Massive Decline in Butterfly Populations on Both Sides of the Atlantic

Butterfly populations are facing dramatic declines on both sides of the Atlantic. Monarch populations worldwide have been declining for years and recent counts by the U.S. Center for Biological Diversity found a 68 percent decline over the past two decades.

The loss of a key food source for monarchs is raising concern. Changing weather patterns, habitat destruction, and pesticides are destroying milkweed and starving butterflies. The monarch’s undertake a multi-generational migration, a 2,000 mile journey from Mexico to Canada. Many fear that the monarch is plummeting toward extinction.

Butterflies in Britain suffered their seventh worst year on record in 2017. Annual monitoring showed native species suffered significant declines and two species had their worst season on record. The UK Butterfly Monitoring Scheme says seven of the worst 10 years have occurred since the turn of the century.

Researchers discovered high declines of butterflies in urban areas, where vehicle pollution has caused nitrogen levels to soar. There is evidence of correlation between butterfly declines and high levels of nitrogen pollution.



Photo: “Scarce swallowtail, Scabius flower and Polistine wasp” by BMC Ecology is licensed under CC BY 2.0