The wildlife we have lost: the species dying out as sixth mass extinction takes off

It’s hard to overstate the potential scale of loss of the world’s precious wildlife, writes Jane Dalton

Sumatran orangutans are among species critically endangered (Getty Images/iStockphoto)

According to climate activists, climate crisis and the linked biodiversity crisis will dwarf the Covid-19 pandemic in their effect on our world.

It’s hard to overstate the potential scale of loss of the world’s precious wildlife as the sixth mass extinction happens around us.

Time and again in recent years, scientists have sounded the alarm over the rate at which human activity is wiping out species, many of which inhabited the planet long before we did.

In the past two weeks, yet more warnings have been issued – this time more dire than ever – in an attempt to force world leaders and policymakers into action.

Wildlife charity  WWF warned that nature is in freefall, while  the UN’s fifth Global Biodiversity Outlook said biodiversity is declining at an unprecedented rate while the pressures driving the decline are intensifying.

Populations of mammals, birds, fish, amphibians and reptiles have crashed by more than two-thirds - 68 per cent - on average globally in less than 50 years, WWF found.

Since 1970 the global human population has more than doubled from 3.7 to 7.6 billion, with intensive agriculture and deforestation the main drivers of natural destruction.

Some of the species humanity has driven to extinction in the past half-century include:

Western black rhino: A combination of hunting and clearing habitats for agriculture proved fatal for the West African black rhinoceros before it was declared extinct in 2011.  

Caspian tiger: The Caspian tiger was one of the largest big cats in the world – males could be nearly 3m long. Its habitat was destroyed by people clearing land for farming and the remaining individuals were hunted to extinction in the 1970s.  

Spix’s macaw: This was one of eight bird species, half of them in Brazil, confirmed extinct or suspected extinct in the wild in 2018. Deforestation was said to be the cause, and a few individuals were bred in captivity.

Pyrenean ibex: A sub-species of the Iberian wild goat, it became extinct in 2000 after the males were hunted for their large horns, which curled backwards.  

Golden toad: One common in Cosat Rica, it’s not been seen since 1989. A warming planet, disease and air pollution were thought to be responsible.  

Bramble Cay melomys: A rodent native to the northern Great Barrier Reef, it was thought to have been unable to survive the climate crisis, and was officially declared extinct by the Australian government last year, having last been seen in 2009, .

Mauritius turtle dove: This species is thought to have disappeared from Mauritius because of deforestation and rats. It was declared extinct by the IUCN in 2014.

Meanwhile, more animal and plant species than ever before in human history are threatened with extinction. A UN report last year estimated the number at a million.  

The dying out of one species can set off a cascade leading to extinctions to others. “Extinction breeds extinctions,” according to the authors of a study in the Proceedings of the National Academy of Sciences.

The study lists 515 animal species with fewer than 1,000 individuals remaining.  

Species now at risk include:

The northern white rhino: In 2018, the last male northern white rhino, called Sudan, died of natural causes, aged 45, in northern Kenya. Only two northern whites remain in the world, both female and the last of the species.

Sixteen other animals are listed by the International Union for Conservation of Nature (IUCN) as critically endangered, including: the Amur leopard, the black rhino, the orangutan, three species of African gorilla, Sumatran elephants, orangutans and rhino, Sunda tigers and Vaquita porpoises.

All tigers are under threat from human activity such as poaching and habitat loss, and are listed as endangered by the IUCN, with only about 3,900 left in the world.

Not to be underestimated is the threat to insects. Half a million are at risk of extinction, with scientists warning their disappearance would be “catastrophic” for humankind.