The list of other disappearing groups is growing. In the last 500 years 187 species have become extinct, 90 per cent of which were insular species, says the study. The new approach confirms 80 per cent of the current IUCN Red List and reclassifies nine species. Eight of them, including three birds, the poo-uli, the Pernambuco pygmy-owl and the cryptic treehunter, are added to the growing list of confirmed or near extinctions. But not only birds are in danger of dying out. The list of other disappearing animals is also rapidly growing. At least 1,000 vertebrate species have become extinct in the last 5 centuries. And the latest Red List assessment indicates that more than 26,000 of the world’s species are now endangered. According to scientists our actions are a key factor in this so-called sixth mass extinction.


Falling Walls: Gerardo, most extinctions have occurred on islands until recently. The Spix’s macow now seems to be extinct in Brazil and the extinction crisis is also unfolding in large countries – why?

Gerardo Ceballos: Until recently most extinctions have occurred on islands, because they are small and species with small populations are more prone to extinctions. Now, extinctions are occurring on continents too, and my study on population extinctions indicates that this extinction crisis is unfolding on continents due to human activities: Habitat loss and fragmentation, illegal trade an overexploitation, pollution, invasive species and climate change are some of the main factors. Ecosystems are being destroyed to plant crops such as soy and oil palms, and to cattle grazing.

Falling Walls: How many of the world species are threatened?

Gerardo Ceballos: The most recent evaluation indicates that some 30% of all species are endangered. IUCN has analysed population trends of 91.000 species and found out that 26,000 are threatened (27%). We found out that 32% of 27,600 vertebrates have declining populations. So, both population and species extinction are accelerating.

Falling Walls: How do scientists assess if a species or a population is extinct?

Gerardo Ceballos: Accurate assessments are complicated because species are not uniformly distributed, and many are difficult to find. In order to evaluate the status of a species, information on its population size and geographic range is required. That’s why scientists use a variety of census methods to evaluate those parameters and the causes of decline depending on the species. For example, in large mammals and birds, aerial censuses are a common technique. Camera-traps for example are now widely used to evaluate large and medium size mammals.

Falling Walls: What can we do to prevent extinction?

Gerardo Ceballos: The most important thing is: to get involved in trying to save species and ecosystems. At a local and personal level, we have to reduce our consumption. With our consumption decisions we can force companies that are destroying tropical forests to change. At a national level, we have to act as well: move to more renewable economies; promote nature reserves; prohibit illegal trade especially of endangered species.

Saving the rhino and other endangered species is a gigantic task that has to be undertaken, regardless of its costs and efforts. Our own fate is at stake just as theirs is. The future will be implacable in its judgement of our actions.

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