The Naturalist's CornerWritten by Don Hendershot
Dancin' on the dunes
“Look at the butterflies!” I said.
“I know, I’ve been counting them – 27, 28, 29, 30, 32,” said my wife Denise.
“They’re still coming, “ I said.
“41, 43, 44,” she said.
I could see orange butterflies bouncing in the wind. “They must be migrating monarchs,” I said and went off for my binoculars.
I returned and glassed the aerial acrobats. “They’re not monarchs, they’re gulf fritillaries,” I said.
“63, 64, 65,” she said.
We were at Litchfield Inn on Litchfield Beach, S.C. celebrating our tenth wedding anniversary sans the kids and all I could think was, “I wish Izzy was here to see this.”
I went out on the boardwalk that crosses the dunes, from the Inn to the beach. There, quartering on the prevailing Atlantic wind as adept as any sailor, was a seemingly endless progression of gulf fritillaries.
Gulf fritillaries are striking butterflies. It has a wingspan of nearly four inches. The upper sides are bright golden-orange with black markings. When it folds its wings, it shows a brownish under wing with large, elongated, iridescent silver spots.
The gulf fritillary ranges from South America northward through Central America, the West Indies, Mexico and into the southern U.S. as a permanent resident. I spoke with Chris Marsh, executive director of Spring Island Trust at Spring Island, S.C. and he said, “The cut off line for gulf fritillaries as permanent residents on the east coast appears to be around Charleston [S.C.]” And Carlos Chacon, manager of natural history at the Coastal Discovery Museum on Hilton Head Island, S.C. said, “I have gulf fritillaries in every stage from eggs to adult butterflies right now.”
In spring and summer, the gulf fritillary follows its host plant, passionflower, northward. It has been recorded as far north as Manitoba along the east coast and as far north as San Francisco on the west coast. But as summer wanes, these bugs mass and begin to travel southward. However, unlike their famous migrating cousins the monarch butterfly, the physiology and life cycle of the gulf fritillary doesn’t change. While the monarch that hatches in September or October and begins the thousand(s) mile journey back to Mexico doesn’t sexually mature till the next spring, the gulf fritillary’s life cycle remains basically constant and in warmer climes it will reproduce year round.
The dune dance seems to progress down the coast. We observed the parade at Litchfield Beach on September 19; a web page (Sea Pines blog) from Hilton Head noted that October was a great month for, “...a seemingly endless procession of migrating Gulf Fritillaries...”
And if you get out this fall to look for migrating monarchs keep an eye out for gulf fritillaries. I have often seen them associated with monarchs in the fall.