When I caught sight of an orange butterfly visiting my planters yesterday, I assumed it was a Great Spangled Fritillary, a butterfly I see in the holler every year and a species I observe for the National Phenology Network. I grabbed my binoculars to verify the species.
Clearly this was not a Great Spangled Fritillary! It's wings were longer and narrower, its back had more orange and the spots on the underside of the wings were stringingly bright, and its flight pattern seemed different.
Through the binoculars I could also see three white spots surrounded by black rings. All of these observations together pointed toward the identity of my visitor as a Gulf Fritillary.
This butterfly and the Great Spangled Fritillary, with which I was more familiar, are members of the same family (Nymphalidae) and subfamily (Heliconiiae). Further down the taxonomic chain, however, each is classified in a different tribe. The Great Spangled is a member of the Tribe Argynnini (the true Fritillaries), while the Gulf Fritillary is a longwing or Heliconian butterfly of the Tribe Heliconiini.
According to the guide I use (Glassberg 1999), the resident ranges of the Great Spangled and Gulf fritillaries don't overlap, but the Gulf is known to spread northward as the summer season progresses. Still, I was reluctant to identify this one without careful consideration, since it's November! Is it on its way back south again?
Glassberg's map shows a range for the Gulf Fritillary extending across the southern border of Tennessee, but not up to the northern reaches of the state where I live. On the other hand, Tennessee is a lot skinnier south to north than it is east to west, so maybe it's not all that far for a butterfly to migrate.
Whatever the case, I am totally delighted to have seen one, and glad there were still a few flowers blooming in my planters for it to feed on.
I am still seeing at least two of the Sulphur species -- a pair of the smaller, yellower ones have been visiting the planters as I write this blog. I also saw eastern tailed blues (another species I observe for NPN) in late October. Another new species for me in the holler this September was a Checkered White. Unfortunately I could not get close enough to get good images.
Check out this time lapse video of a Gulf Fritillary chrysallis and the emergence of the adult on YouTube: