Day 209: Yesterday's walk in Pack Forest served a dual purpose: to do a patrol for invasive plants and to pay a visit to Butterfly Alley. I've made several trips to the Alley over the last two months, but with very little success. I missed the emergence of the Mourning Cloaks, one of the first species to appear in the spring. The Commas follow a month or so later, and are usually quite numerous. Their heavy bodies and ragged wings make them very distinctive, but issues arise when trying to determine whether an individual specimen is Polygonia faunus or Polygonia satyrus.
This problem opens the door for me to explain a little about field-guide photography. When you are taking pictures of specimens for identification purposes, it is important to capture as many markings or features as possible. You should also maintain a good depth of field for your subject; having the entire critter in focus is mandatory. The background can sometimes be helpful in making a positive ID if the habitat gives clues as to what plants may be host species, but it should not be so cluttered that it becomes a lesson in camouflage.
Let's take Mr. Comma as an example of art vs. science. As hard as I tried to sneak up on him from a better angle, I could not get into a position where the view of the lower margin of the hind wing was not obscured by the curled, dry fern. Seen in the dorsal view, Polygonia faunus shows a darker border than Polygonia satyrus. Without that crucial piece of information and lacking a ventral view, I can only say that based on previous observations at this site, I believe (but am not positive) that this is Polygonia faunus.
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