The danger of extermination threatens certain species of birds, particularly migratory birds, due to: the killing of birds during their breeding seasons and (for migratory birds) during their return flight to their nesting ground; the capture or killing of birds or the collecting of their eggs for commercial exploitation; the use of methods of mass killing or capture of birds (which also often causes them unnecessary suffering); the rapid disappearance of suitable breeding grounds for birds as a result of human intervention; and the increasing destruction of birds by hydrocarbons, water pollution, insecticides and other poisons.
Every year hundreds of thousands of migratory birds are slaughtered by Maltese hunters. Laws protecting these birds are rarely enforced. Severe drought in the Sahel zone of western Africa in the 1970s and early 1980s has devastated British populations of the migratory whitethroat, sedge warbler and sand martin.