I never get tired of watching butterflies, or taking photos of them. This one is an Eastern Tiger Swallowtail -- one of about six or seven that I saw visiting a butterfly bush in a nearby plot. They are called Swallowtails because the slender tips on the end of their wings resemble the tails of swallow birds. With a wingspan that can be as wide as 6.5 inches, Swallowtails are the largest butterfly we have in the D.C. area. (I learned that at our National Zoo, which has a butterfly garden.)
Female Eastern Tiger Swallowtails can be either yellow or dark blue. When they are dark, they look similar to another butterfly called the Pipevine Swallowtail, which eats a plant called pipevine. The pipevine plant contains toxins that make the butterflies poisonous to predators. So as the female Tiger Swallowtails mimic Pipevines, it helps them survive. I also learned here that when Swallowtail caterpillars hatch, they resemble bird droppings -- which is another mechanism to fool predators.
I always find it interesting to learn things like this -- how different species have adapted to survive. I've always been a bit of a wannabe biologist, and I think the garden helps me satisfy some of my natural curiosity about the world. Plus the photos... I just love taking the photos.