MARY LOUISE KELLY, HOST:
About a million animal and plant species are threatened with extinction. A stark United Nations report earlier this year found human activities are driving this decline. Marie Cusick of member station WITF reports on one rare butterfly that's largely disappeared from the East Coast but has found refuge in a surprising place.
MARIE CUSICK, BYLINE: Regal fritillary butterflies used to be common across the U.S. They're still around in the Midwest, but in the East, to see them, you have to sign up for a special guided tour that happens only a few times each summer.
UNIDENTIFIED PERSON #1: Is everybody excited to see some butterflies today?
(APPLAUSE)
UNIDENTIFIED PERSON #1: Yeah?
CUSICK: The group is at the Fort Indiantown Gap military base to catch a glimpse of this charismatic insect with vivid orange wings dotted with black and white spots. On a recent July morning, visitors pile into their cars to caravan out to a grassy field.
MARK SWARTZ: All right, everyone. Convoy's about to leave.
CUSICK: Wildlife biologist Mark Swartz leads the group as police direct traffic.
UNIDENTIFIED PERSON #2: (Over radio) Updating numbers for the butterfly tour.
CUSICK: This is a lot of manpower for some butterflies.
SWARTZ: Yes, it is. It takes a lot of coordination, and it occasionally breaks down, and that's when we have problems.
CUSICK: This time, the Air Force didn't get the memo. Swartz had them reroute their training flights at the last minute.
SWARTZ: That's why I was a little upset that there was a problem because...
(SOUNDBITE OF GUNFIRE)
SWARTZ: There, they're shooting. So that's a .50-caliber machine gun.
CUSICK: With the plane safely out of the way, Swartz hops out of his car and leads the tour through the field. It doesn't take long to spot a butterfly flapping by. People quickly grab their cameras.
SWARTZ: There's a regal coming across.
CUSICK: A military base may seem a surprising haven for wildlife, but it can be because it isn't welcoming to people and development. Swartz says the activity here also helps create meadows.
SWARTZ: There may also be tanks and other military vehicles that go in and tear up the ground that essentially set back what would turn into trees back into a grassland.
CUSICK: It's exactly what the butterflies like, and it's where the plants they feed on grow.
This is Michael Bean's second time on the tour. He drove up from Washington, D.C., for the day just to see the regals.
MICHAEL BEAN: It's heartwarming to see as many people as there are here today. I'm going to guess there are 200 people or more. And that's quite remarkable to come out to see a rare insect.
CUSICK: No one is quite sure why the regal fritillaries nearly disappeared in the East. About a hundred miles from the base, in Philadelphia, the Academy of Natural Sciences of Drexel University is home to one of the oldest insect collections in North America. Entomology curator Jon Gelhaus says a prominent 19th century naturalist named Titian Peale left behind many specimens and notes showing he was able to find regal fritillaries in the city.
JON GELHAUS: We can see here in Peale's handwriting, collected in the vicinity of Philadelphia by T.R.P., Titian Ramsay Peale, 1831.
CUSICK: The regal fritillary's decline in recent decades fits into a broader pattern of biodiversity loss driven by factors like habitat destruction, invasive species and climate change. Gelhaus explains, butterflies are especially important to humans because as pollinators, they play a critical role in food production.
GELHAUS: We're not just protecting nature for some kind of ideal intrinsic kind of value; it's wonderful we're protecting nature; aren't we good? These things actually do things for us.
CUSICK: Researchers in Pennsylvania are working to introduce the regal fritillaries to new habitats in hopes they can expand their range beyond the military base. For NPR News, I'm Marie Cusick.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
