European Bison recovering but 31 species declared extinct by the IUCN Red List.

According to latest update of the International Union for Conservation of Nature (IUCN)’s Red List of Threatened Species on 10 December 2020, the European bison (Bison bonasus) alongside 25 other species are making a recovery; whilst 31 species have been declared extinct, making a total of 902 species declared as extinct in 2020.

The IUCN’s Red List (updated at least twice a year) is one of the most comprehensive and authoritative indicators of the health of world’s biodiversity and it classifies species which are at high risks of global extinction into nine categories. There are now 128,918 species on the IUCN Red List, of which 35,765 are threatened with extinction.

The European bison, Europe’s largest land mammal, originally only survived in captivity in the early 20th century and was reintroduced into the wild in the 1950s. According to the Red List update in December 2020, the European bison ‘s risks of extinction has descended from being “Vulnerable” to a less serious grading of “Near Threatened” in light of the positive outlook on its population growth: its wild population has grown from 1,800 in 2003 to 6,200 in 2019. Although there are currently 47 free-ranging European bison herds, with the largest subpopulations found in Poland, Belarus and Russia, the IUCN SSC Bison Specialist Group warns that only 8 of the herds are large enough to be genetically viable in the long run, and the species will continue to remain dependent on ongoing conservation measures.

As commented by Dr Rafał Kowalczyk, co-author of the new assessment and member of the IUCN SSC Bison Specialist Group:

“Historically, European bison were reintroduced mostly to forest habitats, where they don’t find enough food in winter. However, when they move out of the forest into agricultural areas, they often find themselves in conflict with people. To reduce the conflict risk and the bison’s dependence on supplementary feeding, it will be important to create protected areas that include open meadows for them to graze.”

On the other hand, all of the world’s freshwater dolphin species are now considered to be threatened with global extinction with the tucuxi (Sotalia fluviatilis), a small grey dolphin species found in the Amazon river system, moving into the “Endangered” category. According to the IUCN, the population of the tucuxi has severely depleted as a result of incidental mortality or bycatch casualty in fishing gear, damming of rivers and pollution. The IUCN advises that the elimination of gillnets in the river system, the reduction of the number of dams in tucuxi habitats, alongside a ban on the deliberate killing of tucuxis are essential to enable the population to recover.

Altogether, there are 31 species that have been declared extinct, including 15 freshwater fish species endemic to Lake Lakao and its outlet in the Philippines (its drastic decline believed to be due to the introduction of predatory invasive species and destructive fishing methods) and 3 Central American frog species. The IUCN believes that one of the main drivers behind the extinction of the frogs is due to chytridiomycosis disease and airborne pollution.

The lost shark (Carcharhinus obsoletus), which was only formally described in the Red List last year, is now declared to be critically endangered (and possibly extinct). This species was last sighted in 1934 and its habitat in the South China Sea remains one of the most overexploited marine regions in the world. Thus, the IUCN believes that it is unlikely to survive under this heavy pressure and its lack of sightings has led naturalists to conclude that it is more than likely to be extinct.  

A number of plant species are also under pressure and threatened with extinction in the wild. For example, the protea family of plants, including three macadamia species that produce the farmed macadamia nut crop, are deemed to be threatened. Almost one-third of the assessed oak tree species are also threatened with extinction, with the highest number of threatened species found in China and Mexico as a result of real and imminent threats of land clearance for agriculture and logging.

In Hong Kong, the Chinese white dolphin, a variety of Indo-Pacific humpback dolphin, is also classified as “Vulnerable” on the Red List, with residential and commercial development and transport corridors listed as its main threats to survival. The Hong Kong Grouper, which was once a significant source of fishery and common type of fish found in wet markets during the 1960s and 1970s, continues to be classified as an “Endangered” species. Studies showed that its population collapsed during the 1990s due to a mixture of unsustainable fishing practices and overexploitation. According to the Food and Agriculture Organization (FAO) annual landings statistics reported by Hong Kong, it showed a near 100% decline in the Hong Kong Grouper population between 1993 and 2013.

Courtesy of Nicole Liang

Main sources: The Guardian and IUCN.