A study published in the medical journal The Lancet looked at the possible outcome if all the birds, insects, and other creatures that pollinate food crops were to disappear. The study's prediction? If this happens, people in many parts of the world could face a sharp increase in malnutrition, disease, and death.
Bird, animal, and insect pollinators are becoming rarer or are going extinct for many reasons including habitat destruction, the spread of diseases and parasites that affect them, pesticide use, and climate change. Researchers evaluated the supplies of 224 types of food in 156 countries and quantified the nutritional content that is dependent on pollinators like birds, bees and other insects, and animals such as bats. They then determined how much of a nutritional deficit the people who depend on these crops would suffer if those pollinators disappeared.
The study found that dietary changes that would be due to crop failures caused by the extinction of pollinators might increase mortality by 2.7%.
Working with the hypothesis that all pollinators disappear, the study found that an additional 71 million people could become deficient in vitamin A. For the nutrient folate, 173 million people would become deficient. These numbers would be in addition to the current population that is deficient in these nutrients.
Total pollinator extinction could reduce global supplies of fruit by 23%, vegetables by 16%, and nuts and seeds by 22%, the researchers calculated.
It is not known when, if, or to what extent pollinators could go extinct. But there is already evidence of declining populations around the world. In the United States, colonies of honeybees have seen yearly losses of 30% since 2006. There has been a 15% annual die off in European honeybee colonies. There have been significant declines in wild pollinator populations in North America, Asia and Europe in the last 30 years, with several species going extinct.
Pollination results in the production of fruits and seeds. It happens when pollen from the male part of a flower moves to the female part. Some plants spread pollen on the wind. Others must have insects and animals spread the pollen for them. Insects like bees, wasps, moths, butterflies, and beetles are the most common pollinators. Other pollinators include hummingbirds, bats, possums, lemurs and geckos.
Richer people and countries would be able to afford any price hikes caused by food shortages, the study noted. Poorer people would be disproportionately affected.
This is the first study to link worldwide declines in pollinators to human health.