Distance to international border shapes the distribution pattern of the growing Little Bustard Tetrax tetrax winter population in Northern Iran

The Little Bustard Tetrax tetrax is a Near Threatened grassland bird that is fully migratory within its eastern population, wintering in large numbers across the south Caucasus and northern parts of Iran. The species' habitat selection has been comprehensively studied in its western European range, but very limited information is available for its eastern population. Surveys carried out between 2010 and 2015 show a considerable population increase and probable range expansion in the region. We modelled the suitability of potential winter habitat for the species and found that distance to country border, land cover and altitude were the most important variables in predicting habitat suitability. There is still considerable hunting pressure in Iran and distance to border is likely to be related to strict hunting prohibition along the border belt imposed for military purposes. This represents an opportunity for the conservation of the species, where management efforts should aim at ensuring the maintenance of suitable land cover.