Abstract
We have pointed out 272 plant and 217 animal, altogether 489 taxa in the diet of Great Bustard on the basis of data received from 9 (10) countries for Otis tarda tarda (Portugal, Spain, United Kingdom, Germany, Austria, Slovakia, Hungary, Ukraine, Kazakhstan, former Soviet Union). Out of 272 plant taxa, 40 were classified as cultivated plants, 232 wild plants and weeds. From the latter, 43 taxa were monocotyledons and 189 were dicotyledons. Animal food is shared among Annelida (n = 3), Arthropoda (189) Mollusca (2) and Vertebrata (23) phyla. Arthropods are mostly represented with Insecta (181), Arachnoidea (3), Chilopoda (2), Diplopoda (2) and Crustacea (mostly Isopoda) (1) classes. The component of the diet is possibly not related to selection but to the change of the abundance and availability of food and the ever present demand for animal food needed for the organism. Owing to the high number of taxa known as food, Great Bustard is definitely a generalist species. Due to the wide spectrum of animal taxa and because of the ability to subsidize the inefficient quality of food with quantity, Great Bustards can be regarded as a species with positive adaptation ability. It can be explained with a wide plant and animal food spectrum that Great Bustards even in intensive agricultural habitats can find food with indispensable quantity and quality.