PARIS - Birds are delaying their annual winter migration to Africa from France because of the unseasonally warm weather, a French bird protection group said on Thursday.
The autumn was the warmest in France since 1950, with temperatures 2.9 degrees Celsius (5.2 F) above seasonal norms, the national weather agency has said. "Long distance migratory birds – those that spend the winter in tropical Africa – seem to be particularly late in leaving this autumn," the League for the Protection of Birds said in a statement. 
The league's network of birdwatchers have spotted swallows all over France, including in the north, as well as warblers, which usually leave in August or September.
"This phenomenon is just another sign that we are seeing rapid and major climate changes that the birds are having to face, especially the migrators," it said.
Bird migration patterns can change over time but the league said it wondered whether they would be able to adapt quickly enough to the rapid changes in climate.