Butterfly Surprise........

I was taking our small dog down the stairs for him to go outside.  I looked over and did see this butterfly that was very dark.  Compared to the other butterflies it looked like a bird.  I went in to get the camera and returned to capture one photo. It was a hyperactive one as it flipped back and forth on the phlox as if it was its last meal. One other shot was a failure as it flitted off.  Black swallowtail butterfly is its identity.  I am thinking it is the male because of the colors of blue on its back.  I do see a yellow one flitting by and I did see a monarch out there but nothing else was landing on the phlox.