Disoriented by erratic weather, birds are changing migration habits and routes to adjust to warmer winters, disappearing feeding grounds and shrinking wetlands, a migration expert says.
Failure to adapt risks extinction. Birds face starvation when they arrive too early or too late to find their normal diet of insects, plankton or fish. In the north, some birds have stopped migrating altogether, leaving them at risk when the next cold winter strikes.
Climate change adds another threat to bird life already under pressure from human intrusions like coastline development and loss of habitat.
Greenhouse gases are predicted to raise the Earth’s average temperatures by at least 3.6 degrees. The warming is predicted to drive up to 30% of known animal species to extinction, and migrating birds are especially vulnerable.
Climate change can strike at each stage of their annual trek, from breeding ground to rest stops to their final destination.
Studies have found arctic permafrost and tundra where many species breed are melting. Even moderate rises in sea levels can swamp wetlands where birds stop to feed. Deserts are expanding, lengthening the distance between rests.
“Species that adapted to changes over millennia are now being asked to make those adaptations extremely quickly because of the swift rise in temperatures,” said Robert Hepworth, executive secretary of the Convention on Migratory Species.
“We don’t know how many will survive. We will lose species,” he said.