Scientists estimate that 179 species of bird have gone extinct since the year 1500. Around 90 percent of those losses happened on islands, as in the case of the Mauritius night heron and the Tasmanian emu. And about half of the avian extinctions took place at the hands, or paws, of invasive mammals. Rabbits, for instance, took over the Laysan rail’s Hawaiian home turf, and cats and stoats rid New Zealand of its laughing owl. Biologists attribute yet another 25 percent of the extinctions to hunting and trapping, the fate of many a dodo.
But the extinction record, after half a millennium spent replaying this island invasions groove, now seems to be skipping to another track, the mainland.
“What we’re seeing increasingly is a growing wave of extinctions washing over the continents,” says Stuart Butchart, chief scientist at BirdLife International, an avian conservation group.
A new study, published in Biological Conservation by Butchart and colleagues at BirdLife and the University of Cambridge, now classifies eight more species as extinct or suspected to be extinct—and six of those are native to continents, not islands.
The causes of these avian losses are also not the typical invasive species or overhunting variety, but instead are heavy on deforestation and habitat destruction. Surely, such threats aren’t unique to modern times, but the findings suggest that we may have reached a tipping point.
“The scale of the impacts that we’ve had on the environment is now such that we’re pushing a whole suite of species toward extinction,” says Butchart. In other words, even the world’s larger landmasses can’t buffer all the blows of humanity’s ecological assaults.
Take the Pernambuco pygmy-owl of Brazil. Scientists officially described the raptor only in 2002, basing their observations on the skins of two birds found back in 1980 instead of on live specimens. If the pygmy-owl was once widespread, it’s not anymore, thanks to rampant illegal logging and the habitat fragmentation that comes with it. According to the new report, the species has lost “virtually all” of its lowland forest home. And despite several focused attempts to find one, no one has seen a Pernambuco pygmy-owl in 17 years.
Using a new algorithm that accounts for the intensity of a species’ threats, the timing and reliability of sightings of the animal, and how hard we’ve searched for it, Butchart and his colleagues propose that the Pernambuco pygmy-owl’s status be changed from “critically endangered” to “critically endangered (possibly extinct).”
You may be wondering why scientists don’t just pull off the Band-Aid and label the owl extinct with a capital E? Well, this is where things can get tricky. If scientists make the extinction call too soon, Butchart says the label may cement the fate of any animals possibly still out there.
The case of the Cebu flowerpecker is a prime example. During the 1950s, Cebu Island in the Philippines was thought to be in environmental collapse after years of rampant logging. “People had basically assumed that all the island’s forests had been cleared and therefore a bird called the Cebu flowerpecker and a handful of other endemic subspecies there had gone extinct,” says Butchart.
So conservationists started prioritizing islands near Cebu instead. This is how a researcher named Rob Timmins came to be on Negros Island in 1992. By chance, he happened to train his binoculars across the Tañon Strait and saw a surprising amount of Cebu forest remaining. When he went to inspect the woods, he found what appeared to be a living, breathing Cebu flowerpecker. Just one problem: The primary way to distinguish these small songbirds is by the patch of red feathers on their green backs, and Timmins was colorblind.
Long story short, another scientist, Guy Dutson, joined the search, and he and Timmins were able to verify that the flowerpeckers had been eking it out on Cebu all that time. The discovery was excellent news, but for Butchart it raises the question of what could have been. By 2005, scientists had determined that between 85 and 105 of these colorful birds remained, with the population trending downward. “Had we not given up on them, we could have implemented conservation efforts that would have saved much more of the habitat,” Butchart says. “Perhaps the species would not now be in such dire straits.”
This is what scientists refer to as the Romeo error, a nod to Shakespeare’s star-crossed lovers and their tragic, preventable ends. We can’t, of course, leave a light on for every species that’s gone M.I.A. Doing so would lead to wasting finite resources on potential ghosts while the confirmed living languished.
And so it is with little ado that Butchart and his algorithm propose the most severe status for Brazil’s cryptic treehunter and Alagoas foliage-gleaner. Neither has been officially seen since 2007 and 2011, respectively, and this despite intensive efforts to find them. For the scientists, there is no longer any reasonable doubt that their flames have been extinguished—snuffed out by logging, gold mining, road building, ranching, and all the other human activities that carve up rainforests like a Christmas goose. In a word, extinct.
The Spix’s macaw, also of Brazil, has met a similar fate. While the names of other birds on this list of the newly lost—Javan lapwing, Eskimo curlew, New Caledonian lorikeet—probably don’t ring any bells, the Spix’s macaw became famous in 2011 for its starring role in the animated kids’ movie Rio. This large, vibrantly blue parrot has also been a darling of the exotic pet trade—which seemed to be its only home.
“This species is really enigmatic,” says Butchart. “For over 150 years, it was only known from small numbers of birds in the caged bird trade, and no one knew where these birds were coming from.”
Then, in 1985, scientists discovered a tiny population of three macaws living in the Amazon rainforest. Unfortunately, poachers are suspected of nabbing all three for the pet trade. Another male Spix’s macaw turned up in 1990, which kicked off a flurry of conservation efforts as scientists tried to get the parrot to mate with a captive female. But it wasn’t meant to be, and the male died five years later.
“There have been no records since then despite quite a lot of field work at the location of the last known birds,” says Butchart. Because a handful of the parrots still remain in captive breeding programs run by the Brazilian government, the study recommends the Spix’s macaw be officially relisted as “extinct in the wild”—yet another label qualifying our impact on biodiversity.
The study, however, brings some good news with the bad. In the eight years it took Butchart’s team to complete its analysis, two thought-to-be-gone species popped up in the wild—the Belem curassow of Brazil and the Tachira antpitta of the Venezuelan Andes. And there may be more like them.
“There’s an increasing army of birdwatchers across the world, as well as professional conservationists, who are visiting every last tract of natural habitat on the planet,” says Butchart. “I would expect that quite a few of the species we’ve kept in the category of critically endangered will be rediscovered in the coming years.”
We’d best start keeping their habitats around just in case, for those maybe extinct species and the many others, avian or otherwise, heading in that direction.
onEarth provides reporting and analysis about environmental science, policy, and culture. All opinions expressed are those of the authors and do not necessarily reflect the policies or positions of NRDC. Learn more or follow us on Facebook and Twitter.