From the dodo on the island of Mauritius to the golden toad of Costa Rica, the creatures driven to extinction by human activity are many and varied.
People have been causing animal, plant and other species to become extinct for the past 10,000 years or more through actions including hunting, habitat, destruction, pollution, the spread of invasive species and climate change.
As human populations grow, the rate of species extinction is intensifying. Scientists estimate it has reached a level hundreds, or even thousands, of times greater than would be expected naturally.
The latest global Red List of endangered species, published by the International Union for Conservation of Nature (IUCN) at the recent Cop28 climate conference in Dubai, revealed that well over a quarter of them are threatened with extinction.
General-Director of the International Union for Conservation of Nature
“There's no reason why we have to be in this situation,” Dr Grethel Aguilar, director general of the IUCN, said, adding that maintaining biodiversity was key to ensuring human survival.
“Nature is here to help us, so let us help it back,” she said.
Climate change is a growing threat because it affects food availability, alters seasonal patterns, disrupts reproduction, decreases freshwater levels, causes saltwater to move up rivers and allows invasive species to expand their range.
Craig Hilton-Taylor, head of the Red List, said species across the world are under “huge pressure”.
“It's climate change interacting with other threats that have pushed the species over the edge,” he said.
The new edition of the list, which was first published in 1964, focuses on freshwater fish species, more than a fifth of which (3,086 out of 14,898) are at risk of extinction.
Out of the total of 157,190 species that are assessed, 44,016 – or 28 per cent – were found to be at threat of extinction.
This threat looms over 41 per cent of amphibians, 29 per cent of mammals and 11 per cent of bird species.
The Red List categorises species as extinct, extinct in the wild, critically endangered, endangered, vulnerable, near-threatened or of least concern.
There are also “data deficient” and “not evaluated” categories for species that have yet to be fully assessed.
Threat to species
Perhaps the most famous extinct creature is the flightless bird, the dodo – Raphus cacullatus – which was eliminated in the 17th century because of hunting and nest predation by introduced pigs.
“Birds thought to represent the last individuals were killed on the offshore islet Ile d'Ambre in 1662,” the dodo's IUCN listing states.
More recently, the golden toad was declared extinct in 2004, following its last confirmed sighting in 1989, with climate changed often blamed.
The creature – Incilius periglenes – used to live in just a few square kilometres of forest in Costa Rica.
The male was a dramatic orange colour, while the female was mostly black with red and yellow spots.
Other animals on the IUCN Red List include the blue whale – Balaenoptera musculus – the world's biggest animal, which was last assessed in 2018.
These giants of the seas can measure up to 100 feet in length and can weigh nearly 200 tonnes – which is as much as 33 African elephants, according to the conservation organisation WWF.
The blue whale is classified as endangered – two categories up from extinct in the wild – and, while there are only between about 5,000 and 15,000 mature individuals remaining, the population is increasing.
On land, the jaguar – Panthera onca – is one of the species classified as near-threatened.
Although this is just one category up from least concern, jaguar numbers fell by an estimated 20 to 25 per cent in the two decades up to its most recent assessment in 2016.
The lion – Panthera leo – is one category further away from safety, listed as vulnerable.
The three species of orang-utan – the Bornean (Pongo pygmaeus), the Sumatran (Pongo abelii) and the Tapanuli (Pongo tapanuliensis) are all critically endangered.
The saiga antelope – Saiga tatarica – which is found mostly in Kazakhstan, has moved from critically endangered to near-threatened.
The Central South Pacific green turtle and the East Pacific green turtle (Chelonia mydas) are listed in the latest IUCN Red List as endangered and vulnerable to extinction, respectively, as warmer temperatures affect hatching rates, rising seas inundate nests and drown their young and fishing vessels catch them.
Criticisms of the list
Only about two per cent of the estimated eight million species of animals, plants, fungi and other organisms on Earth have been assessed for the list.
The list came under criticism in a recent paper titled, “The global influence of the IUCN Red List can hinder species conservation efforts”, by more than 20 researchers.
A key issued raised was that the list can “overlook local and regional contexts”, which, especially in poorer countries, may result in what the scientists described as “improper allocation of conservation resources”.
Species in the data-deficient category have been found to be at risk of extinction. However, because they are not included in the main Red List categories, it is suggested that it is difficult to attract funds for their conservation.
Organisms with very limited ranges are also said to miss out on an assessment, potentially putting them at greater risk of extinction.
However, the IUCN Red List is seen as being the most comprehensive conservation database of species of all kinds across the globe and it grows with each update.
The aim is to reassess each species included at least every decade.
Successful conservation
Amid the widespread threats faced by nature, the new IUCN Red List highlights conservation successes, such as that involving the scimitar-horned oryx, which, like the Arabian oryx, is now thriving in the wild in large part thanks to breeding efforts in the UAE.
The recent IUCN Red List, published in December, revealed that the scimitar-horned oryx – Oryx dammah – is now classified as endangered, a two category improvement on its previous listing as extinct in the wild.
This is based on an assessment carried out in November 2022.
Habitat loss and hunting for meat and horns resulted in the species, which lived across North Africa north and south of the Sahara desert, disappearing and being classified as extinct in the wild in 2000.
The Environmental Agency Abu Dhabi (EAD) has played a pivotal role in conserving the species, thanks to its breeding programme at the Deleika Wildlife Management Centre, from where creatures are flown to Chad for release.
Mr Hilton-Taylor said that EAD's efforts had been central to the successful return of the species to the wild.
“They’ve been a key international partner behind the success of that species,” he said.
At last 331 scimitar-horned oryx calves have been born in the wild, Mr Hilton-Taylor said, which should prove significant in helping the population to grow, as there are only around 150 recorded mature individuals in the wild.
As well as the efforts of organisations like EAD, which Mr Hilton-Taylor praised for being able to carry out conservation efforts at the required scale, the work of local authorities and conservation non-governmental organisations has proved important.
It was essential to have “local community buy-in” to these conservation efforts to ensure that the animals were not put at risk from poaching.
“You have to bring the local people in so they understand the benefits of having these animals in their community, so they get employment because there are tourism opportunities,” he said.
