30% of land birds may die by 2100

Climate change may cause as many as 30% of all land-bird species to become extinct by 2100 because food will become scarce as temperatures increase, according to a Stanford University study.

Rising temperatures will limit the availability of plants and animals that serve as food for birds, according to the study, published this week in the journal Conservation Biology.

Food will be more difficult to find as lowlands become warmer and plant and animal species on which birds feed vanish or move to higher elevations, the study says. The shift will put birds in competition for food with other species over smaller and smaller areas.