The idea that animals thought to be gone forever can return captures the human imagination. This phenomenon, often called “extinct animals coming back,” encompasses a range of biological and conservation outcomes. These include the surprising rediscovery of species that secretly persisted in hidden refuges and the monumental effort required to bring a species back from the brink of total collapse. These stories offer compelling proof that extinction is not always certain and that dedicated human intervention can successfully reverse environmental decline.
Clarifying How Extinct Animals Return
A species can be considered to have “returned” through two distinct biological pathways. The first involves a species that was simply lost to science, where a small population survived undetected for decades or even centuries after being formally declared extinct. Their extreme rarity or remote habitat made them invisible to researchers, leading to a premature declaration of their demise. The second pathway involves species that were functionally extinct, meaning their numbers were so critically low that natural recovery was impossible without intensive human help. Their return is a testament to successful, sustained conservation programs that stabilized their numbers and allowed them to rebound to sustainable levels.
Species Rediscovered After Decades
The most dramatic examples of species returning are those genuinely thought to be extinct globally, only to be found alive. One famous rediscovery is the Coelacanth (Latimeria chalumnae), a lobe-finned fish known only from the fossil record and believed to have vanished 66 million years ago. In 1938, a South African museum curator discovered a strange, large blue fish caught by a trawler near the Chalumna River. This unexpected living specimen confirmed that a lineage thought to be completely extinct had persisted in deep-sea environments.
Another remarkable case involves the Lord Howe Island stick insect (Dryococelus australis), often called a “tree lobster.” This large, flightless insect was eradicated from its native Lord Howe Island in the 1920s by introduced rats and was declared extinct. Decades later, in 2001, a small population was discovered clinging to life on a single, isolated volcanic sea stack known as Ball’s Pyramid. More recently, the Black-naped Pheasant-pigeon from Papua New Guinea was rediscovered in 2022 after being lost to science for 140 years. These rediscoveries often occur in remote, inaccessible habitats, confirming that the initial “extinction” was merely a failure of human observation.
Dramatic Population Rebounds
The recovery of species from near-extinction represents the power of targeted conservation efforts. The Southern White Rhinoceros (Ceratotherium simum simum) provides a success story, having been reduced to fewer than 100 individuals in South Africa by the late 19th century. Subsequent efforts in the 1950s and 60s involved large-scale translocations to establish new, protected populations across Africa. These intensive efforts, focused on protection and range expansion, allowed the population to rebound to over 20,000 individuals by 2012, moving the species off the most threatened categories.
The American Bison (Bison bison) is another example of a massive comeback, reduced from tens of millions to fewer than 1,000 animals by the late 1800s due to commercial hunting. Recovery began with the protection of a remnant herd in Yellowstone National Park and the transfer of genetically important bison to tribal and conservation herds. The current strategy emphasizes metapopulation management to maintain genetic diversity, helping the population grow to approximately 500,000 today.
Similarly, the South Atlantic Humpback Whale population was reduced to 450 individuals by the 1950s after intensive commercial whaling. The global moratorium on commercial whaling, put in place by the International Whaling Commission, allowed the species to recover strongly. The population has since rebounded to around 25,000, illustrating how international legal protection and the removal of the primary threat allow marine populations to recover toward their historic levels.
What These Returns Teach Us
These stories of species returning from presumed extinction offer profound lessons for conservation science. The unexpected rediscovery of animals highlights the importance of continued surveying, particularly in remote or under-explored regions that may serve as natural refugia. It also underscores the value of local and Indigenous knowledge, as many of these “lost” species were still known to people living in the area.
The dramatic population rebounds demonstrate that conservation works when efforts are sustained, well-funded, and targeted at the root cause of the decline. Implementing strong legal protections, banning harmful chemicals, restoring habitats, and actively managing small populations through techniques like translocation are proven methods for species recovery. Ultimately, these successes showcase the incredible resilience of nature, but they also serve as a reminder that the biodiversity crisis requires constant vigilance and proactive management.