Habitat Suitability Modeling of Great Bustard, Otis tarda, using ENFA and GIS

During the last century, the global population of the Great Bustard (Otis tarda) has decreased and this species is now considered vulnerable. In Iran, the status of this species is much more critical and its distribution is limited to a few areas of Bukan county. We modeled the suitability of habitat for Great Bustards in Bukan County with the goal of determining the most important of distribution limiting factors of this valuable, rare and endangered bird in order to conservation and The map of effective factors including landform, land use, water resources and human factors was prepared using field data, previous available data, interpretation of satellite images, and their processing and analysis in GIS. To prepare the map of the variables, the circular, distance, and frequency analyses and for normalization of the maps, Box-Cox conversion were used. The model validation and the map classification of habitat suitability to desirable and undesirable classes were conducted using the Boyce index. The marginality factor (1.28) indicated that Otis tarda tends to live in marginal habitats. Low tolerability (0.1) and high specialization (9.2) scores also indicate that it is a special species within the county. According to our suitability map, only 6.5% (16000 ha) of the study area consists of desirable habitat.