northeast-flora-and-fauna

Sometimes members of the same species can look quite different, usually due to sexual dimorphism. For the female Eastern Tiger Swallowtail though, butterflies of the same sex can also look very different. Here is the dark morph of the Eastern Tiger Swallowtail. All dark morphs are females, and this morph is usually seen later in the season, August and onward. It actually has the underlying pattern that the yellow morph Eastern Tiger Swallowtails (see below) has, but instead of a black-on-yellow pattern the dark morph is more like a dark-black-on-light-black pattern. The dark morph is considered to be participating in Batesian mimicry , since they resemble the poisonous Pipevine Swallowtail . July 28, 2021 at Sourland Mountain Preserve Photo 148654982, (c) jpviolette, some rights reserved (CC BY-NC) I didn't see a yellow morph female Eastern Tiger Swallowtail on this trip, but the yellow morph female Eastern Tiger Swallowtail looks fairly similar to the males. They're yellow-an...