Migratory species at risk worldwide, with a-fifth in danger of extinction, landmark U.N. report says

From African elephants searching for water, to turtles crossing seas to nest, to albatrosses on their ocean-spanning searches for food, the world's migratory species are under threat across the planet, according to a landmark report Monday.

The first-ever State of the World's Migratory Species assessment, which focusses on the 1,189 species covered by the U.N. Convention on the Conservation of Migratory Species of Wild Animals (CMS), found that one in five is threatened with extinction and 44 percent are seeing their populations decline.

Humans are to blame, by destroying or breaking up habitats, hunting, and polluting areas with plastics, chemicals, light and noise.