They might seem strange bedfellows – butterflies and grenades – but the other day I got to see firsthand how these two seemingly incompatible objects are existing harmoniously on the same tract of land. Specifically I am referring to the rare Regal fritillary butterfly and Fort Indiantown Gap (FIG), an Army National Guard training center in central Pennsylvania.
The Regal fritillary butterfly was once found in 50 of Pennsylvania’s 67 counties but thanks to changes in land use (fewer small farms, more housing developments, old fields growing into forests, etc) these orange and black butterflies can now only be found in Pa. at FIG. In fact, this is one of only two sites in the northeast where people can see them (the other is a smaller site at Radford Army Ammunition Plant in Virginia). Other populations live in states like Montana, Colorado and Oklahoma.
So the only two sites in the east where this butterfly can be found both are Army properties? When thinking about what goes on at a place like FIG – Guard members learning how to drive tanks, throw grenades and practice shooting targets with machine guns – it is hard to imagine that butterflies and the plants that support them could survive, but in fact they are thriving, thanks to the work of some great biologists. When the butterfly was first discovered at the site, the Guard agreed to prohibit training exercises on over 200 acres of the property so that research could be done to determine the habitat requirements of the butterfly. The biologists discovered that the plants that the butterflies and their caterpillars feed on need the disturbances created by the military activities to survive. The tank tracks and periodic fires from ordnance prevent trees from growing up and shading out the milkweed, thistles and violets that sustain the butterflies and their larva.
The discovery that human intervention is what is keeping the Regal fritillary butterfly’s habitat on-site at FIG has inspired the biologists to use this as a model for other landowners in the area. State parks like Memorial Lake and Swatara, along with National Park Service sites like Gettysburg and Valley Forge, are working with staff from FIG to create their own warm season grass and thistle/milkweed/violet meadows on their properties to reintroduce these beautiful butterflies to more sites throughout the state. Perhaps one day these sunny-colored butterflies will once again be found in dozen of Pa. counties?
Want to see the butterflies in person? FIG is closed to the public but occasionally has organized tours of the butterfly meadows. For more information about tours and FIG, go to http://www.dmva.state.pa.us/portal/server.pt/community/featured_topics/13476/regal_fritillary_butterflies_at_fort_indiantown_gap/726675.