© ALAMYTwo European turtledoves, whose numbers are plummeting across the Mediterranean.
A new study finds that an estimated 25 million migrating birds are killed as they fly over Mediterranean countries each year. The deaths—by gun, net, or glue-covered traps—include several threatened species. Most of the birds end up being eaten as delicacies. Some are shot for sport, while others are captured alive and sold in the caged-bird trade.
Many bird species living in the Mediterranean are in decline owing to habitat loss, said Stuart Butchart, head of science at BirdLife International and a coauthor of the study. This mass killing could further threaten many species while also affecting the region's environment.
"Birds play an integral role in ecosystems, from pollinating plants and dispersing their seeds to controlling populations of insect pests," Butchart said. "Disturbing the balance of ecosystems by substantially changing bird abundance through illegal killing and other impacts will certainly have impacts beyond the birds themselves."
He cited the example of India, where some vulture species have declined by 99 percent or more because of poisoning by the veterinary drug diclofenac. The drug is used to treat livestock and contaminates vultures when they feed on dead animals. "This has led to a rapid increase in the feral dog population, as vultures no longer dispose of animal carcasses, and consequent increases in rabies cases among people," Butchart said.
