Pop quiz: How many endangered species can you name? Odds are, your list is something like: tigers, rhinos, gorillas, orangutans, pandas. If you’re a diehard endangered species aficionado, you may have even said Amur leopard, black rhino, mountain gorilla, Bornean orangutan — ah, but not giant pandas, which were upgraded from “endangered” to “vulnerable” a few years ago.
When I set out to write this story, all I wanted to know was which species are actually closest to extinction. Which ones really might vanish tomorrow? Turns out, that’s a terribly complicated question.
The official, exhaustive endangered species list is maintained by the International Union for Conservation of Nature — the IUCN’s (in)famous Red List. Of the 120,356(!) plants, animals and fungi the group has assessed, 882 are declared extinct, 6,807 are critically endangered, and 11,731 are just endangered. These determinations are based on a number of variables and rankings. Since nobody wants to read a list of “The 18,000 (or So) Most Endangered Species,” I decided to narrow things down by focusing on critically endangered vertebrates — animals with backbones, such as birds, reptiles, amphibians, mammals and fish. There are 1,983 critically endangered vertebrate species.
Species can earn a “critical” badge for many reasons. If their population size has been reduced a certain amount over a certain time period. If their geographic range has shrunk a bunch. If their individual population sizes are small or shrinking. They can also be critically endangered if the species is down to fewer than 50 individuals. That earns the species an IUCN “D” rating, which never looks good on a report card. Currently, there are 235 Ds.
I downloaded the IUCN dataset and started going through each species to see what their story was. Turns out over 200 of the 235 might already be extinct — these are animals like the Siamese Bala-shak, a fish last seen in Thailand in 1974, or the Guanacaste Hummingbird, which apparently is only known from a specimen collected in — wait for it — 1895.
For the sake of this story, I crossed off all the species that haven’t been spotted since, say, 2010. Yes, they could still be out there. But they also might … not. There were also a few that have recovered a bit since reaching the 50-animals-left mark; I cut them out, too. That left us with 32 — my 32 most endangered species (that are probably not already extinct.) Let’s meet them.
A Tahiti petrel, a close relative of the critically endangered Fiji petrel. (Credit: Pierre-Louis Stenger/iNaturalist)
This seabird (Pseudobulweria macgillivrayi) hangs mostly on the open sea off Fiji’s Gau Island. When it does come ashore (to breed), it’s faced with hungry predators like rats, feral cats and pigs — all introduced species on their island home. It’s hard to count their numbers, since they spend so much time off land. But, experts think there are fewer than 50 pairs remaining. Locals are on board with conservation efforts, and the bird even appears on Fiji’s 20-dollar bills.
Javan rhinoceros (Credit: Scott Nelson/Wikimedia Commons)
There are three subspecies of Javan rhino (Rhinoceros sondaicus) — or there were. Two are already extinct, thanks to excessive poaching for their horns. The last group lives on the western end of the island of Java, where around 50 adults remain. Their last remaining habitat is also being taken over by a palm (Arenga obtusifolia) that crowds out all the rhino’s preferred foods, as well as some Javan banteng, a cow relative that’s likely eating the rhino’s food. There are no Javan rhinoceroses in captivity.
This 18-inch-tall parrot (Amazona imperialis) was once found on the mountains of Dominica, a small island nation in the Caribbean. Their population was doing all right (if 300 birds is all right) until 2017, when Hurricane Maria knocked down a third of the trees on the island and stripped the rest of their leaves and fruits. This reduced the parrot’s numbers to an all-time low. It evidently forced the birds to move outside their usual mountainy range and into the lowlands. About six months after Maria, 11 birds were spotted, but experts think there are fewer than 50 out there.
Guam rail (Credit: Josh More/Flickr)
This flightless bird (Hypotaenidia owstoni), native to the island of Guam, nearly went extinct in 1987 when the last known wild examples disappeared, thanks to predation from the invasive brown tree snake. Luckily, enough birds in captivity made for an effective breeding program, and new populations have since been established on nearby islands, Rota and tiny Cocos. After many years and over 1,200 birds released into the wild, the population on Cocos appears to be self-sustaining, meaning the bird is officially not extinct in the wild. For now.
El Laurel Rocket Frog
El Laurel rocket frog (Credit: Felipe Campos/iNaturalist)
This frog (Hyloxalus delatorreae) lives at the Ecuador-Colombia border, confined to a small marshy area in the Andes mountains. Experts estimate there are fewer than 50 left. The frog’s biggest problem: chytridiomycosis, an infectious disease caused by a fungus. The population is now so small that, if its marsh is destroyed, it could wipe out the entire species.
Santa Catarina’s Guinea Pig
Santa Catarina’s guinea pig (Credit: Carlos H. Salvador/Wikimedia Commons)
Off the shore of Brazil, on a teeny island called Ilhas Moleques do Sul, there lives a group of 42 wild guinea pigs (Cavia intermedia). Luckily, the island is protected as part of Serra do Tabuleiro State Park, but that doesn’t mean people can’t still show up to the island and hunt or trap the rodents, which is considered their biggest threat.
Sulu hornbill (Credit: Lorenzo Vinciguerra/iNaturalist)
The Sulu hornbill (Anthracoceros montani) lives on one island in the Philippines, Tawi-Tawi in the Sulu archipelago, where its forest habitat was rapidly cleared to create palm oil plantations. In recent years, deforestation on the island seems to have slowed, as much of the remaining forest is in harder-to-reach rugged mountain areas. But locals have been known to harvest the birds for food and trade, even occasionally using the hornbills as target practice. Experts estimate there are fewer than 20 pairs remaining.
Gilbert’s potoroo is closely related to other, more common potoroos like these two spotted at the Cleland Wildlife Park in South Australia. (Credit: Julie Burgher/Flickr)
Australia’s rarest marsupial, this rabbit-sized critter (Potorous gilbertii) lives only on Mount Gardner in Western Australia. After being discovered in the mid-1800s, these potoroos were thought to be extinct until found again in 1994. Efforts are underway to reintroduce them to a few other spots, but for now, their main population is teetering around 40 individuals. Researchers think they’re sensitive to wildfires — they prefer long-unburned shrublands — as well as predation by introduced foxes and feral cats.
Chinese Crested Tern
Terns are like seagulls, yet sleeker and with cooler hairdos. But their numbers are few. The Chinese crested tern (Thalasseus bernsteini) took a bad turn (sorry) in 2012, when breeding adults were down to just 12. These days, they’re thought to have bounced back to 30 or 40. They’re typically found hanging out with other seabirds, like China’s great crested terns or black-tailed gulls in South Korea. Seabird eggs can be valuable, and the biggest threat to these birds is egg collection by humans.
Two vaquitas (Credit: Paula Olson/NOAA/Wikimedia Commons)
This dolphin relative (Phocoena sinus) lives only in the Gulf of California. In 2003, there were maybe 33 vaquitas left. The biggest driver of its decline has been fishing, as the marine mammal is often caught in nets as bycatch or killed by boats. Researchers expect it will be extinct within a decade.
Addax (Credit: Sergei25/Shutterstock)
Once abundant across sub-Saharan Africa, this antelope-like grazer (Addax nasomaculatus) has been reduced to a single population in the deserts of Niger. In 2008, the China National Petroleum Corporation was given oil exploration rights smack in the middle of their last remaining turf, reports National Geographic, which brought in an influx of new disturbances (including humans with guns). In 2012, Niger fought back, establishing the Termit and Tin Toumma National Nature Reserve to protect the addax and other threatened species in the area. Poachers are still a problem, though. Estimates put current addax numbers around 30.
The Alagoas antwren has some less-endangered, look-alike cousins, like the leaden antwren. (Credit: Cullen Hanks/iNaturalist)
This little gray bird (Myrmotherula snowi) lives in a spot of forest in eastern Brazil, where maybe 30 individuals remain. Their forest is shrinking, mostly due to logging and clearing for pastures and sugarcane plantations. Conservation efforts are underway, and much of its remaining range is now protected in lands owned by the Murici Ecological Station, private reserve Frei Caneca, Birdlife and SAVE Brazil.
Tahiti monarch (Credit: Agami Photo Agency/Shutterstock)
In 2015, estimates say 13 breeding pairs are all that is left of this tropical bird (Pomarea nigra). It nests in Tahiti’s forested valleys near streams, where its home has been invaded by non-native plants (like the velvet tree), predators (like black rats) and competitors (like the red-vented bulbul bird).
West Gippsland Galaxias
West Gippsland galaxias (Credit: Tarmo A. Raadik via IUCN)
This cute little swimmer (Galaxias longifundus) is the only fish to make the list. Now living in a single creek in southeastern Australia, this fish has been nearly eaten to extinction by invasive trout. Wildfires and other disturbances increase the amount of sediment washing into their creek, which interferes with their reproduction. Experts say the fish has over a 70 percent likelihood of extinction within the next 20 years. The IUCN estimates there are between 25 and 75 mature individuals left.
A closely related species to the critically endangered Hainan gibbon is the southern yellow-cheeked gibbon. (Credit: Dmitry Ivanov/iNaturalist)
Off the coast of China, near Vietnam, a couple dozen gibbons (Nomascus hainanus) live in a small habitat on the island of Hainan. Their numbers hit a low point in 2003, when only 13 individuals were found living on a single mountainside in the Bawangling National Nature Reserve. Since then, they’ve likely bounced back to at least 25, though they’re hard to find and therefore hard to count.
Madagascar pochard (Credit: Frank Vassen/Flickr)
This diving duck (Aythya innotata) — closely related to scaups, canvasbacks and redheads, if you know your waterfowl — was once found in Madagascar’s wetlands. Thought to be extinct, it turned up in 2006 and is now hanging on with about two dozen individuals living at a secluded inland lake. Its biggest threat seems to be habitat loss to agriculture, but other factors like rats, who feast on their nests, and tilapia, who eat their favorite foods likely have an impact as well.
Cerulean paradise flycatcher (Credit: Agami Photo Agency/Shutterstock)
This little blue bird (Eutrichomyias rowleyi) only lives on the Indonesian island of Sangihe and after 100-plus years was almost declared extinct before it turned up again in 1998, deep in forested valleys of the island. More extensive surveys revealed the bird was hiding out in at least 14 valleys. Today, experts think there is “virtually no chance of any birds occurring away from [Mount] Sahendaruman,” with estimates that there are between 21 and 100 individuals left.
A red wolf in captivity. (Credit: B. McPhee/USFWS/Wikimedia Commons)
The only carnivore to make the list, the red wolf (Canis rufus) actually went extinct in the wild in 1980. In 1987, wildlife officials reintroduced a population to North Carolina, where it was momentarily successful with as many as 100 individuals. Today, though, the wolves’ protected area can only support about 20 or 30 animals, and their numbers are continually threatened as they interbreed with coyotes and face hostile humans.
Black-winged starling (Credit: Doug Jansonjj/Wikimedia Commons)
This songbird (Acridotheres melanopterus) only lives on the island of Java, Indonesia. Its downfall has been the caged bird trade — it’s widely captured by humans. Once common across even agricultural landscapes, its last hideout seems to be mangrove forests. In 2014, 149 captive-bred birds were stolen from a conservation center aiming to release them to boost their numbers. Researchers think there are about 20 of these birds left in the wild.
Ornate Ground Snake
Ornate ground snake (Credit: Gregory Guida/IUCN)
Also known as the St. Lucia racer, this snake (Erythrolamprus ornatus) is only found on Maria Major, a tiny Caribbean island off St. Lucia. Experts hope to reintroduce it to mainland St. Lucia someday, but only if they can get its main predator in check: the introduced mongoose. In 2012, researchers estimated there were about 18 of the snakes left on Maria Major.
Orange-bellied parrot (Credit: JJ Harrison/Wikimedia Commons)
Breeding only in southwestern Tasmania, experts estimate that 14 of these Australian parrots (Neophema chrysogaster) remained in the wild as of 2017, only two of them females. The couple hundred birds in captivity should keep the species alive, but the parrots haven’t responded well to captive-breeding and release programs. The main reason for their decline is likely disease and loss of their specialized forest-border habitats.
Bali myna (Credit: Jonathan Leung/Flickr)
Like its cousin, the black-winged starling on neighboring Java, this myna (Leucopsar rothschildi) is another Indonesian island bird poached nearly to extinction for the caged bird trade. Conservation groups are working on captive breeding programs to boost their numbers, but it’s unclear how much this is helping. At its worst, in 2001, there were about six birds left. A colony of captive-reared birds were briefly doing well on Nusa Penida Island, but even their numbers dropped to about 12 birds by 2015. Forty more were released in April 2019 — microchipped, so that if caught and sold police can confirm they were poached from the wild.
Burmese Roofed Turtle
Closely related to the Burmese roofed turtle, the red-crowned roofed turtle is also critically endangered. (Credit: K S Gopi Sundar/iNaturalist)
Fewer than 10 of these turtles (Batagur trivittata) remain in the wild. They used to occur in abundance in Myanmar river valleys, but human collection of eggs, juveniles and adult turtles has driven them near extinction. Its last remaining habitat is now under consideration for a hydroelectric reservoir, which would flood out the last of its kind. More recently, wildlife officials have captive-reared nearly 1,000 turtles, with plans in place to release them into the wild to boost their numbers.
Fatu Hiva Monarch
An early 19th century illustration of the Fatu Hiva Monarch. (Credit: Louis Isidore Duperrey & Rene-Primevere Lesson/Wikimedia Commons)
This black bird (Pomarea whitneyi) lives on one tiny island in French Polynesia. It was common until 2000, when black rats were first observed on the island. In 2017, surveys suggest as few as four pairs might have been breeding. The monarch’s forest is relatively intact — for now — but the rats, as well as feral cats from nearby agricultural areas, pose a serious threat to the last few birds.
Arnhem Land Gorges Skink
Arnhem Land Gorges skink is a member of the genus Bellatorias, like this lizard. (Credit: Alan Wigginton/iNaturalist)
This Australian lizard (Bellatorias obiri) is now mostly confined to the Kakadu National Park in Australia’s Northern Territory. Perhaps five or 10 skinks are thought to remain, despite extensive searching. Their remaining habitat is threatened by both wildfires and feral cats.
Antioquia brushfinch (Credit: edwinmunera/iNaturalist)
In 1971, researchers found three birds of an unknown species in the Andes. The species wasn’t seen again until 2018. Very little is known about this bird, except that there are likely very few individuals, and about 70 percent of the forest habitat in its known range has already been cleared for pasture and agriculture. Nevertheless, Colombian conservationists are at work to save the bird.
Sahafary Sportive Lemur
Nine of the sportive lemurs are critically endangered, including the red-tailed sportive lemur. (Credit: Frank Vassen/Flickr)
Sportive lemurs are named after the boxer-like stance they take when threatened. Once thought to be all the same lemur, genetic analyses have revealed over two dozen separate species. The rarest is the Sahafary sportive lemur (Lepilemur septentrionalis), found in a tiny area in northern Madagascar. Although experts estimated there were 100 left in 2007, their forest habitat has shrunk dramatically since then, losing about 1.1 percent each year. During surveys in 2012 and 2013, researchers only found three individuals.
Miles’ Robber Frog
Miles’ robber frog (Credit: Jonathan Kolby/iNaturalist)
Cusuco National Park in Honduras is likely the last holdout for this critically endangered amphibian (Craugastor milesi). After not being spotted since 1983, it was thought to be extinct until a few more were found in 2008 and 2013. Although researchers have looked for the frog since then, no more have been found. It’s unclear whether its decline was also due to the chytrid fungus, but habitat destruction is likely the biggest threat today. Even within the borders of the national park, people still build roads, log for timber and cultivate crops — like cardamom, coffee and flowers. Since the frogs live in leaf litter near stream banks, even foot traffic from tourists can be a disruptive issue.
It was once thought that the bare-faced curassow (pictured) and the Belem curassow were one and the same, but taxonomists later figured out they were two distinct species. (Credit: Ondrej Prosicky/Shutterstock)
Topping out at 3 feet 6 inches in length, this Amazonian bird (Crax pinima) lives in some of the most threatened forests in the world, where it’s rarely spotted. Researchers on an expedition to Brazil’s Gurupi Biological Reserve spotted a male and female in 2017, though, so it’s thought there are at least a few still out there. Even in the “protected” reserve, illegal logging, grazing and farming continues to threaten the bird’s last remaining habitat.
Vietnamese Pond Turtle
Vietnamese pond turtles (Credit: Danny Ye/Shutterstock)
In Vietnam, a Rua Trung Bo, or Vietnamese pond turtle (Mauremys annamensis), can fetch a pretty penny in the illegal trade. It’s probably only hanging on in one or a few small wetlands, the IUCN suspects, and in recent decades only one wild individual has been confirmed. The species has faced some habitat losses as well, like their natural wetlands being converted to rice paddies. But it’s expected they could live just fine in those human-dominated areas — if they would only stay out of sight. The species is widely sought after for traditional medicine (it’s believed that its blood can cure heart disease) and the pet trade.
Fernandina Giant Tortoise
In February 2019, researchers found this tortoise on Fernandina Island. (Credit: Galapagos National Park Directorate/GTRI)
This Galapagos tortoise (Chelonoidis phantasticus) was thought to be extinct until a conservation official spotted one on an expedition in 2019. The 100-year-old female is now living at a breeding center on a nearby island while researchers look for more of her kind. Experts think their numbers are so low because of frequent lava flows on their island.
Bahama nuthatch (Credit: Tom Benson/Flickr)
Another island bird down to the last of its kind, this little brown bird (Sitta insularis) lives in Caribbean pine forests on Grand Bahama Island, which has been subject to extensive logging and development. The single population may have been doing all right prior to September 2016, when Hurricane Matthew hit; since then, only a single bird has been recorded.