Quantcast

300+ Mammal Species Could Still Be Discovered, Scientists Say

Sumatran Orangutan Conservation Programme / Maxime Aliaga

By Sara Novak

You can't protect an animal that you don't know exists. Tapanuli orangutans, for example, are found only in the Tapanuli region of Sumatra; they were only identified as a species last year, when scientists found them to be genetically different from other Bornean and Sumatran orangutans. With just 800 left, this newly discovered species is the most critically endangered ape.

It's hard to believe that with only seven great ape species on the planet—Tapanuli, Sumatran and Bornean orangutans, eastern and western gorillas, chimpanzees and bonobos—a species could have gone undiscovered until 2017. But, in fact, new research shows that many mammals still fly under the radar.


The olinguito, a carnivorous member of the raccoon family, wasn't discovered in Colombia and Ecuador until 2013. The Burrunan dolphin was found in the waters off Australia in 2011. In a new study published in the journal Ecology and Evolution, Molly Fisher and other researchers at the University of Georgia used a predictive model to conclude that 303 mammals have yet to be discovered.

Most of these unknown mammals, the researchers found, are likely in tropical regions of the world, many of which are threatened with habitat destruction. This makes discovering them a race against time before they go extinct. "If a species goes extinct before we discover it, how can we know what went wrong? If we lose a species without knowing it existed, we lose a lot of information," said Fisher.

Fisher said that she chose to study mammals because they are the most charismatic of terrestrial species, and therefore more likely to be protected. But less glamorous creatures, like plants and arthropods, are disappearing at even faster rates than mammals, which is worrying to scientists.

"We're concerned about why extinction rates are on the rise," said Fisher. "We're losing a lot of biodiversity, most of which exists in our remaining forests in places like the Amazon." Some researchers now talk about "biological annihilation," citing cascading extinctions, dwindling population sizes, and range shrinkages among vertebrate species.

Sumatran Orangutan Conservation ProgrammeMaxime Aliaga

Fisher and her team employed scientific modeling to measure discovery and extinction rates. Without direct interaction, however, it's impossible to know whether a species has disappeared completely or just hasn't been seen in a while. This occurred recently with the Guadalupe fur seal, a species found in California and Mexico that was rediscovered after years of suspected extinction.

The model used by the University of Georgia researchers is similar to one used to predict the remaining unknown number of plant species in 2011. It was constructed by counting the total number of species discovered and described by scientists from 1760 through 2010 by five year increments. "The model utilizes a statistical technique called 'maximum likelihood,' which allows scientists to approximate the total number of species that are likely to have existed in order to produce the number of descriptions actually recorded by taxonomists, scientists who classify new species," said Fisher.

As the number of such scientists has increased, so has the number of classifications accounted for in the model. The researchers also noted "taxonomic efficiency" or how good scientists are at discovering new species. Like the Tapanuli orangutan, many species once thought to be identical are, upon closer inspection, found to be genetically distinct. Dr. Michael Krützen from the Department of Anthropology at the University of Zurich was part of the team that helped discover the Tapanuli using genomic analyses from orangutan samples. He said that Tapanuli orangutans differ significantly, most notably in tooth and skull shape, from those outside the region, because their populations had been disconnected for at least 20,000 years. But with so few of them left, it's easy to see why the species wasn't discovered until recently.

Fisher and her team approximate that 5,860 mammal species currently exist. She was surprised to find that Europe and Asia had a significant number of undiscovered mammals. The model showed that 10 percent of species in this part of the world have yet to be discovered, possibly because many are located in lightly populated Siberian regions.

Reposted with permission from our media associate SIERRA magazine.

Sponsored
William Happer, head of proposed White House climate panel, in the lobby of Trump Tower in 2017. Jabin Botsford / The Washington Post via Getty Images

The White House is assembling a climate change panel to be headed by a known climate denier who once took money from a coal company to testify at a hearing and who has compared criticism of carbon dioxide to Hitler's demonization of the Jews.

William Happer, a Princeton physicist who has never trained as a climate scientist, joined the Trump administration in September 2018 as senior director for emerging technologies at the National Security Council (NSC).

Read More Show Less
by [D.Jiang] / Moment / Getty Images

By Alena Kharlamenko

Tofu is a staple in vegetarian and vegan diets.

Read More Show Less
Sponsored
KarinaKnyspel / iStock / Getty Images

2018 saw a number of studies pointing to the outsized climate impact of meat consumption. Beef has long been singled out as particularly unsustainable: Cows both release the greenhouse gas methane into the atmosphere because of their digestive processes and require a lot of land area to raise. But for those unwilling to give up the taste and texture of a steak or burger, could lab-grown meat be a climate-friendly alternative? In a first-of-its-kind study, researchers from the Oxford Martin School set out to answer that question.

Read More Show Less
Three scissor-tailed flycatcher fledglings in a mesquite tree in Texas. Texas Eagle / CC BY-NC 2.0

By Gary Paul Nabhan

President Trump has declared a national emergency to fund a wall along our nation's southern border. The border wall issue has bitterly divided people across the U.S., becoming a vivid symbol of political deadlock.

Read More Show Less
PeopleImages / E+ / Getty Images

By Daniel Ross

Hurricane Florence, which battered the U.S. East Coast last September, left a trail of ruin and destruction estimated to cost between $17 billion and $22 billion. Some of the damage was all too visible—smashed homes and livelihoods. But other damage was less so, like the long-term environmental impacts in North Carolina from hog waste that spilled out over large open-air lagoons saturated in the rains.

Hog waste can contain potentially dangerous pathogens, pharmaceuticals and chemicals. According to the state's Department of Environmental Quality, as of early October nearly 100 such lagoons were damaged, breached or were very close to being so, the effluent from which can seep into waterways and drinking water supplies.

Read More Show Less