Biologists from the U.S. Fish and Wildlife Service recapture a previously banded Florida Grasshopper Sparrow at a private ranch near Loxahatchee to bring in for captive breeding. With less than a hundred individuals, the species is fighting to stay afloat. Photo: Mac Stone

Conservation

Inside the Race to Save the Florida Grasshopper Sparrow, North America’s Most Endangered Bird

The only hope to prevent extinction may be to remove some of the last birds from the wild for captive breeding. This summer scientists scrambled to collect enough sparrows before the breeding season’s end.

North America’s most endangered bird hardly qualifies as “charismatic megafauna.” It is not a big sexy animal, not the kind you’d see on a state flag. It’s a tiny bird that lives on something in central Florida called the dry prairie, which feels vast when you’re standing in the middle of it but which today covers maybe a tenth of its historic extent. The dry prairie is also home to spotted skunks, and snakes, and red imported fire ants. And sometimes cows. And an unknown but presumably growing number of antibiotic-resistant bacteria and parasites and other pathogens. All of which are bad for the Florida Grasshopper Sparrow. When you’re just a few inches long and you live for maybe four years and you’re the potato chip of the food chain and everybody’s out to eat you, you’ve got troubles.

Which explains why, in January 2014, a dozen members of the Florida Grasshopper Sparrow Working Group came together to collectively gnaw at the question of whether, under what circumstances, and in what specific ways to commence a captive-breeding program for what was (and is) generally recognized to be the continent’s most endangered bird. The assembled biologists, land managers, conservationists, and researchers at the Archbold Biological Station in Venus, Florida, were the very people who had been—and would continue to be—heroically dedicated to doing whatever could be done to save the sparrow in the wild. But now the bird’s plunging numbers were forcing them to consider the possibility that something more urgent needed to happen.

Let’s stipulate this: There is something fundamentally wrong-feeling and queasy-making about attempting to save a bird from extinction by capturing a small but significant number of its last remaining healthy wild specimens and putting them in what is, no matter how roomy or well-festooned with appropriate vegetation, a prison. It’s the sort of Sophie’s Choice that leaves biologists and all lovers of wildlife feeling gutted. As one participant declared at some point during the two-day workshop, “I would rather have this species go extinct than to see it in a cage.”

The sparrows' coloring keeps them well camouflaged, and their ground-dwelling and -foraging habits keep them well out of sight amongst the grasses. Photo: Mac Stone

But others in the room weren’t willing to adopt that absolutist position. The members of the working group were, after all, acutely mindful of—and in some cases had experienced firsthand—the most recent previous extinction of a North American bird 30 years ago, when the Dusky Seaside Sparrow blinked off the landscape right here in Florida. In that case, by the time the decision was made to deploy the last resort—to bring some sparrows in for captive breeding—the last resort had left the station: The only wild Dusky Seaside Sparrows to be found were five unpaired males, and soon the Dusky Seaside Sparrow was no more. The Florida Grasshopper Sparrow Working Group was determined not to repeat the mistake.

“These are wild birds; we want them in the wild,” says Reed Bowman, who is the director of avian ecology at Archbold and who was at the 2014 workshop. “There’s a huge amount of uncertainty [with captive breeding]. But one thing I can tell you is certain is that if they go extinct in the wild and we don’t have a captive-breeding program, they will be extinct.”

And so, in the face of a loudly ticking clock, the group came to a decision, though hardly an easy one. The official report from the workshop captured the painful ambivalence well, citing one member who framed the dilemma this way: “If we set the wrong course now . . . can we live with knowing that captivity caused extinction? Or . . . can we live with thinking that captivity could have saved the species if we had tried it?” The report continued: “In reality, given the population projections constructed by panelists, it seems the options before the [working group] have very similar likelihoods of success and failure. The [group] will be rewarded if they select an option that succeeds and never know if there even was an option for success if they fail.”

A sparrow nest on the prairie floor is a rare find. Photo: Mac Stone

The option they selected was to proceed, carefully, with captive breeding. And for the subsequent breeding seasons, the actions taken were careful indeed. Most collections were made on a rescue basis, largely from nests under imminent threat of flooding, and in that fashion two captive-breeding colonies were established. But those specimens were mostly eggs and hatchlings, only rarely the adult birds needed to ensure successful breeding and to school their progeny in wild-bird behaviors. Heading into this year’s breeding season it was again uncertain whether the U.S. Fish and Wildlife Service (USFWS) would bring in the sparrows needed to properly seed a breeding program. But then the season’s first count of wild birds came in, and it was dire. And finally it was clear to everyone that there was no case left to be made that captive breeding was more likely to “cause” an extinction than prevent one.

“We’re looking at imminent extinction of the Florida Grasshopper Sparrow in the wild in a year or two,” says Paul Reillo, the founder and president of the Rare Species Conservatory Foundation (RSCF), whose Jurassic Park about 15 miles straight west of the current U.S. president’s winter White House is home to several dozen critically endangered mountain bongo antelope, more than 80 endangered Red-browed Amazon parrots, and one of the two sparrow captive-breeding efforts now underway. “This might be the last opportunity to build a platform for the future. This season we’re going to grab onto whatever is left on the table. We should save everything that has a chance of living, because this is the last gasp for this species.”

 

Audubon Florida science coordinator Paul Gray has been working on the Florida Grasshopper Sparrow since he arrived 22 years ago in a role that included managing a 7,000-acre dry-prairie sanctuary that the organization had bought in 1980. Two years after his arrival, and after a lobbying campaign spearheaded by Audubon, the state bought an adjacent 48,000-acre ranch and established the Kissimmee Prairie Preserve State Park. (Audubon sold the sanctuary to the state in 2001 to be folded into the park.) “When the state bought the preserve, they had hundreds of sparrows out there,” Gray says. “And there were also three other subpopulations on three different conservation holdings. I thought, ‘Great, we’ve saved the grasshopper sparrow! It's going to have enough places to live into the future.’ ”

The classic dry prairie at Three Lakes near Miami, Florida, is carefully managed to meet the sparrows' needs. But even here, the birds are not faring well. Photo: Mac Stone.

Then the Florida Grasshopper Sparrow subpopulation crashed at one of the other holdings, the Avon Park Air Force Range just across the Kissimmee River to the west of the park—apparently plummeting from roughly 130 singing males in 1999 down to just 13 in 2003. “We had endless meetings and discussions and couldn’t figure out what had happened,” Gray says. “And then over the years the Kissimmee Prairie population just dwindled and dwindled.”

By now, the Florida Grasshopper Sparrow has been functionally extirpated at Kissimmee Prairie; not a single breeding pair was found there this year. At Avon Park the tiniest of subpopulations somehow persists, with five males this year (two of which remained bachelors). A private ranch (which the USFWS requests not be identified) hosts a comparably puny subpopulation; the field techs who monitor the place counted five mated pairs this summer, plus a dozen unpaired males. Which leaves Three Lakes Wildlife Management Area, a 63,487-acre expanse of pristine habitat intensively and beautifully managed on the sparrows’ behalf by the Florida Fish and Wildlife Conservation Commission (FWC). But Three Lakes is bottoming out, too: This season it looks like it will have been home to no more than 16 sparrow pairs.

The kind of population decline Gray describes is not the way things typically work out there in the natural world, at least absent some obvious and calamitous cause. And it’s even more of a head-scratcher when you consider that Florida Grasshopper Sparrows do not have any issues with reproducing. In fact, they make babies in bulk. From the time they build their first nest of the season in, say, mid-April to their final effort at outlasting the rain sometime in August, a single breeding pair can produce as many as five clutches of eggs, three to five eggs in a clutch. That's potentially 25 offspring a year; in order for the population to increase, just three of them—12 percent—need to successfully incubate, hatch, fledge, and survive the winter. Even so, the population continues its inexorable fall.

Over the years, and recently with ever-greater urgency and ingenuity, USFWS field biologists and their land-manager partners have responded to the dizzying array of predatory and climatic perils the sparrows face by developing an equally dizzying armamentarium of interventions, up to and including transforming each newly discovered nest into a little fenced compound on the prairie.

USFWS field techs Natalie Sweeting (foreground) and Rebecca Windsor clear away grasses around a new nest-protection fence. Photo: Mac Stone

The constant state of high alert, combined with the all-too-frequent incidence of nests failing anyway, can lead to heartbreak and burnout. Just listen to USFWS recovery biologist Sandra Sneckenberger, who has been engaged in the Florida Grasshopper Sparrow work out of the Service’s Vero Beach office since 2008, describe the 2016 breeding season: “Last year the birds started nesting, and we got this huge deluge of rain, so we lost all those. Pretty much every bird’s first clutch: gone. They start again right away, make a new nest, lay eggs. Second rainstorm: gone. That happened three times last year. After the first time, we put in monitoring wells so we knew where the water table was on the landscape. We lifted nests—figured out how to use shovels and a little dirt to lift nests up just enough so the birds wouldn’t know we’d done anything. Everybody had a portable incubator for eggs. One time I’m with the crew grabbing eggs and there’s lightning striking all around us. At the ranch we’d install fences against mammal predators and snakes, and an electrical fence around that because of cows. Still—with all that—as soon as the eggs hatch and there’s a nice fleshy body, fire ants eat it. Out of 20 nests at the ranch last year there was one nest that made it. Every other one, it got predated at the egg stage or the crew came upon it after it got mauled by ants. You go through all that work and see that carnage repetitively—it gets to you. My dentist knows that it’s sparrow season because my gums bleed so bad because I’m stressed out so much. You’re always on call and you’re doing a bunch of work and trying so hard, and you can’t help but get attached to these birds. The birds are trying so hard to make it happen. The birds won’t give up.”

 

Paul Reillo is a tall, wiry guy, all angles and elbows; he lopes across the Rare Species compound shifting from one urgent task to the next, tattered off-white Rare Species Conservatory Foundation T-shirt swinging loosely from his coat-hanger shoulders. (It’s hard to tell whether his wardrobe features just one RSCF shirt that he wears every day, or multiple clones, each dotted with a similar smattering of dirt and sweat.) Today is June 27, deep into the breeding season, and Reillo is beginning, finally, the process of building sparrow enclosures.

If you’re going to bring in wild, critically endangered birds, you need to have specially made enclosures—big enough to give them some semblance of wilderness and sufficient room for foraging; situated outside for acclimation purposes yet protected against incursions from predatory snake and pathogen-carrying insect alike; planted with appropriate grassland ground cover so that fledglings feel at home. Also they can’t cost too much. And of course now that time is getting short, they need to be simple enough that they can be built quickly under serious time constraint.

Paul Reillo spruces up a sparrow enclosure with vegetation at the Rare Species Conservatory Foundation in Loxahatchee, Florida. Here, the birds are enabled to mate, nest, and lay their eggs in the relative safety of a more controlled environment. Photo: Mac Stone

The simple schematic Reillo has designed is a 6 x 6 x 12-foot frame with a staple-gun-secured floor of galvanized quarter-inch wire mesh and five other sides wrapped in a stretchy superscreen guaranteed (as long as you get the fairings right) to keep out the critters you want kept out. Take three of those frames and arrange them at right angles out on the lawn behind the open carport bays where we’re making these things, slap a prefab steel screen door on each and connect the three via a foyer that functions as an airlock against escape and unnecessary human contact, carpet the enclosures with soil and greenery, and voilà!—you’ve got a sparrow collection/breeding pod. Make two of those, to accommodate the six family units slated (weather and predators permitting) to be brought in, and do all of this with a cobbled-together crew of USFWS rogues, local artists, a journalist, and a couple of field techs from Kissimmee Prairie—who don’t really have any sparrows to look after anyway—each of whom shows up whenever they manage to carve out the time to do so.

Meanwhile, the insanely focused and iterative breeding work itself must go on. When I met Reillo for the first time, after he and his wife, Karen, had welcomed me to their house on the Rare Species compound, he took me into a small side room—in a more normal home, it might have been an office—where he had an important twice-daily task to perform. He opened one of the two incubators parked in the closet that spanned one wall and proceeded to manually nudge-turn a dozen or so jelly-bean-size eggs that looked so fragile they could have been spun from sugar. These were “day one” eggs, Reillo explained: eggs that had been brought in to this mechanical simulacrum of a nest—with its metal rollers that rotate the eggs on a precise but perhaps overly regular schedule and its temperature that can be calibrated down to the hundredth of the Celsius degree—within hours of being laid, before they could benefit for even a day from the far more nuanced knowledge of a mother sparrow sitting and jostling and creating the optimal conditions for incubation in an actual nest.

Paul Reillo uses a technique called “candling” to reveal the embryonic development of a Florida Grasshopper Sparrow. The eggs will incubate for about 11 days before hatching. Photo: Mac Stone

Reillo and his colleagues have gotten the incubation protocols refined up to a point: Give them an egg that’s been in a nest under a female sparrow for three days and they’ll take it through the remainder of the 11-day incubation period and successfully hatch it pretty much every time. But they had yet to hatch a day-one egg. Reillo had been obsessively tweaking the various factors he can control—temperature, rotation, air circulation, humidity—trying to figure out just what it takes, what that magical set of nest-approximating conditions might be that will cultivate, not kill, the sparrow embryos within. But success had eluded him so far.

The reason this maddening stumble toward replicating nature’s methods is even necessary in this particular instance is that these eggs were the progeny of last season’s hand-reared captives, not of the experienced, proven wild adult breeding pairs that are the optimal founders of a captive-breeding colony. (The unschooled first-time mothers had laid the eggs and then dumped them outside the nest and never bothered with them again.) But this is the fundamental nature of embarking on such an effort with a species that has never been bred in captivity before. Nothing is known in advance; everything must get figured out along the way.

A week after I was introduced to the day-one eggs, Reillo managed to get one to hatch. Two days later, he hatched another: He’d cracked the nut. (Ultimately a dozen of the eggs hatched.) The temperature they already knew works to incubate eggs from day four onward is 37.65°C; the temperature that gets them from day one to day four turns out to be 37.68°C. Point-oh-three degrees Celsius: That’s the tiny gradation that makes all the difference.

A hatchling shares an incubator at Reillo’s home with “day-one eggs” that were laid outside the nest and neglected shortly thereafter. Photo: Mac Stone

Of course, what you get when you hatch a day-one egg is a day-one chick—a chick that must be hand-fed by humans straight out of the egg, a special formula the consistency of thick pancake batter administered every half-hour, syringe into gaping beak. This isn’t the first time Rare Species has dealt with day-one chicks, and unfortunately they’ve found them to be almost as challenging as day-one eggs. Last year when May flooding threatened for the second time to drown every clutch on the prairie, the field techs conducted an emergency egg harvest, rushing more than three dozen of them to Reillo’s safe harbor. After candling them, he determined that 23 were still viable (the fact that he could tell the state of their embryos meant they’d been in the nest for at least three days). Those went into the incubator, and all but two successfully hatched.

“That just began the difficulty, of course,” Reillo says. The diet that works so well in chicks that are just a few days older seemed to go right through these hatchlings. Despite heroic round-the-clock, all-hands efforts and ongoing adjustments to the protocol, they just withered away; of the 21 chicks successfully hatched, 11 didn't make it. “If the parents are successful in feeding them for a few days, they stimulate the immune system somehow, seeding the gut with gastric juices that have the full complement of gut flora,” Reillo says. “And the result is that we have had 100 percent success, every single nestling brought to us that is at least three days of age lives—a hundred percent. Doesn’t seem to matter how sickly the damn thing is. As long as it’s not dead and the parents have fed it, we’ll raise it fine. That’s remarkable.” But if the parents haven’t fed it, the success rate plummets.

Taking on the role of parents, biologists prepare a grasshopper buffet after relocating a nest of three hatchlings. During the one-and-a-half-hour transport to the Rare Species Conservatory, they will stop several times to feed each chick. Photo: Mac Stone

And the problems with day-one chicks seem to compound dramatically when the chick is hatching from a day-one egg. For one thing, these chicks were weighing in at as much as 40 percent lighter than the roughly 1.5 grams of a normal tiny Florida Grasshopper Sparrow hatchling. That historic first-ever chick hatched from a day-one egg died within days—as did the next, and the next. In all, of the dozen chicks that Reillo miraculously managed to hatch from day-one eggs, only one has survived. Captive breeding is not for the faint-hearted.

 

I suspect that a common misperception exists among that subset of people who are even aware of the Endangered Species Act (ESA): the belief that, once a species is listed as endangered, the federal government—the Fish and Wildlife Service in particular, if your awareness runs that deep—has some sort of absolute responsibility to do (and fund the doing of) everything possible to keep said species from going extinct. It’s what I thought, anyway.

Apparently, that is not the case. Early this year, word came down that the USFWS, which over the past four years had disbursed more than a million dollars in Florida Grasshopper Sparrow–recovery funds, would not commit to further financial support for the program. “When I heard the bad news that this program wasn’t going to get supported, the sparrows weren’t going to get any funding, it was like getting shot in the chest,” says Sandra Sneckenberger, who, don’t forget, works for the USFWS. “This is what we do, what the Fish and Wildlife Service does: We protect endangered species. If we don’t—isn’t the public going to wonder, ‘If you don’t do this, who is going to do it?’ ”

But here’s the thing: The USFWS Southeast Region office, out of Atlanta, oversees the agency’s work in 10 states plus Puerto Rico and the U.S. Virgin Islands. That territory is home to about 400 animal and plant species that have been declared endangered under the ESA. (The regional office is also obligated to evaluate roughly 400 additional at-risk species to determine whether they’re candidates to be listed.) The total annual budget for this work is $14 million. “That’s about $35,000 per species,” says Leopoldo Miranda, the USFWS assistant regional director. (And that’s if you’re counting only the 400 currently listed species.)       

A Florida Grasshopper Sparrow calls from a perch on a private ranch in south Florida. Biologists use these vocalizations to help locate inconspicuous nests throughout the year. Photo: Mac Stone

And, quite reasonably and sometimes unreasonably, not all species are created equal from a USFWS-funding standpoint. For instance, captive-breeding programs for just two of them, the red wolf and the Puerto Rican Parrot, eat up a relatively hefty $1.2 million and $900,000 a year respectively. “It’s a really tough decision, because we all want to keep funding all the species at the right levels, but definitely we don’t have that capacity,” Miranda says. “In terms of programs like the red wolves and parrots, it’s mostly a historical thing. We made that decision ‘way back when’ to have captive-breeding populations and we’re fully committed to those and now we are where we are.”

All of which is to say, while Fish and Wildlife, from a rhetorical standpoint, declares its undying commitment to the Florida Grasshopper Sparrow (“I want to be able to go back and tell everybody, my kids, that we did everything we could to save that species,” as Miranda puts it), from a financial standpoint it’s stepping aside. “There are reasons to be optimistic” about the Florida Grasshopper Sparrow’s chances of overcoming extinction, says Larry Williams, the USFWS’s Florida state supervisor for ecological services. “But I think it’s appropriate for the Service to say, ‘How much can we continue to invest in this species given all the other species we need to give attention to?’ “

In mid-May, at the urgent behest of other members of the working group, Williams issued a formal letter on USFWS stationery declaring that “our previous funding sources are no longer available in amounts that would fully fund the program”—a declaration that Reillo and others argued was essential if they were to somehow attract outside funding to make up the difference. As Reillo puts it, “It’s almost impossible to garner independent support for anything that’s seen as a federal program.”

Since that letter was issued, a web page has been set up under the auspices of the Fish & Wildlife Foundation of Florida to receive tax-deductible donations to directly fund Florida Grasshopper Sparrow recovery work. But, so far at least, no coordinated fundraising effort has coalesced—mainly because, who has the time? As Reed Bowman, Archbold’s avian ecology director, who oversees the sparrow monitoring and recovery work on the ranch, concedes: “I’m not sure I have the bandwidth to go out seeking foundation grants for money that the Fish and Wildlife Service used to spend.”

After a successful capture, field biologists Windsor and Sweeting break down the mist net once the sun is too high up. In bright light, the sparrows are more likely to see the gossamer trap. Photo: Mac Stone

So as the Service’s field biologists prepared to collect from the prairie the birds that were needed to give the long-shot captive-breeding program its best chance to succeed, they did so without knowing where the money to keep the program going—hundreds of thousands a year—would come from.

 

On a Friday in early July, the USFWS convened another working-group session, something of a coda to the 2014 meeting, this time less about whether to collect the birds and more about how many and from where. Reillo attended reluctantly; his enclosures were nowhere near complete, and he felt the time would be far better spent holding a drill and a staple gun than relitigating a decision that as far as he was concerned had been made long ago. But in the end he drove the two hours north to Vero Beach. And maybe it was a good thing that he made the trip. “There was actually a point after five-plus hours of deliberation where somebody said, ‘I want to backtrack a little bit and question the whole idea of the urgency of collection,’ ” he said afterward, his voice still carrying evidence of the dismay he must have felt in the moment. “That’s when I said, ‘People, do not kick this thing down the road. This is the last year. I do not think they’ll be able to collect even six pairs. And if the collection isn’t done now, then really you have to say it’s never going to happen.’ ”

Ultimately, the decision was made to bring in six pairs. At that point, two nests at the ranch had already hatched; the nestlings were expected to fledge by the following Thursday, so the plan was to capture the birds on Wednesday—five days hence. Then, over the weekend, first one nest and then the other were swarmed with fire ants, the nestlings killed, the parents escaping to establish another nest somewhere nearby and start the cycle anew.

Over the past decade, USFWS recovery biologist Sandra Sneckenberger has seen the Florida Grasshopper Sparrow population hit many new lows. Photo: Mac Stone

The techs were monitoring two other nests at the ranch, and Sneckenberger decided to bring those in as early as possible. Then the storms began. “At lunch we started getting worried about the family we were about to collect,” Sneckenberger says. “We had the techs go out there, and the nest was flooded big time. Totally flooded. And it had a just-hatched chick. And one pipping egg with its little beak sticking out, and one other egg.” They raced to rescue those just-hatching birds and rush them over to the Avon Park Air Force Range, to place them in another nest that was also just hatching. One of the techs at Avon Park fed the day-one chick overnight, and he and another tech took turns standing vigil over the nest. “They kept running out there to check whether it was flooding, and ended up lifting that nest three times,” Sneckenberger says. “We’d have calls, and they’d be like, ‘It’s still really wet, we can lift it again. We’d totally be breaking all the protocols.’ But what’s the alternative?”

The next day, the mist nets were strung at the ranch and the techs managed to capture the female parent and bring it to Reillo’s enclosures; a bachelor male was later brought in to join her. Against all odds, every one of the eggs that had been taken to Avon Park hatched and successfully fledged. With luck, one or two will survive through winter. That Friday, another breeding pair was captured from the other monitored nest at the ranch and successfully transported to Rare Species.

Windsor ages a wild-caught Florida Grasshopper Sparrow while Sweeting writes down the data. Photo: Mac Stone

And then, for nearly a month, the collection efforts stalled: one wild breeding pair captured, another male and a female collected separately and cobbled together to form a second pair, four enclosures still empty. This pause was basically a function of the natural rhythms of the prairie; as Sneckenberger explained, “The landscape had to dry out so birds would nest. You can’t find a pair if they’re not nesting.” But even so, Reillo was having a hard time containing his impatience. “We’ve got four empty spaces that I’m either going to fill or set on fire,” he said, ever sardonic, on August 3. “I’m going to put pygmy marmosets or butterflies in them just to make a statement.”

And then, suddenly: Six new nests were discovered. In relatively quick succession the field biologists collected a family of seven, then a pair, then a family of five. Finally, on Friday, August 18, Sneckenberger and her crew netted a solo male from Three Lakes—the final sparrow to be captured this season, possibly ever—and delivered it to Rare Species to be paired with a female sparrow that had been rescued from Avon Park in June. All of the cages had been filled. They weren’t all proven pairs, ongoing funding is yet to be secured, and there is certainly no telling whether captive breeding will ultimately succeed. But at least, finally, the USFWS, the Florida Grasshopper Sparrow Working Group, and all the rest of us will have the chance to find out whether captive breeding can save the most endangered bird in North America.

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