Wandering Butterflies Sometimes Go North in Late Summer
Ro Wauer, September 7, 2003, The Victoria Advocate, © 2003
Those of us living in South Texas expect to see monarchs on their southern migration during late summer and fall, and we seldom are disappointed. From late August through November, monarchs from all across North America pass through our area en route to their wintering grounds in the mountains of northern Mexico. Their story is well documented, one of nature's most fascinating wildlife adventures.
But those of us in South Texas also are privileged to experience very different butterfly phenomena, that of wandering butterflies heading north. Some of these strays are Mexican species that are very rarely found in the United States. Although they can be somewhat expected in the Lower Rio Grande Valley, those that come so far north as Victoria, Goliad, Dewitt, and surrounding counties are exciting for those of us that pay attention to such unusual occurrences. For instance, during the last few days, I recorded a white angled-sulphur in my yard near Mission Valley, and Derek Muschalek discovered a ruddy daggerwing in his yard west of Yorktown.
The white angled-white is a huge butterfly, almost the size of a monarch, with leaf-green underwings and white upperwings with a large yellow spot. I discovered my angled-sulphur nectaring on a firebush, but when I approached it swiftly flew up, circled and landed on a nearby hackberry leaf. I could easily see it from where I was standing, but when I approached to get a photography, it blended into the vegetation so perfectly that I had to return to the earlier spot five times to zero in on the location before I located it up close. Then I was able to approach to within four feet; it remained still, I suppose believing that its color and leaf-shape when perched would keep it protected.
Derek's ruddy daggerwing is an even larger butterfly, with a wingspan of about three inches. Its underside is reddish brown with dark streaks that provide it wonderful camouflage when perched. The upper side is brilliant orange-red with narrow black streaks and long tails. Its color and shape are so out of ordinary that almost anyone seeing this butterfly could not help but be impressed. It is one gorgeous creature!
The concept of butterflies and other animals moving north instead of south in late summer and fall is one that has been recognized by biologists for many years, but not fully understood. This dispersal from their breeding grounds occurs with a large number of animals. Most often it is the male of the species that moves on after breeding. This wandering behavior may serve as a way to disperse species over a wider area to conserve a food supply for the young, to take advantage of feeding sites elsewhere, or it may function as a way to colonize new territory. Buff-bellied hummingbirds, the large species that is a full-time resident in many of our yards, often wanders along the Gulf Coast to Louisiana in fall. And western hummingbirds, such as Anna's and Allen's, wander east to the Gulf Coast on occasion.
There are several butterflies that we can expect only during the late summer and fall months. Already a few of the more common, regular fall species have put in their appearance, at least in my garden. The early species include zebra heliconian, orange-barred sulphur, common mestra, and ocola skipper. Based on previous years, I know that I can also expect Julia heliconian, white peacock, soldier, and Laviana white-skipper any day.
My "Checklist of Central Gulf Coast Butterflies" includes 149 species that have been recorded within the12 county area. I have recorded 96 of those within my own yard. Any of my readers interested in receiving a copy of this 4-page checklist, send me a stamped self-addressed envelope and will I send you a copy. My address is 315 Padre Lane, Victoria, TX 77905. Enjoy the butterflies!