The Coues check list of North American birds

Many other species were described from specimens collected by nineteenth-century expeditions that provided only vague indications of the collecting site, such as, 'South America'. Try resolving the status of some rare species when you have only that broad hint where to look! The songs, behaviour, and habitat preferences of such species are unknown. Hence we do not know where to seek them, nor how to identify them if we glimpsed or heard them. The status of many tropical species cannot be classified either as 'definitely extinct' or 'definitely in existence', but just as 'unknown'. Instead, it becomes a matter of chance which species happens to attract the attention of some ornithologist, becomes the object of a specific search, and hence may be recognized as possibly extinct. Here is an example. The Solomon Islands are another of my favourite bird-watching areas in the tropical Pacific Ocean, and will be recalled by older Americans and Japanese as the site of some of the fiercest fighting in the Second World War. (Remember Guadalcanal, Henderson Field, President Kennedy's PT boat, the Tokyo Express?) The ICBP lists one Solomon bird species, Meek's crowned pigeon, as extinct ...»