Birds have been known as the harbingers of fortunes, the omens of godly presence, and their flight and habits have fascinated human beings since the dawn of time. Today, pollution, habitat destruction, and the infestation of invasive species of plants and animals are threatening whole species of birds. Global warming and invasive species kill their food supplies, urban sprawl and over-farming level their homes, and many birds just can’t keep up. Some of the most famous extinct animal species have been birds. Everyone knows the story of the passenger pigeon and the dodo bird – perhaps these won’t share the same fate.
Source: Wikipedia and Travel with a Challenge.