Sixth mass extinction threat grows, 515 species may vanish soon: Study
Among those facing extinction, 243 (47%) are continental and 272 (53%) insular (island-dwelling). Most of them are from South America, followed by Oceania, Asia, Africa, North and Central America, and then Europe with less than 1% of them.Updated: Jun 05, 2020 00:17 IST
A recent analysis of data has warned of an acceleration in the sixth mass extinction. For the analysis published in Proceedings of the National Academy of Sciences on June 1, scientists examined available data related to 29,400 species of terrestrial vertebrates and found that 1.7% of them, or 515 species of mammals, birds, amphibians, reptiles, have fewer than 1,000 individuals each and are on the brink of extinction including in India.
Among those facing extinction, 243 (47%) are continental and 272 (53%) insular (island-dwelling). Most of them are from South America, followed by Oceania, Asia, Africa, North and Central America, and then Europe with less than 1% of them. The greatest numbers of mammals on the brink extinction are in Asia and Oceania. Most such birds live in South America and Oceania. The distribution of species on the brink extinction shows they also include those in the biodiversity hotspots of the Himalayas and the Western Ghats.
Indian experts said the analysis should drive home the message that India can help secure the hotspots and more species from going extinct. “Many of the results are a re-emphasis of the threats to species and processes, but I think the timing of this paper is most important given the [Covid-19] lockdown. ...the authors acknowledge biodiversity is crucial to human and ecosystem resilience, but in the Indian context, we are seeing environmental governmental decisions that are contrary to what scientists are calling for the world over,” said Nandini Velho, a conservation biologist.
Scientists like Velho have over the past three months raised concerns over a hydropower project in biodiversity-rich Dibang Valley and the National Wildlife Board’s approval to coal mining inside Assam’s Dehing Patkai Elephant Reserve.
Velho said of the 515 species, forest owlet in Central India, Nilgiri marten (Western Ghats), Bugun liocichla (Arunachal Pradesh), Bengal florican (Assam), great Indian bustard (northwest India), white-winged wood duck (northeast India) will disappear soon.
“The findings of this paper are similar to the findings of the intergovernmental science policy platform on biodiversity and ecosystem services, which suggests that species are on the verge of extinction which will also lead to larger collapses. In India this is specially pertinent as we have species that are naturally or historically low in number. And a wide range of factors are interacting with them. Several Indian species are mentioned in the paper. The Kolar-leaf nosed bat, named in this paper is found in only one cave in Kolar. If the stigma against bats due to fake covid spreads, the entire population could be made extinct. And the Great Indian Bustard is threatened by increasing transmission lines in Kutch, Gujarat. The White-bellied Heron has less than ten known individuals in India. and its habitat is threatened by submergence by proposed dams like Demwe in Arunchal Pradesh,” said Neha Sinha of the Bombay Natural History Society.
National Autonomous University of Mexico and Stanford University scientists led the analysis based on the IUCN Red List of Threatened Species and Birdlife International database. The analysis said in view of the current extinction crisis and the lack of widespread actions to halt it, it is very important that scientists “should metaphorically take to the streets”. This is because the current mass extinction is happening at a far larger scale and more rapidly than those recorded in the past.
“Thousands of populations of critically endangered vertebrate animal species have been lost in a century, indicating that the sixth mass extinction is human-caused and accelerating. The acceleration of the extinction crisis is certain because of the still fast growth in human numbers and consumption rates. In addition, species are links in ecosystems, and, as they fall out, the species they interact with are likely to go also. In the regions where disappearing species are concentrated, regional biodiversity collapses are likely occurring,” the analysis said.
The analysis also shows that those pushed to the brink of extinction have lost their historic geographic range. Assuming that an average mammal or bird population occupies 10,000 km2, it suggests that during the last two centuries, around 3,600 populations of the 48 mammal species and 2,930 populations of the 29 bird species examined have disappeared. Those mammal and bird species have lost around 95% and 94% of their geographic range since 1900, according to the analysis.
It said such major losses of populations and species will destroy the ecosystem, goods, and services, which will impact human well being while citing the example of Covid-19. The analysis said the pandemic is linked to wildlife trade and has recommended a strict ban on it in China, Vietnam, Indonesia, and other Asian countries. It has suggested that food be made available to the poor in Africa to prevent dependence on bushmeat. “There is no doubt that there will be more pandemics if we continue destroying habitats and trading wildlife for human consumption as food and traditional medicines,” the analysis said.