While many people will be little moved by the loss of ‘creepy crawlies’, a massive extirpation of insects spills over to affect the numbers of birds, frogs, reptiles and fish that rely on insects as food, and the decline of these in turn affects larger animals. It impairs the successful pollination of plants which provide up to a third of the world’s food supply, as well as the renewal of landscapes and forests. Modern plants have evolved largely to depend on insects to fertilise them: lose insects and the whole web of life attenuates and, in some cases, collapses. Like a string of tumbling dominoes, the fall of ecosystems in turn reaches all the way to humans, undermining our own wellbeing through the loss of the services which natural systems provide—clean water, air, food, waste recycling, pollination of crops and seed dispersal of plants, building and furnishing materials, medical drugs, health and recreation.
Here is a bird’s eye view of what’s happening to the world’s wildlife, summarised by the California-based Centre for Biological Diversity :
• FROGS: about 2100 of the world’s 6300 known frogs, toads and salamanders are in danger, with an extinction rate 25–45,000 times above ‘normal’.
• BIRDS: 12 % of the world’s 10,000 known bird species are classified as endangered, and 200 of these are on the brink of extinction.
• FISH: Worldwide 1851 species of fish—21 % of all fish species evaluated — were deemed at risk of extinction by the IUCN in 2010
INSECTS: Of the 1.3 million known insect and invertebrate species, the IUCN has evaluated about 10,000 species: about 30 % of these are deemed at risk of extinction.
• MAMMALS: Half the globe’s 5491 known mammals are declining in population and a fifth are clearly at risk of disappearing forever. 1131 mammals across the globe are classified as endangered, threatened, or vulnerable.
• PLANTS: Of the world’s 300,000 known species of plants, the IUCN has evaluated 13,000 and found more than two thirds of these are threatened with extinction.
• REPTILES: Globally, 21 % (or 600) of the total evaluated reptiles in the world are deemed endangered or vulnerable to extinction (Centre for Biodiversity 2016 ).
Source: J. Cribb, Surviving the 21st Century, DOI 10.1007/978-3-319-41270-2_2