Abstract:

he degree and causes of destruction of Great Bustard nests were studied in eastern Hungary in 1990-1993. 29.5% of 95 known clutches hatched successfully, 17.9% were predated, 49.5% were unsuccessful due to other reasons mainly including the nest desertion and success of 3.1% was unknown. The main egg predators were Hooded Crow, fox and dog. Buffer zones of various sizes were created around some nests during mowing. It appears that areas of at least 900m 2 of standing vegetation around nests gave the best chance of successful hatching in spite of the predation risk and disturbance. It seems likely that the degree of incubation has an effect on nest desertion.