The strange relationship between the regal fritillary and the training grounds at Fort Indiantown Gap in northern Lebanon County will be demonstrated once again this year, as the Pennsylvania National Guard runs its annual guided tours of the rare butterfly's home on the firing ranges.
Visitors will be able to experience the only population of the butterfly in Pennsylvania on Friday, July 5; Saturday, July 6; Thursday, July 11; and Friday, July 12.
Each tour will begin at 10 a.m., leaving from the Recreation Center in Building 13-190, located at the intersection of Asher Miner Road, Clement Avenue and Route 443. However, participants will want to arrive about a half-hour early to fill out the necessary paperwork, attend a mandatory safety and orientation briefing, and receive driving instructions. No reservations are required.
Each tour will run about three hours, and will include walking along dirt roads and mowed trails in wild areas of the 17,000-acre military post. Participants will have opportunities to exit the tours earlier if needed.
Tours have been offered for more than 10 years.
Regal fritillaries are listed as critically imperiled in Pennsylvania and vulnerable worldwide. The population at Fort Indiantown Gap is one of only two, and the larger of the two, in the eastern U.S. Through loss of habitat the species has become pretty much extinct east of the Mississippi with the exception of the site at Fort Indiantown Gap and the smaller population at the Radford Army Ammunition Plant in Virginia.
Regal fritillary habitat must include at least 5,000 violets per acre for the larvae (caterpillars) to eat, about 150 milkweed and thistle per acre for the adult butterflies to take nectar from, and 30-75 percent vegetation cover of native warm-season bunch grasses like little bluestem and broomsedge.
Regular disturbances, but not cultivation, on training areas and firing ranges at Fort Indiantown Gap have maintained that habitat as an unintended consequence. However, through a Department of Defense Legacy project, with support from Pennsylvania's Wild Resource Conservation Program, biologists have been trying to enhance additional habitat at FIG for the butterfly through methods like prescribed burning and to recreate suitable habitat to enable introductions at Gettysburg National Military Park and several Pennsylvania state parks.
The announcement of this year's tour schedule included a statement from retired Brig. Gen. Jerry Beck, deputy commander of the Fort Indiantown Gap National Guard Training Site: "Fort Indiantown Gap is one of the busiest National Guard training centers in the country. And although the primary purpose of the installation is the training of soldiers for their combat mission, we also place a very high priority being environmentally friendly and conserving precious land and ecosystems for the future.
"Our guided butterfly tours promise to be an exciting and educational afternoon because our biologists are knowledgeable not only about butterflies, but birds, plants and other insects."
Visitors will want to bring cameras and binoculars for the up-close experience.
The tours will include information about efforts to restore native grassland habitat across Pennsylvania and efforts to raise regal fritillary caterpillars from eggs in a lab. That latter effort is supported with a grant from the Pennsylvania Wild Resource Program and conducted in partnership with ZooAmerica North American Wildlife Park and Pennsylvania State University, with the goal is returning the regal fritillary to areas where the species was located in the recent past.
The regal fritillary is considered a Pennsylvania responsibility species of immediate conservation concern and is the symbol of the Pennsylvania Natural Heritage Program.
Fort Indiantown Gap is home to 112 Pennsylvania Wildlife Action Plan priority species, and provides a wide variety of habitats for 36 species of mammals, 143 breeding species of birds, 34 species of reptiles and amphibians, 25 species of fish, 792 species of plants, and many notable species of invertebrates including 85 species of butterflies and 243 species of moths.
The installation also features 1,000 acres of scrub oak and pitch pine barrens and 3,000 acres of native grassland habitat - the largest in the state.
It's the only live-fire, maneuver military training facility in Pennsylvania, balancing one of the region's most ecologically diverse areas with a military mission that annually supports 19,000 Pennsylvania National Guard personnel and more than 130,000 other states' Guard, military, law enforcement and civilian personnel each year.