Fort Indiantown Gap

All posts tagged Fort Indiantown Gap

By Derek Stoner, Conservation Project Coordinator

A female Regal Fritillary rests briefly on a yarrow plant at Fort Indiantown Gap. Image by Derek Stoner.

While soldiers train nearby to help in the fight for freedom, we wander along the carefully mowed fields amidst vast meadows ablaze with the colors of black-eyed susans, bull thistle, butterflyweed, yarrow, monarda, and other wildflowers.  Our eyes scan back and forth for the winged creatures that visit these flowers in search of nectar.   The flowers are seeking the same thing we are: butterflies.  In this unique location, one special butterfly is the attraction: the Regal Fritillary

A Great-spangled Fritillary glides above a male Regal Fritillary nectaring on Monarda. Image by Derek Stoner.

These gorgeous butterflies have a discerning taste when it comes to choosing habitat: weedy fields in poor soils that have plenty of violets, the host plant for the Regal Fritillary.  And not just any field will do, as these butterflies thrive in areas of disturbance.  A field that burns every few years spurs re-growth of violets and favorite nectar sources(thistles and milkweeds).   Where do you find such habitat?  At a military training ground, of course.

The sign says it all: You may want to watch your step while searching for butterflies. Image by Derek Stoner.

For the third year in a row, the Delaware Nature Society led a trip to Fort Indiantown Gap in Pennsylvania.  For several days each summer, this National Guard training base opens to the public for tours of its very special treasure.  Naturalists from the Fort led an assemblage of more than a hundred curious folks eager to see these winged wonders.  Amidst firing ranges, rusting battle tanks, ripped parachutes hanging in trees, and the multiple hand grenade training areas, we tiptoed along the trails in search of the rare Regals.  We saw plenty of Regals– likely 50 or more individuals out of an estimated population of more than 1,500 at the base.  That’s the largest single population of this insect in the entire world!

The Delaware state butterfly, the Tiger Swallowtail, is just one of the 81 species of butterflies documented at Fort Indiantown Gap. Image by Derek Stoner.

The intensely-managed and altered habitat at the Fort attracts a diversity of insect species, and our group  identified 25 butterfly species during our visit.  In the vibrant meadows we found other fritillary species like Great-spangled and Variegated, along with other beauties like Bronze Copper, Common Wood Nymph, Zebra Swallowtail, and Pearl Crescent.

If you are interested in butterflies join Delaware Nature Society staff member, Sheila Vincent on the program Butterflies for Grownups, Saturday August 7, 1:00 – 4:00 p.m.  Additionally, if you would like to help with a special citizen science project, we invite you to join us for the annual Butterfly Count sponsored by the North American Butterfly Association.  This year’s count will be held on Saturday, July 31,  beginning at 9:00 a.m.  Armed with nets, cameras, and notebooks, we will document all the butterflies we can find (and identify) at Ashland Nature Center and Burrows Run Preserve.  To register for this free event, contact Sheila Vincent at 302-239-2334, ext. 125.