Solutions
10.30.2019

Song of the Mountain Chicken

These giant frogs—once a delicacy on two Caribbean islands—were almost wiped out by disease and natural disasters. But their resilience and years of dedicated conservation efforts have kept hope for the species alive.

The propeller plane passed through thick clouds, twisting and dipping in the wind like a toy on a string. Its flight to Montserrat—a small volcanic island in a chain of more than a dozen Caribbean territories and nations that curves from Puerto Rico to South America—was just 20 minutes. For 28 of the plane’s occupants, though, it was the culmination of 30 hours of travel from Europe, plus a decade of labor. The pilot and the plane’s lone human passenger, Luke Jones, sat in seats up front; the 28 crouched on shredded paper, each within a cloth bag nested inside one of six wooden crates. If any of those 28 frogs called out in instinctive recognition of their ancestral home, it would have been impossible to hear over the engines’ roar. But when the plane landed and the engines shut off, the animals were deathly silent.

Jones had expected this; the frogs—most commonly called mountain chickens (Leptodactylus fallax)—dislike disturbance. Still, he worried. Had the hold depressurized on the connecting flight from the UK? Had the noise and stress of travel been too much? Or, as he and the rest of the Mountain Chicken Recovery Programme team on both sides of the Atlantic Ocean dared to hope, would the frogs arrive safely on the island that their grandparents had been evacuated from a decade earlier, in a desperate bid to save the species? Jones is the coordinator for the project, a joint venture among several groups, including Montserrat’s Department of Environment, the Zoological Society of London, and the Durrell Wildlife Conservation Trust, based on the island of Jersey off the north coast of France. He likened the experience to awaiting the birth of a child, though at 26, with scruffy facial hair and an occasional man bun, he doesn’t have kids of his own.

Plenty of others held vigil on the ground and the airport roof, including the governor, local lawmakers, and a musician playing steel drums and singing folk songs about mountain chickens. Such a welcome for a couple dozen frogs may seem excessive. But mountain chickens are not only among the most endangered frogs in the world; they are also a symbol of home for Montserratians living on the island and overseas, and used to be one of the island’s best-known delicacies. Their common name derives from their pale flesh, which, yes, reportedly tastes like chicken. The once-abundant frogs had been all but absent from Montserrat since a deadly fungus devastated them in 2009.

After unloading the plane, Jones and the rest of the team didn’t linger amid the celebrations. They drove the crates on two flatbed trucks to a field hospital at the Montserrat National Trust, a conservation organization with a botanical garden. There, the frogs might lend their voices to the island’s nighttime soundscape for the first time in years.

Assuming, that is, that they had survived the flights.

The animals native to Montserrat and the other islands in the Caribbean’s Lesser Antilles arose from ancestors that arrived from elsewhere, via wind, wing, and natural rafts spat from the mouths of rivers emptying the northeast coast of South America into the sea. Scientists believe mountain chickens evolved on a single island, after their own South American precursor arrived between 23 and 34 million years ago. From there, their journey was more gustatory than serendipitous. People moving through the Lesser Antilles as many as 5,000 years ago likely developed a taste for mountain chickens and brought the frogs along as they traveled, introducing them to several other islands.

In 1872, humans reshaped the frogs’ range yet again when they brought nine mongooses from India to Jamaica to control rats on sugar cane plantations. The voracious, weasel-like predators eat whatever they can catch, and mountain chickens are prime, meaty targets. Only two islands with mountain chickens escaped the ensuing Caribbean-wide mongoose population explosion: Montserrat and mountainous, rainy Dominica, a few islands to the southeast.

To a human outsider, mountain chickens might not look as appetizing as the more familiar avian variety. Including their legs, they can grow to well over a foot long, and they have a heaviness that seems to surpass even their formidable size; the largest approach two pounds. Wavy, dark green and brown splotches and stripes adorn their beige heads, backs, and legs, helping them blend into the forest floor. But being eaten is a defining characteristic of mountain chickens. Seemingly everyone who has lived on these islands, from indigenous inhabitants to European colonizers to the descendants of their slaves, has dined on the “white, tender, and delicate” flesh of the frogs, as a Dominican missionary in 1694 described it. In recent decades, tourists also started coming to the islands, seeking out the frogs. Mountain chickens “put Montserrat on the map,” says Philemon Murrain, who goes by Mappie and works for the Montserrat National Trust. Presented with the smells of fried bird and fried frog, adds local guide James Daley, a former Forestry Officer who goes by Scriber, “you would never go to that poultry section.”

On Montserrat, people mostly hunted frogs to sell to hotels, where cooks breaded and fried them for guests. But some Montserratians also turned to them as a cheap source of protein when other meat was too expensive, heading for the mountains with kerosene lamps and collecting the amphibians by the sackful. On Dominica, hunting mountain chickens for personal consumption was much more common; the frog, known there as crapaud, was the island’s national dish.

In the early 2000s, though, local officials and conservationists began to see signs that Dominica’s frogs were struggling. Estimates at the time put the yearly take of mountain chickens at between 18,000 and 36,000 animals, implicating overhunting as a primary threat. But residents also started calling Dominica’s Forestry Division with reports of sick or dead mountain chickens. Arlington James, a Forestry officer at the time, remembers a friend phoning in late 2002. “‘Arlington,’” he asked, “‘what is happening to our mountain chicken? What is happening to our crapaud?’”

Dominica’s chief veterinary officer ordered that carcasses be sent to a lab in the United Kingdom, which confirmed that the cause was what scientists and conservationists monitoring the frogs had suspected: chytrid fungus. Then only recently identified, the fungus is one culprit behind widespread declines of amphibians around the world, alongside habitat loss and pollution. 

Hoping to understand the extent of the die-offs, the Forestry, Wildlife, and Parks Division teamed up with conservation groups to broaden ongoing mountain chicken surveys, and Dominica’s government banned hunting of the frogs in 2004. But there was little left to save: In just 18 months, mountain chickens had all but disappeared from Dominica.

The last stronghold on Montserrat would soon fall as well. The small island imported much of its produce from Dominica—easy transport for a stowaway tree frog, which could carry the fungus. In early 2009, Montserrat forestry officials began finding dead and dying mountain chickens.

As dusk fell one evening in May of that year, a group of men wound their way up a narrow path in the eastern hills of Montserrat, among them Scriber and Mappie, as well as other forestry officials and conservation scientists. They carried dozens of small cloth bags with them; each, they hoped, would contain a mountain chicken by night’s end.

Their destination was Fairy Walk, a stream-fed, boulder-strewn patch of forest on the island’s eastern side, accessible only by a two-and-a-half hour hike. It was among the last places on the island that remained free of chytrid. The frogs were so thick then that the crews’ headlamps shone in whole galleries of eyes. It was like being at a rave, Scriber says, “where everybody would have a glowstick in their hand.” The men worked through the darkness, catching and bagging frogs much as hunters once did. Toward dawn, they tied the bags to long branches and carried them back down from the mountains, their catch destined for captive breeding facilities in Europe. These frogs would never again set webbed foot on Montserrat—but, if all went to plan, their descendants would.

Montserrat is an island of many peaks, flanked by coastal settlements. The highest point, the active Soufrière Hills Volcano, is often obscured by clouds and smoke. Around it, the rough terrain is cloaked in dense forest or covered in swaths of ash from recent eruptions. Huge-leafed plants, broad enough to cover a person’s back, rise up a dozen feet, seeking what dappled sunlight manages to filter through the thick canopy; ropy roots dangle from above, seeking new ground. During the day, birds call through the trees. As night comes, the sounds build: a background layer of shrill, stridulating insects, overlaid with the high-pitched, robotic chirps of tree frogs. But soon after the 2009 evacuation, the forests lost their concertmaster. Small pockets of surviving mountain chickens dwindled, then disappeared. The call of the mountain chicken—a trilling, chirruping yelp, like a small, yapping dog with something in its throat—no longer filled the rainy dark. “It should be a symphony,” Scriber says now in a far off way, as if listening to something beyond hearing. “When it echoes into some of those valleys … Oh my gosh.”

Call of wild mountain chickens on Dominica (recorded by Geoffrey Giller)

Fortunately, the frogs that Scriber, Mappie, and the others had caught were thriving on the other side of the ocean. Within two years of the evacuation, conservation researchers at Durrell began flying captive-bred mountain chickens back home. By then, nowhere on the island remained safe from chytrid, so the researchers and their partners at the Montserrat Department of Environment released them near a stream, easily accessible for monitoring, called Sweetwater Ghaut (pronounced “gut”), where they had once flourished. The researchers knew the frogs might be headed to their deaths, like astronauts sent on a one-way mission to Mars, but they hoped their sacrifice would provide crucial information for future generations.

The losses were heavy; 22 frogs died in transport when the temperature in the cargo hold of their plane unexpectedly plummeted. Then, in 2012, a small plane carrying Mike Hudson—a PhD student who would later become a major player in mountain chicken conservation—crashed en route from Antigua to Montserrat. The pilot and two other passengers were killed, but Hudson survived. After recovering in the UK, he continued to work on the project from afar, analyzing the data from the released frogs.

The team successfully reintroduced 121 mountain chickens over three years. As they tracked the animals via implanted radio transmitters, they found that, while some quickly succumbed to chytrid, others persisted for more than a year. Still, one by one, the frogs all vanished. Like so many other species before them, it seemed that mountain chickens might persist only in captivity, absent from the world’s wild ecosystems.

But on Dominica, even though surveyors searching along transects once dense with frogs no longer heard their trills, residents had begun reporting mountain chicken calls to Forestry officials. In 2011, Forestry officials and a volunteer from Durrell found six wild juvenile frogs. Swabs indicated the presence of the fungus, and those mountain chickens weren’t seen again. In subsequent years, though, more young but sexually mature frogs turned up, plus handfuls of older ones.

Inexplicably, Dominica’s mountain chicken population was growing. Had they developed resistance to chytrid? Could their survival be a key to saving not only this species on Dominica and Montserrat, but also other frogs that had suffered from chytrid around the world? Either way, their re-emergence was a rare good turn for the species, a ray of light through the clouds that illuminated a path forward.

There are two ways to find mountain chickens at night. The first is by their call, sometimes deceptive since the sound can ricochet down the hillsides. Once you have an idea of where a frog is, though, the surefire method is to use light to catch the reflection of its eyes, which shine a distinctive salmon color—that glowstick flicker in the night.

On a cool, clear evening in July, I joined a field crew on a survey for wild frogs on Dominica—the descendants of the fungus epidemic’s survivors. The goal of these surveys, a collaboration among the Forestry Division, a local NGO called WildDominique, and the Zoological Society of London, is to get a better handle on exactly how many wild mountain chickens are left on Dominica. Nina White, a PhD student at the University of Cardiff who is trying to understand how Dominica’s mountain chickens have survived chytrid, sat shotgun on the drive to the survey site. Tiffany Mason, a 20-year-old Junior Amphibian Tech with the Forestry Division, sat in back. Passing close-cropped pastures, the truck bounced up a dirt road, then rolled to a stop by a dilapidated fence. As soon as the engine went quiet, we heard one, then two male frogs calling into the night. On foot, we veered off a wide grassy path into the nearby woods, fighting through vines and brambles. Before long, one of the team spotted the telltale eyeshine. A male, his throat pouch distended, perched on a small boulder, and fell silent when we approached.

There’s something special about seeing an endangered species in its natural habitat, alive despite all the odds stacked against it, right here where its distant ancestors lived, an unbroken biological line that connects it to its forebears.

White didn’t linger to appreciate the moment. Standing precariously on a wet log behind the frog’s perch, she started to slip and lunged for her target. The frog gave a startled croak-squeak as White covered it with her gloved hands, then wrapped her fingers around its waist.

After a few exclamations of delight from the rest of the team—this was the first wild mountain chicken Mason had seen, despite participating in numerous surveys—they got down to business. Mason pulled out a mint-green, medical-looking device to check if this frog had been caught and tagged with a chip during past surveys. The reader beeped: Number 80640, a.k.a. Big Joe.

“Hey buddy,” Mason crooned at the frog, whose long, meaty legs dangled helplessly for the moment. Mason and the rest of the team formed a tight cluster in the dense forest, their headlamps a bright pool in the night as they swabbed, measured, and weighed. Two more males called in the distance.

The swabs were bound for Wales, where White will look to see whether the frogs that survive on Dominica are somehow special. Studies of other frogs have indicated that some species may host microbes on their skin that keep chytrid in check. If that’s the case with these Dominican mountain chickens, it could provide a tool for helping the frogs on Montserrat, as well.

“I feel accomplished,” Mason declared after the swabbing. Another member of the crew returned the frog gently to his perch, and we moved back through the underbrush, leaving bruised leaves and broken branches in our wake, to seek out the others calling in the night. Big Joe gave a few tentative chirrups—apparently none the worse for wear.

That these frogs are here at all is evidence not just of their resilience through chytrid, but also through a massive natural disaster—one that simultaneously energized local conservation efforts.

In 2017, Hurricane Maria wrought almost unimaginable destruction: trees rendered into branchless spires and the roads filled with debris, logs, and cars. Dozens of people died. The roof of Dominica’s sole mountain chicken breeding facility collapsed, killing two of the three frogs housed there. In the wild, there had been perhaps 100 frogs before the hurricane; Maria “devastated every site,” says Mike Hudson, now a conservation research fellow with Durrell and the Zoological Society of London, who oversees the scientific aspects of the Montserrat reintroduction and advises White’s research on Dominica. But frogs like Big Joe survived. “Trying to put a number on it now is exceptionally hard,” says Hudson. His best guess is that about 40 wild mountain chickens made it through the hurricane—the last of their kind in the world. 

Despite their vulnerability, the ranks of the frogs’ allies are growing among a new generation, thanks in part to the founder of WildDominique, a 24-year-old named Jeanelle Brisbane. Though she wasn’t able to join my outing, Brisbane usually accompanies the survey crew on their nighttime rounds. She grew up on Dominica; the mountain chickens’ call “was a huge part of my childhood,” she remembers, but “it’s fading from my mind, now, what it used to be like back then.” When she set out to study what Dominican school children knew and felt about wildlife on the island, though, it was worse for them: they had little or no direct experience of mountain chickens to forget, and their knowledge of the other unique wildlife on Dominica was, Brisbane says, “depressing.” After the hurricane hit, she saw a clear need for a country-wide conservation organization. “There were a lot of things that needed to get done,” she says, “that weren’t getting done.”

Now, Brisbane serves as a sort of nexus through which Dominica’s mountain chicken conservation efforts flow. Occupying a temporary position with the Forestry Division, she connects Hudson and other Europe-based researchers with local officials. She has a commanding gaze, a deadpan manner, and an air of self-assured calm, despite often being on call to troubleshoot any number of logistical challenges that can ensnare conservation projects, firing off WhatsApp messages while seamlessly carrying on in-person conversations. Before we spoke, she had been digging up the documentation that White would need to include with the frog swabs she planned to take back with her to the UK, then finding syringes and supplies needed to sample blood from invasive iguanas captured the night before. “Through WildDominique,” says Hudson, “it’s exceptionally easy to get things done.”

Mason, the amphibian tech, finds Brisbane inspiring. She thinks more young people should be conservation leaders. “Hopefully we can start a new era of interest and understanding.”

There’s plenty more work to do. Mountain chicken habitat on Dominica isn’t legally protected; all the surveys occur on private property, and landowners could develop anywhere the frogs are found. Durrell Wildlife Conservation Trust and WildDominique have been exploring the possibility of partnering with the Rainforest Trust to create a protected area where Big Joe was caught. Even so, the possibility of future natural disasters—especially as climate change increases the severity of hurricanes—means that the people fighting to keep mountain chickens in the world can’t rely solely on the Dominican frogs’ resilience. Hence the continued efforts on Montserrat, where there’s also reason to be optimistic.

The mood was tense but excited when Luke Jones, Hudson, Scriber, and the rest of the team arrived at the Montserrat National Trust’s multi-building compound and lush gardens in July with their 28 mountain chickens—the first to be reintroduced since 2014. They wasted no time prying the crates open and pulling the frogs from their cloth bags. In one of the first bags they opened, a female was still and lifeless. “That was everybody’s worst nightmare,” Jones remembers. “Your heart just plummets.” 

But as more and more frogs emerged breathing and kicking, it became clear that the dead frog was an anomaly; the rest were hale and hearty. Soon, the team had soaked them all in rehydrating, electrolyte baths and released the mountain chickens into temporary indoor enclosures—wooden, plastic lined-frames draped in mosquito netting—where they could hide among the dry leaves, or tuck into short sections of white PVC pipe meant to serve as shelters.

As the team packed up for the evening, rain started falling outside. Then—a single, quick trill. Everyone in the room froze. Another male responded to the first. The humans quietly slipped out and assembled by the doorway—dead tired, sitting or lying on the floor, listening. 

The mountain chickens were calling again on Montserrat.

Where the mountain chickens’ voices really belonged, though, was in Montserrat’s forests. So a couple of days later, Jones, Hudson, and the rest of the team brought the frogs to a pair of outdoor enclosures in the middle of the woods on a hillside in the northeast of the island. Jones had built the low, prison-like walls from metal fencing and aluminum sheeting. The setup is starkly different from the biosecure world where these frogs were raised, with its specialized UV lights, heated areas, and protocols to prevent contamination.

Here, the frogs are expected to feed on the island’s native insects, which can easily pass through, over, and under the walls that keep the frogs from escaping. Tree frogs that carry chytrid can also get in. If mountain chickens are ever to return to the wild—where chytrid is now ubiquitous—they must somehow co-exist with the fungus. The team plans to support them with small heated, rubber-lined ponds in each enclosure.

“During the [earlier] reintroductions, we found that they spent a lot of time in water, predominantly when they became infected,” Hudson explains. Frogs are cold-blooded, relying on external sources of heat. Some species have been shown to increase their body temperatures in response to sickness, with what Hudson calls a “behavioral fever.”

And mountain chickens can tolerate temperatures well above the temperature that kills chytrid. “We thought, ‘Let’s heat up the ponds,’” Hudson says. In tests with captive frogs, some seemed to relish the warm water. Of course, chytrid wasn’t present in their biosecure facility. So Hudson and his colleagues couldn’t actually test whether infected frogs might use these heated ponds to cure themselves, like miniature, heated Lourdes baths. They’ll have to see if it works here.

The scalability of this approach is another major question. If the heated ponds do seem to help, then that suggests a few different possibilities, says Hudson. One is installing similar solar-power heated ponds across the island. Or ponds could be created with the surrounding canopy trimmed back, so the sun can heat the water passively.

And then there’s the “blue-sky, who-knows-what-will-happen” dream, says Hudson: that if the frogs are repeatedly exposed to the fungus, but able to keep themselves alive through use of the heated ponds, they may develop some immunity to chytrid.

Before 1995, more than 10,000 people called Montserrat home. Then, multiple eruptions of the Soufrière Hills Volcano—the first in centuries—rendered Plymouth, Montserrat’s former capital and largest town, uninhabitable. Pyroclastic flows destroyed several villages and killed 19 people. Witnesses compared the largest eruption to a nuclear explosion. Today, the southern two-thirds of the island are off-limits. Only around 5,000 people now live on Montserrat; the rest remain overseas after evacuating.

“For us, a big part of our being Montserratian … is consideration of Montserratians in the diaspora,” says Shirley Osborne, the Speaker of the Montserrat Legislative Assembly. “It’s a word that every Montserratian knows, now.” She sees parallels between the story of mountain chickens and the story of Montserratians. “Something terrible happened here that destroyed their ability to live in their habitat… and so they had to go elsewhere. And the question is now, can we bring them back?”

Less than a week after they were moved to the outdoor enclosures, I visited the frogs one night with Jones and Calvin Fenton (who goes by Blacka), an expert on mountain chickens working with the team. Almost immediately, we spotted the first one, a large female. Mountain chickens have a certain bearing—forearms cocked slightly outward—that suggests that they know that they’re the biggest, baddest things around. This frog, sitting on the fine, dusty volcanic ash that covers much of the island since the eruptions, seemed at home.

The next day, Jones returned to change out the water in the ponds. He filled large water cooler jugs from a stream named Runaway Ghaut that flows down one of the hillsides. This particular water source was chosen for its easy access, draining right next to the road. But there is also a legend about Runaway Ghaut, posted on a sign nearby: “If you drink from this burn, to Montserrat you will return.” That is, anyone who drinks from the water of this stream is destined to one day return to Montserrat. And the mountain chickens? They’re soaking in it.

 

Nicolas Eguren Cleffi contributed additional reporting for this story.

Geoffrey Giller

Geoffrey Giller is a freelance science journalist and photographer based in Berlin. He has a Master’s degree in environmental science and a special love for amphibians. His writing has also appeared in The New York Times, Discover, Scientific American, and Audubon, among other outlets. You can follow him on Twitter @GeoffreyGiller and see more of his photography and writing on his website.

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