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The other day I posted an image of an Arizona Sister Butterfly, a butterfly that I’d not photographed previously. Today, I’m posting images of a second butterfly that is new to me, one that I observed at the same time and in the same location as the Arizona Sister, near the summit of Mt. Lemmon. This is a Red-spotted Purple Butterfly, a/k/a Red-spotted Admiral.
This butterfly is a woodland species that resides throughout much of the southwestern United States. In summer, individuals show up as far north as South Dakota. It’s a member of the Admiral family of butterflies, a family that includes the relatively well-known Viceroy.
When I first saw this individual I was positive that I was in the presence of a butterfly that is quite common in southern Arizona, the Pipevine Swallowtail. I may be forgiven for my confusion — the two species have very similar coloration and wing patterns, although the Red-spotted Purple Butterfly lacks the little “tail” that is at the trailing end of each of the Pipevine Swallowtail’s hind wings. It is also somewhat smaller than the Pipevine Swallowtail.
Fooling the observer may be the evolutionary purpose of this butterfly’s mimicry of another species. Some species of butterflies have evolved to closely resemble other species that predators find to be unpalatable, and that appears to be the case with the Red-spotted Purple Butterfly’s mimicry of the Pipevine Swallowtail.
Mimicry appears to be something that some species of Admirals are good at. The Red-spotted Purple Butterfly’s cousin, the Viceroy, doesn’t look at all like the Red-spotted Purple Butterly, but it closely copies another species, the Monarch, and for apparently the same evolutionary purpose that the Red-spotted Purple Butterfly mimics the Pipevine Swallowtail. Evidently, predators find Viceroys to be tasty snacks whereas that isn’t the case so much with Monarchs. So, it pays to be thought of as a Monarch, even if you’re wearing a disguise.
Images made with a Canon R5, Canon EF 400mm f4 DO II lens+Canon EF 1.4x telextender, M setting (auto ISO), ISO 800, f6.3 @ 1/500, + 1/3 stop exposure compensation.