Box 9F Decline of the great bustard

Female great bustard, Estremoz, Portugal

Source: P Goriup, Nature Conservation Bureau, UK


The total world population of the great bustard (Otis tarda) is estimated to be under 25 000 birds, of which about 60 per cent occur in Iberia alone. The bulk of the remainder are located in Russia and Ukraine (16 per cent) and Hungary (5 per cent). Over the last 50 years, the great bustard has retreated from western Germany, Poland and Yugoslavia, and just lingers (if at all) in Austria, the Czech Republic, the Slovak Republic, Bulgaria and Romania. By far the main causes for the overall fragmentation and decline of the great bustard since the end of World War 2 are the widespread ploughing of grasslands, and the application of agrochemicals as well as the more recent changes in cropping patterns (from forage to winter cereal crops). Map 9.4 illustrates the changes in distribution of this species in Central and Eastern Europe.

The population levels in Romania are fairly typical of what happened in other parts of Europe. As shown by the following figures, after World War 2, populations increased somewhat with greater arable farming, and then declined dramatically from the 1960s when intensification began:

Year1955 1957 1961 1970 1975 1976 1992
Quantity1110 1440 2200 550 300 29 100(?)

It is no longer possible (if ever it was) for any one country alone to guarantee the future survival of many lowland dry grassland birds. In Hungary, for example, where great bustards are afforded strong protection and a large area of suitable habitat is maintained, the population has declined from over 3200 birds in the late 1970s to 1200 in 1992, because of emigration during hard winters. The population is forecast to decline to 800 by the late 1990s. The problem of the great bustard, and similar species is of such a scale that it can be tackled only on a continental basis, for example by an international agreement under the Bonn Convention on Migratory Species. This could eventually result in reintroducing the great bustard to environmentally sensitive areas holding lowland dry grasslands, with support grants paid to local farmers to manage the habitat. An analysis of satellite data (CORINE Land-cover project) identified natural grasslands as potential habitat areas for the great bustard in Spain. Map 9.5 shows these areas as well as sites where the species has actually been recorded.


Map 9.5 - Distribution of the great bustard (Otis tarda)in Spain

Source: EEA-TF Bird Life