The song was a surprise: A succession of coos like water drops, both monotonous and musical. They sounded sleepy, familiar, and yet just foreign enough to catch ornithologist Rafael Bessa’s attention.
It was a brilliant June afternoon in 2015, and the song fluted from some rock outcroppings near the verdant palms of a vereda, or oasis, in an expanse of shrubby grasslands in southern Brazil. The country’s Amazon rainforest has long captured conservation headlines, but the cerrado—as this mixed savanna of grass, brush, and dry forest is called—covers 20 percent of the country’s landmass, and is more threatened. Bessa himself was there in the state of Minas Gerais to conduct an environmental assessment for a proposed agricultural operation. He had stumbled on the vereda while driving from his hotel to a distant survey site. There was no time to investigate the plaintive call, but the “woo-up…woo-up…woo-up” sounded a bit faster and deeper than the Ruddy Ground-Doves that occur in abundance in the area. Bessa decided to return.
The next day, he managed to record the mysterious call and summon its maker into a nearby bush with the playback. He aimed his camera and took a series of photographs, then zoomed in on the images.
It was indeed a small dove—not necessarily the sort of quarry birders get twisted up over. Its back was an unspectacular greenish-brown, and its head, tail, and breast were a muted ruddy orange, blending to a creamy belly and a set of bony pink feet. But its eyes were arresting pools of spectacular cobalt blue, echoed by little half moons of the same dabbed across its wings.
Bessa’s hands began to shake. “I had no doubt that I found something really special,” he says.
Seeking confirmation, he texted his friend Luciano Lima, the technical coordinator at the Observatório de Aves of the Instituto Butantan, São Paulo’s biological and health research center. Lima had done his master’s degree in a museum with an extensive specimen collection, and agreed to drive to his office to pull up the photos on his computer and see if he could identify the mystery dove.
“I was in my car,” Lima recalls, “and he suddenly sent me one of the pictures, and I almost crashed!”
Lima called Bessa back from the institute: “‘Hey man, you found the bird! You found the bird!’ I remember repeating it to him like a thousand times.”
Bessa had discovered a pocket refuge of Columbina cyanopis, the Blue-eyed Ground-Dove. The creature was exceedingly rare; some suspected it was extinct. Though there had been a few published sightings over the past couple of decades, it hadn’t been documented with hard evidence in 74 years. And Bessa had taken the first-ever photos and recordings of the bird some 600 miles away from the nearest place specimens had been collected.
“There is thousands and thousands, and hundreds of thousands, and millions of thousands of hectares, and he just managed to be in the exactly right place,” Lima marvels.
When Lima himself went out to see the bird a year later, after the rediscovery was announced, he was overcome.
“I don’t have words to describe it,” he says. “It’s like seeing a ghost.”
The reappearance of such ghost species isn’t as unusual as you might think. According to a 2011 review in the journal PLOS ONE, some 144 bird species have been “rediscovered” over the last 122 years, the vast majority of them after 1980. In 1984, ornithologist Dick Watling stumbled on the “extinct” Fiji Petrel after years of searching when a juvenile flew into his head one rainy night.
“A more undignified return to human awareness after 129 years of peaceful oblivion could not be imagined,” Watling later wrote.
In a recent wave of finds, researchers turned up the Banggai Crow, not seen since 1900, in Indonesia in 2007; the Jerdon’s Babbler, undocumented since 1941, in Myanmar in 2014; and, the Blue-bearded Helmetcrest hummingbird in Colombia in 2015, after a 70-year absence.
Against the backdrop of a human-caused sixth mass extinction, it’s tempting to regard such tales as glimmers of light in a dark time. Just as there is a recently coined term for the last individual of a species—an endling—so too is there a much older phrase for those that reemerge—a Lazarus taxon, named after the man Jesus brings back from the dead in the Bible.
Still, rediscoveries say less about miraculous recovery than they do about our limited knowledge of a world we are reshaping at a breakneck pace. As Paul Donald, Nigel Collar, Stuart Marsden, and Deborah Pain wrote in their 2013 book, Facing Extinction, nearly all birds “begin their taxonomic lives—their epistemological existences—as rarities,” known only from one location and a specimen or two. It’s only with consistent attention and study that a more complete picture of a species emerges—where it lives, what it needs, how numerous it is. Even today, though birds are some of the best-studied creatures on Earth, many species remain “inveterate skulkers in the historical undergrowth.”
The 2011 PLOS review found that 40 percent of rediscovered bird species were known only from the original type specimens that led to the first formal description of the species, decades to centuries ago. Some may have been hard to refind because their collector hadn’t noted basic details about the location of capture, let alone life history and habitat requirements. Others may not have been resurveyed or confirmed because they were remote and had secretive habits that made them difficult to track. Or people simply may have not been searching for them. Some were locked away in conflict zones where it was dangerous to search. For example, the Táchira Antpitta—a leggy, quail-sized bird known only from four specimens collected 60 years ago—has been difficult to reconfirm because it was initially found in cloud forests on the Venezuela-Colombia border, an area rife with guerrilla activity and drug trafficking. [Note: the Táchira Antpitta has since been rediscovered by a team led by Venezuelan biologist Jhonathan Miranda, announced in July 2017.]
As the number of searchers and searches has increased—with more taxonomists, bird watchers, ecotourists, and expeditions—so too has the number of rediscoveries climbed, particularly in the tropics where there are vastly more species. Ironically, increasing incursion into and development of wild places has probably also fed the trend.
“If a bird has not been seen in North America or Europe for several decades, then it’s a safe bet that it just isn’t around anymore. Too many people looking, too few places to hide,” explains Neotropical bird expert Tom Schulenberg, a research associate at the Cornell Lab of Ornithology. But “countries in the tropics tend to have less in the way of infrastructure. Fewer roads, fewer scientific institutions, fewer biologists, less money to throw around on pursuits such as searching for lost species.” That leaves more yet to discover—and rediscover.
If a “lost” bird species has made it long enough to be rediscovered, there is the hope of helping them eke out an existence for a little longer.~Tom Schulenberg
For hard-to-find creatures, the difference between steep population decline and actual extinction is a murky one. Often rediscoveries simply reveal that a rare species is getting rarer. Some 86 percent of birds described in the PLOS paper remained highly threatened when they reappeared on the scientific radar, many for decades afterward.
Still, reemergence is also evidence of resilience, and a chance at some kind of redemption. A small population makes a species more vulnerable to random destructive events and inbreeding, but it’s not necessarily a death sentence. Biologists have successfully used interventions such as nest protection and captive breeding to bring California Condors back from 22 individuals in 1981 to more than 200 in the wild in 2014, and Mauritius Kestrels from the last four of their kind in 1974 to a wild population of around 400 in 2012.
If a “lost” bird species has made it long enough to be rediscovered, Schulenberg says, “there is the hope of helping them eke out an existence for a little longer.”
Hunting for Ghosts
That hope is what Daniel Lebbin, vice president of international programs at the American Bird Conservancy, had in mind when he cooked up the organization’s Lost Birds of the Americas project about three years ago. Combing over the International Union for Conservation of Nature’s Red List of Threatened Species, Lebbin made note of some 24 birds that were listed as critically endangered, but hadn’t been seen in the wild for a long time. Then, he eliminated some species that had already been searched for unsuccessfully, and island endemics that had likely been devoured out of existence by invasive species such as rats or killed off by exotic disease. In the end, he was left with just a few continental species whose potentially larger ranges left more room for holdouts.