Making the most of birds as environmental indicators

Never previously has there been such an opportunity for biologists to infor m and advise environmental decision-makers. Ornithologists have a special c ontribution to make because of the extent and quality of the information av ailable to us. This paper focuses on environmental indicators - the process by which complex information about the environment can be encapsulated in some simply understood measures. This paper reviews the properties of effec tive indicators and the contribution that ornithology can currently make. A ttention is given to globally threatened species, common bird monitoring sc hemes, summarising trend data from many species and to spatial questions ab out the distribution of biodiversity.