Test your knowledge on biodiversity loss

You guessed it, the correct answer is 1,000,000.

According to a major 2019 report on the global state of biodiversity by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), an estimated one million species are now threatened with extinction.

You guessed it. The correct answer is 69%.

According to WWF, wild populations of mammals, birds, reptiles and amphibians have declined by 68% since 1970. Over the same period, the global human population has more than doubled, increasing from 3.7 billion to more than 8 billion today. These extra billions of people have all required land, food, water and energy, amongst other finite and renewable resources. These needs have all impacted negatively on the Earth and its wildlife.

You guessed it. The correct answer is Amphibians.

According to the IUCN Red List of Threatened Species, 26% of mammals are at risk of extinction, as well as 41% of amphibians, 21% of reptiles, 13% of birds, 37% of sharks and rays, 33% of reef corals, 34% of conifers and 63% of cycads.

You guessed it. The correct answer is All of the above.

Habitat destruction and overexploitation of animals and plants (such as overfishing and logging), are by far the biggest drivers of wildlife decline. Climate change and pollution have also become increasingly important threats to countless species. All of these drivers are exacerbated by ever more consumers. We cannot stop the extinction tide without slowing and ending human population growth.

You guessed it. The correct answer is True.

The number of tigers estimated to remain in the wild is less than 4,000, while around 7,000 are held captive in the US alone. Wild tiger habitats in Asia are under tremendous pressure from a dense and rapidly growing human population. Poaching for the illegal trade is also a major threat to tigers, as is the retaliatory killing due to attacks on people and livestock.

You guessed it. The correct answer is 32% human, 67% livestock, 1% wildlife.

Unfortunately, wild animals make up only 1% of all vertebrate biomass today, while humans make up 32% and the animals we farm dominate at 67%. Alongside ending population growth, a global shift to more plant-based diets is crucial to stemming biodiversity loss.

You guessed it. The correct answer is Global warming.

Polar bears are listed as vulnerable on the IUCN Red List. They are dependent upon Arctic sea ice for access to their prey. Their dependence on this ephemeral habitat means that global warming poses the most important threat to their long-term survival. The link between population growth and global warming is self-evident – each additional person on the planet adds their own carbon footprint and human population growth acts as a key multiplier of greenhouse gas emissions from all sources.

You guessed it. The correct answer is Critically endangered.

Bornean orangutans are critically endangered, mainly due to the destruction, degradation and fragmentation of their forest habitats, and hunting. The population decreased by more than 60% between 1950 and 2010, and a further 22% decline is projected to occur between 2010 and 2025.

You guessed it. The correct answer is False.

While the construction of infrastructure and the expansion of urban areas contribute significantly to deforestation and forest degradation, and the associated loss of forest biodiversity, agricultural expansion continues to be the main driver, in turn driven by the need to feed ever more people. In 2019, a major international report on global food sustainability stated that 80% of extinction threats to mammal and bird species are due to agriculture.

You guessed it. The correct answer is 8.

There are three species of orangutan (Bornean, Sumatran, Tapanuli), two species of gorilla (Eastern and Western), bonobos, chimpanzees (our closest living relatives), and us! Sadly, all the great apes apart from us are either Critcally Endangered or Endangered on the IUCN Red List.

You guessed it. The correct answer is False.

Large apex predators certainly play vital roles in their ecosystems, for example by keeping herbivore populations in check which benefits native plants. However, size does not determine importance – without insect pollinators such as bees, for example, the entire global food system would collapse and countless species (including humans) would likely go extinct. Worryingly, many crucial small species are also declining in abundance.