Probably the best and easiest way to tell from the dorsal side is the orange inner margin eye spots. In the black swallowtails they have a black bullseye. In the others it is pure orange. In addition, black swallowtail females don't seem to have blue above the medial band, whereas tigers do.
-Elisabeth

Sounds like a great day and you got some great captures!

There is a dark line that borders (scalloped as it is) part of the blue in the Tiger. The Spicebush does not have this and neither does the Black Swallowtail. In some dark tigers you may be able to see faint tiger markings.

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The two "gut" keys for me are

(1) Size: Tigers big, Blacks small. The largest Blacks will be only as large as the smallest Tigers.

(2) Yellow spots. Blacks have double rows of yellow spots on the forewing, double rows of yellow spots on the body, yellow spots on the hindwing ...

Exhibit A: Papilio polyxenes f
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If you're lucky to see the light through the wings, a third key is that female Tigers are really dark brown, not black.

What's hard for me is sexing Black Swallowtails when they are ambiguous. I believe this one is male because of the solid row of yellow spots inside the blue, but he might be best called "metrosexual."

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There are small Tigers that can be the size of a Spicebush. But, this year most of the Tigers are huge and plentiful. They were even out today when it was cloudy and chilly. Nothing much was flying, but they were.

runmede, the 'ghosting' of the tiger stripes is the characteristic that I am most comfortable with WHEN I can detect them. Often the light is not conducive to picking up this trait but when it is, it is really evident. See picture below of an underside view with flash.

Thanks, so much, to all of you who contributed the ID tips. They are extremely important to those of us just getting started in this!

Bob

{{gwi:522014}}

I'm jealous of you all... I haven't had that quantity or quality of butterflies in my gardens this year, nor have I ever taken such beautiful photos. Great job to you all.

I raised the Tiger (Black Form) in the picture. I wintered it over. It survived our porch falling down this past winter when we had over two foot of snow. Just before she finished drying her wings I placed her on her host plant. I wanted to try to give her a hint about where she should be laying when she was ready.