Author: Doreen Fräßdorf

Doreen Fräßdorf ist Autorin und Betreiberin von artensterben.de. Sie recherchiert und schreibt über ausgestorbene und vom Aussterben bedrohte Arten in der Neuzeit – mit Schwerpunkt auf Roten Listen, wissenschaftlichen Studien, historischen Quellen und aktuellen Schutzbemühungen. Ziel ist eine verständliche, faktenbasierte Einordnung komplexer Entwicklungen rund um Biodiversitätsverlust und Artenschutz. Sie ist außerdem Autorin eines Sachbuchs über ausgestorbene Säugetiere der Neuzeit.

Extremely rare species: northern sportive lemur, Devils Hole pupfish, and cherry-throated tanager (© Wikimedia Commons – Lemur: Edward E. Louis, Jr, CC BY-SA 4.0 / Fish: Olin Feuerbacher, Public Domain / Bird: Jens Bokelaar, CC BY-SA 4.0)

7. April 2026 Doreen Fräßdorf

Which animals are threatened with extinction? These 8 species have fewer than 100 individuals

Species extinction is rarely an abrupt event. In many cases, the decline stretches over decades until only small, isolated remnant populations remain. Some of these species now survive with fewer than 100 individuals worldwide. Such extremely small populations are especially vulnerable to chance events, genetic impoverishment, and ongoing habitat loss.

Wolterstorff-Molch (Cynops woltertorffi) - Natural History Museum (London)

The Yunnan lake newt was named by George Albert Boulenger (1905) in honor of the German geologist and zoologist Willy Wolterstorff, who worked extensively on the systematics of salamanders and newts. (© "1946.9.6.32-pic1" - Cynops wolterstorffi (Boulenger, 1905) Collected in China by The Trustees of the Natural History Museum, London, CC BY 4.0, via GBIF)

3. April 2026 Doreen Fräßdorf

Yunnan lake newt—a poorly documented extinction

A newt with a fish-like appearance At the beginning of the 20th century, John Graham collected several animal species previously unknown to science in the southwestern Chinese province of Yunnan. He sent the finds to London, where they were examined by George Albert Boulenger at the Natural History Museum. Boulenger,

Wiederentdeckung von Anolis laevis in der Region San Martín in Peru

The Río Huallaga in the San Martín region in northeastern Peru. The smooth or swordsman anole (Anolis laevis) was rediscovered in the surrounding montane forests of this river system—a habitat now under severe pressure from deforestation and settlement. (© Josue Hermoza, CC BY-SA 4.0, via Wikimedia Commons)

31. March 2026 Doreen Fräßdorf

Peru: Lizard with nose extension rediscovered after more than 150 years – Anolis laevis

In 1876, the American naturalist Edward Drinker Cope described a small lizard from the montane forests of northeastern Peru. What stood out most was an unusual appendage at the tip of its snout—a feature that set it apart from most other species. Cope originally described the species under a different

Saiga antelope (Saiga tatarica) on the steppe: The species has recovered after massive population losses, but remains threatened by fragmenting infrastructure and disrupted migration routes. (© Andrey Giljov, CC BY-SA 4.0, via Wikimedia Commons)

25. March 2026 Doreen Fräßdorf

Migratory species under pressure: Nearly every second species is declining worldwide

Migratory species are among the most fascinating phenomena in nature. Every year, birds, fish and mammals often travel thousands of kilometers between breeding grounds, feeding areas and wintering sites. Yet it is precisely this mobility that makes them especially vulnerable: they depend on intact habitats along their entire migration route.

Only three specimens of Morant's blue have survived — all of them males.

21. March 2026 Doreen Fräßdorf

Morant’s blue – What the females looked like remains uncertain

Three male specimens remain Walter Morant, probably a dedicated collector and observer of nature in what was then the British colony of Natal in southern Africa, was among the early members of the Natural History Association of Natal, founded in 1868. There he gave lectures and exhibited insects—with a particular

Der Sulu-Raupenfänger galt lange Zeit als Unterart des Bindenraupenfängers (Bild).

For a long time, the Sulu cuckooshrike (Coracina guillemardi) was treated as a subspecies of the much more widespread bar-bellied cuckooshrike (Coracina striata, shown here) because of morphological similarities. (© Coracina striata (Boddaert, 1783), Observed in Philippines by dmalerta, CC BY-NC 4.0, via GBIF)

20. March 2026 Doreen Fräßdorf

Chance discovery in the Sulu Archipelago: Long lost cuckooshrike documented after nearly 20 years

In November 2025, the Sulu cuckooshrike (Coracina guillemardi) was documented again for the first time in almost two decades in the remote forests of Tawi-Tawi in the Sulu Archipelago in the southwest of the Philippines. The species was considered lost—not officially extinct, but without any confirmed records for years. The

Illustration of the Floreana giant tortoise — once one of the most distinctive giant tortoises of the Galapagos Islands, today probably extinct in its original form.

16. March 2026 Doreen Fräßdorf

Floreana giant tortoise: From extinction to return

A subspecies of the Galapagos tortoise When the Floreana giant tortoise was still alive, it was part of the extraordinary tortoise fauna of the Galapagos Islands. Hardly anywhere else on Earth did a comparable diversity of giant land tortoises evolve—adapted to different islands, volcanoes, climate zones, and food resources. Today,

Hinter dem Peitschenrochen (Hemitrygon akajei) verbergen sich mehrere kryptische Arten - sogenannte Kryptospezies.

The red stingray (Hemitrygon akajei) was long considered a single species. However, a 2025 study revealed that two outwardly nearly indistinguishable cryptic species were hiding behind the name. One of them was described as the new species Hemitrygon ariakensis—this lineage had remained unrecognized for more than 160 years until molecular genetic analyses confirmed its distinctiveness. (© Naturalis Biodiversity Center, CC0, via Wikimedia Commons)

13. March 2026 Doreen Fräßdorf

Invisible biodiversity: When one species turns out to be many

The Chinese giant salamander was long considered a single species. The animal, which can grow to nearly two meters in length, is one of the largest amphibians on Earth and was regarded as the same species throughout China under the name Andrias davidianus. But genetic analyses brought a surprise to

Flusspferd als eingeschleppte Süßwasser-Megafauna

Hippopotamus – This mammal, weighing up to three tons, is one of the largest freshwater inhabitants on Earth. In Colombia, feral populations exist today after animals escaped from a private collection and spread along the Magdalena River. (© Joachim Huber, CC BY-SA 2.0, via Wikimedia Commons)

10. March 2026 Doreen Fräßdorf

Introduced freshwater megafauna: Benefits and risks of large animals in rivers and lakes

Rivers and lakes are home to some of the largest animals in inland waters—from giant catfish, sturgeons, salmon, and carp to turtles and crocodiles. However, many of these species have been deliberately introduced by humans into new regions. A new global study in the journal One Earth systematically examines for

Dactylonax kambuayai – eine von zwei Beuteltierarten, die wiederentdeckt wurden

A female Dactylonax kambuayai from the Klalik area on the Vogelkop Peninsula. The species is one of two marsupial species recently rediscovered alive after being known only from fossils for a long time. (© Foto: Carlos Bocos, edited, aus: Flannery et al. 2026, Records of the Australian Museum, CC BY 4.0)

7. March 2026 Doreen Fräßdorf

New Guinea: Two marsupials lost for 6,000 years rediscovered

In March 2026, an Australian research team led by zoologist Tim Flannery published two studies with surprising results: On the remote Vogelkop Peninsula in northwestern New Guinea, two marsupial species were found alive that had previously been known only from fossils approximately 6,000 to 7,500 years old. Such rediscoveries are