EFFECTS OF LAND USE AND WILDFIRES ON THE HABITAT SELECTION OF GREAT BUSTARD (OTIS TARDA L.)-IMPLICATIONS FOR SPECIES CONSERVATION

Increasing agricultural activities have been shown to affect soil and vegetation changes leading to serious biodiversity declines throughout the world. These effects are amplified in dry grassland areas, where resulting changes in habitat structure affect threatened animals on long temporal scales. Great bustards (Otis tarda) inhabit open landscapes where fire and grazing have been a part of the natural disturbance regime since historical times. Even fire and grazing are hypothesized to be important factors in the lifecycle of the species, studies are still missing on disturbance-related lekking distribution patterns of great bustards. We analyzed the importance of fires and grazing on the spatial distribution of lekking bustards controlling for habitat types, habitat diversity, distance from roads and social effects. Our standardized dataset spanned 31 years, being one of the largest datasets on bustard lekking. During the 31 years we observed 10 118 individuals at 639 observation points in Hortobagy National Park, East-Hungary. One of the most important predictors for total number of birds and number of males was the area burnt in previous years. We found that increased habitat diversity had a positive effect on female numbers. Models fit on second-and third-year burn data detected no substantial role of burning on lekking distribution. Our results suggest that introduction of a patch-burning management system in lekking areas could increase the availability of optimal lek sites for bustards. As an effective management tool, we suggest applying patch-burning annually in a spatially mosaic structure inside the area occupied by each sub-population unit. Copyright (C) 2016 John Wiley & Sons, Ltd.