Most Wanted Lost Species

The Blanco Blind Salamander is so rare that it has only been found once—in a spot slightly northeast of San Marcos, Texas. It was discovered back in 1951 by workers excavating a small crevice with flowing water in the bed of the then-dry Blanco River. Over the years, the river has changed course, and the spring where they are found is buried under gravel and sediment today. Only four individuals were found at the time of their scientific discovery, and none have been encountered since. The good news is: If any species were going to survive being plugged back into a river orifice, it would probably be the Blanco Blind Salamander. The Blanco Blind Salamander breathes through its skin gills, is depigmented, and likely preys on groundwater invertebrates and even other salamanders in the aquifers where it lives. Threats to this species include declines in the quality and quantity of groundwater on which it depends, small population size across an extremely limited distribution, and contamination of groundwater habitats from surface sources. With the help of our partners who have already started the search, we aim to find out!

The only known individuals of this pygmy seahorse were collected on the coast of Eden, Australia, but the Bullneck Seahorse has never been seen in the wild. Scientists believe it lives in sand beds at the bottom of the ocean (more than 325 feet underwater) and may inhabit gorgonian corals. No information is available about the Bullneck Seahorse’s population density, distribution, ecology, behavior, population trends, genetic structure or life history traits. Dedicated field surveys will require scuba diving and fisheries sampling.

One of the first mammals to be described from a fossil alone, the Dwarf Hutia looks like a guinea pig–esque rodent that once lived all over Cuba and the nearby Isle of Youth. It was last captured by researchers in 1937, but some suspicious poops found in 1978 might have been enough to prove that it’s still out there! If it does still exist, the Dwarf Hutia would most likely be living in the uber-remote Zapata Swamp, and there are probably only a handful of them left. Unlike other rodents that often have many offspring in a litter, a Dwarf Hutia that was brought into captivity back in the day only gave birth to one baby.

What wiped these little guys out? The list of threats to their survival is unfortunately long, starting with invasive species. The Dwarf Hutia had to compete with Black Rats for habitat and food; they also became prey for animals like mongooses and the invasive Walking Catfish, one of the most notorious predators in the Zapata Swamp. Much of their habitat has been destroyed by human hands, or by accidental fires. If we have any chance of uncovering the Dwarf Hutia, we need to better survey Zapata Swamp and manage its invasive species.

What’s in a name? ‘Fat Catfish’ almost says it all. This lost fish species has more rolls than a used tire. The Fat Catfish has only ever been found 9,800 feet high in the Andes mountains, in Lake Tota, where locals call it “Pez Graso,” which can also be translated to “grease fish” — a name, perhaps, both apt and foreboding for a combustible fish. Yes, you read that right. Before the Fat Catfish became a lost species, local people sometimes burned its fat for fuel in their lamps. The mystery of their disappearance, however, remains unanswered. The Fat Catfish was described for the first time by ichthyologist Cecil Miles in 1942, and the last known individual was collected from the wild in 1957. Only nine other individuals had been recorded before then.

The Fat Catfish is also one of the top 10 most wanted freshwater fishes by the Search for Lost Fishes, the freshwater-fish focused initiative of Re:wild’s Search for Lost Species program, in partnership with Shoal.

Find out more about the Search for Lost Fishes.

Himalayan Quails have distinctive red bills and legs, black faces and throats with white foreheads. They infrequently fly, and usually only when flushed. This medium-sized quail belongs to the pheasant family and is known from only two locations in India. The species was first described in 1846 by J. E. Gray from living individuals in the collection of the Earl of Derby at Knowsley Hall. It was not found in the wild until 1865, when Kenneth Mackinnon shot a pair of quails. It was last seen only about a decade later.

The Himalayan Quail is also one of the top 10 most wanted lost birds by the Search for Lost Birds, a collaboration between Re:wild, American Bird Conservancy and BirdLife International.

The Ilin Island Cloudrunner is only known from one individual purchased at a market on the Philippines’ Ilin Island. The species was “found” in the collection at the Smithsonian National Museum of Natural History decades after it was donated. Although surveys with local communities have not revealed knowledge of the species, there are some unverified reports from Mindoro. Scientists don’t know anything about the cloudrunner’s habitat or ecology, but are eager to learn in order to best safeguard the species.

Miss Waldron’s Red Colobus came close to claiming the dubious honor of being the first primate to be declared extinct in more than 500 years after repeated failed searches. But evidence from hunters appeared in 2000 and 2001 that suggested that a very small number of these monkeys may be living in the southeast corner of Côte d'Ivoire. It was first discovered in 1933 by a British museum collector who named it after a colleague on the expedition, Miss F. Waldron, with the last conclusive sighting of the monkey in 1978. No photographs or video of the species alive exist.

Although the quest to find Miss Waldron’s Red Colobus Monkey with partners the Swiss Center for Scientific Research in Côte d’Ivoire and Florida Atlantic University has not yet uncovered photographic evidence of the monkey in question, it has produced striking footage of other rare and endangered primates. This includes the Critically Endangered White-thighed Colobus, Endangered White-naped Mangabey, and the first-ever video of a Critically Endangered Roloway Monkey in the wild, captured high in the canopy of Côte d'Ivoire’s Tanoé-Ehy Forest in west Africa.

The Namdapha Flying Squirrel is only known with certainty from a single individual collected in Namdapha National Park, the largest protected area in the Eastern Himalaya biodiversity hotspot, at altitudes of between 100 and 350 meters (or between 328 and 1,150 feet) above sea level. Although researchers have surveyed the surrounding area for the flying squirrel, there have not been any verified sightings of the species. Scientists believe this lost species occurs in dry deciduous montane forests along streams, and may be restricted to the area of a single valley within the Namdapha National Park.

If the New Zealand Greater Short-tailed Bat still exists, it could be the come-back kid. This species—one of three of New Zealand’s bat species—vanished from New Zealand’s North and South islands following European arrival some 200 years ago. It was subsequently restricted to small predator-free islands until rats were accidentally introduced in 1963. Because this bat species spends an unusual amount of time on the ground, it’s especially susceptible to rats, and the introduction of the invasive species devastated the bat’s remaining population. Rats have since been eradicated from both Big South Cape and neighboring Putauhina Island, and since then there have been several unconfirmed sightings in both places. And in 1999, Mystacina-like echolocation calls were recorded from Putauhina.

This is one of the most endangered rabbits in the world as the result of poaching and habitat destruction. The species, which likely lives in a small, semi-isolated mountain range in the Sierra Madre del Sur, Guerrero, Mexico, is known from only four individuals, the most recent just a skin donated by local hunters in 1998. There are no known photos of this species.

The Pink-headed Duck was always considered rare, but it has not been conclusively seen in the wild since 1949 in India and is known from Myanmar from only two individuals. Unconfirmed reports of Pink-headed Duck sightings in 2006 spurred conservationists to continue to look for it and to try to capture the first photos of a live bird, unsuccessfully. In addition to the deep pink head and neck found on male ducks, these birds lay spherical eggs and likely live in tall, thick elephant grasslands, swamps and floodplains.

In 2017, the Pink-headed Duck eluded a Search for Lost Species expedition team in Kachin State in Myanmar. The team’s interviews with locals suggest that the bird likely spent time at Indawgyi Lake more recently than the last record of the species in Myanmar in 1910, maybe as recently as 2010.

The Pondicherry Shark is a small and stocky gray shark. This species does not grow any longer than about one meter, or three feet, long. The shark was once found throughout IndoPacific coastal waters, from India and possibly extending to the Gulf of Oman into Southeast Asia, and is known to enter freshwater. It may also be found in rivers such as the Hooghli River and Saigon River.

The rediscovery of this lost toad could be the key to better understanding how species rebound from the chytrid fungus that has decimated amphibians worldwide and hit harlequin toads particularly hard. The Scarlet Harlequin Toad has the most restricted geographic range of any Venezuelan Atelopus species and is known from a single stream in an isolated Venezuelan cloud forest.

The South Island Kōkako was last documented in 2007, which makes it one of the most recent species disappearances on our top 25 most wanted lost species list. The South Island Kōkako, also known as the Orange-wattled Crow, made headlines in 2007, the last officially accepted sighting of the species. The accepted record before that was in 1967. Based on this sighting, in 2013, the New Zealand Department of Conservation overturned its 2008 decision to declare the species Extinct. Today, this bird’s IUCN Red List status is Critically Endangered (Possibly Extinct). The South Island Kōkako is known for its haunting, melancholy yet melodious song, with calls that include rich flute and organ notes. If one day this species is rediscovered, New Zealand conservationists believe they can bring it back from the brink of extinction in the same way they helped revive its sister species, the North Island Kōkako, and other native birds including the Kākāpō, Takahē, Black Robin and the Chatham Taiko.

The South Island Kōkako is also one of the top 10 most wanted birds by the Search for Lost Birds, a collaboration between Re:wild, American Bird Conservancy and BirdLife International.

The Togo Mouse was discovered in 1890 in a single location. The two individuals collected at the time are the only clues we have about this species’ natural history because it hasn’t been recorded since. Researchers think the Togo Mouse may occupy parts of Ghana, as well as Togo. Contents found in the teeth and stomachs of the individuals collected indicate that the Togo Mouse’s diet includes insects. Its short tail suggests ground-living rather than a life spent up in the forest canopy.

Two expeditions failed to rediscover the Togo Mouse in the 1990s. Recent interviews with hunters in Ghana suggest local knowledge of the Togo Mouse as recently as 2011. The hunters believe that their activities caused several local small mammal populations to fall,
including Togo Mice. Field staff in the Kyabobo Range National Park, 12 miles west of the site of the Togo Mouse’s original discovery, also say they recognize the species when shown pictures, as do locals, calling it “Yefuli.” There is a pressing need to survey likely forest locations in both countries. Eighty percent of West Africa’s rainforests have already been degraded or cleared for agriculture. We need to act soon to protect any remaining Togo Mouse populations from losing the rest of their forest home—but first we need to make sure they are still around.

This beautiful tropical parakeet is only known with certainty from the Sinú Valley in northern Colombia. BirdLife International estimates that if the bird is not already extinct, no more than 50 likely exist. Despite extensive searches, there have been no confirmed records of the parakeet since 1949. Scientists know very little about the Sinú Parakeet’s reproductive physiology, nutritional needs, ecology or behavior. There are 18 individuals known from four locations in Colombia, two of which have been deforested.

The striking Syr Darya Shovelnose Sturgeon is endemic to the Syr Darya River, and was once found in Kazakhstan, Tajikistan and Uzbekistan. It is among the smallest sturgeon species in the world, growing only up to about one foot long. It was once found in the Aral Sea, but according to NASA, the Aral Sea shrunk by more than 60% between 1973 and 2000. The Aral Sea is now hypersaline and as a result, doesn’t harbor any fish, aside from in a small reservoir. The river has also experienced large levels of water extraction, damming and agricultural pollution. The sturgeon has been listed in the Red Data Book of Kazakhstan since 1978 and has also been featured on stamps.

The Syr Darya Shovelnose Sturgeon is also one of the top 10 most wanted freshwater fishes by the Search for Lost Fishes, the freshwater-fish focused initiative of Re:wild’s Search for Lost Species program, in partnership with Shoal.

Wellington’s Solitary Coral is an endemic species from the Galápagos Archipelago in Ecuador, recorded between two and 43 meters (or six and 140 feet) underwater. Before 1982, this species was considered abundant at some sites, but the El Niño event of 1982 and 1983 destroyed most colonies of this species, except for two populations. But since 2000, scientists have not found the coral even at those two sites, indicating that the species is particularly sensitive to changes in the temperature of water in which they live.

Much mystery has traditionally surrounded this lost species. When the kangaroo was found in the Wondiwoi Peninsula of West Papua in mossy montane forests at an elevation of 1,600 meters, scientists couldn’t figure out how it came to inhabit the higher parts of the Wondiwoi Peninsula—the answer remains elusive as an enduring “zoo-geographical mystery.” Everything we know about the Wondiwoi Tree Kangaroo comes from a single individual, an adult male collected in 1928 by one of the world’s leading evolutionary biologists, Ernst Mayr.

In 2018, a tourist in West Papua took low-quality photos of a species that could possibly be the Wondiwoi Tree Kangaroo. It is imperative that conservation measures are put in place to protect the species once the rediscovery is confirmed through scientific techniques, such as DNA sampling with appropriate permits.

Except for one or two individuals imported for the pet trade, Zugs’ Monitor is completely unknown. It is rarely—if ever—seen by locals, and scientists know nothing about its ecology or natural history. It comes from the Moluccan Islands of East Indonesia, where the number of new Varanus species discovered has increased significantly in recent years. The rainforests of Halmahera Island are a biodiversity hotspot and home to several endemic species.