The Secret Lives of Parks

Learning to Fly

Episode Summary

Raptors such as peregrine falcons and California condors made the endangered species list decades ago, but thanks in part to monitoring and recovery programs in national parks, things have been looking up.

Episode Notes

This year’s historic fledging of a peregrine falcon at Harpers Ferry ― the first in more than 70 years ― is just the latest chapter in the once-endangered species’ recovery. Host Todd Christopher takes a closer look at how raptor monitoring and reintroduction programs in the parks are making a difference for birds of prey including peregrines and critically endangered California condors. Guests include Mia Parsons, Chief of Resources Management at Harpers Ferry National Historical Park, Rolf Gubler, Biologist at Shenandoah National Park, and Wildlife Biologist Gavin Emmons & Condor Program Manager Alacia Welch at Pinnacles National Park. 

Learn more about the Endangered Species Act and the endangered plants and animals that call national parks home at

Original theme music by Chad Fischer

Audio clips courtesy of the National Park Service and Harpers Ferry Park Association 

The Secret Lives of Parks is brought to you by: 

Todd Christopher – Producer & Host
Jennifer Errick – Producer & Host
Bev Stanton – Online Producer
Ismael Gama, Jr. – Creative Content Specialist 

The Secret Lives of Parks is a production of the National Parks Conservation Association. With more than 1.6 million members and supporters, NPCA is the nation’s only independent, nonpartisan advocacy organization dedicated to protecting national parks. Learn more at

Episode Transcription

The Secret Lives of Parks


Todd Christopher:  Peregrine falcons once were endangered. California condors were on the verge of extinction, but thanks in part to raptor programs in national parks, things have been looking up for these marvelous birds of prey. I'm Todd Christopher, and this is the Secret Lives of Parks.

Traces of American history seem to be everywhere in Harpers Ferry National Historical Park. There's the prominent rock along the Appalachian Trail where Thomas Jefferson stood and admired the view. The grounds of the armory raided by John Brown and his compatriots in the run-up to the civil war. The historic college campus where Frederick Douglass once delivered a rousing speech. So much so that the natural beauty of this park where the Shenandoah and Potomac Rivers meet might be easy to overlook, but this summer, visitors who came to Harpers Ferry and turned their eyes upwards towards the cliffs overlooking the town, got to witness a little slice of environmental history, too. Because this year, for the first time since 1950 Harpers Ferry had a peregrine falcon hatch take flight and leave the nest, a process known as fledging. It's an important milestone for a magnificent bird of prey that has spent decades on the endangered species list.

Mia Parsons: Peregrine falcons sort of came back on the scene around 2016, and we've been watching and waiting for a successful fledge.

Todd Christopher: That's Mia Parsons, Chief of Resources Management at Harpers Ferry National Historical Park.

Mia Parsons: There's so much rich natural history in the area. Actually we have historic references to peregrine falcons in Harpers Ferry. They weren't called peregrine falcons during the historic period that they referenced they were, I believe, they were called Duck Hawk, but we have some interesting historic references to them up to the time when they disappeared.

Todd Christopher: Maybe we should back up a step here. While they were never exactly abundant, healthy populations of peregrine falcons were found throughout much of the United States until their numbers suddenly and inexplicably declined in the years following World War II. By the mid 1960s, peregrines had all but disappeared east of the Rockies and were severely reduced in the west. Researchers with the U.S. Fish and Wildlife Service finally found the culprit, the pesticide DDT. Peregrines primarily feed on smaller birds, and if those birds in turn consume contaminated insects and plants, DDT builds up in the peregrines' bodies. One of DDT's breakdown products, a compound called DDE, wreaks havoc with the peregrines' reproduction most notably by causing them to lay eggs with unusually thin shells that break during incubation. The peregrine population plummeted, and the species was listed as endangered in 1970. The EPA widely banned the use of DDT, but it wasn't until 1999 that their numbers had rebounded enough for peregrines to be delisted. Despite this progress, for peregrines to successfully mate and raise young that leave the nest is anything but certain. Here's Mia Parsons again.

Mia Parsons: There's a lot of different factors that could lead to failure. Predation is definitely one. At Harpers Ferry, there was a theory one year that we had evidence of nesting, but we failed to get to a fledge and we thought that maybe the ledge was flooding, that maybe there wasn't enough gravel or substrate on the ledge. And we actually worked with the biologist at Shenandoah to make improvements to the nesting ledge so that it would drain better. We had one season where we just had torrential rain all through the spring. So things like that. And then, there's also the possibility that human activity within the proximity of the nesting sites could affect the success.

Todd Christopher: And in some cases, the proximity of gadgets controlled by humans. The citizen scientists and volunteers who monitor falcons in Harpers Ferry even spotted a mechanized hazard.

Mia Parsons: Drone use, unauthorized drone use in the park could be interfering. We had one case where monitors witnessed a drone sort of getting entangled with a peregrine falcon in the sky.

Todd Christopher: This year's mating pair nested near Maryland Heights, a popular overlook looming high above the Potomac and the vantage point for those quintessential picture postcard views of Harpers Ferry. To protect the falcons park staff enacted partial temporary closures.

Mia Parsons: We really try to find a balance where we keep as much of the park open as is practical while also keeping a protective buffer around the nesting site. People can still hike. They can still get to the overlook. They can still get the amazing photos of the town and those views that they want while still helping us protect the peregrine falcons.

Todd Christopher: And the peregrines' reception at Harpers Ferry this year has been a warm one.

Mia Parsons: I think that the peregrine falcons have generated a lot of positive interest from visitors. We've had a lot of social media and also media attention since the successful fledge this year. So we're really hopeful about that, and we look to weave the story of the triumphant return of the peregrine falcon to this area into the stories that we tell.

Todd Christopher: Word of the successful fledging in Harpers Ferry got around fast, even up river.

Rolf Gubler: That was huge news, and for a number of years, they've had kind of near success. They've had some pairs, but they just never were able to produce young. So this year, with that one young produced, was a real big deal. So, that's very encouraging.

Todd Christopher: That's Rolf Gubler, a biologist and head of the peregrine restoration program at Shenandoah National Park. And I can tell you firsthand what a majestic site a peregrine in the skies above Shenandoah is. I will admit here briefly that I've been fascinated by peregrine falcons since childhood. Maybe it was reading My Side of the Mountain, Jean Craighead George's novel about a boy who runs away to live off the land and raises and trains a peregrine to hunt for him. Maybe it was learning that by diving at speeds over 200 miles per hour, peregrines claim the title of world's fastest animal. Or maybe it was just that they are undeniably cool. Part mythical being, part fighter jet, all in a streamlined package no bigger than a crow. I once spent an unforgettable day sometime in the late nineties, atop Shenandoah's Stony Man Mountain, watching a mated pair of peregrines swoop and dive and flash above the valley below. It was a spectacular site, but it turns out that pair was an outlier. Truly, a couple of rare birds.

Rolf Gubler: In the Nineties, we just saw a very slow recovery, almost nonexistent recovery in the mountains of Virginia. And historically, there were pretty robust numbers in the mountains, Virginia, throughout parts of Shenandoah National Park, parts of the George Washington National Forest, and those sort of mountainous rock outcrop habitats.

Todd Christopher: Peregrines were delisted in 1999, but the numbers in Virginia just weren't keeping pace. So in 2000, the park revived what's known as a hacking program, reintroducing falcon chicks to the natural cliffs of Shenandoah in what is essentially a kind of avian flight school.

Rolf Gubler: So cliff faces and rock outcrops is what they prefer in Shenandoah or places like Acadia, in places like New River Gorge. But yeah, so they'll gravitate to human and manmade habitats such as large bridges over water, large structures like skyscrapers in urban areas for sure. And then they'll prey on some of those urban species like pigeons or rock doves, starlings, and those types of things. And in coastal areas, in some of those big bridges over the big rivers like the James and the Rappahannock, then they'll prey on a lot of your river species, river bird species like shorebirds and things like that.

Todd Christopher: It is those coastal birds that have been helping to restore the peregrine population in and around Shenandoah through hacking programs, and it's a win-win. It's not just helping the recovery of the species as a whole, but also helping to ensure the survival of young peregrines that otherwise might not make it.

Rolf Gubler: The hacking stock, the restoration stock comes from some of those coastal plain bridge nests where some of those young birds, those young falcons are sort of at risk because falcons need updrafts. Decent updrafts for them to sort of... It buffets them when they're first learning to fly. And without those updrafts and being so close to water with sort of no intermediate structure makes those young birds very susceptible to drowning on their first fledge attempt. And sometimes you'll see mortality rates of up to 90% with some of those nests over the years.

Todd Christopher: Shenandoah's partners include Virginia's Department of Wildlife Resources and Department of Motor Vehicles as well as the Center for Conservation Biology at the College of William and Mary, who will identify at-risk nests and coordinate the relocation of peregrine chicks to the hacking site.

Rolf Gubler: They'll come to us in sort of small pet carriers and peregrines are about the size of a large crow. We usually get anywhere between three and eight young peregrines. And they're usually from one or two different nests or cohorts. We have a hack site set up at a place like Franklin Cliffs here at the park. It offers pretty good access for us to get in and get our volunteers in so we can feed those birds, but it also provides this great cliff face, this natural habitat. So on this natural habitat along this cliff face that’s sort of buffered from human use and closed off from human use, we install a hack box.

Todd Christopher: Which of course begs the question: What exactly is a hack box? Gubler explains.

Rolf Gubler: The hack box is sort of like a large doghouse, but it has sort of a hardware cloth opening in the front. So the young birds can see out and acclimate to their surroundings, and it has a slot where we can sort of remotely feed them. So the young birds don't imprint on us, the feeders. We're provisioning them over the first two, two and a half weeks before they learn to fly.

Todd Christopher: And part of feeding the young peregrines means cleaning up the mess that's left behind.

Rolf Gubler: There's doors on the sides so that our folks can get in and clean out sort of the uneaten quail that's not eaten. We don't want too much old material in there that may attract bears or raccoons. So we try to keep that site clean. We try to do that very quickly and discreetly so again, the young birds don't imprint on us.

Todd Christopher: After a couple of weeks, when the birds are around six weeks old, the team does what Gubler calls a soft release. By pulling on a rope from a spot in the woods 50 feet away, the door to the hack box is opened remotely.

Rolf Gubler: The doors open very slowly and there's food placed right out there on the front doorstep. So they come out, they're hungry immediately. They gravitate to that food, and then for a period of a couple hours, they learn how to sort of... They get used to their surroundings and hopefully they take good quality first flights and within five hours, usually all four or five birds fly, typically.

Todd Christopher: With all of this taking place away from the parent birds, it makes me wonder whether the young falcons are hardwired for that first flight. It's a pretty big leap of faith, and as Gubler explained earlier, one that can be fatal in the wrong conditions.

Rolf Gubler: Yeah, they are hardwired and it is instinctual. It is helpful obviously to have brood mates. So brothers and sisters, they will mimic their brood mates and they'll mimic them as they eat, as they learn how to fly, as they learn how to hunt throughout the entire process. And then they'll disperse usually typically sometime in late July, or mid-July. It kind of depends on when we start the hacking process.

Todd Christopher: But before they can disperse, the young peregrines need to master the most important part of being a falcon: hunting.

Rolf Gubler: At that point, when we release them, there's still going to be four, four and a half, five weeks where we continue to feed them, but they're not hunting yet. They have to learn that piece, and that takes about four to five weeks. So we'll continue to feed them. But at this point, we're feeding them outside of the box. They're no longer in the box. They don't want to be in a box ― because they're birds after all.

Todd Christopher: At this point, the site of these magnificent birds taking wing over the mountains and the valleys below is one that visitors are invited to see.

Rolf Gubler: We'll typically have folks out there with spotting scopes and we'll do public education. And the nice thing is adjacent to the hack site, the release site, is a parking lot, is an overlook. Franklin Cliffs Overlook where folks can drive in and really learn about falcons and see them on the wing, which is pretty special for most folks. We don't heavily advertise it, but once the birds are safely on the wing, we will tell our interpretive staff, our education staff and people do... they do know from year to year, they come up and they watch the birds. So it's a real treat for a lot of folks, especially to see these birds on the wing about one or two weeks post-release. It's a very positive program. And it's an opportunity for people to see these rare species in a fairly natural habitat. And then eventually they disperse, and then they're on their own.

Todd Christopher: And this year turned out to be a pretty good one for being on their own. The Virginia Department of Wildlife Resources documented five natural cliff face pairs of peregrines ― the most since reintroduction efforts began. 

Across the country in central California's Pinnacles National Park, another falcon program is having success of its own.

Gavin Emmons: At Pinnacles, the program kind of started as a pilot program in 1984 and then really got going consistently in 1987 and has been... We've had consistent falcon monitoring at the park since then. So it's I think the longest consecutively running raptor monitoring program in the country and certainly in the Park Service.

Todd Christopher: That's Gavin Emmons, wildlife biologist at Pinnacles and head of its falcon monitoring program, which focuses on reducing human-falcon conflict to ensure successful populations. Even unintentionally, park visitors can hinder raptors’ chances for successful breeding, especially peregrines.

Gavin Emmons: I guess they're kind of just high strung species as avian predators, more so maybe than even some other raptors like red-tailed hawks, other sort of large hawk species. Yeah, they seem to be very easily disturbed by people, which you can note by their behavior, if they're starting to dive at people or make scolding calls or alarm calls. And if they do that enough, especially at certain times of year, like when they're selecting nests or starting to incubate eggs, then it just takes time away from their efforts with that. And it can lead to nest failures and abandonment of territories that they selected for breeding.

Todd Christopher: Those kinds of interactions are what inspired Pinnacles' raptor program in the first place.

Gavin Emmons: The program was started in the mid-Eighties, because there were a couple of instances where rock climbing parties went past... Kind of climbed past active nests, especially there was a golden eagle nest, that was active at one of the climbing areas on the west side of the park called The Balconies. And after that, the pair basically abandoned the site.

Todd Christopher: The initial reaction by park managers was that the park should be closed to climbing, which didn't sit well with the climbing community and groups like The Access Fund that work to keep areas open. Everyone agreed that more data was needed to support park management decisions.

Gavin Emmons: And that served kind of as the starting point for climbers and park managers to come together and eventually to agree upon an advisory program, which we have in effect. So there are voluntary closures where we really put the onus on the climbing community to act as good stewards and to stay out of certain areas.

Todd Christopher: And of course, there's something to be said for being birds of a feather.

Gavin Emmons: And there's been a really healthy open line of communication between the climbing community and park managers over the years to maintain those advisories. And I also am a pretty avid climber myself. So in the time that I've been here, I think that that's been a really important bridge between the climbing community and the parks. I guess I talk the talk very easily with the climbing community. I've established a lot of rock climbing routes here at the park. I know most of the community that's been climbing here for upwards of 30 years, so.

Todd Christopher: This has been a banner year for falcons at Pinnacles with nine peregrine fledglings. That represents the highest number in any year since peregrines first reappeared in the park in 2004. And you might even say that results like these are fulfilling the legacy of protection that goes back nearly a century to when Pinnacles was a relatively new national monument.

Gavin Emmons: Certainly seeing peregrine falcons starting to kind of repopulate the park is pretty exciting. The park has a long history of protecting certain areas during raptor nesting seasons. Even in the 1920s and 1930s, you can look on old park maps and see parts of the park that were identified as either sort of sanctuaries or falcon protected areas. And those were used as justifications to expand parts of the park, especially on the west side where you have huge cliffs like Machete Ridge or The Balconies. And part of the justification to include those in the park boundaries was because managers even then recognized that there were these populations of nesting falcons that were significant.

Todd Christopher: Today, that common understanding among park managers, visitors, and the climbing community is a big part of Pinnacles' success.

Gavin Emmons: At this point, I think most climbers, because we've kept climbers and visitors in general in the loop and with really open lines of communication, I think there's a lot of mutual respect. And a lot of the folks that come out climbing at Pinnacles are also pretty excited to see the birds, to see falcons flying around, and condors, and comment on that. And I've had many, many examples of longtime climbers here acting as good stewards and really kind of helping to police and enforce the advisories by really educating other climbers that they come into contact with if they see them entering or considering entering into advisory areas. So, yeah, I think it's definitely been pretty successful over time. Obviously, it's really nice to have some significant success stories in conservation efforts and clearly peregrine falcons are one of them.

Todd Christopher: Alacia Welch is the condor program manager at Pinnacles National Park, a part of the California Condor Recovery Program. She and Gavin Emmons aren't just colleagues at Pinnacles. They're a married couple.

Alacia Welch: So, yeah, I remember arriving in January of 2004 and there was this really cute ranger who worked here.

Gavin Emmons: [Laughter]

Todd Christopher: With wingspans that can reach 10 feet, California condors are the biggest land birds on the continent, and I can't help but ask Welch what it's like to be in close contact with them.

Alacia Welch: Yeah. It's always amazing. It is truly a singular experience when you have a condor fly overhead not too far away. In fact, so close that you can hear the wind whistling through its feathers. I mean, it is a large bird and when it cruises close enough, you can really tell. Yeah, it's a wonderful experience to see and be up close to them. And when you get to watch them interacting, it's also really interesting. They are very curious and they are quite social. So there's a lot of interactions between condors and it's just really fun to watch them as they... I don't know, one pulls the feather of another one or they snuggle their heads together as they're bonding and all of that. So really, really, really fun to watch.

Todd Christopher: And it's an incredibly rare opportunity. It's no exaggeration to say that the California condor is a species that quite literally was pulled back from the brink of extinction. Even today, with a slowly increasing population and programs like the one at Pinnacles dedicated to their recovery, California condors remain listed as critically endangered. There currently are only about 300 individuals in the wild and a couple hundred more in captivity. And unlike peregrine falcons, California condors reproduce very slowly. A mated pair might produce a single egg every two years and can spend up to a year raising a single fledgling.

Alacia Welch: So Pinnacles is a release site for condors that are bred in captivity. And so every year, there are a handful of condors that come from captive breeding facilities to the park to be released here. So we'll hold them for a couple of months in a pen that we have on site here, and then they get released out into the population with the other condors and it usually takes a couple months for them to kind of figure out how to be a condor in the wild. But they usually do fine with that, and then join the rest of the flock.

Alacia Welch: Every condor that's released, as well as those that are bred naturally that come out of nests, we track every single one of them. So they all have ID numbers. They all have tags that are on the wings that reflects those identification numbers and they carry transmitters. So we can really monitor where they go across the landscape. We also monitor them, of course, as far as their nesting goes to see how they're doing with that. And then we also try to capture every condor every year to see how each bird is doing as far as their health and replace those transmitters so that we can continue to track them.

Todd Christopher: If that level of monitoring seems excessive, it's worth remembering that at one point, not that long ago, the population had dwindled to the point where there were just 22 California condors remaining in the world.

Alacia Welch: The lowest population number was in the early 1980s, and at that time it was quite controversial, but it was decided to pull every single condor from the wild into captivity and really focus on a captive breeding program. And then after that, releasing condors back into the wild and really tracking them to figure out what the cause of death was for so many, because before the Eighties, nobody really knew what was causing their decline.

Todd Christopher: It turns out these massive birds, which can live up to 50 or 60 years, sometimes pay with their lives just for fulfilling the ecological role of scavenger.

Alacia Welch: The primary cause of their decline is definitely lead poisoning. And the most common pathway for that is for them to consume an animal that was shot with a lead bullet. And there's many different reasons why there would be animals on the landscape that were shot, but condors have a really good ability to find dead stuff out there. And so when they find something that was shot with a lead bullet and they consume parts of that bullet, they can get lead poisoning and die from that.

Todd Christopher: And so like the peregrine falcon, the condor’s decline resulted from the consequences of human activity, but also like the peregrine, its recovery can stem from education and changes in human behavior.

Alacia Welch: So, for condors, the main way that we will be able to recover them is really working toward encouraging hunters to use non-lead ammunition when they're hunting, or anybody who's shooting an animal on the landscape to use a non-lead bullet for that. And so that's our biggest hurdle and the best way we're going to get out of condors being critically endangered is by switching to that non-lead ammo.

Todd Christopher: But Welch is optimistic about the condor’s path, and with good reason.

Alacia Welch: And we feel... And a lot of studies have looked at it, if we can get lead poisoning to be either a negligible or totally non-existent problem for condors, that they would be a totally recovered species. We would be looking at them like we look at the peregrines. If we can get rid of that one risk to them, then they will succeed on the landscape. They will be a successful... A real success story at that point.

Todd Christopher: When you hear the hope and commitment in Alicia Welch and Gavin Emmon’s voices, you begin to realize that for everyone working on these programs, from Mia Parsons and the volunteers at Harpers Ferry to Rolf Gubler and his conservation partners at Shenandoah, that it really is a labor of love.

Gavin Emmons: Yeah, of course.

Alacia Welch: Yeah, absolutely.

Gavin Emmons: Yeah. I mean, I think for both of us, on a personal note, of course it feels like kind of an honor and a privilege to be able to work with these species in beautiful areas. And despite the ongoing trials and tribulations, I mean, obviously that passion sustains us and helps us to do this work over time. And yeah, I feel like it's an important effort and yeah, like with so many species and habitats, it's well worth the fight to try to preserve them and to restore them when needed.

Todd Christopher: And thanks to their efforts, things are in every way, looking up. 

Todd Christopher: The Secret Lives of Parks is a production of the National Parks Conservation Association. Episode 5, “Learning to Fly,” was produced by Todd Christopher with moral and technical support from Jennifer Errick and Bev Stanton. More at Original theme music by Chad Fisher. Audio clips courtesy of the National Park Service and the Harpers Ferry Park Association. Learn more about the Endangered Species Act and the endangered plants and animals that call national parks home at For more than a century, the National Parks Conservation Association has been protecting and enhancing America's national parks for present and future generations. With more than 1.6 million members and supporters, NPCA is the nation's only independent, nonpartisan advocacy organization dedicated to protecting national parks. Learn more and join us at