spots and brilliance to match.



Other specimens of dark females may have reduced
spots, brilliance, or other reduced markings but, they
sometimes make-up for this in other ways.

Here below, I show a female with a blue presence
located along the costal margin of the forewings.
A rather un-common trait but, found here and there.
Just another variation on the theme...

[kevinkk]

It is a great post. I'm always learning something new. It also goes to show the difficulty that can happen with correct id for species, when
you're not aware of forms and subtle variations, and just go with pictures out of a book. I suppose it might depend on how much that book cost-

[exoticimports]

If you want to see stunning aberrations of the females. journals.flvc.org/holarctic/article/download/114357/109718

[livingplanet3]

Definitely one of my favorite species of US butterflies.

[exoticimports]

Some males do have blue on the HW. The more south one goes, the less blue.

[gaspipe]

Are dark form specimens found in same range as regularly colored ones ? And is the dark form present in all subspecies?

[exoticimports]

Aug 15, 2021 18:55:18 GMT -8 gaspipe said:

Are dark form specimens found in same range as regularly colored ones ? And is the dark form present in all subspecies?

Read my monologue on Tigers in Field Studies. The dark females
Are not present in NE from mid PA north. There is a
Similar split in MN or so.