Birds, bees, bats, butterflies and other species that pollinate North American plant life are steadily vanishing, according to a study released recently by the National Research Council. This “demonstrably downward” trend could damage dozens of commercially important crops, scientists warned, since three-quarters of all flowering plants depend on pollinators for fertilization.
Domesticated honeybees, which pollinate more than 90 commercial crops in the United States, have declined by 30 percent in the last 20 years. In fact, U.S. farmers had to import honeybees last year for the first time since 1922, underscoring the extent of the problem.
A number of factors have reduced pollinators’ numbers in recent decades, the researchers said. Introduced parasites such as the varroa mite have hurt the honeybee population, and pesticides have also taken a toll. Bats, which carry pollen to a variety of crops, have declined as vandalism and development have destroyed some of their key cave roosts.
“Despite its apparent lack of marquee appeal, a decline in pollinator populations is one form of global change that actually has credible potential to alter the shape and structure of terrestrial ecosystems,” said May R. Berenbaum, an entomologist at the University of Illinois.
Animal pollinators fertilize more than 187,500 flowering plants worldwide.
Image: Bumblebee, Bombus terrestris (source).