The Eastern Gorilla – the largest living primate – has been listed as Critically Endangered due to illegal hunting, according to the latest update of The IUCN Red List of Threatened Species released this week at the IUCN World Conservation Congress taking place in Hawai’i.
Four out of six great ape species are now Critically Endangered – only one step away from going extinct – with the remaining two also under considerable threat of extinction.
The IUCN Red List update also reports the decline of the Plains Zebra due to illegal hunting, and the growing extinction threat to Hawai’ian plants posed by invasive species. Thirty eight of the 415 endemic Hawaiian plant species assessed for this update are listed as Extinct and four other species have been listed as Extinct in the Wild, meaning they only occur in cultivation.
The IUCN Red List now includes 82,954 species of which 23,928 are threatened with extinction.
Threat from illegal hunting
The Eastern Gorilla (Gorilla beringei), which is made up of two subspecies, has moved from Endangered to Critically Endangered due to a devastating population decline of more than 70% in 20 years.
Its population is now estimated to be fewer than 5,000. Grauer’s Gorilla (G. b. graueri), one subspecies of Eastern Gorilla, has lost 77% of its population since 1994, declining from 16,900 individuals to just 3,800 in 2015.
Killing or capture of great apes is illegal, yet hunting represents the greatest threat to Grauer’s Gorillas. The second subspecies of Eastern Gorilla, the Mountain Gorilla (G. b. beringei), is faring better and has increased in number to around 880 individuals.
Four of the six great apes – Eastern Gorilla, Western Gorilla, Bornean Orangutan and Sumatran Orangutan – are now listed as Critically Endangered, whilst the Chimpanzee and Bonobo are listed as Endangered.
‘To see the Eastern gorilla – one of our closest cousins – slide towards extinction is truly distressing. We live in a time of tremendous change and each IUCN Red List update makes us realise just how quickly the global extinction crisis is escalating. Conservation action does work and we have increasing evidence of it. It is our responsibility to enhance our efforts to turn the tide and protect the future of our planet.’
IUCN’s director general
The once widespread and abundant Plains Zebra (Equus quagga) has moved from Least Concern to Near Threatened. The population has reduced by 24% in the past 14 years from around 660,000 to a current estimate of just over 500,000 animals.
In many countries Plains Zebra are only found in protected areas, yet population reductions have been recorded in 10 out of the 17 range states since 1992. The Plains Zebra is threatened by hunting for bushmeat and skins, especially when they move out of protected areas.
Three species of antelope found in Africa – Bay Duiker (Cephalophus dorsalis), White-bellied Duiker (Cephalophus leucogaster) and Yellow-backed Duiker (Cephalophus silvicultor) – have moved from Least Concern to Near Threatened.
While the populations of these species within protected areas are relatively stable, those found in other areas are decreasing due to continued illegal hunting and habitat loss.
‘Illegal hunting and habitat loss are still major threats driving many mammal species towards extinction. We have now reassessed nearly half of all mammals. While there are some successes to celebrate, this new data must act as a beacon to guide the conservation of those species which continue to be under threat.’
Coordinator of the mammal assessment at Sapienza University of Rome
Threats from invasive species
Invasive species such as pigs, goats, rats, slugs and non-native plants are destroying the native flora in Hawai’i. The latest results show that of the 415 endemic Hawai’ian plant species assessed so far for The IUCN Red List (out of around 1,093 endemic plant species), 87% are threatened with extinction, including the Endangered ‘Ohe kiko’ola (Polyscias waimeae), a beautiful flowering tree found only on the island of Kauai.
Thirty Eight have been listed as Extinct, including the shrubs ‘Oha Wai (Cyanea eleeleensis) and Hibiscadelphus woodii. Four species have been listed as Extinct in the Wild including the Haha (Cyanea superba), last seen in the wild in 2003.
Invasive species are the main threat to all of these species, with many being threatened by more than one invasive species. The IUCN Species Survival Commission (SSC) Hawai’ian Plant Specialist Group anticipates the remaining species to be assessed will also be highly threatened.