In the past centuries many birds became extinct. At first many birds died out, due to the colonization of many islands in the Pacific, Australia and New Zealand by the Polynesians. Secondly many more birds died out, due to the exploration and colonisation of many parts of the world by Europeans, such as the well known dodo (right-hand picture).
The main reasons for the extinction of these birds at that time were hunting and the introduction of non-native animals, such as rats, cats, dogs, pigs, mongooses, etc. And many birds have since died out due to the activities of humans in current history. The main cause of extinction of birds right now is the destruction of their natural habitats.