Ever heard of Jackson’s climbing salamander? How about the silver-backed chevrotain or Wallace's giant bee? These curious sounding animals all have at least one thing in common: they were once suspected extinct until intrepid researchers tracked them down. The natural world is full of fascinating species that for several years have eluded scientists and slipped under the radar. Here's a look at five species that were 'rediscovered' in 2023:

De Winton's golden mole

Image © Nix Souness

Moles have acute hearing and are able to detect vibration from movement above ground, which makes tracking them down particularly tricky. So how do you unearth a golden mole that hasn't been documented since 1936? With science. An expedition team working in the dunes of South Africa's northwest coast employed a technique that has never been used before to detect golden moles: environmental DNA (eDNA). The team collected over 100 soil samples and using DNA material like skin cells or bodily excretions that animals shed when they move through their habitats, they conducted complex genetic analysis on each one to determine which species were hiding beneath the surface.

It took over a year, but they were finally able to determine that De Winton’s golden mole (Cryptochloris wintoni) still lives. “Though many people doubted that De Winton’s golden mole was still out there, I had good faith that the species had not yet gone extinct,” said Cobus Theron, senior conservation manager for EWT and a member of the search team. “I was convinced it would just take the right detection method, the proper timing, and a team passionate about finding it. Now not only have we solved the riddle, but we have tapped into this eDNA frontier where there is a huge amount of opportunity not only for moles, but for other lost or imperiled species.”

Attenborough’s long-beaked echidna

Photo © Expedition Cyclops 2023

For more than 60 years, Attenborough’s long-beaked echidna (Zaglossus attenboroughi) – a species that is exactly as weird as it sounds – remained hidden from science in Indonesia’s Cyclops Mountains. On a quest to rediscover the egg-laying mammal, an expedition team led by Indonesian NGO Yayasan Pelayanan Papua Nenda (YAPPENDA), with students from Cenderawasih University (UNCEN) and supported by researchers from Oxford University trekked into the tropical rainforest in the province of Papua and set up over 80 remote camera traps. After four weeks in the high-altitude forest, the team's efforts had turned up unsuccessful. Then, on the final day of their ascent up the Cyclops Mountains, on the final SD card, the last three images made it all worthwhile: the elusive echidna had been caught on camera.

“Possessing the quills of a porcupine, the snout of an anteater, and the feet of a mole, the echidna is as much a chimera as its mythological namesake,” said James Kempton, postdoctoral researcher at the University of Oxford and leader of the expedition. “Like the duck-billed platypus, they are monotremes—egg-laying mammals that have evolved independently of other mammals for over 200 million years. Before this expedition, we knew of only four monotreme species certain to have survived to the modern day: sole survivors that protect a unique and fragile evolutionary history. Attenborough’s long-beaked echidna is another, crucial guardian of this ancient lineage, and finding it after years of preparatory toil and weeks of discomfort in the field, was a moment of pure catharsis.”

Dusky tetraka

Image © John C. Mittermeier

For 24 years, the dusky tetraka (Xanthomixis tenebrosa) – a small, ground-hopping songbird from the tropical forests of Madagascar – eluded ornithologists. Birding in dense forest environments can be challenging and locating birds usually involves listening out for their calls. When researchers finally spotted a dusky tetraka dancing through the undergrowth, the sighting occurred near a rushing river which may help explain why it took so long to rediscover the elusive songbird.

Sadly, deforestation has likely reduced large swathes of the tetraka's habitat and researchers were surprised to find the bird at a lower elevation than expected suggesting that it may have altered its behaviour. “Now that we’ve found the dusky tetraka and better understand the habitat it lives in, we can look for it in other parts of Madagascar, and learn important information about its ecology and biology,” expedition leader Lily-Arison Rene de Roland, the Madagascar program director for the Peregrine Fund, explained to Mongabay.

Fagilde’s trapdoor spider

Image © Sergio Henriques

It was pioneering female entomologist Amélia Bacelar and her husband Fernando Frade who first described the Fagilde’s trapdoor spider (Nemesia berlandi) back in 1931. Their description was brief, but for close on 100 years, it remained the only concrete scientific evidence that the species exists. That is, until earlier this year when an expedition led by the Global Center for Species Survival at the Indianapolis Zoo painstakingly combed the leaf litter around Fagilde and inside the village limits and eventually uncovered a horizontal burrow that housed an adult female and her 10 babies. DNA tests determined that it was a Fagilde’s trapdoor spider. The team had found their arachnid.

"This is a remarkable species. Fagilde’s trapdoor spider is as Portuguese as Fado and it is our duty to ensure it remains part of our natural heritage. Its continued existence is a testament to Fagilde and the Vale Carcia people who have protected their local forests," said Sérgio Henriques, invertebrate conservation coordinator at the Global Center for Species Survival at the Indianapolis Zoo and the leader of the expedition that rediscovered the spider.

Pernambuco holly tree

Image © Fred Jordão

It was back in 1861 that the Pernambuco holly (Ilex sapiiformis) – an inconspicuous Brazilian tree with small white flowers – was first described by science using a specimen collected 23 years earlier. Since then, over 90% of tropical Atlantic Forest that once dominated the area where the tree was found has been reduced to sugarcane plantations and only small fragments of forest remain. Despite this, an expedition team scoured the area and uncovered four trees on the fringes of a sugarcane plantation in the city of Recife, Brazil.

“The moment when we found Ilex sapiiformis, it seemed that the world had stopped turning its gears,” local researcher Juliana Alencar said in a statement. “Finding a species that hasn’t been heard of in nearly two centuries doesn’t happen every day. It was an incredible moment, and the emotion of it was felt throughout the entire team. When I looked at Professor Milton Groppo, I saw that he had tears in his eyes.”

“It was like finding a long-lost and long-awaited relative that you only know by old portraits,” said Groppo, a researcher at the University of São Paulo.