Is there any aerodynamic obstacle to gliding in great bustard?

Abstract

Gliding and soaring are important flight styles, which reduce the energy consumption of birds. Most of the migratory birds and raptors take advantage of these flight styles in order to stay in the air much longer. However, gliding and soaring cannot be seen in the great bustard Otis tarda, which prefers continuous flapping flight style. This study has been focused on possible glide ratio performance, which is not related to the weight of the great bustard. In this study, the glide performance of the great bustard is proved and calculated by CFD simulations. Results show that although great bustard is known as poor flyer, there is no aerodynamic obstacle to perform gliding or soaring. The possible reasons such as the lack of longdistance migrations and feeding behaviour are discussed.